Bathyamaryllis biscayensis, Kaim-Malka, R. A., 2014

Kaim-Malka, R. A., 2014, New Lysianassoid Amphipods from the North Eastern Atlantic Ocean, Zootaxa 3821 (5), pp. 551-566 : 559-564

Bathyamaryllis biscayensis n. sp.

( Figs. 7–11 )

Type material. HOLOTYPE. Adult female, with oostegites not completely developed, 9.76 mm. Collected in the North Eastern Atlantic Ocean (Bay of Biscay) on 24 August 2002. Cruise VITAL on R/V "L'Atalante" ( IFREMER). Meriadzek Terrace ( Fig.1 ). Depth: 1460 m, 47°36'N, 8°25'W. Holotype deposited in the Muséum National d'Histoire Naturelle (Paris) N°: MNHN-IU-2013-11268.

PARATYPES. 2 specimens collected with the Holotype, in the same station. They are deposited in the Muséum National d'Histoire Naturelle (Paris) N°: MNHN-IU-2013-11269. 1 specimen collected on 28 August 2002. Cruise VITAL on R/V "L'Atalante" ( IFREMER). Saint Nazaire Terrace ( Fig.1 ). Depth: 1550 m, 46°15'N, 4°43'W. Specimen deposited in the Muséum National d'Histoire Naturelle (Paris) N°: MNHN-IU-2013-11270. Male unknown.

Etymology. The name species refers to the type locality.

Diagnosis. Blind species. Lateral cephalic lobe triangular. Coxa 4 very broad, covering a great part of coxa 3 and 5. Coxa 5 very broad. Basis of pereopod 6 and pereopod 7 subquadrangular, posterior margin crenate. Epimeral plate 3 very broad and very extended posteriorly, posteroventral corner ended with a little acute tooth.

Description. HOLOTYPE female, 9.76 mm ( Fig. 7 ). Head: much deeper than long, without eyes, blind species. Rostrum anteriorly truncated. Lateral cephalic lobe reduced, triangular shaped and slightly curved anteriorly. Anterior margin with notch (concavity), not extended into a slit ( Fig.7 , 8 A). Antenna 1: a little shorter than Antenna 2. Peduncle article 1> article 2> article 3, peduncular article 1 ball-shaped proximally (slightly), distal margin without spine; flagellum 25 articulated. Accessory flagellum with 5 articles ( Fig. 8 B, C). Antenna 2: broad, slightly longer than antenna 1; flagellum with 26 articles ( Fig. 8 D). Epistome and upper lip: fused ( Fig. 8 E). Mandible ( Fig. 9 E, F): molar a small flap; palp elongated, some setae on the distal part of the last article. Lower lip ( Fig. 8 F): bilobate, each lobe fringed distally with hairs; projection of outer lobe elongated and pointed. Maxilla 1 ( Fig. 8 G): inner plate long, apical part rounded with 2 short setae and some hairs; outer plate elongated with spine teeth distally; palp absent. Maxilla 2 ( Fig. 8 H): the two plates are subequal in length, the outer one broader than the inner one; the inner margin of each plate fringed with setae. Maxilliped ( Fig. 8 J, K): inner plate subrectangular, elongated with numerous hairs on the distal part; internal margin of the outer plate minutely serrate; palp slender and elongated, longer than outer plate, articles 2 and 3 with long setae; dactylus reduced with 2 subapical setae, unguis absent.

Pereon. Gnathopod 1 ( Fig. 9 A): coxa 1 small and roughly rectangular; basis rectangular and elongated, basis> merus+carpus+propodus; carpus <propodus; dactylus simple. All the articles are ornamented with little setae. Gnathopod 2 ( Fig. 9 B, C): coxa 2 smaller than coxa 3, inferior part of the coxa 2 triangular rounded shaped, length = 2.3 width; basis very long and narrow, length basis = carpus + propodus; carpus and propodus long, roughly rectangular (carpus> propodus), these two articles ornamented with setae; dactylus short and slender. Pereopod 3 ( Fig. 9 D): coxa 3 rectangular shaped, anteroventral corner rounded, posteroventral corner ended with a little acute tooth; the different articles are elongated, slender with numerous spines; basis the longer article, carpus and propodus subequal, dactylus long (1/2 propodus length) curved and stout. Pereopod 4 ( Fig.10 A, B): coxa 4 very broad, covering a great part of coxa 3 and coxa 5, anterior and posterior margin straight, subparallel, anteroventral corner rounded, ventral margin convex, posterior concavity 1/3 length of the coxa 4; the different articles are elongated, slender with numerous spines; propodus as long as carpus, dactylus long (1/2 propodus length) curved and stout. Pereopod 5 ( Fig.10 C): coxa 5 very broad, bilobate; basis: inferior margin of the lobe straight, posterior margin very slightly crenate, posteroventral corner subquadrate; the different articles are elongated, slender with numerous spines; propodus> carpus>merus; merus with a posterior lobe; dactylus long (1/2 propodus length) curved and stout. Pereopod 6 ( Fig.10 D, E): coxa 6 small, roughly square; basis subrectangular (length =1.5 width), posterior margin crenate, ventral margin convex; the different articles are elongated, slender with numerous spines; propodus> carpus> merus; merus with a very little posterior lobe; dactylus long (1/2 propodus length) curved and stout. Pereopod 7 ( Fig.10 F, G): coxa 7 roughly square, smaller than coxa 6; basis rectangular (length =1.4 width), posteroventral corner subquadrate, posterior margin strongly crenate; the different articles are elongated, slender with numerous spines; propodus> carpus> merus; merus with a very little posterior lobe; dactylus long (1/2 propodus length) curved and stout.

