Nymphon martinicum, 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 : 63-66

Nymphon martinicum sp. nov.

urn:lsid:zoobank.org:act:2B7EA480-66C1-4449-BC75-DB7D3459CBF7

Fig. 14

Nymphon sp. 4 – Sabroux et al. 2019b: 1531, tab. 1, fig. 3.

Material examined

Holotype MARTINIQUE • ♂; Les Anses-d’Arlet; 14°29.7ʹ N, 61°05.4ʹ W; depth 19 m; 7 Sep. 2016; st. AB155; MNHN-IU-2016-889/ MK411198 .

Paratypes MARTINIQUE • 2 ♀♀, 1 juv.; same collection data as for holotype; MNHN-IU-2016-1280 • 1 ♀; Bellefontaine; 14°39.7ʹ N, 61°09.6ʹ W; depth 12 m; 30 Sep. 2016; st. AB372; MNHN-IU-2016-1033 • 1 ♂; Rocher du Diamant; 14°26.5ʹ N, 61°02.4ʹ W; depth 24 m; 14 Sep. 2016; st. AB173; MNHN- IU-2016-1159 • 1 ♂ carrying larvae; Pointe de la Baleine; 14°31.1ʹ N, 61°05.9ʹ W; depth 17–19 m; 30 Sep. 2016; st. AB369; MNHN-IU-2016-1257 • 3 ♀♀ gr.; Presqu’Île de la Caravelle; 14°48.4ʹ N, 60°52.8ʹ W; depth 23–25 m; 20 Sep. 2016; st. AB197; MNHN-IU-2016-1299 • 1 ♂; same collection data as for preceding; MNHN-IU-2016-1319 • 1 ♀ preadult?; Presqu’Île de la Caravelle; 14°46.5ʹ N, 60°51.5ʹ W; depth 15 m; 22 Sep. 2016; st. AB350; MNHN-IU-2016-1304 • 1 juv.; Pointe de la Baleine; 14°31.1ʹ N, 61°05.9ʹ W; depth 24 m; 30 Sep. 2016; st. AR413; MNHN-IU-2016-1221.

Etymology

From the Latin neologism Martinicus, - a, - um (adj.): Martiniquese.

Description (holotype, ♂, MNHN-IU-2016-889)

BODY. Trunk completely segmented, cuticle smooth. No dorsomedian tubercle. Ocular tubercle near oviger base and positioned anterior to 1 st lateral processes, rounded, as wide at base as high, with 2 large horn-like lateral sense organs on its tip; 4 pigmented eyes. Preocular neck long, as high as base width. Oviger base touching 1 st lateral processes. Lateral processes without ornamentation, well separated by more than once and up to twice their own diameters between 1 st, 2 nd and 3 rd lateral processes and by slightly less than their own diameter between 3 rd and 4 th lateral processes.

PROBOScIS. Rounded and large, reaching distal margin of chelifore scape in lateral view, about as long as cephalon and 1 st trunk segment.

ABDOMEN. Medium-sized, not reaching beyond lateral processes, directed diagonally. No basal segmentation.

CHELIFORE. 2-articled, reaching far beyond proboscis, carrying scarce setae. Scape 1-articled, 5.5 times as long as wide. Chela large, palm longer than fingers. Fingers sub-equal in length, bearing simple and bifurcated teeth, 17 on inmovable finger and 15 on movable finger.

PALP. 5-articled. 1 st shortest, as long as wide. 2 nd article longest, about 11 times as long as wide, with a few distal setae. 3 rd article about 0.8 times as long as 2 nd, carrying setae on distal half. 4 th article about half as long as 5 th, carrying setae mostly on ventral side. 5 th article 0.9 times as long as 3 rd, carrying many ventral setae.

OvIGER. 10-articled. 1 st article shorter than wide. 2 nd article about ⅓ as long as wide. 3 rd article about 3 times as long as maximal width. 4 th article more than twice as long as 3 rd. 5 th article longest, about 1.6 times as long as 4 th, setose, widening near distal part. 6 th article about 0.7 times as long as 4 th, setose. 7 th article longest within strigilis, 8 th, 9 th and 10 th articles subequal. Strigilis formula 13:10:9:11. Strigilis spines compound, carrying many lateral teeth, proximalmost shortest and spatulated, median spines longest, oblong to lanceolate), distalmost spatulated, longer than proximalmost. Intermediary position spines roughly intermediary in shape. Terminal claw about as long as 10 th article.

LEGS. Slender, setose. Coxa 1 about 1.5 times as long as wide. Coxa 2 about 2.5 times as long as coxae 1 and 3 together. Coxa 3 about 1.5 times as long as wide. Femur about 16 times as long as wide and about twice as long as coxa 2, ventrally carrying one row of hardly conspicuous cement glands and cement gland pores, 45 glands counted. No cement gland tube. Tibia 1 less than 0.1 times as long as femur. Tibia 2 longest, even slenderer, about ¼ as long as tibia 1, setose. Tarsus medium-sized, trapezoid, one spine distally on inner surface. Propodus straight, slender, about 2.5 times as long as tarsus, and 0.15 times as long as tibia 2. Main claw short, about ¼ of propodal length, curved. Auxiliary claws present, curved, slightly longer than main claw. Both main claw and auxiliary claws with small denticles on inner surface.

MEASUREMENTS (mm). Trunk 1.59; abdomen 0.20; proboscis 0.75; chelifore scape 0.55; chela palm 0.41; chela fingers 0.31; coxa 1 0.16; coxa 2 0.97; coxa 3 0.21; femur 1.88; tibia 1 2.04; tibia 2 3.00; tarsus 0.19; propodus 0.45; main claw 0.11; auxillary claw 0.15.

Sexual dimorphism

5 th ovigeral article distally inflated only in males. Female chela palm not as wide as in males.

Individual variability

Chela teeth number variable, 12 to 19 on immovable finger, and 14 to 17 on movable finger. Strigilis formula variable, from 9 to 13 spines on each strigilis article, with generally more spines on 1 st strigilis article. In one specimen (MNHN-IU-2016-1304), strigilis formula drops to 8:7:7:7, which may be linked to preadult stage.

Remarks

Nymphon martinicum sp. nov. belongs to the aequidigitatum group. It greatly resembles N. floridanum Hedgpeth, 1948 , and differs from this species by the ocular tubercle, which is simple and conical in N. floridanum , while it is rounded in Martinique specimens with two conspicuous, horn-like lateral sense organs ( Hedgpeth 1948; Child 1992a; Müller & Krapp 2009). We describe this species as new to science based on those morphological differences, with strong support from CO1 data: the p-distance between the sequenced specimen and N. floridanum GenBank sequence DQ390073 ( Arango & Wheeler 2007) is equal to 0.147 (see Appendix).

This species was collected on both the Atlantic and Caribbean coasts.

Depth range

12– 25 m.

Figures

Fig. 14. Nymphon martinicum sp. nov. A–K. Holotype, ♂, MNHN-IU-2016-889. L–M. Paratype, ♀, MNHN-IU-2016-1033. A. Body, dorsal view. B. Body, lateral view (same scale as A). C. Ocular tubercle, frontal view. D. Palp. E. Chelifore. F. Leg. G. Tarsus and propodus. H. Close-up of ventral surface of propodal claws. I. Oviger. J. Oviger strigilis. K. Pointed teeth of oviger strigilis. L. Chela (same scale as E). M. Ocular tubercle, frontal view (same scale as C).