taxonID	type	description	language	source
038BAE5EFFD3A237FB43F8A2FF02FE17.taxon	description	E. smithi sp. nov. Côte d’Ivoire (this paper) not widened apically in lateral view. Median lobe with ventral impression wide in lateral view; apical disc ca.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFD3A237FB43F8A2FF02FE17.taxon	etymology	Etymology. The species name refers to the bilobate apex dian lobe bifid (Figs 8 P – R, T, V, X). ................................ ........................................................... E. limicola group of the median lobe which is a unique character of this species. Adjective. – Lateral ridge of the pronotum interrupted in the mid-	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFD3A237FB43F8A2FF02FE17.taxon	biology_ecology	Biology. No data available. dle (Fig. 10 G). Median lobe in lateral view compressed	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFD3A237FB43F8A2FF02FE17.taxon	distribution	Distribution. Only known from two close localities in dorsoventrally (Figs 11 B, E, H); ventral projection of southern Nigeria (Fig. 13 A). median lobe bar-like (Fig. 6 H). ....................................... .................................................. E. carinaticollis group Eupotemus cameroonensis sp. nov. (Figs 8 D – F, 9 D – F) Eupotemus limicola group	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFD3A237FB43F8A2FF02FE17.taxon	materials_examined	Material examined. H ඈඅඈඍඒඉൾ: J (BMNH): ʽHolo- / type // BRITISH Eupotemus bilobatus sp. nov. CAMEROON. / Manfe, 7 - 11. i. 1949 / B. Malkin coll. // Rain forest; clear (Figs 8 A – C, 9 A – C) / stream: Gravel and / sand. // Metepitopus / occidentalis Type! / JK. Balfour-Browne det. // HOLOTYPE / Afrometopus / cameroonensis / Material examined. H ඈඅඈඍඒඉൾ: J (BMNH): ʽUmuahia / J L. G / P. D. Perkins // New species to / coll. + n. g. was a / specimen in D. 2.2.1 3. ix. – 4. x. 1960 // C. E. Tottenham / collection / B. M. 1974 - 587. ʼ P * ò * © * ò- / see its pinlabelsʼ. ඍඒඉൾඌ: NIGERIA: A ൻ ං ൺ: 1 J 1 ♀ 4 spec. (BMNH, NMPC): ʽUmuahia / 3. ix. – 4. x. 1960 / J. L. Gregory // C. E. Tottenham / collection / B. M. Differential diagnosis. Very similar to the other species of 1974 - 587 ʼ; 3 ♀♀ (BMNH): ʽUmudike / J. L. Gregory / 10 - 13. iv. 1960 // the E. limicola species group from which it can be reliably C. E. Tottenham / collection / B. M. 1974 - 587 ʼ. distinguished by male genitalia only. The aedeagus (Figs	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFD3A237FB43F8A2FF02FE17.taxon	diagnosis	Differential diagnosis. Very similar to the other species of 8 D – F) differs from other species except E. ophioglossus the E. limicola species group from which it can be reliably in the moderately widened apex of the paramere in latedistinguished by the male genitalia only. The aedeagus is ral view (Figs 8 E, U) and the very elongate and distally unique in the following characters: deeply bilobate apex rounded (not bilobate) apical disc of the median lobe. In of the median lobe (Figs 8 A, C; not bilobate in all other all these aspects it resembles E. ophioglossus from which species), apices of parameres not widened in lateral view it only differs in the shape of the ventral fork (Fig. 8 T) (Figs 8 B, S; more or less widened in all other species) which is only shallowly emarginate. Externally, it can be and ventral fork rather narrow and shallowly excised only distinguished from E. smithi by the complete ridge on (Fig. 8 R; in contrast to E. cameroonensis, E. limicola and elytral interval 3 (see under E. smithi for details). E. ophioglossus). Externally, it can be only distinguished Description. Body 2.65 mm long and 1.60 mm wide. Dorfrom E. smithi by the complete ridge on elytral interval 3 sal surface black. Habitus and sculpture as in Figs 9 D – F; (interrupted posteriorly in E. smithi). The coloration of all ridge on elytral interval 3 not interrupted; ridge on interval examined specimens is paler (brown to dark brown Figs 5 interrupted anteriorly and just before its posterior end; 9 A – C) than in all other species examined. ridge on interval 7 complete until posterior 0.1 of elytral	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFD3A237FB43F8A2FF02FE17.taxon	description	Description. Body 2.8 – 3.3 mm long (holotype 2.9 mm) length. Elytral punctures connected by low elevated line. and 1.5 – 1.8 mm wide (holotype 1.6 mm). Dorsal color- Aedeagus (Figs 8 D – E, T – U): 0.80 mm long. Parameres ca. ation brown to dark brown. Habitus and sculpture as in 1.5 × longer than phallobase, moderately bisinuate on outer Figs 9 A – C; ridge on elytral interval 3 not interrupted face, moderately widened apically in lateral view. Median throughout; ridge on interval 5 interrupted anteriorly and lobe with ventral impression rounded in lateral view; apical disc ca. twice as long as wide, concave in lateral view, its apex rounded. Phallobase basally with narrow, slightly asymmetrical manubrium.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFD3A237FB43F8A2FF02FE17.taxon	etymology	Etymology. The species name refers to Cameroon where the only known specimen was collected. Adjective.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFD3A237FB43F8A2FF02FE17.taxon	biology_ecology	Biology. No data available.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFD3A237FB43F8A2FF02FE17.taxon	distribution	Distribution. Only known from the type locality (Fig. 13 A).	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCDA233FBD4FF1AFC78F97C.taxon	description	(Figs 8 M – Q, 9 G – I)	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCDA233FBD4FF1AFC78F97C.taxon	materials_examined	Material examined. H ඈඅඈඍඒඉൾ: J (MRAC): ʽHOLOTYPUS // Biot. No 14 / banks de / vase // I. R. S. A. C. – MUS. CONGO / Kivu: Kitutu, terr. Mwenga / riv. Lubushwa 650 m / B. 14 N. Leleup 12 - IV- 58 // TYPE // J. Delève det. 1966 / Eumetopus / limicola n. sp. // Aedeagus / drawn by / P. D. Perkinsʼ. P * ò * © * ò ඍඒඉൾඌ: 9 ♀♀ (MRAC), 1 J 1 ♀ (IRSNB): same locality data as the holotype.