Atlantapseudes nigrichela , Bacescu 1978

Atlantapseudes nigrichela Băcescu, 1978 (Figs 2, 3) Atlantapseudes nigrichela Băcescu, 1978, 317–322 [in part], fig. 1B–D, K. Atlantapseudes curvatus Esquete & Cunha, 2017, 61, 65–72, 87, figs 2–6 Atlantapseudes curvatus: García-Herrero et al. 2021a, 66; García-Herrero et al. 2021b, suppl. 2, 3. Material examined. Holotype: ovigerous female (393/30686, Muzeul Național de Istorie Naturală “Grigore Antipa,” TBL = 5.85 mm), Stn 396, Atlantic Ocean, western Portugal (41°17'4"N, 09°15'7"W), 900 m depth, silty or sandy-silty bottom, cruise “Thalassa,” September 1972. Paratypes: three females (TAN 032-1–3, TBL = 5.60 mm, 5.20 mm, 4.20 mm, respectively, Muzeul Național de Istorie Naturală “Grigore Antipa”), Atlantic Ocean, western Portugal, without other data; three males (49217-1–3, TBL = 4.50 mm, 3.75 mm, 4.10 mm, respectively, Muzeul Național de Istorie Naturală “Grigore Antipa”), Stn 407, Atlantic Ocean, western Portugal (40°33'5"N, 09°24'0"W), 740 m depth, silty or sandy-silty bottom, cruise “Thalassa,” 1 September 1972. Amended diagnosis. Rostrum tridentate. Pereonite-1 lateral margin with posterior spine but without anterior spines. Lateral margin of pereonites 2 and 3 with one anterior spine and one posterior spine. Lateral margin of pereonites 4–6 with anterior spine but without posterior spines. Squama more than 2.5 times longer than antennal article-3. Labial palp with three spiniform setae. Maxillipedal palp article-2 with two outer distal setae. Cheliped with carpus bearing two ventral long setae. *, We treated as Atlantapseudes sp. in this study. †, We synonymized with A. nigrichela in this study. Supplemental description of holotype. The holotype was strongly deformed and had lost several parts, but we observed the following character states: tridentate rostrum (left part partly broken) (Fig. 2A), a spine present on mid-lateral margin of cephalothorax (Fig. 2B), each eye lobe with anterior spine (Fig. 2A), pereonite-1 with spine on posterolateral margin, a spine present on anterolateral and posterolateral margin of pereonites 2 and 3 (Fig. 2C–F), a spine present on subanterior lateral margin of pereonites 4–6 (Fig. 2F–H), the squama about 3.3 times longer than antennal article-3 (Fig. 2I) and the cheliped with basis and merus each bearing ventro-subdistal spine and carpus bearing two long ventral simple setae (Fig. 2B). Supplemental description of paratypes. Cephalothorax and pereonites 1–6 (Fig. 3A–D) similar to those in holotype; squama about 3.1 times longer than antennal article-3; labial palp with three spiniform setae (Fig. 3E); maxillipedal palp article-2 with two outer distal setae (Fig. 3F); pereopod-3 coxa with spine (Fig. 3D) (see also Supplementary File S1). Remarks. The holotype of A. nigrichela had (1) a tridentate rostrum; (2) pereonite-1 with a posterolateral spine; and (3) pereonites 2 and 3 with one anterolateral spine and one posterolateral spine. All three states were also found in three female and three male paratypes. We did not detect states (2) and (3) in the monodentate individuals of “ A. nigrichela ” (Băcescu 1978, fig. 1A; Błażewicz-Paszkowycz et al. 2011, fig. 6), but did find them in A. curvatus, which has a tridentate rostrum (Esquete & Cunha 2017, fig. 2A). Those character states were summarized in Table 1. The type locality of A. nigrichela is near the area where A. curvatus has been reported (Fig. 1B). The holotype of A. nigrichela was collected at 900 m depth, within the known depth range of A. curvatus (497–1001 m) (Supplementary Table S1). Based on these morphological and distributional similarities, we concluded that A. curvatus is a junior synonym of A. nigrichela. We found that the specimen designated as the allotype and one designated paratype had a monodentate rostrum. Based on this morphology, we identified them as Atlantapseudes sp. (see below). One female designated as a paratype (TAN 032-4) was badly deteriorated and could not be identified to species level.