Ascorhynchus iguanarum, Sabroux & Hassanin & Corbari, 2022

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 : 38-41

Ascorhynchus iguanarum sp. nov.

urn:lsid:zoobank.org:act:AF5026C5-94E5-4B01-BBC1-684199D91CBE

Fig. 7

Ascorhynchus sp. 5 – Sabroux et al. 2019b: tab. 1, fig. 3.

Material examined

Holotype MARTINIQUE • subadult; Le Robert; 14°43.2ʹ N, 60°50.6ʹ W; depth 23 m; 25 Sep. 2016; st. AB405; MNHN-IU-2016-1047/ MK411035 .

Paratype MARTINIQUE • juv.; E of Le Robert ; 14°40.1ʹ N, 60°51.1ʹ W; depth 14 m; 18 Sep. 2016; st. AB191; MNHN-IU-2016-1190/ MK411077 .

Etymology

From Latin iguana, - ae, 1 st decl. (fem.), genitive plural. Named after the green iguanas of Fort SaintLouis, the sharp teeth of which are painfully remembered by the first author, resembling the shape of the dorsomedian trunk tubercles of this new species.

Description (holotype, MNHN-IU-2016-1047)

BODY. Trunk stout, smooth, completely segmented. Trunk segments 1 to 3 bearing tall dorsomedian pointing tubercles, slightly curved anteriorly. Ocular tubercle shorter than dorsomedian tubercles, about 2.5 times as tall as wide, with acute tip, bearing four pigmented eyes distally. Lateral margin of cephalon carrying pointy tubercle near ocular tubercle. Oviger base touching first lateral processes. Lateral processes about as long as wide, 4 th pair shortest, well separated by less than half their own diameter, distally bearing a dorsomedian pointing tubercle, without any seta or spine at tip.

PROBOScIS. Very movable, pyriform, proximal part narrow, inflated before mid-length, tapering and blunt distally. Longer than cephalon and first trunk segment together.

ABDOMEN. Horizontal, long, extending beyond coxa 2 of 4 th leg. Distal part inflated, carrying few setae. Abdomen segmented at base.

CHELIFORE. 2-articled, shorter than proboscis. Scape 1-articled, carrying seta at mid-length and 3 additional setae at distal margin. Chela not functional, bearing one lateral seta. Finger oriented ventrally.

PALP. 10-articled, with setae mostly on ventral side of last 5 articles. 1 st article shorter than wide, carrying dorsal pointy tubercle. 2 nd article shortest, shorter than width. 3 rd article subequal to 5 th article and longer than other articles, with scarce spines. 4 th article slightly longer than wide. 5 th article with one long lateral seta on outer surface near proximal end, plus several small spines near distal end. 6 th article bent, as long as wide, with setae on ventral surface. 7 th and 8 th articles subequal, about 1.5 times as long as wide. 9 th and 10 th articles subequal, about as long as wide.

OvIGER. 10-articled, with scarce setae. 1 st article shortest, as long as wide. 2 nd article about twice as long as wide. 3 rd article 1.5 times as long as wide, glabrous. 4 th and 5 th articles subequal in length, 5 th article curved. 6 th and 7 th articles subequal. 6 th article twice as long as wide. 7 th article longest within strigilis, 8 th, 9 th and 10 th articles subequal. Strigilis with 2 rows of compound spines. Terminal claw short, with blunt tip.

LEGS. Slender with scarce setae. Coxa 1 shorter than wide, dorsodistally with 2 tubercles, each surmounted with spine. Coxa 2 slightly longer than maximal width, with ventral seta. Coxa 3 as long as wide, with ventral setae. Femur and tibia 1 subequal in length. Tibia 2 longest, about ⅕ longer than tibia 1 or femur, with many long setae on dorsal surface and shorter setae on ventral surface. Tarsus mediumsized, trapezoid. Propodus straight, about 0.6 times as long as tibia 2, sole with 8 small spines. Main claw curved, about 0.4 times as long as propodus. No auxiliary claw.

MEASUREMENTS (mm). Trunk 1.13; abdomen 0.39; proboscis 0.73; chelifore 0.21; coxa 1 0.14; coxa 2 0.29; coxa 3 0.18; femur 0.57; tibia 1 0.57; tibia 2 0.71; tarsus 0.09; propodus 0.38; main claw 0.15.

Sexual dimorphism

No female currently available.

Individual variability

The paratype is a juvenile, which presents developed chelae as expected, and is overall smaller in size.

Remarks

The high, curved, conical dorsomedian tubercles of this species is a strong diagnostic character for this species. Only Ascorhynchus athernus Child, 1982 shows dorsomedian tubercles comparable in size and longer than the ocular tubercle, but it is otherwise very dissimilar to A. iguanarum sp. nov. This species is morphologically close to A. castelli ( Dohrn, 1881) , which can be found in the same region, from which it can be discriminated not only by the higher dorsomedian tubercles, but also by the larger tubercles on the lateral processes, the presence of small pointy tubercles on the 1 st article of the palp and at the base of palp insertion, the absence of a spur on the dorsodistal margin of tibiae 1 and the smaller distance between the lateral processes.

The two specimens were collected on the Atlantic coast of Martinique.

Distribution

Only known from Martinique.

Depth range

14– 23 m.

Figures

Fig. 7. Ascorhynchus iguanarum sp. nov., holotype, ♂, MNHN-IU-2016-1047. A. Body, dorsal view. B. Body, lateral view (same scale as A). C. Palp. D. Oviger, with close-up of strigilis spines. E. Third leg. F. Tarsus and propodus of third leg.