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCDA233FBD4FF1AFC78F97C.taxon	diagnosis	Differential diagnosis. Very similar to the other species of the E. limicola species group from which it can be reliably distinguished by the male genitalia only. The aedeagus (Figs 8 M – Q) differs in rounded apex from E. bilobatus and in the widely expanded parameres in lateral view from all species except E. smithi. From E. smithi it may be distinguished by the much shorter phallobase, more deeply excised ventral fork of the median lobe, and the complete ridge on elytral interval 3.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCDA233FBD4FF1AFC78F97C.taxon	description	Redescription. Body 2.5 – 3.1 mm long (holotype 2.7 mm) and 1.4 – 1.7 mm wide (holotype 1.5 mm). Dorsal surface brown to dark brown. Habitus and sculpture as in Figs 9 G – I; ridge on elytral interval 3 not interrupted; ridge on interval 5 interrupted anteriorly and sometimes also throughout its length or just before its posterior end; ridge on interval 7 complete throughout or interrupted in posterior 0.2 – 0.3 of elytral length. Elytral punctures connected by low elevated line. Aedeagus (Figs 8 M – Q): 0.90 mm long. Parameres ca. 1.8 × longer than phallobase, moderately bisinuate on outer face, strongly widen- ed apically in lateral view. Median lobe with ventral impression narrow in lateral view; apical disc ca. 1.6 × longer than wide, concave in lateral view, its apex very weakly sinuate. Phallobase basally with narrow, slightly asymmetrical manubrium.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCDA233FBD4FF1AFC78F97C.taxon	biology_ecology	Biology. No data available.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCDA233FBD4FF1AFC78F97C.taxon	distribution	Distribution. The species was originally described from the Democratic Republic of Congo (locality of most specimens examined) and Côte d’Ivoire (based on a single female). The female from Côte d’Ivoire was not found in the collections. However, the newly collected specimens from Côte d’Ivoire all belong to a very similar but different species (E. smithi sp. nov.) and we suppose the same applies for the female paratype examined by D ൾඅජඏൾ (1967). We hence exclude Côte d’Ivoire from the distribution range of E. limicola. Eupotemus ophioglossus sp. nov. view. From E. limicola it differs in a shallowly excised (Figs 8 G – I, 10 D – F) ventral fork. Eupotemus smithi differs from all species of	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCDA233FBD4FF1AFC78F97C.taxon	materials_examined	Material examined. H ඈඅඈඍඒඉൾ: J (NHMW): ʽGABON / Bissok the group externally in the largely interrupted keels on the (Oyem) / 3. - 10.2.1991 / leg. Bilardo // Eupotemus limicola (Del.) / det elytral intervals 3, 5 and 7. Jäch 1998 ʼ. P * ò * © * ò ඍඒඉൾ J: 1 (NHMW): ʽTOGO: Plateux / Pref. Kloto, Description. Body 2.6 – 3.1 mm long (holotype 2.8 mm) ca. 5 km from / Konda (village), 9. II. 2006 / leg. Komarek & Houngue and 1.4 – 1.7 mm wide (holotype 1.5 mm). Dorsal surface (28) // 06 ° 58 ’ 05.3 ” N 00 ° 34 ’ 18.2 ” E, ca. 510 m a. s. l / small stream in prim. forestʼ. brown to black. Habitus and sculpture as in Figs 10 A – C; ridge on elytral interval 3 interrupted posteriorly; ridge on	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCDA233FBD4FF1AFC78F97C.taxon	diagnosis	Differential diagnosis. Very similar to the other species of interval 5 interrupted in posterior half to fourth; ridge on the E. limicola species group from which it can be reliably interval 7 interrupted in posterior half to third of elytral distinguished by the male genitalia only. The aedeagus length. Elytral punctures connected by low elevated line. is unique in the shape of the ventral fork of the median Aedeagus (Figs 8 J – L, X – Y): 0.90 mm long. Parameres lobe which is very deeply excised (Fig. 8 V), otherwise ca. 1.8 × longer than phallobase, strongly sinuate on outer it resembles that of E. cameroonensis by the moderately face, strongly widened apically in lateral view. Median widened apex of the paramere in lateral view (Figs 8 H, W) lobe with narrow ventral impression in lateral view; apical and in the narrow elongate apical disc of the median lobe disc ca. 1.5 × longer than wide, concave in lateral view, its (Fig. 8 G). Externally, it can be only distinguished from E. apex rounded. Phallobase basally with narrow, slightly smithi in the complete ridge on elytral interval 3 (see under asymmetrical manubrium. E. smithi for details). Variation. The single male from Tai National Park is Description. Body 2.6 – 2.7 mm long (holotype 2.6 mm) brachypterous, smaller than the remaining specimens exa- and 1.3 – 1.4 mm wide (holotype 1.3 mm). Dorsal surface mined (2.6 mm long), and the ridges on its elytral intervals brown to black. Habitus and sculpture as in Figs 10 D – F); 3, 5 and 7 are completely subdivided into a series of elonridge on elytral interval 3 not interrupted; ridge on interval gate tubercles. Yet, it corresponds with the macropterous 5 interrupted anteriorly and posteriorly; ridge on interval specimens from Yéale village, with which it also agrees in 7 interrupted in posterior 0.2 – 0.4 of elytral length. Elytral all details of the aedeagus morphology. We hence consider punctures connected by low elevated line. Aedeagus (Figs this specimen conspecific to the holotype and hypothesize 8 G – I, V – W): 0.80 mm long. Parameres ca. 2.2 × longer that the differences may correlate to the brachyptery. than phallobase, strongly sinuate on outer face subapically, Etymology. This species is named after Richard E. L. moderately widened apically in lateral view. Median lobe Smith, who is the founder of the African Natural History with ventral impression