taxonID	type	description	language	source
03DB87D7977BBC22FEDC24418129FDA4.taxon	description	(Figs 1 – 5)	en	Toledo, Mario, Bilton, David T., Balke, Michael, Schizzerotto, Antonio, Villastrigo, Adrián (2023): A new, putatively semisubterranean, Rhithrodytes diving beetle from southwestern Sardinia (Coleoptera: Dytiscidae). Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 63 (1): 125-133, DOI: 10.37520/aemnp.2023.006, URL: http://dx.doi.org/10.37520/aemnp.2023.006
03DB87D7977BBC22FEDC24418129FDA4.taxon	materials_examined	Type locality. Italy, Sardinia, Carbonia-Iglesias province, Riu Siuru 4 km NW Domusnovas, 39 ° 21.55 ′ N 08 ° 37.14 ′ E, 260 m a. s. l. Type material. HOLOTYPE: J, labelled: “ 16. VI. 2022 Italy, Sardinia, CI / Riu Siuru, 4 km NW Domusnovas / 39 ° 21.55 ’ N 08 ° 37.14 ’ E, 260 m / Balke, Bilton, Schizzerotto & Toledo leg. ” (ZSM), with red holotype label and DNA voucher label: “ DNA voucher MB 8956 ” (ZSM). PARATYPE: J same data as holotype and with red paratype label (CTB).	en	Toledo, Mario, Bilton, David T., Balke, Michael, Schizzerotto, Antonio, Villastrigo, Adrián (2023): A new, putatively semisubterranean, Rhithrodytes diving beetle from southwestern Sardinia (Coleoptera: Dytiscidae). Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 63 (1): 125-133, DOI: 10.37520/aemnp.2023.006, URL: http://dx.doi.org/10.37520/aemnp.2023.006
03DB87D7977BBC22FEDC24418129FDA4.taxon	description	Description. Habitus. Body shape (Fig. 2) elongate- - oblong, no discontinuity between posterior angles of pronotum and base of elytra, lateral sides of elytra almost parallel, maximum width just before middle of elytral length; dorsoventrally flat (Fig. 3 A); colouration pale on both dorsal and ventral sides, ventral segments and parts of elytra almost transparent. Appendages uniformly reddish-yellow; eyes small (Fig. 4 A). Head relatively large in proportion, anterior margin forming a rather prominent, regular curve. Eyes apparently functional, but small in proportion to head (Fig. 4 A); ommatidia irregular in size, maximum 9 in longest series. Surface weakly shining, with visibly impressed isodiametric microreticulation and sparse fine punctures (Fig. 4 A). Colouration uniformly reddish-yellow. Antennomeres 3 – 10 as long as or longer than wide; terminal antennomere slightly darkened. Pronotum subrectangular; lateral sides almost subparallel posteriorly, rounded anteriorly; weakly but visibly sinuate in lateral view. Anterior angles rather prominent; lateral rim well developed along each side. Anterior margin with impressed, transverse irregular puncture row; with sparse and fine punctures between lateral rims and disc; disc and scutellar process without punctures; surface with well impressed isodiametric microreticulation. Colouration reddish-yellow, with indistinct infuscations along anterior and posterior margins. Elytra elongated, almost parallel-sided in anterior half, apical third regularly acuminate; lateral margins straight in lateral view, gently curving anteriorly over approximately basal sixth of length (Fig. 3 A). Microreticulation isodiametric, more impressed than on head and pronotum, with fine and irregular discal punctures arranged longitudinally, most of them bearing yellow decumbent setae. Colouration yellow with wide, poorly defined, weakly darker area posteriorly along suture and slightly expanded apically. Venation of metathoracic wings visible through elytra. Legs. Metatibiae and metatarsi slender and quite long, with very sparse natatorial setae on inner face. Pro- and mesotarsi not strongly expanded; protarsal claws unmodified. Venter (Fig. 2 A) uniformly reddish-yellow; entirely isodiametrically microreticulated, with additional impressed pits. Prosternal process elongate, rounded apically, barely touching anteromedial metaventral process. Metacoxal lines clearly visible, reaching metaventrite. Epipleuron quite abruptly narrowed before mid-length; oblique carina visible near shoulder. Abdominal ventrites II and III fused with suture barely visible. Male genitalia. Median lobe (Fig. 2 C), straight in lateral view, with apical hook strongly developed; parallel-sided in ventral view, with acuminate tip visible at apex; acuminate tip strongly developed and clearly visible in ventro-apical view. Parameres (Fig. 2 C) elongate, with narrow, rounded, setose apex. Measurements. Holotype: BL = 2.7 mm; BL-H = 2.35; EW = 1.2 mm. Paratype: BL = 2.7 mm; BL-H = 2.35; EW = 1.2 mm.	en	Toledo, Mario, Bilton, David T., Balke, Michael, Schizzerotto, Antonio, Villastrigo, Adrián (2023): A new, putatively semisubterranean, Rhithrodytes diving beetle from southwestern Sardinia (Coleoptera: Dytiscidae). Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 63 (1): 125-133, DOI: 10.37520/aemnp.2023.006, URL: http://dx.doi.org/10.37520/aemnp.2023.006
