Xiphocaridinella kumistavi (Marin, 2017)

Marin, I. N. & Barjadze, Sh., 2022, A new species of stygobiotic atyid shrimps of the genus Xiphocaridinella (Crustacea: Decapoda: Atyidae) from the Racha-Lechkhumi and Kvemo Svaneti, with a new record of X. kumistavi from the Imereti, Western Georgia, Caucasus, Invertebrate Zoology 19 (1), pp. 24-34 : 31-33

Xiphocaridinella kumistavi (Marin, 2017)

Fig. 3 .

MATERIAL EXAMINED. 1 non-ovigerous ♀ (pcl. 6.8 mm, tl. 18.0 mm), 1 ♂ (pcl. 7.0 mm, tl. 20.0 mm), ZMMU Ma-6216, SW Caucasus, Georgia, Imereti region, Tskaltubo district, Dzedzileti village, Sataplia –Tskaltubo karst massif, Satevzia Cave , 42°25′52.01″N 42°33′58.12″E, coll. E. Maghradze, 2.12.2020 ; 1 ♂, 3 ♀♀, 2 juvs, IZISU AC-NT-00001- 6 , same locality and data as above .

BRIEF DESCRIPTION. Medium-sized shrimp with swollen body. CARAPACE ( Fig. 3A–D ) smooth, with short dorsal postrostral carina in frontal part. ROSTRUM relatively long, slender, reaching midlength to distal margin of second antennular segment, sharply pointed distally, unarmed. EYES

( Fig. 3A, C ) partly covered by carapace; cornea rounded, reduced and feebly marked, without pigment; eyestalk stout, swollen, cylindrical, about as long as wide. PEREOPODS I ( Fig. 3E ) similar in males and females; basis with well-developed exopod overreaching carpo-meral articulation; ischium about 4 times as long as wide; merus slender, about 4 times as long as wide, equal to ischium in length; carpus relatively stout in males and slightly more slender in females, significantly widening distally, slightly longer than merus, about 4 times as long as maximal width; palm relatively stout, about as long as wide, subcylindrical in cross-section, smooth; fingers relatively slender, smooth, with blunt distal margins, about 4 times as long as proximal width, furnished with a row of stiff plumose setae. PEREOPODS II ( Fig. 3F ) similar to pereopod I in males and females; coxa with well-developed slender epipod and setobranch; basis with well-developed exopod overreaching carpo-meral articulation; ischium about 3 times as long as wide, with straight margins, unarmed; merus slender, about 5 times as long as wide, longer than ischium; carpus slender, about 8 times as long as wide, slightly widening distally, longer than merus; palm relatively stout, similar to palm of pereopod I, about as long as wide, subcylindrical in cross-section, smooth; fingers relatively slender, smooth, tapering distally, about 4 times as long as proximal width, with simple and straight cutting edges, with broad blunt distal margin, armed with a row of stout strong plumose setae. PEREOPOD III ( Fig. 3G, I ) with coxa bearing setobranchs and small distally blunt epipod; basis nearly as long as wide, with well-developed exopod almost reaching midlength of merus; ischium with well-marked distoventral spine; merus about 6 times as long as wide, with 2 well marked spines along ventral margin; carpus with small subdistal spine; propodus in males ( Fig. 3G ) widening distally, armed with numerous short spinules along distal 1/3 of its flexor margin and pair of long slender spines at distal flexor angle; dactylus in males ( Fig. 3H ) with flexor margin armed with dense brush of small, simple spine-like setae; with curved acuminate unguis; propodus in females not particularly widened distally, armed with 4–5 spines along proximal half of flexor margin; dactylus in females ( Fig. 3J ) about 3 times longer than wide, ventral margin armed with 6–7 small spines, unguis curved and acuminate; second (accessory) unguis triangular, sharp, slightly larger than flexor spines, about half length of terminal unguis.

REMARKS. The studied specimens from the Satevzia Cave are morphologically similar to the specimens from the Kumistavi Cave. Minor morphological differences are as follows: 1) the toothless rostrum in all examined specimens (n=8) from the Satevzia Cave, while the and armature of the rostrum is greatly in the Kumistavi Cave from a short toothless to a long curved rostrum with a large number of dorsal and ventral spines (see Marin, 2017); and 2) the meri of ambulatory pereiopods, especially pereiopod III, armed with 2 spines (vs. usually 3 spines in the specimens from the Kumistavi Cave (see Marin, 2017)). However, significant differences in these traits have also been observed in a series of samples from the type locality (see Marin, 2017a) and can be explained by the intraspecific variability with an evidence of a low genetic divergence between the two populations (see above). The development of a long, armed rostrum in Troglocaris -like shrimps is usually associated with the presence of active predators in the subterranean habitats, for example, cave salamander Proteus anguinus Laurenti, 1768 ( Amphibia: Caudata : Proteidae ) (Jugovic et al., 2011) or fishes (common river goby Neogobius cf. melanostomus (Pallas, 1811) (Teleostei: Gobiidae ) in the Kumistavi cave (see Marin, 2017a)). It is obvious that in the small Satevzia Cave such predators are absent.

GENBANK ACCESSION NUMBERS. OL704740, OL704741 .

DISTRIBUTION. The species was originally described from the Kumistavi Cave , 42°22′35.8″N 42°36′03.2″E.The newly discovered population from the Satevzia Cave , 42°25′52.01″N 42°33′58.12″E, expands the distributional range of the species in the Sataplia-Tskaltubo karst massif .

Figures

Fig. 3. Xiphocaridinella kumistavi (Marin, 2017) from the Satevzia Cave, ♂ (pcl. 7.0 mm, tl. 20.0 mm) (A, B, E–G, H) and ♀ (pcl. 6.8 mm, tl. 18.0 mm) (C, D, I, J), ZMMU Ma-6216: A, C — front of carapace, dorsal view; B, D — front of carapace, lateral view; E — pereopod I; F — pereopod II; G, I — pereopod III; H, J — dactyli of pereopod III. Рис. 3. Xiphocaridinella kumistavi (Марин, 2017) иЗ пеЩеры СатевциЯ, ♂ (pcl. 7,0 мм, tl. 20,0 мм) (A, B, E–G, H) и ♀ (pcl. 6,8 мм, tl. 18,0 мм) (C, D, I, J), ZMMU Ma-6216: A, C — переднЯЯ часть карапакса, вид сЗади; B, D — переднЯЯ часть карапакса, вид сбоку; E — переопод I; F — переопод II; G, I — переопод III; H, J — дактилусы переоподы III.