Parabrachypoda lusitanica Pešić & Smit, 2024

Pešić, Vladimir, Smit, Harry, Girão, Dinis, Iannucci, Alessio, Stur, Elisabeth & Ferreira, Sónia, 2024, New records of aturid water mites from Portugal, with the integrative description of one new species (Acari, Hydrachnidia, Aturidae), Ecologica Montenegrina 80, pp. 209-219 : 211-217

Parabrachypoda lusitanica Pešić & Smit sp. nov.

https://zoobank.org/ urn:lsid:zoobank.org:act:FD9BD85E-9370-4E12-8103-14D7C1FA2BEC

Figs 1-4

Material examined — Holotype ♂, dissected and slide mounted ( RMNH), Portugal, Beja, Mértola , São João dos Caldeireiros, 37.626°N, 7.810°W, 17 May 2023, leg. Ferreira, Benitez-Bosco, Ekrem, Stur & Turaccio, sequenced (Voucher ID: BGE _00110_B01; BOLD ID: BSNTN488-23 ) . Paratype: 1♂ ( RMNH) same data as the holotype, preserved in Koenike-fluid (sequenced; BOLD ID: BSNTN947- 23 ) .

Diagnosis (Female unknown) — Dorsal shield nearly as wide as long, posterior margin medially projecting; a pair of posteriorly directed, pointed sheaths located laterally near the posterior end of ventral shield; gonopore anteriorly surrounded by well sclerotized lips, Ac-1 located on the surface of these sclerotized lips, numerous setae anteriorly in transverse line, and posteriorly from the level of Ac-3; IV-L-4 distally with one curved, spatula-shaped seta, IV-L-4 digitiform ventral extension apically with three different setae (one longer flanked by two stout setae, one thicker, peg-like, the other thinner).

Description — Male (holotype) — Idiosoma dorsally 470 long and 493 wide, ventrally 500 long. Colour yellowish with one unpaired anterior and a pair of posterolateral violet marks (see Fig. 1A ). Dorsal shield nearly as wide as long, posterior margin medially projecting and with excretory pore placed terminally dorsal on a projection ( Fig. 1A ). Anterior margins of Cx-I extending slightly beyond frontal margin, gnathosomal bay 128 deep; distance between IV-L insertion 271. A pair of posteriorly directed pointed sheaths located laterally near the posterior end of ventral shield ( Figs. 1A , 2 ). Posterior margin of the venter forming a rounded concave ridge. Gonopore in distal part flanked by welldeveloped sclerotized lips, Ac-1 located on the surface of these sclerotized lips, acetabula arranged in an obtuse triangle, numerous fine setae, anteriorly from the level of Ac-2 longer, and posteriorly from the level of Ac-3 shorter ( Fig. 2 ). Ejaculatory complex 116 long.

Palp as illustrated in Figs. 2 B-C: length/height: P-1, 49/19; P-2, 73/52; P-3, 36/33; P-4, 113/36; P-5, 36/20/; palpal segment relatively stout (length/height ratio P-2, 1.4; P-3, 1.1; P-4, 3.1); P-1 with one dorsal seta; P-2 ventral margin nearly straight, distally forming a short blunt projection; P-3 ventral margin concave; P-4 proximally narrow, in the centre, near the insertion of two ventral setae slightly elevated to form an obtuse projection near the insertion of the stronger ventral seta, a slightly thickened seta and a finer seta laterally on a further blunt elevation, dorsal surface (medially and ventrally) of P-4 with several fine setae. Capitulum ventral length 102; chelicera 134 long.

Legs: I-L and II-L as shown in Figs. 4 A-B, surface of I-L-6 and II-L-6 with numerous fine setae; III-L as illustrated in Fig. 4C , III-L-5 distally enlarged, here with four dorsal club-shaped setae, one of them longer than the other three ( Fig. 4C inset); IV-L-4-6 as shown in Figs. 4 D-E; IV-L-4 distally enlarged, here bearing six to seven setae, two of them heavy (one curved, spatula-shaped seta, shifted more to ventrodistal margin, the other straight and longer), the remaining slender and pointed, and forming a prominent digitiform ventral extension apically with three different setae (one longer flanked by two stout setae, one thicker, peg-like, the other thinner); IV-L-5 thickened, length/height ratio 3.3, dorsal margin curved, ventral margin, with scattered setae, in proximal part a peg-like setae; IV-L-6 slightly curved, length/height ratio 5.3, ventrally with a row of longer setae; claws modified as given in Figs. 3A (inset), anterior claw longer than posterior claw.

Number of swimming setae: II-L-4. 2, II-L-5: 3; III-L-4: 5; IV-L-5. 6. Dorsal length: I-L-2-6: 55, 81, 122, 139, 131; II-L-1-6: 72, 63, 91, 134, 144, 128; III-L-1-6: 66, 69, 94, 103. 98, 134; IV-L-1-6: 116, 88, 80, 69, 188, 166.