03DB87D7977BBC22FEDC24418129FDA4.taxon	diagnosis	Differential diagnosis. An oblong, flat, almost parallel sided Rhithrodytes (Fig. 2), with small eyes in proportion to the head. Colouration uniformly pale yellowish-reddish (note that the holotype in Figs 3 & 4 has darkened somewhat following DNA extraction; for more accurate representation of colour, see Fig. 2 A). Natatory setae reduced. On the basis of these characters, Rhithrodytes pantaleonii sp. nov. has a very distinctive external morphology and cannot be confused with any other species of the genus. The male genitalia (Fig. 2 C) are rather similar to those of R. sexguttatus (Fig. 2 D), differing by the straighter profile of the median lobe in lateral view, with a narrower apical hook, by the narrower, more strongly acuminate apex of the median lobe in ventral view, and by the narrower apex of the parameres.	en	Toledo, Mario, Bilton, David T., Balke, Michael, Schizzerotto, Antonio, Villastrigo, Adrián (2023): A new, putatively semisubterranean, Rhithrodytes diving beetle from southwestern Sardinia (Coleoptera: Dytiscidae). Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 63 (1): 125-133, DOI: 10.37520/aemnp.2023.006, URL: http://dx.doi.org/10.37520/aemnp.2023.006
03DB87D7977BBC22FEDC24418129FDA4.taxon	etymology	Etymology. The new species is dedicated to Prof. Roberto Pantaleoni (University of Sassari), who kindly supported our trip in Sardinia. It is a noun in the genitive case, standing in apposition.	en	Toledo, Mario, Bilton, David T., Balke, Michael, Schizzerotto, Antonio, Villastrigo, Adrián (2023): A new, putatively semisubterranean, Rhithrodytes diving beetle from southwestern Sardinia (Coleoptera: Dytiscidae). Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 63 (1): 125-133, DOI: 10.37520/aemnp.2023.006, URL: http://dx.doi.org/10.37520/aemnp.2023.006
03DB87D7977BBC22FEDC24418129FDA4.taxon	biology_ecology	Ecology. The Riu Siuru is a small, rocky lowland stream, flowing in a North-South direction over a calcareous substrate. Due the relative drought conditions in Spring- Summer 2022, we found the stream partially dried out and therefore focused on a ca. 15 m reach which had numerous residual pools and some flow (Fig. 5). Areas immediately above and below this stretch were found to be entirely dry. The new species was collected by digging between gravel and sand, very close to the water’s edge and was very rare or at least difficult to find with hand nets. Other associated aquatic Coleoptera were Gyrinidae: Gyrinus urinator Illiger, 1808, Gyrinus caspius Ménétriés, 1832; Dytiscidae: Agabus binotatus Aubé, 1837, A. rufulus Fairmaire, 1859, Colymbetes schildknechti Dettner, 1983, Meladema lepidoptera Bilton & Ribera, 2017, Bidessus minutissimus (Germar, 1824), B. saucius (Desbrochers, 1871), Hydroglyphus geminus (Fabricius, 1792), Hydroporus analis Aubé, 1838, Graptodytes exsanguis (Bedel, 1925), G. flavipes (Olivier, 1795), Stictonectes optatus (Seidlitz, 1887), Deronectes moestus moestus (Fairmaire, 1858), Scarodytes fuscitarsis (Aubé, 1838); Hydrophilidae: Laccobius neapolitanus Rottenberg, 1874, Anacaena globulus (Paykull, 1798), Limnohydrobius convexus (Brullé, 1835); Hydraenidae: Hydraena sardoa Binaghi, 1961, H. subsequens Rey, 1886, Limnebius perparvulus Rey, 1884, L. mucronatus Baudi, 1872, Ochthebius dilatatus Stephens, 1829; Limnichidae: Pelochares versicolor (Waltl, 1838). Of these, Graptodytes exsanguis and Hydraena sardoa were the most abundant.	en	Toledo, Mario, Bilton, David T., Balke, Michael, Schizzerotto, Antonio, Villastrigo, Adrián (2023): A new, putatively semisubterranean, Rhithrodytes diving beetle from southwestern Sardinia (Coleoptera: Dytiscidae). Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 63 (1): 125-133, DOI: 10.37520/aemnp.2023.006, URL: http://dx.doi.org/10.37520/aemnp.2023.006