narrowly rounded in lateral view; Research Trust (ANHRT). apical disc ca. twice as long as wide, weakly concave in Biology. Specimens from Yéalé village were all collected lateral view, its apex rounded. Phallobase basally with at light in the middle of the village which is surrounded narrow, slightly asymmetrical manubrium. by a belt of secondary forests and plantations followed by Etymology. The latinised Greek noun ophioglossus means intact forest. The brachypterous specimen in the Tai NP was ‘ a snake tongueʼ, in reference to the unique shape of the collected by sifting and washing plant debris accumulated ventral fork of the median lobe in this species. after a flood (M. Geiser & E. Ruzzier, pers. comm.). Biology. The paratype was collected at the small stream Distribution. The species was collected in two lowland in a primary forest. localities in western Côte d’Ivoire close to the border to Distribution. Known from two rather distant localities, one Liberia, situated ca. 220 km apart (Fig. 13 A). in southern Togo and one in northern Gabon (Fig. 13 A). Unidentified specimens Eupotemus smithi sp. nov. of the Eupotemus limicola group (Figs 2 A, C, E – F, H; 3 A – B, J, Q; 4 C, K – L, Q; 5 A, D, J, M; 6 A – F; 8 J – L, X – Y; 10 A – C) Material examined. CAMEROON: 1 ♀ (NMPC): Mamengole, iv. 1949, lgt. Tesárek. GABON: 1 ♀ (NHMW): Batéké Plateau National Park,	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCDA233FBD4FF1AFC78F97C.taxon	materials_examined	Material examined. H ඈඅඈඍඒඉൾ: J (macropterous) (BMNH): ʽCÔ- camp Ntsa, ʽforêt denseʼ [= dense forest], 8 – 13. ix. 2008, A. Bilardo lgt. TE D’IVOIRE, 380 m, / Yeale Village, Mt. Nimba / 07 ° 31 ’ 35.3 ” N 08 ° 25 ’ 20.1 ” W, / 18 - 29. IV. 2016 Light Trap, // Aristophanous, M., / Geiser, M., Moretto, P., leg., / BMNH (E) 2016 - 109, / Trip Ref. CI- 003 (ANHRT Eupotemus carinaticollis group 17) ʼ. P * ò * © * ò ඍඒඉൾඌ: 14 spec. (incl. DNA voucher MF 2207. W) (BMNH, NMPC): same data as the holotype.; 1 spec. (BMNH): ʽCÔTE D’IVOIRE, Eupotemus carinaticollis (Basilewsky, 1956) 380 m, / Yéalé Village, Mt. Nimba / 07 ° 31 ’ 35.3 ” N 08 ° 25 ’ 20.1 ” W, / (Figs 11 A – C, 12 A – C) 8. V. 2016 // Aristophanous, M., / Geiser, M., Moretto, P., leg., / BMNH (E) Material examined. H ඈඅඈඍඒඉൾ: J (MRAC): ʽHOLOTYPUS // COLL. 2016 - 109, Trip / Ref.: CI- 003 (ANHRT 17) ʼ; 1 J (brachypterous) (BMNH): MUS. CONGO / Urundi: Rumonge 800 m / 7 - III- 1953 / P. Basilewsky ʽCÔTE D’IVOIRE, 174 m, / Tai NP, Tai Research Station, / 05 ° 49 ’ 59.8 ” N, // Georyssus / carinaticollis / n. sp. Type / P. Basilewsky det., 19 // J. 07 ° 20 ’ 32.0 ” W, / 14 - 23. xi. 2015 // Leaf litter by river bank / Aristophanous, Delève det. 1966 / Eumetopus / carinaticollis / Basilewsky // Aedeagus M., / Moretto, P., Ruzzier, E. leg., / BMNH (E) 2015 - 177 ʼ. / drawn by / P. D. Perkinsʼ.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCDA233FBD4FF1AFC78F97C.taxon	diagnosis	Differential diagnosis. Very similar to the other species of Additional specimens examined: DEMOCRATIC REPUBLIC the E. limicola species group from which it can be reliably OF THE CONGO: 1 J 1 ♀ (MRAC): Kivu: Uvira, vest. de forêt sclerophylle [= remnants of a sclerophyll forest] / I- 1958 N. Leleup. distinguished by the male genitalia only. The aedeagus (Figs 8 J – L, X – Y) differs from all species except E. limicola Differential diagnosis. Very similar to the other species by the largely widened apex of the parameres in lateral of the E. carinaticollis species group from which it can be reliably distinguished by the male genitalia only. The aedeagus differs from E. uluguru sp. nov. in the apically widened and subapically constricted parameres (Fig. 11 A). This character is shared with E. taianus sp. nov. from which E. carinaticollis differs in the narrower and more elongated median lobe.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCDA233FBD4FF1AFC78F97C.taxon	description	Redescription. Body 2.9 – 3.4 mm long (holotype 2.9 mm) and 1.6 – 1.8 mm wide (holotype 1.7 mm). Dorsal surface black. Habitus and sculpture as in Figs 12 A – C; ridge on elytral interval 3 and 5 complete throughout; ridge on interval 7 interrupted posteriorly. Elytral punctures connected by low elevated line. Aedeagus (Figs 11 A – C): 0.85 – 0.90 mm long. Parameres ca. 1.8 × longer than phallobase, constricted subapically, widened at apex. Median lobe 3.4 × longer than wide, apical part narrowing in apical fourth, sides of median lobe narrowing to apex in a straight line. Phallobase basally with narrow symmetrical manubrium.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCDA233FBD4FF1AFC78F97C.taxon	biology_ecology	Biology. Unknown. The labels of the Burundi specimens indicate that they were collected in remnants of a sclerophyll forest (i. e. in a dry forest with hard-leaved trees).	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCDA233FBD4FF1AFC78F97C.taxon	distribution	Distribution. The species is known from two localities situated around the northern part of Lake Tanganyika, one in the Democratic Republic of Congo, the other in Burundi (Fig. 13 B).	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFC9A231FBACF8DDFDFAF8A9.taxon	description	(Figs 11 D – F, 12 G – I)	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFC9A231FBACF8DDFDFAF8A9.taxon	materials_examined	Material examined. H ඈඅඈඍඒඉൾ: J (DNA voucher MF 2248) (BMNH): ʽCÔTE D’IVOIRE, 174 m, / Taï NP, Taï Research Station / (SRET) / 05 ° 50 ’ 00 ” N 07 ° 20 ’ 32.0 ” W, / 25. III- 17. IV. 2017, MV light // Aristophanous, A., / Aristophanous, M., / Geiser, M., Moretto, P., leg., / BMNH (E) 2019 - 93 ʼ.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFC9A231FBACF8DDFDFAF8A9.taxon	diagnosis	Differential diagnosis. Very similar to the other species of the E. carinaticollis species group from which it can be reliably distinguished by the male genitalia only. The aedeagus resembles that of E. carinaticollis by the subapically constricted and apically widened parameres but differs in the wider median lobe with convex sides subapically. From E. uluguru it differs in the apically widened parameres.