Bathyporeia guilliamsoniana ( Bate, 1857 )

D’Acoz, Cédric D’Udekem & Vader, Wim, 2005, New records of West and South African Bathyporeia, with the description of four new species and a key to all species of the genus (Crustacea, Amphipoda), Journal of Natural History 39 (30), pp. 2759-2794 : 2786

publication ID	https://doi.org/ 10.1080/00222930500190129
persistent identifier	https://treatment.plazi.org/id/0395C179-3949-A96B-9175-FE80FA626E5A
treatment provided by	Carolina
scientific name	Bathyporeia guilliamsoniana ( Bate, 1857 )
status

Treatment

Bathyporeia guilliamsoniana ( Bate, 1857)

Thersites Guilliamsonia Bate 1856, p 59 View in CoL (nomen nudum).

Thersites Guilliamsoniana Bate 1857, p 146 View in CoL .

Bathyporeia pontica Marcusen 1867, p 359 .

Bathyporeia norυegica G. O. Sars 1891, p 128, Plate 43.

Bathyporeia megalops Chevreux 1911, p 184 , Figure 6 View Figure 6 , Plate 10 Figures 1–11 View Figure 1 View Figure 2 View Figure 3 View Figure 4 View Figure 5 View Figure 6 View Figure 7 View Figure 8 View Figure 9 View Figure 10 View Figure 11 .

Bathyporeia pelagica ; Chevreux 1925, p 295, in part (list, no description) (not B. pelagica ( Bate, 1857)) ; Chevreux and Fage 1925, p 94 (in part: Canarian record only).

Bathyporeia guilliamsoniana ; Watkin 1938, p 216, Figure 1 View Figure 1 a–g; d’Udekem d’Acoz 2004, p 46, Figures 26–36; d’Udekem d’Acoz and Vader forthcoming, Figures 12–20 View Figure 12 View Figure 13 View Figure 14 View Figure 15 View Figure 16 View Figure 17 View Figure 18 View Figure 19 View Figure 20 (ubi syn.). Bathyporeia sunniυae Bellan-Santini and Vader 1988, p 237, Figure 4 View Figure 4 ; Bellan-Santini 1989, p 378, Figure 254.

Material examined

Seven specimens (two adult males with a dorsal pair of posteriorly directed spines on urosomite 1 and with eyes very big but not dorsally merged, one immature male of the morphotype ‘‘ sunniυae ’’, three adult females (two ovigerous) of the morphotype ‘‘ sunniυae ’’, two juveniles of the morphotype ‘‘ sunniυae ’’), Canary Islands, La Luz [Gran Canaria], Melita St. 283 [28 ° 099N, 15 ° 259W], sand, 4 m depth, 10 January 1890, previously identified as ‘‘ Bathyporeia pelagica ?’’ by E. Chevreux, MNHN-Am 5455.

Ecology. In sand, from extreme lower shore to 75 m depth (d’Udekem d’Acoz 2004).

Distribution. From southern Norway ( Sars 1890 –95 as B. norυegica) to Western Sahara (d’Udekem d’Acoz et al. forthcoming), Mediterranean, Black Sea (d’Udekem d’Acoz and Vader forthcoming).

Discussion

d’Udekem d’Acoz and Vader (forthcoming) observed (1) that the absence of posteriorly directed spines on the first urosomite was the only character differentiating Bathyporeia sunniυae Bellan-Santini and Vader, 1988 from B. guilliamsoniana ; (2) that B. sunniυae and B. guilliamsoniana were often found together in the same sample; and (3) that specimens identifiable as B. sunniυae were always either females or immature males, never adult males. They concluded that in the absence of new evidence, B. sunniυae should be considered a junior synonym of B. guilliamsoniana . So far the morphotype ‘‘ sunniυae ’’ was only known from the Mediterranean Sea. It is recorded here for the first time in the east Atlantic. It is worth mentioning that the polymorphism of B. guilliamsoniana has similarities with that of B. pilosa . Female B. pilosa have almost never posteriorly directed spines on the first urosomite, while in some populations over 20% of adult male B. pilosa have such spines. For example, a sample of 86 B. pilosa from Wemeldinge ( the Netherlands) collected on 23 April 2003 by the first author ( TMU 12 241) consists of eight adult males with posterior spines, 28 adult males without posterior spines, 21 immature males without posterior spines, and 29 females without posterior spines. Furthermore, in Bathyporeia species such as B. elegans Watkin, 1938 which always have posterior spines of the first urosomite, those spines are usually longer in adult males than in other specimens, confirming that the extent of dorsal spination of the first urosomite is partly related to sex and maturity.