Female: unknown.

Etymology — The name refers to the geographical provenance (from Latin lusitanicus, Lusitanian, Portuguese) from where the new species is described.

Species delimitation using DNA barcodes — We used a COI dataset with 79 sequences of water mite specimens of the family Aturidae listed in Table 1 and Supplement material 1 for phylogenetic analyses. Hungarohydracarus subterraneus from Bosnia and Herzegovina was used to root the tree. The NJ tree is presented in Fig. 5 . The COI tree sequences retrieved from two specimens from Portugal, which form a unique cluster (BOLD:AFN8479), appeared as a sister group (albeit with a low support) to the sequence belonging to Parabrachypoda montii , a rhitrobiontic species widely distributed in Europe. The mean K2P genetic distance between COI sequences of Parabrachypoda lusitanica sp. nov. and P. montii was estimated at 26.3%.

Remarks — In regard to the position of the genital field (located close to the posterior margin of the ventral shield) and similar shape of palp (P-2 with a very short, rounded distoventral projection) and setation of IV-L, the new species from Portugal is placed in genus Parabrachypoda . Currently, the latter genus, includes five species known from the Western Palaearctic, i.e. P. modesta (Koenike, 1911) , known from Central and eastern Europe, P. baderi Di Sabatino & Cicolani, 1991 , known from central Mediterranean ( Italy: Abruzzo, Sicily, Sardinia; France: Corsica; Sabatino & Cicolani, 1991, Gerecke et al. 2014) and Turkey (Esen et al. 2014), Parabrachypoda mutila (Walter, 1928) , known from the West Mediterranean area ( Algeria, Tyrrhenian islands - Gerecke et al. 2014), P. montii (Maglio, 1924) known from central and southern Europe and P. orientalis Pešić & Esen, 2013 . The latter species was originally described from Turkey (Esen et al. 2014), and includes also populations under the (erroneous) name of P. mutila from Crimea ( Tuzovskij 1978, including also the reared larval stage) and Turkey ( Pešić et al. 2006). From all these species, the new species from Portugal can be separated by the unique shape of dorsal shield (nearly as wide as long, posterior margin medially projecting) and genital field (gonopore anteriorly surrounded by well sclerotized lips, Ac-1 located on surface of these sclerotized lips, numerous setae around the gonopore, anteriorly in transverse line, and in a field postero-medially of Ac-3. Moreover, the presence of a pair of posteriorly directed pointed sheaths located laterally near the posterior end of ventral shield is an unique feature and not present in other species of the genus.

In regard to IV-L setation, males of Para b rachypoda mutila resemble the new species in the presence of three different apical setae on the ventral digitiform extension of IV-L-4 (one fine, longer seta flanked by two stout setae, one of them thicker than the other). However, in the latter species IV- L-5 is much slenderer, with subparallel dorsal and ventral margins, bearing numerous longer ventral setae. In P. lusitanica IV-L-5 is thickened and with more curved dorsal margin, more similar to B. orientalis , ventral setae in proximal part peg-like. Moreover, the distal margin of IV-L-4 of P. mutila lacks the characteristic spatula-like seta present in the new species.

Distribution — Portugal; known only from the type locality ( Fig. 6 ) in the Alentejo region (Southern Portugal).

Figures

Figure 1. Photographs of Parabrachypoda lusitanica Pešić & Smit sp. nov., male paratype (BGE_00110_B01): A – idiosoma, frontal view; B – A – idiosoma, ventral view. Photographs by F. Sesti.

Figure 2. Parabrachypoda lusitanica Pešić & Smit sp. nov., male holotype (BGE_00110_B01): A – idiosoma, dorsal view; B – palp, lateral view; C – palp, medial view. Scale bars = 100 μm.

Figure 3. Parabrachypoda lusitanica Pešić & Smit sp. nov., male holotype (BGE_00110_B01): ventral shield. Scale bar = 100 μm.

Figure 4. Parabrachypoda lusitanica Pešić & Smit sp. nov., male holotype (BGE_00110_B01): A – I-L-2-6; B – II-L (in inset: claw, enlarged 2x); C – III-L (in inset: claw and a club-shaped seta, enlarged 2x); D – IV-L anterior (in inset: IV-L-4 digitiform ventral extension, and claws, enlarged 2x); E – IV-L posterior. Scale bar = 100 μm.

Figure 5. Neighbour-Joining tree of the family Aturidae, obtained from 79 nucleotide COI sequences listed in Table 1 and Suppl. material 1. Hungarohydracarus subterraneus Szalay, 1943 was used to root the tree. BINs are based on the barcode analysis from 15 December 2024.

Figure 6. Photograph of the type locality (São João dos Caldeireiros) of Parabrachypoda lusitanica sp. nov. Photograph by P. Gadawski.