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFC9A231FBACF8DDFDFAF8A9.taxon	description	Description. Body 2.8 mm long and 1.5 mm wide. Dorsal surface black. Habitus and sculpture as in Figs 12 G – I; ridge on elytral interval 3 complete throughout; ridge on interval 5 interrupted posteriorly; ridge on interval 7 interrupted in posterior fourth. Elytral punctures connected by low elevated line. Aedeagus (11 D – F): 0.90 mm long. Parameres ca. 2.0 × longer than phallobase, indistinctly constricted at midlength, strongly constricted subapically, apex widened. Median lobe 2.5 × longer than wide, narrowing from midlength to apex, sides convex subapically. Phallobase basally with narrow symmetrical manubrium. Etylomogy. The species name refers to the Taï National Park in which the only known specimen of this species was collected. Adjective.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFC9A231FBACF8DDFDFAF8A9.taxon	biology_ecology	Biology. Unknown, collected at light.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFC9A231FBACF8DDFDFAF8A9.taxon	distribution	Distribution. Known only from the type locality in southwestern Côte d’Ivoire (Fig. 13 B).	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCBA231F951F898FAD9F8C3.taxon	description	(Figs 11 G – I, 12 D – F)	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCBA231F951F898FAD9F8C3.taxon	materials_examined	Material examined. H ඈඅඈඍඒඉൾ: J (MRAC): ʽHOLOTYPUS // Coll. Mus. Tervuren / Mission Mts. Uluguru / L. Berger, N. Leleup / J. Debecker V / VIII / 71 // Tanzanie: Mts. Uluguru / Morogoro Campus Fac. / Agric. Piège. Lum. U. V. / alt. 600 m V-VI / 71 // J. Delève det. 1966 / Eumetopus / carinaticollis (Basil.) // HOLOTYPE / Afrometopus / uluguru / P. D. Perkinsʼ. P * ò * © * ò ඍඒඉൾ: 1 J (NHMW): ʽTANZANIA: Morogoro / 560 m a. s. l. / light trap, III-IV. 1987 / coll. Pócs & Sontera // Eupotemus / carinaticollis (Bas.) / det. M. Jäch 1999 ʼ. Additional material. Additional specimens from the same collecting event (same collectors, date and locality data) should be deposited in the HNHM but could not be located instantaneously (Gy. Makranczy, pers. comm.).	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCBA231F951F898FAD9F8C3.taxon	diagnosis	Differential diagnosis. Very similar to the other species of the E. carinaticollis species group from which it can be reliably distinguished by the male genitalia only. The aedeagus differs from both remaining species in the continuously narrowing parameres which are not widened at apex (Figs 11 G, I).	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCBA231F951F898FAD9F8C3.taxon	description	Description. Body 2.9 mm long (holotype 2.9 mm) and 1.6 mm wide (holotype 1.6 mm). Dorsal surface black. Habitus and sculpture as in Figs 12 D – F; ridge on elytral interval 3 complete throughout; ridges on interval 5 and 7 interrupted posteriorly. Elytral punctures connected by low elevated line. Aedeagus (Figs 11 G – I): 0.90 mm long. Parameres ca. 1.8 × longer than phallobase, continuously narrowing towards apex, not widened apically. Median lobe 3.0 × longer than wide, apical part narrowing in apical third, sides slightly concave subapically. Phallobase basally with narrow asymmetrical manubrium.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCBA231F951F898FAD9F8C3.taxon	etymology	Etymology. The species name refers to the Uluguru Mts. where this species was collected. Noun in apposition.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCBA231F951F898FAD9F8C3.taxon	biology_ecology	Biology. Unknown, both specimens were collected at light.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCBA231F951F898FAD9F8C3.taxon	distribution	Distribution. Both known specimens were collected at the same locality in eastern Tanzania (Fig. 13 B).	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCBA23EFBCEF84AFB28F786.taxon	description	(Figs 2 M – Q; 3 C – D, L – O; 4 A – B, D, H, L – M; 5 C, I, L; 6 S – Z; 7 A – C; 14 – 15)	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCBA23EFBCEF84AFB28F786.taxon	description	(2002), Sκ * ò අൾ & J ඟ * ö * ü (2003), H * ò ඇඌൾඇ (2004), F ං κ ගඹൾκ & R ඒඇൽൾඏ ං * ö * ü locality, 13. iv. 2019, A. Prokin lgt. (2015).	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCBA23EFBCEF84AFB28F786.taxon	discussion	Comments. Eumetopus acutimontis was so far only known	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCBA23EFBCEF84AFB28F786.taxon	diagnosis	Diagnosis. Moderately large species (body length 2.6 – 4.3 from Hainan Island, China. The specimens from Vietnam mm); body brown to black, partly with a metallic sheen correspond well with the drawing of the male genitalia by (especially on pronotum and elytral tubercles; Figs 14 – J ං & J ඟ * ö * ü (1998 a), and their external morphology agrees 15); eyes not divided completely into dorsal and ventral with the female paratype deposited in the NHMW. This portion (Fig. 4 A); anterior oblique portion of clypeus is the first record of E. acutimontis from continental Asia divided from posterior parts by a ridge (Fig. 4 B); lab- and from Vietnam. rum strongly narrowed posteriorly (Fig. 2 J); mandibular Biology. All specimens were found on the wet sandy banks apex bidentate (Figs 2 M – L); apical maxillary palpomere of the Shuoi-Ngang river, by washing out the shore sedilong, strongly asymmetrical (Fig. 2 M); mentum slightly ment (Figs A – D); the specimens were floating at the water wider than long, with series of long setae along anterior surface when they were washed from the sandy shore. margin (Figs 2 N – O, 4 D); pronotum 0.7 – 0.8 × as long as Adults of some Hydrophilidae, Byrrhinus