Dorsiceratus denizae, George & Tönjes & Yurtdaş, 2025

Dorsiceratus denizae sp. nov.

Figs 12 View Figure 12 , 13 View Figure 13 , 14 View Figure 14 , 15 View Figure 15

Locus typicus.

Angola Basin, station #346/5 -9   GoogleMaps , geographic position 16°16.9'S, 05°27.0'E, depth 5,389 m, tropical southeast Atlantic Ocean.

Type material.

The type material was collected during research cruise M 48 / 1, expedition DIVA 1, of RV METEOR.

• Holotype: female, collected on 27. 07. 2000 at the type locality; mounted on 1 slide, collection number SMF 37292/1 ; GoogleMaps • PT 1 : female, collected on 27. 07. 2000 at station #346/8 -1 (AB C), geographic position 16°17,0'S, 05°27,0'E, depth 5,390 m; mounted on 1 slide, collection number SMF 37293/1 ; GoogleMaps • PT 2 : female, collected on 14. 07. 2000 at station #325/7 -4 (AB S), geographic position 19°58,4'S, 02°59,8'E, depth 5,448 m; mounted on 1 slide, collection number SMF 37294/1 . GoogleMaps

Etymology.

The epitheton of Dorsiceratus denizae sp. nov. is fondly dedicated to SY’s daughter, Miss Deniz Yurtdaş. Gender: feminine.

Description of female.

Habitus (Fig. 12 View Figure 12 ) slender and cylindrical, with inconspicuous boundary between pro- and urosome. Body length of holotype from rostral tip to end of FR 686 µm (mean 717 µm, range: 686–747 µm, n = 3), cphth and body somites dorsally with some sensilla and tube pores. Frontal peak on cphth well-developed, with anterior cephalothoracic setular tufts (ACST). Cphth and first three free thoracic somites dorsally with slender spinulose cuticular processes (CLDP, DT 1 – DT 3), that bear a sensillum at their tips and are accompanied by another sensillum at their bases. Rostrum fused with cphth, strongly constricted, slightly longer than broad and cleft at its tip, with 2 sensilla and 1 tube pore. Last thoracic and first abdominal somite fused into a GDS; former segmental demarcation still indicated by few dorsal spinules and pair of sensilla. Free thoracic body somites laterally with setular tufts.

P 2 – P 6 - bearing somites dorsally with 1 tube pore. First abdominal somite (= posterior half of GDS) and the following two abdominal somites dorsally with row of flexible setules on posterior margin; first and second abdominal somites additionally with 2 pairs of sensilla. Penultimate somite dorsally with tube pore on posterior margin. Telson shorter than broad, slightly trapezoidal from dorsal view. Anal operculum basally flanked by a pair of sensilla; apically with long spinules, which increase in length from the outer edges towards the centre.

FR (Fig. 13 A View Figure 13 ) approximately 7 times longer than basal width, slender, equipped with 7 setae. Setae I and II located at mid-length of ramus; seta I minute, bare; seta II much longer, bipinnate; seta III (broken in Fig. 13 A View Figure 13 ) arising subapically; setae IV and VI small and bare, inserting apically on outer and inner edges, respectively; seta V longest; seta VII (broken in Fig. 13 A View Figure 13 ) positioned dorsally at subapical part of FR. FR additionally with 1 short broad and 1 slender tube pore on the ventral apical margin.

A 1 (Fig. 13 B View Figure 13 ) 4 - segmented. First segment longest, with long spinules on anterior margin, distally with 1 biplumose seta. Second segment reaching 2 / 3 of first segment, with 6 setae. Third segment almost as long as first, with row of spinules on posterior margin and with 3 bare and 1 bipinnate setae along anterior margin; moreover, subapically, 1 seta and 1 strong aes arise from acrothek, accompanied by 2 bare setae. Fourth segment smallest, with 10 setae (4 of which broken) and 1 aes. Setal formula: I – 1, II – 6, III – 7 + aes, IV – 10 + aes.