Litorogammarus karadagiensis Marin & Palatov & Copilaș-Ciocianu 2023, comb. nov.
Creators: name: Marin, Ivan
name: Palatov, Dmitry
name: Copilaș-Ciocianu, Denis
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Talitridae
Litorogammarus
Litorogammarus karadagiensis

description: Litorogammarus karadagiensis (Grintsov, 2009) comb. nov.
Figs 9–13
Echinogammarus karadagiensis Grintsov, 2009: e-23, fig. 1 [type locality—Batiliman, Crimea,].
Material examined. 10 ÔÔ, 10♀♀, LEMMI — Northeastern Black Sea, Russian Federation, southwestern Caucasus, Krasnodar Krai, Novorossiysk area, Durso village, pebble beach, 44°40’41.1”N 37°33’44.1”E, under the upper layer of pebble and stones, with hand net, coll. Palatov D.M. & Marin I.N., 20.07.2021.
Diagnosis. Head with oblique anteroventral lobe. Pleon with urosomite I armed with a pair of submedian posterior long simple spines; urosomite II with 1 marginal long spine on each side and a pair of median long spines; urosomite III with 1 long and 1small marginal spines of each side. Antenna I with 3-segmented accessory flagellum. Antenna II without calceoli both in males and females. Gnathopods I–II densely covered with long plumose setae. Pereopods V–VII: basis (article 2) with convex dorsal margin, especially in PV, and well-marked ventral lobes. Epimeral plates with sharp but not produced posteroventral angles.
1 sequences obtained in Copilaș-Ciocianu et al. 2022.
Short description. Head with oblique anteroventral lobe (Fig. 13 a). Eye reniform, well pigmented. Pleon (Fig. 13 f) with urosomite I bearing a pair of submedian posterior long simple spines; urosomite II with 1 marginal long spine on each side and a pair of median long spines; urosomite III with 1 long and 1small marginal spines of each side (Fig. 13 f). Antenna I smooth, non-setose, with 3-segmented accessory flagellum, with small aesthetascs (Fig. 9 a, b). Antenna II slightly shorter that AI, with long ventral setae, without calceoli both in males and females (Fig. 9 c). Upper lip (labrum) with convex distal part (Fig. 10 a). Lower lip (labium) with mostly reduced inner lobes (Fig. 10 b). Mandible with outer lobe subequal to inner lobe, not expanding distally, with short incisor teeth (Fig. 10 c–f). Maxilla I with outer plate bearing a marginal row of hairbrush-like setae, with outer lobe subequal to inner lobe, distal segment of palp expanding distally (Fig. 10 g). Maxilla II with outer lobe equal to inner lobe, bluntly expanding distally (Fig. 10 i). Maxilliped with outer and inner plates wide, distally bluntly rounded, with long plumose setae (Fig 10 j). Gnathopod I shorter and wider than GnII, not sexually dimorphic, bearing long plumose setae, propodus (palm) with convex slightly oblique palmar margin (Fig. 9 d). Gnathopod II not sexually dimorphic, bearing long plumose setae, subrectangular and elongated, about 3 – 4 times as long as wide, with oblique palmar margin (Fig. 9 e). Pereopods V–VII with relatively stout and robust segments armed with short strong spines, basis (article 2) with convex dorsal margin, especially in PV, and well-marked ventral lobes; dactylus stout (Fig.11). Pleopods with 2 elongated hooks and 1–2 thick bristles in retinacules (Fig. 12 f). Uropod III similar in male and females, robust, with outer ramus broad, about 4 times as long as wide, with reduced distal article furnished with numerous long simple distal setae (Fig. 12 i). Epimeral plates with sharp but not produced posteroventral angles (Fig. 12 a–c). Telson entirely clefted, with teardrop-shaped lobes bearing clusters of strong stout apical and submedian spines (Fig. 12 d).
Coloration. Body and appendages translucent. Eyes cornea silver or brown.
Body size. The largest collected ♀ has tbl. 4.0 mm; the largest collected Ô has tbl. 4.0 mm.
GenBank accession number. ON258047, ON258095 (Copilaș-Ciocianu et al. 2022).
Habitat and distribution. Widely distributed species presently known along the northeastern Black Sea coast, from Batiliman, Laspi Bay (type locality), Karadag Bay (Grintsov, 2009, 2016) to Durso (present study). Small pebble-dwelling species, living together with Ch. oliviiformis under the upper layer of the pebble, boulder and stones, where both species forms sufficiently large aggregations of heterosexual and different-aged individuals. For the detailed biological features see Grintsov (2016).
Taxonomic remarks. The complete re-description of the species using SEM micrographs is presented by Grintsov (2022). Litorogammarus karadagiensis (Grintsov, 2009) comb. nov. can be easily identified among congeners and Echinogammarus -like taxa by long plumose setae densely covering mouthparts and gnathopods, which are actually unique within the Ponto-Caspian amphipods. The species can be also easily identified by 3- segmented accessory flagellum of AII and convex dorsal margin of basis of PV.
description: Published as part of 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., pp. 483-517 in Zootaxa 5297 (4) on pages 498-505, DOI: 10.11646/zootaxa.5297.4.2, http://zenodo.org/record/8009123