sp. (Limnichiwide, hood covering head forming anterior third of its dae) and a larva of Eulichas Jakobson, 1913 (Eulichadidae) length; ventral surface of the hood with set of parallel were collected from the same microhabitat. For video of a ridges (Fig. 3 D); prosternum (Fig. 3 C) slightly elevated living specimen, see Supplementary File S 1. medially, ca. 0.25 × as long as procoxal cavity; procoxal cavity open posteriorly (Fig. 3 C); elytron with scutellary Eumetopus asperatus (Champion, 1919) stria (Fig. 15); elytra with tubercles on alternate intervals (Figs 14 B, 15 B) (Fig. 15); mesanepisterna narrowly separated by anterior	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCBA23EFBCEF84AFB28F786.taxon	materials_examined	Material examined. INDIA: U ඍඍൺඋൺκΗൺඇൽ: 5 spec. (NHMW, NMPC): portion of mesoventrite; mesoventrite posteromesally 30 km NNE Bageshwar, west of Loharket Village, 1800 – 1900 m, with high bulge (Fig. 3 L); metaventrite ca. as long as 24. vi. 2003, Z. Kejval & M. Trýzna lgt. mesocoxa, posteromesally with large central and a pair of	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCBA23EFBCEF84AFB28F786.taxon	discussion	Comments. Except for the holotype, this species has not lateral smooth elevated areas (Fig. 3 L); middle and hind been recorded from Uttarakhand. femora with posterior spine (Fig. 4 M); phallobase long and conical; parameres subdivided into dorsal and ventral Eumetopus bullatus (Sharp, 1875) lobe; median lobe thin, peg-like, without projections (Figs (Figs 6 Z, 14 C, 15 C) 6 V – Z); sperm pump present (Fig. 6 Y); male sternite IX circular (Fig. 6 U). Material examined. INDIA: M ൺΗൺඋൺඌΗඍඋൺ: 4 JJ 4 ♀♀ (NHMW, NMPC): ca. 15 km E Sawantwadi, 15 ° 55 ′ N 73 ° 53 ′ E [coordinates on Identification. The genus was revised by J ං & J ඟ * ö * ü (1998) original labels (15 ° 55 ′ N 75 ° 53 ′ E) are incorrect, Z. Kejval, pers. comm.], who also illustrated the male genitalia for all species riverside, 40 m, 22. v. 2006, Z. Kejval lgt. known at that time. One additional species was described by J ඟ * ö * ü (2002) who provided an updated identification Comments. The species was so far only known from the key. The latest recognized species was described by holotype with the type locality ‘ Indiaʼ (S * ü * ò * © ඉ 1875, J ං & Sκ * ò අൾ & J ඟ * ö * ü (2003) and compared to its closest relative. J ඟ * ö * ü 1998). This is therstfi precise record, confirming the occurrence in India. List of species (8 described species) Eumetopus flavidulus (Sharp, 1890) E. acutimontis Ji & Jäch, 1998 China (Hainan; J ං & J ඟ * ö * ü 1998 a), (Figs 14 D, 15 D, J) Vietnam (this paper) E. asperatus (Champion, 1919) India: Himachal Pradesh, Uttarakhand; Material examined. INDIA: M ൺΗൺඋൺඌΗඍඋൺ: 4 JJ 4 ♀♀ (NHMW, Nepal (J ං & J ඟ * ö * ü 1998 a, Sκ * ò අൾ & J ඟ * ö * ü NMPC): ca. 15 km E Sawantwadi, 15 ° 55 ′ N 73 ° 53 ′ E [coordinates on 2003, H ൾ * ô * ò ඎൾ * © 2006 b, this paper) original labels (15 ° 55 ′ N 75 ° 53 ′ E) are incorrect, Z. Kejval, pers. comm.], E. bullatus (Sharp, 1875) India: Maharashtra (this paper). riverside, 40 m, 22. v. 2006, Z. Kejval lgt. A ඇൽΗඋൺ P උൺൽൾඌΗ: 1 J 1 ♀ E. flavidulus (Sharp, 1890) India: Andhra Pradesh, Kerala, Maha- (SLC): Vijayawada, Krishna River, 16.511 ° N 80.614 ° E, 16. ii. 2014, K. rashtra, Meghalaya, Odisha; Sri Lanka Tomkovich lgt. (J ං & J ඟ * ö * ü 1998 a, this paper) E. maindroni (Régimbart, 1903) India: Gujarat, Maharashtra, Tamil Comments. First record for Andhra Pradesh and Maha- Nadu (R ඣǤ ං ආ * ô * ò * © ඍ 1903, J ං & J ඟ * ö * ü rashtra. 1998 a, this paper) E. schuelkei Jäch, 2002 Laos (J ඟ * ö * ü 2002) Eumetopus maindroni (Régimbart, 1903) E. tibialis Ji & Jäch, 1998 northern Thailand (J ං & J ඟ * ö * ü 1998 a) (Figs 14 E, 15 E) E. weigeli Skale & Jäch, 2003 Nepal (Sκ * ò අൾ & J ඟ * ö * ü 2003), India: Uttarakhand (this paper). Material examined. INDIA: M ൺΗൺඋൺඌΗඍඋൺ: 3 JJ 1 ♀ (NHMW): ca. 15 km E Sawantwadi, 15 ° 55 ′ N 73 ° 53 ′ E [coordinates on original labels (15 ° 55 ′ N 75 ° 53 ′ E) are incorrect, Z. Kejval, pers. comm.], riverside, Eumetopus acutimontis Ji & Jäch, 1998 40 m, 22. v. 2006, Z. Kejval lgt. G ඎ ඃ ൺඋൺඍ: 1 J 5 ♀♀ (SLC): Junagadh, (Figs 6 S – Y, 14 A, 15 A, I) Girnar Mt., 21.526 ° N 70.48 ° E, 20 – 31. x. 2012, at light, K. Tomkovich lgt.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFCBA23EFBCEF84AFB28F786.taxon	materials_examined	Material examined. VIETNAM: KΗ ගඇΗ H ණൺ P උඈඏ.: 1 J 1 ♀ with Comments. The species was so far known only from the egg case (IBIW): Ba Ho Waterfalls National Park, river Shuoi-Ngang, type specimens (R ඣǤ ං ආ * ô * ò * © ඍ 1903, J ං & J ඟ * ö * ü 1998 a) from 12 ° 23.131 ′ N 109 ° 08.052 ′ E, 18. iv. 2018, A. Prokin & A. Sazhnev leg.; 12 the Indian state of Tamil Nadu. Here we report it from JJ 9 ♀♀ (2 ♀♀ with egg case) (IBIW, NMPC): same locality, 2. v. 2018, Gujarat and Maharashtra for the first time.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFC5A23FF97AFF65FB54FE9B.taxon	description	(Figs 14 G, 15 G, K)	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFC5A23FF97AFF65FB54FE9B.taxon	materials_examined	Material examined. THAILAND: R ൺඇඈඇǤ: 1 ♀ (NMPC): Ban Na env., 9 ° 34 ′ N 98 ° 42 ′ E, K. Majer lgt.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFC5A23FF97AFF65FB54FE9B.taxon	discussion	Comments. The species was so far only known from northern Thailand. The above specimen from southern Thailand is a female, but corresponds to the paratypes of E. tibialis in all aspects, including the body size and the dorsal sculpture of the elytron.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFC6A23CF890FF66FA54FE97.taxon	description	(Figs 14 H, 15 H, L)	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFC6A23CF890FF66FA54FE97.taxon	materials_examined	Material examined. INDIA: U ඍඍൺඋൺκΗൺඇൽ: 5 JJ 2 ♀♀ (1 ♀ with egg case), 1 spec. (BMNH): ‘ India: U. P., Dehra Dun, Phandowala. Suawa R. 1. iv. 1928. H. G. Champion. // Brit. Mus. 1928 - 518 ʼ.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFC6A23CF890FF66FA54FE97.taxon	discussion	Comments. These specimens agree with the holotype of E. weigeli examined by us in all details of external morphology and male genitalia. The species was previously known only from Nepal, we record it as new for India.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFC7A238F95DFF66FE6EFB57.taxon	description	(Figs 2 R – Z, a – l; 3 E – I, K, P; 4 E – G, I – J, N – P, R; 5 B, E – F, G – H, K, O – P; 6 I – R; 16)	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