Pleon. Epimeral plate 1 ( Fig.11 A): anterior and posterior margin straight, ventral margin rounded. Epimeral plate 2 ( Fig.11 B): anterior corner round, ventral margin slightly convex, posterior corner slightly acute. Epimeral plate 3 ( Fig.11 C): very broad and very extended posteriorly, anterior margin straight, ventral margin slightly curved, posterior margin broadly convex, with a notch immediately above acute posteroventral corner.

Urosome. Carina straight, scarcely rounded. Uropod 1 ( Fig.11 D): long, peduncle and rami of same length, rami of equal size; many little spines on peduncle and rami. Uropod 2 ( Fig.11 E, G): shorter than Uropod 1, U1 / U2 = 1.21; rami of inequal length, inner ramus longer than outer ramus, inner ramus moderately constricted. Outer ramus / inner ramus = 0.7; peduncle as long as outer ramus; many little spines on the two rami. Uropod 3 ( Fig.11 F): short, U1> U2> U3; U1 / U3 = 1.64; peduncle shorter than rami; rami lanceolate and of equal length; some spines on peduncle and rami.

Telson ( Fig.11 H): triangular, apical end of each lobe rounded, no setae; cleft 0.53 of the length.

Discussion. This new species belongs to the Amaryllididae family as defined by Lowry and Stoddart (2002). This family includes two subfamilies: the Vijayiinae and the Amaryllidinae . The determination of the genera belonging to the Vijayiinae may be sometimes difficult with the key families given by these authors. However, this new species has the whole characters defined in the diagnosis of the Bathyamaryllis genus and belongs to it.

The genus Bathyamaryllis was created by Pirlot (1933) and contains 6 species: B. haswelli ( Stebbing, 1888) , B. pulchellus ( Bonnier, 1896) , B. perezii Pirlot, 1933 , B. ouvea Lowry & Stoddart, 1994 , B. kapala Lowry & Stoddart, 2002 , B. biscayensis n. sp..

Bathyamaryllis biscayensis n. sp. has the uropod 3 outer ramus 1-articulate, and can be separated from Bathyamaryllis ouvea Lowry & Stoddart, 1994 and Bathyamaryllis kapala Lowry & Stoddart, 2002 which have the uropod 3 outer ramus 2-articulate. Bathyamaryllis biscayensis n. sp. has the lateral cephalic lobe reduced, triangular-shaped with the anterior margin slightly curved. These characters permit the separation of this species from Bathyamaryllis haswelli ( Stebbing, 1888) , Bathyamaryllis pulchellus ( Bonnier, 1896) and Bathyamaryllis perezii Pirlot, 1933 , which have the lateral cephalic lobe quadrate-shaped and the anterior margin straight.

Figures

FIGURE 1. The Bay of Biscay with the position of the stations where the new amphipods species were collected. M: Meriadzek Terrace; N: Saint Nazaire Terrace.

FIGURE 7. Bathyamaryllis biscayensis n. sp., holotype female. Scale 2 mm.

FIGURE 8. Bathyamaryllis biscayensis n. sp., holotype female. A: Head; B: Antenna 1; C: Enlargement of antenna 1 and the accessory flagellum; D: Antenna 2; E: Epistome and upper lip; F: Lower lip; G: Maxilla 1; H: Maxilla 2; J: Maxilliped; K: Maxilliped, enlargement of the distal part of the palp. Scales: E, K: 0.2 mm; C, F, G, H, J: 0.5 mm; A, B, D,: 1 mm.

FIGURE 9. Bathyamaryllis biscayensis n. sp., holotype female. A: Gnathopod 1; B: Gnathopod 2, note the oostegite not completely developed; C: Gnathopod 2, enlargement of propodus and dactylus; D: Pereopod 3, with enlargement of: a part of coxa 3, a spine and the dactylus, note the oostegite; E: Mandible; F: Mandible, part of the inner side. Scales: A, C, E, F: 0.5 mm; B, D: 1 mm.

FIGURE 10. Bathyamaryllis biscayensis n. sp., holotype female. A: Pereopod 4, note the size of the coxa and the oostegite; B: Pereopod 4, enlargement of the dactylus; C: Pereopod 5, note the coxa bilobate and the basis margin slightly crenate; D: Pereopod 6, note the small coxa and the basis margin crenate; E: Pereopod 6, enlargement of the margin crenate; F: Pereopod 7, note the small coxa and the basis margin crenate; G: Pereopod 7, enlargement of the margin crenate. Scales: B, E, G: 0.5 mm; A, C, D, F: 1 mm.

FIGURE 11. Bathyamaryllis biscayensis n. sp., holotype female. A: Epimeral plate 1; B: Epimeral plate 2; C: Epimeral plate 3, note the size of the plate; D: Uropod 1; E: Uropod 2, note the inequal length of the rami; F: Uropod 3; G: Uropod 2, enlargement of the apical part of the inner ramus; H: Telson. Scales: G: 0.1 mm; H: 0.5 mm; A, B, C, D, E, F: 1 mm.