Atlantapseudes nigrichela Băcescu, 1978

Esquete, P. & Cunha, M. R., 2017, The Apseudomorpha (Crustacea: Tanaidacea) of the Gulf of Cadiz and Horseshoe Continental Rise (NE Atlantic): A taxonomic review with new records, species, and ecological data, Zootaxa 4276 (1), pp. 61-95 : 64-65

Atlantapseudes nigrichela Băcescu, 1978

Atlantapseudes nigrichela Băcescu 1978: 317 –322: fig. 1. Santos & Hansknecht 2007: 38 (identification key). Błażewicz- Paszkowycz et al., 2011: 10–16, figs. 6–9 (description of material from the GoC).

Material examined. Gulf of Cadiz—Mud volcanoes. Gemini MV: St. 64PE253_08, 444 m, 2 neuters; St. 64PE253_ 10, 432 m, 1 ovigerous ♀; St. 64PE253_ 11, 438 m, 3 specimens; St. 64PE253_ 13, 516 m, 7 neuters; St. 64PE253_14, 575, 3 neuters; St. 64PE253_ 15, 600 m, 2 neuters ( DBUA 0001997.01–06 ) ; St. 64PE268_ 19, 430 m. Lazarillo de Tormes MV: St. 64PE253_38A, 494 m, 2 neuters; St. 64PE253_38C, 497 m, 2 neuters (DBUA0001997.07–08). Meknès MV: St. MSM01–3_ 319, 695 m, 2 ♂♂, 3 neuters (DBUA0001999.01). Yuma MV: St. TTR16_AT 604, 1030 m, 1 ♀, 5 neuters; St. TTR16_AT 605, 975 m, 7 neuters (DBUA0002000.02).

Ginsburg MV: St. TTR16_AT 607, 983 m, 1 ♂, 1 neuter (DBUA0002000.03). Captain Arutyunov MV: St. MSM01–3_ 180, 1323 m, 12 neuters; St. MSM01–3_ 194, 1379 m, 1 neuter (DBUA0001999.02–03).

Gulf of Cadiz—Carbonate and coral mounds. Pen Duick Escarpment: St. 64PE237_05B, 535 m, 1 neuter; St. 64PE237_ 10, 538 m, 2 neuters; St. 64PE237_13A, 546 m, 3 neuters; St. 64PE237_ 14, 546 m, 1 ♂; St. 64PE237_16A, 660 m, 1 neuter; St. 64PE237_16B, 665 m, 1 neuter; St. 64PE237_30B, 550 m, 3 specimens; St. 64PE237_ 31, 559 m, 3 neuters (DBUA0002001.01–08); St. TTR16_AT 600, 610 m, 4 neuters; St. TTR16_AT 602, 556 m, 1 ♂, 2 neuters (DBUA0002000.04–05); St. 64PE253_ 21, 560 m, 2 ♂♂, 4 neuters; St. 64PE253_ 28, 642 m, 1♂, 1 neuter; St. 64PE253_ 39, 560 m, 1 ♂; St. 64PE253_ 42, 637 m, 1 neuter; St. 64PE253_44A, 3 specimens; St. 64PE253_ 51, 624 m, 1 neuter; St. 64PE253_ 52, 622 m, 2 neuters; St. 64PE253_ 53, 651 m, 6 neuters; St. 64PE253_ 56, 622 m, 2 neuters; St. 64PE253_ 57, 598 m, 1 neuter; St. 64PE253_ 58, 606 m, 9 specimens; St. 64PE253_ 59, 637 m, 9 neuters (DBUA0001997.09–20). Mound B: St. 64PE268_11A, 489 m, 4 neuters; St. 64PE268_13A, 475 m, 1 specimen; St. 64PE268_ 23, 498 m, 2♂♂, 3 neuters; St. 64PE268_ 25, 490 m, 12 specimens (DBUA0001998.02–05). Mound C: St. 64PE268_45, ca. 800 m, 1 neuter; St. 64PE268_46, ca. 720 m, 1 neuter; St. 64PE268_51, ca. 740 m, 1 neuter (DBUA0001998.06–08). Mound D: St. 64PE268_ 40, 473 m, 1 ♀; St. 64PE268_ 42, 451 m, 2 ♀♀, 3 neuters (DBUA0001998.09–10). Mound M: St. MSM01-3_ 321, 732 m, 1 ♀, 5 neuters (DBUA0001999.04).

Gulf of Cadiz—Off mound and reference samples. El Arraiche area: St. 64PE237_19A, 547 m, 2 neuters (DBUA0002001.09); St. 64PE237_ 23, 559 m, 3 neuters (DBUA0002001.10); St. 64PE253_ 17, 612 m, 3 neuters; St. 64PE253_ 33, 542 m, 2 ♀♀, 4 neuters; St. 64PE253_ 34, 542 m, 1 neuter; St. 64PE253_ 36, 542 m, 1 specimen (DBUA0001997.21–24); St. 64PE268_09, 428 m, 1 neuter (DBUA0001998.11). Carbonate Province: St. 64PE253_ 19, 908 m, 1 neuter (DBUA0001997.25); St. 64PE268_05, 581 m, 1 neuter; St. 64PE268_ 54, 750 m, 1 neuter; St. 64PE268_55, ca. 700 m, 1 neuter (DBUA0001998.12–14).

Additional material: Holotype, ♀ ( GANMNH 393 /30686), 0 9.1972, west Portugal , 41°17’4’’N, 09°15’7’’W, 900 m depth. Allotype, ♂; ( GANMH 394 /30687), same data as holotype; 1 ♀, 3 neuters, ( GANMNH TAN- 079 / 49217), cruise Thalassa, 0 1.09.1972, W Portugal, 40°33’05’’N, 09°24’W, 740 m depth.

Other records in the GoC. See Błażewicz-Paszkowycz et al. (2011).

Remarks. This species was described by Băcescu (1978) from off north of Portugal, and redescribed by Błażewicz-Paszkowycz et al. (2011), using material from the GoC. In the original description, Băcescu (op. cit.) illustrated the rostrum of three specimens, which remarkably differed in the shape of the rostrum: while one female specimen ( Băcescu 1978, fig.1A) is illustrated with rounded shoulders (in accordance with the abovementioned redescription), the others are tridentate ( Băcescu 1978, fig.1B, C). This suggest that there was more than one species in his collection (see species described below), and therefore the tridentate rostrum should not be considered a character of Atlantapseudes nigrichela . The material examined herein is in full accordance with the redescription ( Błażewicz-Paszkowycz et al. 2011), including the shape of the rostrum.

After a close examination of the material attributed to A. nigrichela from the collections of GANMNH, we determined that two specimens previously designated as “ paratypes ” by Băcescu (1978) were in fact specimens of an undescribed species that also occurs in the Gulf of Cadiz and is described below.

Distribution and Ecology. Băcescu (1978) found the species in muddy bottoms between 740 and 1250 m depth, at the slope off northern Portugal. In the GoC (see also Błażewicz-Paszkowycz et al. 2011), A. nigrichela is distributed in the Moroccan slope, at the El Arraiche field and Carbonate province, including the PDE, and at the Deep Field at maximum depth of 1379 m. It was found in the craters of active mud volcanoes (i.e., Meknès , Gingsburg, Yuma and Captain Arutyunov). In Kidd MV, it occurred in quantitative samples from the crater, flank, and near the volcano. It was also found in coral mounds, in silt/clay sediments with coral debris. When vertical stratification was investigated, specimens of A. nigrichela were identified from the top layer to a maximum of 5–10 cm.