038BAE5EFFC7A238F95DFF66FE6EFB57.taxon	diagnosis	Diagnosis. Small to moderately large species (body length 1.2 – 3.7 mm); body reddish to black, without metallic sheen (Figs 16 A – F); eyes completely divided into dorsal and ventral portion (E. trogoides group; F ං κ ගඹൾκ et al. 2011: fig. 12) or not (remaining groups; F ං κ ගඹൾκ et al. 2011: fig. 11); anterior portion of clypeus not divided from posterior parts; labrum not strongly narrowed posteriorly (Fig. 2 R, X, g – i); mandibular apex tridentate (Figs 2 S, Y, e – f); apical maxillary palpomere long, strongly to weakly asymmetrical (Figs 2 T, Z); mentum ca. as long as wide, without setae along anterior margin (Figs 2 V, j – l); pronotum 0.7 – 0.8 × as long as wide, hood covering head forming anterior third of its length; ventral surface of the hood with set of parallel ridges (Figs 3 F, H); prosternum without median elevation, ca. 0.3 × as long as procoxal cavity (Figs 3 E, G); procoxal cavity closed posteriorly (Figs 3 E, G, I); mesanepisterna narrowly separated by anterior portion of mesoventrite (E. costatus group; Fig. 3 K) or meeting mesally (E. mendeli group; Fig. 5 B) (other groups not examined); mesoventrite posteromesally with high transverse ridge (Fig. 3 K); metaventrite ca. as long as mesocoxa, without large smooth elevated areas (Figs 3 K, 5 B); middle and hind femora without posterior spine; phallobase short and wide; parameres simple; median lobe flat, with a pair of ventral projections or without any projections (Figs 6 L – R); sperm pump absent; male sternite IX U-shaped (Fig. 6 K). Identification. The genus was revised by P ൾ * © κ ං ඇඌ (2012) who also provided a key to the species groups and illustrated all species. List of species (56 described species) Epimetopus plaumanni species group Epimetopus costatus species group E. multiportus Perkins, 2012 Uruguay, Paraguay (P ൾ * © κ ං ඇඌ 2012) E. plaumanni (Costa Lima, 1954) Brazil (Santa Catarina, Nova Teu- E. acuminatus Perkins, 2012 Guatemala (P ൾ * © κ ං ඇඌ 2012) tonia) (C ඈඌඍ * ò L ං ආ * ò 1954, P ൾ * © κ ං ඇඌ E. angustus Perkins, 2012 Panama, Venezuela, Ecuador, Peru 2012) (P ൾ * © κ ං ඇඌ 2012) E. vianai Balfour-Browne, 1949 Argentina (B * ò අൿඈඎ * © - B * © ඈඐඇൾ 1949, E. apocinus Perkins, 2012 Mexico, Costa Rica (P ൾ * © κ ං ඇඌ 1979, O අ ං ඏ * ò 1986, P ൾ * © κ ං ඇඌ 2012) 2012) E. vulpinus Perkins, 2012 Brazil (Rio Grande do Sul), Uruguay E. arizonicus Perkins, 2012 USA (Arizona) (P ൾ * © κ ං ඇඌ 2012) (P ൾ * © κ ං ඇඌ 2012) E. ballatoris Perkins, 2012 Venezuela, Trinidad and Tobago (P ൾ * © κ ං ඇඌ 2012) Epimetopus lanceolatus species group E. bifidus Perkins, 2012 Mexico (P ൾ * © κ ං ඇඌ 2012) E. lanceolatulus Perkins, 2012 Brazil (Mato Grosso), Paraguay E. burruyacu Oliva, 1986 Argentina (Tucuman) (O අ ං ඏ * ò 1986) (P ൾ * © κ ං ඇඌ 2012) E. costaricensis Perkins, 1979 Mexico, Belize, Costa Rica, Guate- E. lanceolatus Perkins, 2012 Brazil (Mato Grosso) (P ൾ * © κ ං ඇඌ 2012) mala, Honduras, Panama (P ൾ * © κ ං ඇඌ 1979, 2012) Epimetopus trogoides species group E. costatus (Leconte, 1874) USA (Texas, Arkansas) (P ൾ * © κ ං ඇඌ 2012) E. clandestinus Perkins, 2012 Brazil (Mato Grosso), Venezuela E. ecuadoriensis Perkins, 2012 Ecuador (P ൾ * © κ ං ඇඌ 2012) (P ൾ * © κ ං ඇඌ 2012) E. fisheri Perkins, 1979 Mexico, Honduras (P ൾ * © κ ං ඇඌ 2012), E. deceptus Perkins, 2012 Brazil (Mato Grosso) (P ൾ * © κ ං ඇඌ 2012) USA (Arizona) (P ൾ * © κ ං ඇඌ 1979) E. fimbriatus Perkins, 2012 Brazil (Mato Grosso) (P ൾ * © κ ං ඇඌ 2012) E. hintoni Balfour-Browne, 1949 Argentina (O අ ං ඏ * ò 1986, needs confir- E. tridens Perkins, 2012 Brazil (São Paulo) (P ൾ * © κ ං ඇඌ 2012) mation), Bolivia (B * ò අൿඈඎ * © - B * © ඈඐඇൾ E. trogoides (Sharp, 1874) Brazil (Mato Grosso, São Paulo) 1949, P ൾ * © κ ං ඇඌ 2012) (P ൾ * © κ ං ඇඌ 2012); records by R ඈ * ö * ü * ò E. inaequalis Perkins, 2012 Ecuador, Peru (P ൾ * © κ ං ඇඌ 2012) (1969) from Brazil and by O අ ං ඏ * ò E. lacordairei Orchymont, 1933 Bolivia, Brazil (Mato Grosso), Pa- (1986) from Argentina need verifi- raguay (O * © * ö * ü ඒආඈඇඍ 1933, P ൾ * © κ ං ඇඌ cation 2012) E. venezuelensis Perkins, 2012 Venezuela (P ൾ * © κ ං ඇඌ 2012) E. latilobus Perkins, 2012 Costa Rica (P ൾ * © κ ං ඇඌ 2012) E. latisoides Perkins, 2012 Panama (P ൾ * © κ ං ඇඌ 2012) Epimetopus tuberculatus species group E. latus Perkins, 2012 Colombia, Venezuela (P ൾ * © κ ං ඇඌ 2012) E. tuberculatus Rocha, 1969 Brazil (Minas Gerais) (R ඈ * ö * ü * ò 1969, E. lobilatus Perkins, 2012 Costa Rica (P ൾ * © κ ං ඇඌ 2012) P ൾ * © κ ං ඇඌ 2012) E. microporus Perkins, 2012 Honduras, Panama (P ൾ * © κ ං ඇඌ 2012) E. mucronatus Perkins, 2012 Mexico, Honduras (P ൾ * © κ ං ඇඌ 2012) E. oaxacus Perkins, 2012 Mexico (P ൾ * © κ ං ඇඌ 2012) Records of Epimetopus E. panamensis Perkins, 1979 Panama (P ൾ * © κ ං ඇඌ 1979, 2012) from Africa and the Arabian Peninsula E. plicatus Perkins, 2012 Venezuela (P ൾ * © κ ං ඇඌ 2012) Specimens examined. ZAMBIA: 1 ♀ (BMNH): Kabwe, Kasanka NP, E. punctipennis Perkins, 1979 USA (Arizona, Texas, Oklahoma), 12 ° 32 ʹ 28 ʺS 30 ° 12 ʹ 42 ʺE, light trap – Edwards funnel, 30. xi. – 1. xii. 2012, northern Mexico (P ൾ * © κ ං ඇඌ 1979,2012) Smith & Takano lgt. SAUDI ARABIA: 1 J (NMPC): Jizan Prov., ʻWadi E. rectus Perkins, 2012 Costa Rica (P ൾ * © κ ං ඇඌ 2012) Atoudʼ, 8. ii. 