Litorogammarus mazestiensis ( Marin & Palatov, 2021 ) Marin & Palatov & Copilaș-Ciocianu, 2023

Marin, Ivan, Palatov, Dmitry & Copilaș-Ciocianu, Denis, 2023, The remarkable Ponto-Caspian amphipod diversity of the lower Durso River (SW Caucasus) with the description of Litorogammarus dursi gen. et sp. nov., Zootaxa 5297 (4), pp. 483-517 : 505

Litorogammarus mazestiensis ( Marin & Palatov, 2021) comb. nov.

Fig. 18 a, b

Echinogammarus mazestiensis Marin & Palatov, 2021: 3 , figs 1–3 [type locality—Mazesta, Sochi].

Material examined. 5 ÔÔ, 5♀♀ , LEMMI — Northeastern Black Sea, Russian Federation, Krasnodar region, Sochi area, estuary of the Mazesta River , 43°32’35.3”N, 39°47’28.5”E, under stones and among river pebbles, hand net sampling, Marin I.N. & Palatov D.M. leg., 16.05.2019 .

Diagnosis. Head with oblique anteroventral lobe (see Marin & Palatov, 2021: Supplementary Figure S5 b ). Pleon with urosomite I bearing a pair of long median setae; urosomite II with 1 marginal long spine on each side and a pair of median short spines; urosomite III with 1 long marginal spine of each side (see Marin & Palatov, 2021: Figure 3 g ). Antenna I smooth, non-setose, with 6-segmented accessory flagellum (see Marin & Palatov, 2021: Figure 2 b ). Antenna II slightly shorter that AI, with long ventral setae, without calceoli both in males and females. Pereopods V–VII: basis (article 2) with straight dorsal margin and feebly marked ventral lobes (see Marin & Palatov, 2021: Supplementary Figure S3 ). Epimeral plates with sharp and produced posteroventral angles.

GenBank accession number. OP466441, OP466428 (this study).

Habitats and distribution. The species is presently known only from its type locality, the mouth (estuary) of the Mazesta River , Sochi area, SW Caucasus, Russia (see Marin & Palatov, 2021), living under pebble and stones, where it forms significant aggregations .

Figures

FIGURE 2. General view of the gammarid species found in the Durso River:A, B—Pontogammarus robustoides (Sars, 1894); C, D—Chaetogammarus trichiatus Martynov, 1932; E—Dursogammarus dromaderus Marin & Palatov, 2022; F—Litorogammarus dursi sp. nov.; G—Pectenogammarus oliviiformis (Greze, 1985) comb. nov.; H—Litorogammarus karadagiensis (Grintsov, 2009) comb. nov.

FIGURE 3. Maximum-likelihood phylogenetic tree based on COI. Number above nodes represent ultrafast bootstrap (UFBS) and Shimodaira-Hasegawa approximate likelihood ratio test (SHaLRT) values. Number below nodes represent posterior probabilities (PP). Strongly supported nodes in all analyses are shown with green circles. Species from Durso River are indicated with red arrows. Taxonomically relevant taxa are shown with various colors. Species belonging to Chaetogammarus are shown with dotted branches.

FIGURE 5. Litorogammarus dursi sp. nov., holotype Ô, ZMMU Mb-1243: a—upper lip; b—lower lip; c—left mandible; d—same, incisor process and pars incisiva; e—right mandible; f—same, incisor process and pars incisiva; g—left maxilla II; h—maxilla I; i—maxilliped.

FIGURE18.SEMphotographsof Litorogammarusmazestiensis(Marin&Palatov,2021)comb.nov. (a,b)andPectenogammarus oliviiformis (Greze, 1985) comb. nov. (c–f); a, c—head; b—palmar margin of chela of GnII; d, f—urosomal segments; e—chela of GnII.