Gilvossius tyrrhenus ( Petagna, 1792 )

Marin, Ivan, 2021, Burrowing mud shrimps (Decapoda: Axiidea & Gebiidea) of the northeastern Black Sea and their external parasites, Zootaxa 5039 (4), pp. 571-583 : 574

publication ID	https://doi.org/ 10.11646/zootaxa.5039.4.8
publication LSID	lsid:zoobank.org:pub:1BDA2D59-E624-4409-AD5F-FBBE0DC71C9F
persistent identifier	https://treatment.plazi.org/id/038287B4-FFC3-8120-FF6B-780EFE6F8CBB
treatment provided by	Plazi
scientific name	Gilvossius tyrrhenus ( Petagna, 1792 )
status

Treatment

Gilvossius tyrrhenus ( Petagna, 1792) View in CoL

( Figs 1 c, d View FIGURE 1 ; 2 b, d, f, h View FIGURE 2 ; 3 b, e, f, h View FIGURE 3 ; 5 d View FIGURE 5 )

Astacus tyrrhenus Petagna, 1792: 418 , pl. 5 fig. 3.

Callianassa laticauda Otto, 1821: 11 .

Callianassa stebbingi Borradaile, 1903: 547 View in CoL .

Material examined. BLACK SEA : Crimean Peninsula : 2♂♂ ( ZMMU Ma-6197 and Ma-6198), 2 ovigerous ♀♀ ( ZMMU Ma-6199 and Ma-6200)— Kruglaya Bay (Omega), 44°35’51.8”N 33°26’40.8”E, depth 0.5–1.5 m, burrows fine sand and sand with sea grass, with yabbi pump, coll. I. Marin, 14.06.2020 GoogleMaps ; 5♂♂, 7 ovigerous ♀♀ ( LEMMI)— same locality and date; 2♂♂, 3 ovigerous ♀♀ ( LEMMI)— Kazachiya Bay , 44°34’10.8”N 33°24’47.1”E, burrows in fine sand and sand with sea grass, with yabbi pump, coll. I. Marin, 10.06.2020 GoogleMaps .

Remarks. Gilvossius tyrrhenus can be separated from the co-occurring congeneric G. candidus by the following morphological features ( Ngoc-Ho 2003): the peduncle of antenna I is slightly longer than the peduncle of antenna II in G. tyrrhenus ( Fig. 3 b View FIGURE 3 ), while they are mostly equal in G. candidus ( Fig. 3 a View FIGURE 3 ); the meral hook of the major cheliped in males is blunt distally in G. tyrrhenus ( Fig. 3 e, f View FIGURE 3 ), rather than acuminate distally in G. candidus ( Fig. 3 c, d View FIGURE 3 ); the dactylus of major chelipeds is almost equal to palm in length in G. tyrrhenus ( Fig. 3 e, f View FIGURE 3 ), while it is significantly shorter than palm in G. candidus ( Fig. 3 c, d View FIGURE 3 ); the carpus of major chelipeds in females is about 1.5 times longer than wide, widening distally in G. tyrrhenus ( Fig. 3 h View FIGURE 3 ), while it is almost quadrate in G. candidus ( Fig. 3 g View FIGURE 3 ); the carpus of the minor cheliped is wider proximally than distally and wider than the palm in G. tyrrhenus , whereas it is not wider proximally than distally and as wide as the palm in G. candidus ; the border of the dorsal plate on the uropodal exopod is closer to the exopodal margin in G. tyrrhenus ( Fig. 2 h View FIGURE 2 ) than in G. candidus ( Fig. 2 g View FIGURE 2 ); the telson is about as long as wide in G. tyrrhenus ( Fig. 2 d, f View FIGURE 2 ), while wider than long in G. candidus ( Fig. 2 c, e View FIGURE 2 ). In addition to those morphological characters, the body size is larger in G. candidus than in G. tyrrhenus (tl. (♂) 81 mm in G. candidus vs. tl. (♂) 58 mm in G. tyrrhenus ). The chelipeds are sometimes pinkish in G. tyrrhenus , rather than always white in G. candidus (see Fig. 1 View FIGURE 1 ); the telson and uropods are also pinkish or yellowish in males of G. tyrrhenus ( Figs 1 View FIGURE 1 ; 2 h View FIGURE 2 ), although they are always white in G. candidus ( Figs 1 View FIGURE 1 ; 2 g View FIGURE 2 ). Ngoc-Ho (2003) also mentioned the color variation in G. tyrrhenus .

Parasites. Three of collected specimens of G. tyrrhenus were infested with the rhizocephalan cirriped Parthenopea subterranea Kossmann, 1874 (Thecostraca, Rhizocephala, Parthenopiidae) (see Fig. 4 d View FIGURE 4 ); the parasite has already been recorded from the Black Sea (Sevastopol Bay), but without collection data and information on host species ( Øksnebjerg, 2000). Copepods of the genus Clausidium were found attaching to the carapace and pleon on these shrimps, similar to G. candidus (see above). It is possible that these copepods are genus specific to the host. Unidentified scale worms ( Polychaeta: Polynoidae ) were also found in burrows of these mud shrimps.

Distribution. The species is distributed in the northeastern Atlantic and the Mediterranean: Southern North Sea, Eastern Atlantic ( Ireland, English Channel) to the coast of Guinea ( Ngoc-Ho, 2003); the entire Mediterranean including Tyrrhenean, Aegean, Ionian, Adriatic basins ( Petagna, 1792; Saint Laurent & Bozic 1976; Števčić, 1990; de Vaugelas, 1991, 1998; Dworschak, 1992; Ngoc-Ho, 2003; Sakai, 2011); intertidal and shallow subtidal zones down to 20 m or deeper ( Dworschak, 1998), burrowing in fine sand or muddy sand with or without seagrass (d’Udekem d’Acoz, 1986; Števčić, 1990; Dworschak, 1992). The occurrence of the species in the Black Sea is re- ported for the first time.