2016, 17 ° 48 ʹN 42 ° 22 ʹE, 245 m, J. Bezděk & D. Král lgt. E. robustus Perkins, 2012 Panama (P ൾ * © κ ං ඇඌ 2012) E. simplex Perkins, 1979 Costa Rica, Nicaragua, Panama, Comments. Both specimens belong to the Epimetopus Venezuela (P ൾ * © κ ං ඇඌ 1979, 2012) costatus species group, i. e. the group for which the mor- E. spatulus Perkins, 2012 Peru (P ൾ * © κ ං ඇඌ 2012) E. steineri Perkins, 2012 Ecuador (P ൾ * © κ ං ඇඌ 2012) phology of the male genitalia needs to be examined for E. transversoides Perkins, 2012 Peru (P ൾ * © κ ං ඇඌ 2012) species identification. The specimen from Zambia (Fig. E. transversus Perkins, 2012 Bolivia (P ൾ * © κ ං ඇඌ 2012) 16 E) is a female and hence cannot be identified. The speci- E. trilobus Perkins, 2012 Venezuela (P ൾ * © κ ං ඇඌ 2012) men from Saudi Arabia (Figs 16 F – G) seems to correspond Epimetopus mendeli species group to E. burruyacu, i. e. the species endemic to Argentina. E. angulatus Balfour-Browne, Bolivia (B * ò අൿඈඎ * © - B * © ඈඐඇൾ 1949, Both specimens were collected at light. We contacted the 1949 P ൾ * © κ ං ඇඌ 2012) collectors of both specimens who excluded the possibility E. coleuncus Perkins, 2012 Argentina, Bolivia (? O අ ං ඏ * ò 1986 as of confusing or mixing the samples with those from South E. angulatus, P ൾ * © κ ං ඇඌ 2012) America. The specimen from Saudi Arabia is from the same E. flavicaptus Fikáček, Barclay Ecuador (F ං κ ගඹൾκ et al. 2011) collecting event (same collectors, date and locality data) & Perkins, 2011 E. graniger (Mulsant, 1851) Colombia (P ൾ * © κ ං ඇඌ 2012) as the four specimens of the South American (likely Ar- E. mendeli Fikáček, Barclay Peru (F ං κ ගඹൾκ et al. 2011, P ൾ * © κ ං ඇඌ gentinian) Chaetarthria reported by F ං κ ගඹൾκ & L ං ඎ (2019: & Perkins, 2011 2012) 251). Most likely, these specimens have been mislabeled. E. peruvianus Perkins, 2012 Peru (P ൾ * © κ ං ඇඌ 2012) E. thermarum species group Discussion E. arcuatus Perkins, 2012 Paraguay (P ൾ * © κ ං ඇඌ 2012) The aim of this study was to publish the newly accu- E. balfourbrownei Rocha, 1969 Brazil (Mato Grosso) (R ඈ * ö * ü * ò 1969, mulated data on the family Epimetopidae which became P ൾ * © κ ං ඇඌ 2012) available due to the newly collected material. Fresh alcohol E. clypeatus Perkins, 2012 Guyana (P ൾ * © κ ං ඇඌ 2012) E. surinamensis Perkins, 2012 Suriname (P ൾ * © κ ං ඇඌ 2012) specimens enabled us to provide the first DNA sequences E. thermarum Schwarz & USA (Arizona, Texas), Mexico, of Eumetopus and Eupotemus. The new material from Barber, 1917 Belize, Guatemala, Costa Rica, Africa made it possible to dissect some specimens and Panama, Venezuela, (S * ö * ü ඐ * ò * © ඓ & perform morphological comparative studies based on B * ò * © * ô ൾ * © 1918, R ඈ * ö * ü * ò 1969, P ൾ * © κ ං ඇඌ all three genera. New records complementing the data 2012) on the distribution of all three genera became available. the air bubble is usually partly formed with the help of the Yet, it is very clear that the knowledge about the family antenna (H * © * ô ගඹൾκ 1950), and the antennal modifications remains rather limited in some aspects; these are defined in Georissidae and Epimetopidae may hence correspond and discussed below. to the adapted way of the gas exchange not necessarily indicating a close relationship of both families. Phylogenetic position of the family. It was mention- Larvae. Larvae are so far only known for a few species ed above that there is an apparent and strong conflict of the genus Epimetopus (R ඈ * ö * ü * ò 1967, 1969; C ඈඌඍ * ò et between the position of the Epimetopidae revealed by al. 1988; A * © * ö * ü * ò ඇǤൾඅඌκඒ 1997; F ං κ ගඹൾκet al. 2011; R ඈmorphological and molecular characters. Analyses based ൽ * © ං Ǥ ඎൾඓ et al. 2020) but unknown for the other two genera. on morphology always place Epimetopidae as sister to Epimetopus larvae are all characterized by the adaptations Georissidae, irrespectively of what kind of characters are for the underwater processing of the prey by piercing and used, and whether adult or larval data are included (H * ò ඇඌൾඇ sucking: the adapted form of the mandibles, the enlarge- 1991; B ൾඎඍൾඅ 1994, 1999; A * © * ö * ü * ò ඇǤൾඅඌκඒ 1998; B ൾඎඍൾඅ ment of the epistomal lobes and the reduction of the labrum & K ඈආ * ò * © ൾκ 2004; B ൾඎඍൾඅ & L ൾඌ * ö * ü ൾඇ 2005; B ൾ * © ඇ * ü * ò * © ൽ (R ඈൽ * © ං Ǥ ඎൾඓ et al. 2020). They are often associated with et al. 2009; F ං κ ගඹൾκ et al. 2012). In contrast, molecular reductions of spiracles and the closure of the tracheal analyses, despite not being conclusive about the phylo- system (R ඈൽ * © ං Ǥ ඎൾඓ et al. 2020). Similar morphology of genetic position of the Epimetopidae never place them the head and mouthparts, associated with underwater prey close to Georissidae (B ൾ * © ඇ * ü * ò * © ൽ et al. 2006, 2009; S * ü ඈ * © ඍ processing evolved independently in Epimetopidae and in & F ං κ ගඹൾκ 2013; M * öK ൾඇඇ * ò et al. 2014; L ඳ et al. 2020). three unrelated groups of the Hydrophilidae (F ං κ ගඹൾκ et If the molecular data are correct, it would imply that the al. 2018, R ඈൽ * © ං Ǥ ඎൾඓ et al. 2020). Moreover, R ඈൽ * © ං Ǥ ඎൾඓ supposed synapomorphies of Epimetopidae + Georissidae et al. (2020) noticed that the lineages sister to those with evolved in both groups independently, as a result of con- piercing-sucking mouthparts often have very different vergent evolution. We document here that Epimetopidae morphology of the head and a tracheal system well correinhabit moist sandy shores of streams of standing waters, sponding to the usual hydrophilid morphology. In addition, i. e. the same environment as most Georissidae (M ൾඌඌඇൾ * © at least in two cases in the Hydrophilidae (Laccobiini and 1965, 1972; F ං κ ගඹൾκ & F * ò අ * ò ආ * ò * © ඓ ං 2010; L ං ඍඈඏκ ං ඇ & Berosini), the lineage with piercing-sucking larval adaptati- F ං κ ගඹൾκ 2011; L ං ඍඈඏκ ං ඇ 2018) and some riparian groups ons contains