Pycnogonum cf. pusillum Dohrn, 1881

Sabroux, Romain, Hassanin, Alexandre & Corbari, Laure, 2022, Sea spiders (Arthropoda: Pycnogonida) collected during the Madibenthos Expedition from Martinique shallow waters, European Journal of Taxonomy 851 (1), pp. 1-141 : 110-113

Pycnogonum cf. pusillum Dohrn, 1881

Fig. 30

Pycnogonum pusillum Dohrn, 1881: 207 , pl. 16 figs 4–8.

Pycnogonum pusillum – Carus 1885: 288. — D’Arcy Thompson 1909: 540. — Bouvier 1922: 115; 1923a: 61. — Schimkewitsch 1929: 6–7, 18. — Helfer & Schlottke 1935: 298. — Stock 1952: 1–6, fig. 1a–b; 1964: 32; 1968b: 36, fig. 30. — Barnard 1954: 155–156, fig. 33. — Bourdillon 1954b: 155. — Hoenigman & Stock 1955: 534. — Monniot 1962: 273. — Krapp 1983: 412–413. — Arnaud 1987: 51. — Munilla 1993: tab. 4. — Piscitelli & Barone 2000: tab. 1. — Chimenz Gusso & Lattanzi 2003: tab. 1. — Dunlop et al. 2007: 59, fig. 45. — Lehmann et al. 2014: 165 (list), 168, figs 53, 55. — Soler-Membrives & Munilla 2015: tab. 2. — Colasanto & Galli 2021: tab. 1.

Pycnogonum (Retroviger) pusillum – Stock 1990: 232.

Pycnogonum cf. pusillum – Sabroux et al. 2019b: 1525, tab. 1.

nec Pycnogonum littorale (Strøm, 1762) – Zavodnik 1968: 46, 49.

Type material

Pycnogonum pusillum Dohrn, 1881 . Syntypes (?) (see Dunlop et al. 2007): ZMB _Pyc_52 (not examined). Type locality: Naples Bay, Italy.

Material examined

MARTINIQUE • 1 ♀; Passe du Brigot; 14°33.8ʹ N, 60°47.6ʹ W; depth 17 m; 16 Sep. 2016; st. AB183; MNHN-IU-2016-815 • 1 ♀; Le Vauclin; 14°30.5ʹ N, 60°48.5ʹ W; depth 2 m; 10 Oct. 2016; st. AB419; MNHN-IU-2016-860.

Remarks

The Martinique specimens resemble the original illustration in Dohrn (1881) by their body shape, the conical proboscis being distally truncated and the relative sizes of the legs articles and main propodal claws; they similarly present the same tubercles on the lateral processes and first coxae as represented by Stock (1952), also illustrated by Lehmann et al. (2014) and Munilla & Soler-Membrives (2014). Unlike in Stock (1952), however, the specimens have a tubercle posterior to the ocular tubercle that is barely visible in dorsal view, and the auxiliary claws are longer (about half as long as the main claw). Since there is no available molecular data for comparison, we regard these two females as belonging to Dohrn’s species for now.

The specimens are also morphologically very close to the Australian species Pycnogonum carinatum Staples, 2002 , from which they chiefly differ by the presence of auxiliary claws in the Martinique material, as well as by the more granulous dorsal surface of the legs and the cleft spines on the propodal sole in the type material P. carinatum ( Staples 2002) .

Distribution

Pycnogonum pusillum is known from the Western Mediterranean (Balearic Sea, Adriatic Sea, Thyrrenian Sea, Ionian Sicily), and the Eastern Atlantic ( Morocco, Angola, South Africa, Cap Verde).

Depth range

Pycnogonum pusillum was recorded from 0.5 to 1200 m. The present material was sampled at 2 and 17 m.

Figures

Fig. 30. Pycnogonum cf. pusillum Dohrn, 1881, ♀, MNHN-IU-2016-815. A. Body, dorsal view. B. Body, lateral view (same scale as A). C. Third leg. D. Tarsus and propodus of third leg.