Nymphon pacitae, Antolínez & Ramil, 2025

Nymphon pacitae View in CoL sp. nov.

( Fig. 7–8 View FIGURE 7 View FIGURE 8 )

Holotype. Maurit-0911: MU200 , 1♀ ( MNCN 20.03 About MNCN /984).

Etymology: This species has been dedicated to the mother of the first author, Mª Pacita Fernández Fidalgo, without whose love and support she would not have come this far.

Diagnosis. Nymphon pacitae sp. nov. is characterized by the presence of a tricuspid ocular tubercle, lateral process with a conical tubercle and setae at the sides, immovable finger with 21 teeth and movable finger with 24 teeth, 3 rd, and 4 th palp articles subequal, propodus slightly longer than tarsus and main claw 1/2 of the propodus.

Description. Trunk slender and elongated, completely segmented. Cephalon Y-shape, 0.7 times the size of the trunk, low and blunt tubercle with some setae near to the insertion of each cheliphores. Neck very short, marked only by a proximal constriction. Lateral processes 1.5 longer than wider; separated by 0.2 times their own diameter, with a dorsodistal conical tubercle with a couple of setae on each of the sides. Abdomen conical straight a little bit downward, reaching the end of the 1 st coxa from 4 th leg. Proboscis globular and short, 1.5 times longer than wide. Ocular tubercle 2 times longer than wide and 45º inclined in the direction of the proboscis; tricuspidate tip; the central tubercle bigger than the 2 lateral sense organs that are disposed anterior of the tip; eyes full pigmented. Cheliphores long and robust; scape longer that the proboscis; chela more than twice as long as the scape; chela fingers almost 3 times longer than the palm, with the immovable finger with 21 teeth and movable finger with 24, all similar size. Palp 5-articled; 2 nd article the longest; 3 rd and 4 th about equal in length; 5 th article slightly longer than the previous one; the 2 distal articles especially setose. Oviger 10-articled: 5th article the longest; articles 7–10 (strigilis) with compound denticles, 6:5:3:5; terminal claw armed with 7 teeth. Legs relatively slender, 6 times as long as trunk; coxa 2 nearly twice as long as coxa 1 or coxa 3; femur wide and curved; tibia 1 1.5 times longer than the femur; tibia 2 slightly longer than the femur; tarsus 2/3 the length of the propodus; propodus slightly curved; main claw a little more than 1/2 of the propodus; no auxiliary claws. Female gonopores located ventrodistal on coxa 2 of the four pairs of legs: oocytes in femur of all legs.

Measurements of holotype (mm): trunk length: 1.38; trunk width: 0.58; abdomen length: 1.18; Proboscis length: 1.01; width: 0.68; Cheliphore: total length: 3.82; scape: 0.7; chela: 1.56; fingers: 1.17; palm: 0.4; Palp: total length: 1.17; art.1: 0.15; art.2: 0.42; art.3: 0.19; art.4: 0.17; art.5: 0.23. Third leg: total length: 8.59; coxa 1: 0.45; coxa 2: 0.89; coxa 3: 0.56; femur: 1.41; tibia 1: 2.13; tibia 2: 1.7; tarsus: 0.41; propodus: 0.67; claw: 0.37. Oviger length: 3.67.

Remarks. The presence of a tricuspidate ocular tubercle formed by the mucronate tip and the anterior position of the lateral sense organs is reminiscent of the ocular tubercle present in Nymphon tricuspidatum Soler-Membrives & Munilla, 2011 , collected from the continental slope off Asturias and Galicia ( Spain). However, in N. tricuspidatum , the eyes are slightly pigmented, lateral processes are smooth, and the chela have 21–31 long teeth with 4–6 smaller teeth between them (Soler-Membrives & Munilla, 2011; Munilla & Soler-Membrives, 2014). In our specimen, the eyes are fully pigmented, the lateral process carries a dorsal protuberance, and the teeth of the chela are uniform in size, clearly separating both species.

Nymphon granulatum Arnaud & Child 1988 and Nymphon grus Stock, 1991 share some features with N. pacitae sp. nov. such as the presence of tubercles or spines in the lateral process, the absence of auxiliary claws, and a similar number of teeth in the chela, but there are also some differences. In N. granulatum the ocular process is tall but blind, with very small lateral sense organs and main claw less than half the length of the propodus. Nymphon grus has a long neck, the ocular process is low and blunt, and the main claw is 2/3 the length of the propodus. In addition, in both species article 3 of the palp is longer than article 5.

Geographical distribution. The sole specimen was collected from the northern coasts of Mauritania at 352 m depth.