Moserius talamonensis n. sp.

(Figs 7, 8, 21C)

urn:lsid:zoobank.org:act: 5D3C40FC-F78A-4E30-950D-A1FF3F68179D

Moserius sp. – Taiti 2007: 94.

TYPE MATERIAL. — Holotype. ♂, Parco Regionale della Maremma, Grotta di Gianninoni, 1594 T/GR, 42°34’09”N, 11°07’16”E, Punta del Corvo, Talamone, Orbetello, Prov. Grosseto, leg. S. Taiti, G. A. Gruber and C. Rossano, 3.IV.2004 (MZUF 9669) . Paratypes. 36 ♂, 26 ♀, same data as holotype (MZUF 9669); 3 ♂, 3♀, same data (MNHN-IU- 2017-1440) .

DIAGNOSIS. — A species of Moserius characterized by the disposition of the dorsal ornamentation on the pereonite 1 with 4 + 4 longitudinal ribs almost as long as tergites and a small tubercle between ribs 2 and 3.

ETYMOLOGY. — The new species is named after the locality of sampling (Talamone, Province of Grosseto), where the cave is located.

DESCRIPTION

Maximum length: ♂, 3 mm; ♀, 3.4 mm. Body colourless, ovoidal, outline not interrupted between pereon and pleon; pereon tergites very convex, with epimera obliquely directed outwards (Fig. 7A). Dorsum bearing ribs and tubercles (Fig. 7A, B): cephalon with three small tubercles on front margin, two large central tubercle with 3 + 3 rounded tips, and 3 + 3 tubercles near rear margin; pereonite 1 with 4+ 4 longitudinal ribs almost as long as tergites and a small tubercle between ribs 2 and 3; pereonites 2-6 with 3+ 3 longitudinal ribs almost as long as tergites and reduced rib externally; pereonite 7 with 2 +2 ribs almost as long as tergites, reduced rib and small tubercle externally; pleonite 3 with two large paramedian tubercles. Cephalon (Fig. 7B) with short, subquadrangular frontal lateral lobes directed outwards and not protruding compared with median lobe. Eyes absent. Pereonites with rounded posterior corners (Fig. 7A). Pleonites 3-5 (Fig. 7A) with large epimera directed backwards. Telson (Fig. 7C) slightly wider than long, with distal part trapezoidal, with concave sides and truncate apex. Antennula (Fig. 7D) of three articles with three aestethacs at apex. Antenna (Fig. 7E) with fifth article of peduncle slightly longer than flagellum; flagellum with three articles, second article with two aesthetascs. Mouth parts as in the previous species. Uropod (Fig. 7F) with flattened protopod; exopod shorter than endopod, with tuft of apical setae; endopod with a sigle apical seta.

Male

Pereopod 1 (Fig. 8A) with no distinct modifications. Pereopod 7 (Fig. 8B) ischium with straight sternal margin, merus very convex on tergal margin, carpus with distal lobe on sternal margin. Genital papilla as in Fig. 8C. Pleopod 1 (Fig. 8D) exopod with a rounded lobe on outer margin and straight medial margin, rounded apex; endopod distinctly longer than exopod, second article with parallel sides, distal part slightly bent outwards and rounded apex. Pleopod 2 (Fig. 8E) exopod triangular, with concave outer margin and straight medial margin; endopod much longer than exopod with distal part bent outwards and bifid apex. Pleopod 3-5 exopods as in Figs 8 F-H.

REMARKS

Moserius talamonensis n. sp. differs from all the other species in the number and disposition of the dorsal tubercles on the cephalon and on the pereonite 1; from M. inexpectatus also in the absence of dorsal tubercles on the pleonites 4 and 5 and telson, and in the male pleopod 1 exopod with a rounded instead of sinuous distal margin. In the shape of the male pleopod 1 exopod, the new species is similar to M. elbanus and M. gruberae n. sp., from which it differs also in the shape of the distal part of the male pleopod 1 endopod.