Nymphon anaramosae, Antolínez & Ramil, 2025

Nymphon anaramosae View in CoL sp. nov.

( Fig. 3–4 View FIGURE 3 View FIGURE 4 )

Holotype. Bissau-0811: BS192, 1 ♂. ( MNCN 20.03 About MNCN /984)

Etymology. This species has been dedicated to Dr. Ana Ramos for her study of the benthic fauna of the African coast.

Diagnosis. Nymphon anaramosae sp. nov. is characterized by an immovable finger with 31 teeth and movable finger with 36 teeth, 4 th and 5 th palp articles subequal, shorter femur than tibiae, tibia 2 with 4 strong ventrodistal spines, propodus slightly longer than tarsus, main claw ¾ of propodus and small auxiliary claws.

Description. Trunk slender and elongated, completely segmented. CephalonY-shaped, 0.8 times the size of the trunk; neck moderate 1½ longer than wide. Lateral processes smooth, 1.3 longer than wider and separated by the same distance as their own diameter. Abdomen upward 45º, short and conical in shape. Proboscis slightly setose cylindrical and widened in the middle part. Ocular tubercle as longer as wide; blunt with lateral sense organs; eyes pigmented. Cheliphores slightly setose; scape same length than the proboscis; chela longer than the scape; chela fingers subequal to the palm; immovable finger with 31 teeth and movable finger with 36 teeth; teeth of the movable finger shorter than those of the immovable one. Palps 5-articled; 2 nd article the longest, 4 th and 5 th articles subequal and shorter than the 3 rd article; 2 distal articles strongly setose. Oviger 10-articled. Article 5 with distal apophysis. Articles 7–10 with compound denticles, 11:10:9:11; terminal claw with 5 teeth. Legs slender and setose, 10 times as long as trunk; coxa 2 more than twice as long as coxa 1 or coxa 3, which are similar in length; femur shorter than tibia 1 and tibia 2; tibia 2 with 4 strong ventrodistal spines; tarsus slightly shorter than propodus, both with 12 ventral spines; main claw almost 3/4 of the propodus; auxiliary claws short, 5 times shorter than the main claw.

Measurements of holotype (mm): trunk length: 1.37; trunk width: 0.51; abdomen length: 0.43; Proboscis length: 0.96; width: 0.4; Cheliphore: total length: 2.21; scape: 0.96; chela: 1.24; fingers: 0.66; palm: 0.59; Palp: total length: 2.1; art.1: 0.11; art.2: 0.76; art.3: 0.54; art.4: 0.36; art.5: 0.32. Third leg: total length: 15.44; coxa 1: 0.49; coxa 2: 1.09; coxa 3: 0.5; femur: 2.56; tibia 1: 3.84; tibia 2: 4.27; tarsus: 0.92; propodus: 1.02; claw: 0.75; auxiliary claw: 0.15. Oviger length: 2.21.

Remarks. The small size of the auxiliary claws is a distinctive feature for some Nymphon species. Nymphon adami Giltay, 1937 , Nymphon akanthochoeros Bamber & Thurston, 1995 , Nymphon benthos Hedgpeth, 1949 , Nymphon brachyrhynchum Hoek, 1881 , Nymphon inerme Fage, 1956 , Nymphon leptocheles Sars, 1888 , Nymphon nakamurai Munilla & Soler-Membrives, 2015 , Nymphon neumayri Gordon, 1932 , Nymphon spinifex Stock, 1997 and Nymphon vulsum Stock, 1986 share this characteristic, but there are some morphological differences from N. anaramosae sp. nov. (see Table 2). The most appreciable difference is the number of finger teeth on the chela. Only one species ( N. brachyrhynchum ) has more teeth (53–41 vs. 36–31); other species always have fewer teeth than observed in new species.

Related to other features included in Table 2, N. vulsum shares with N. anaramosae sp. nov. the same length sequence for palp articles (2>3>4 = 5) and tarsus length, slightly shorter than the propodus in both species. Nevertheless, the main claw is longer, the number of finger teeth is lower (25–27 vs. 36–31), and the number of spines in the propodus is higher (30 vs. 11).

In N. inerme , N. nakamurai , and N. neumayri , the length of the tarsus is almost equal to the propodus (close to 100%), but in N. anaramosae it is only 90% of the tarsus length. In addition, these three species have fewer teeth in fingers, the length sequences of palp articles are different, and the main claw is smaller, with the exception of N. vulsum in which the main claw is longer. Moreover, in N. inerme the ocular tubercle is absent, and in N. nakamurai the lateral processes are separated by 2–3 times their diameter. Just one species, N. akanthochoeros , shares the length of the main claw with N. anaramosae sp. nov. (3/4 of the propodus), but all the features considered in Table 2 are clearly different, and the neck is shorter and has non-pigmented eyes.

Nymphon spinifex does not share with N. anaramosae sp. nov. any of the features listed in Table 2, and the ocular tubercle and eyes are lacking, the posterior rim of trunk segments 2 and 3 display 3 and 2 long mid-dorsal setae, respectively, and the lateral processes are also associated with long setae.

Geographical distribution. The sole specimen was collected from Guinea-Bissau at 24 m depth .