significantly more species than its sister clade of Hydrophilidae (e. g., Chaetarthria Stephens, 1835 and in which larvae process the food above the water. This Thysanarthria Orchymont, 1926: P ൾ * © κ ං ඇඌ 1976, F ං κ ගඹൾκ observation resembles the situation in the Epimetopidae. & L ං ඎ 2019). Chaetarthria and Thysanarthria are deeply The species-rich Epimetopus with 56 species has larvae nested clades of the Hydrophilidae (S * ü ඈ * © ඍ & F ං κ ගඹൾκ with piercing-sucking mouthparts. Its sister Eupotemus 2013) and are not closely related to Epimetopidae. Still, has only eight known species and the larvae are unknown. they bear some of the characters considered as synapo- Hence, we cannot exclude that larvae of Eupotemus and morphies of Georissidae + Epimetopidae: they have a very Eumetopus may be not adapted for piercing-sucking food long antennal scape, a bulbose pedicel, strongly reduced processing, and hence may look different from those of (yet not totally absent) pubescence on the ventral body Epimetopus in head and mouthpart morphology and in surface, reduced gula and hence fused gular sutures, and the development of the larval tracheal system. The first they bear numerous digitiform sensilla on the base of the instar larvae of Eumetopus and Eupotemus can be obtained maxillary palpomere IV (F ං κ ගඹൾκ & L ං ඎ 2019). Moreover, from the egg cases carried by the females and should be the mentum of Thysanarthria bears series of long setae studied in detail. along its anterior margin (F ං κ ගඹൾκ & L ං ඎ 2019: fig. 3 A), Egg cases carried by females. Egg cases are carried by strongly resembling the situation found in Eumetopus (Fig. females of all three epimetopid genera, and hence represent 4 D). These convergences with Hydrophilidae indicate that a synapomorphy of Epimetopidae. Similar behavior is the convergent evolution of these characters cannot be a present in two unrelated lineages of Hydrophiloidea: the priori excluded for Georissidae and Epimetopidae. Addi- Spercheidae (F ං κ ගඹൾκ 2019 d) and the Helochares group tional studies on the biology and functional morphology of the hydrophilid subfamily Acidocerinae (S * ü ඈ * © ඍ et al. of both latter families are needed to understand whether 2021). The egg-carrying behavior is considered as derived their biology and the morpho-functional adaptations to in the Hydrophiloidea (H * ò ඇඌൾඇ 2000), i. e., it evolved indedeal with the riparian environment are indeed identical pendently in each mentioned lineage and may be adaptive. or just analogous. For example, the pronotal hood is a This seems to be corroborated by the slightly different way unique character shared by both families. The studies of in which the egg cases are carried in each group (H * ò ඇඌൾඇ the function of the hood including the parallel ridges on 2000). The purpose of this adaptation and whether similar its ventral side (see Biology of Epimetopidae above for or clade-specific evolutionary pressures led to the evolution current hypotheses) and a detailed comparative study of of this behavior remains to be tested. these structures between Georissidae and Epimetopidae Monophyly and internal topology of Epimetopus. Our may reveal useful information. The gas exchange is ano- morphological analysis failed to reveal the monophyly of ther unusual aspect which is shared by Georissidae and the genus Epimetopus (Figs 1 B – C). In contrast, the DNA- Epimetopidae: both clades lack the hydrofuge pubescen- - based analysis indicated Epimetopus as monophyletic. ce, which, in other Hydrophiloidea, holds the ventral air The taxon sampling was different in both analyses. Hence, bubble (F ං κ ගඹൾκ 2019 c, this paper). In Hydrophiloidea, both topologies may not be incongruent: the paraphyly of Epimetopus in the morphology analysis is caused by the member of the E. costatus group which is likely not involved in the molecular analysis. All Epimetopus species have posteriorly closed procoxal cavities, unlike any other epimetopids, based on which we consider the paraphyly of Epimetopus as unlikely. However, we cannot totally exclude it based on our data. Epimetopus is morphologically much more diverse than Eumetopus and Eupotemus. This is evident even from our limited taxon sampling containing two Epimetopus species, i. e. representatives of the E. costatus and E. mendeli groups. The comparison of these two species revealed numerous differences, e. g., in the form of the prothoracic hypomeron (compare Figs 3 E and G), in the form and sculpture of the meso- and metaventrite (compare Figs 3 K and 5 B, for additional SEMs of E. mendeli see also F ං κ ගඹൾκ et al. 2011), in the form of the trochanters (with dorsal plates in E. costatus group, without such plates in E. mendeli) and in the tarsal formula (5 - 5 - 5 in E. mendeli, 4 - 4 - 4 in E. costatus group). These differences indicate that the E. costatus group may indeed have a rather isolated position within Epimetopus; that needs to be tested by analyses with a wider species sampling covering all species groups of Epimetopus. Some other species groups also show apparent differences, e. g., in the eye morphology (completely divided in E. trogoides group, partially divided in other species; compare Figs 11 and 12 in F ං κ ගඹൾκ et al. 2011) and in the morphology of the male genitalia (with ventral projections likely corresponding to those of Eupotemus or without such projections; Figs 6 L – R and genitalia illustrations in P ൾ * © κ ං ඇඌ 2012). Additional studies are needed to understand the evolution of these characters within the genus and to confirm the monophyly of Epimetopus.	en	Fikáček, Martin, Matsumoto, Keita, Perkins, Philip, Prokin, Alexander, Sazhnev, Alexey, Litovkin, Stanislav, Jäch, Manfred A. (2021): The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1): 1-34, DOI: 10.37520/aemnp.2021.001, URL: http://dx.doi.org/10.37520/aemnp.2021.001
