Acanthephyra fimbriata Alcock & Anderson, 1894

Acanthephyra fimbriata Alcock & Anderson, 1894

Fig. 1 View FIGURE 1 (A–E)

Acanthephyra armata .— Wood-Mason and Alcock, 1892:359, fig. 2 [not A. armata A. Milne-Edwards].

Acanthephyra armata var.— Wood-Mason, 1892, pi. 3: fig. 1.

Acanthephyra armata var. fimbriata Alcock &Anderson, 1894: 156 [type-locality: the original specimen, described and illustrated but not named in 1892, it was reported in the Andaman Sea off Little Andaman; 11°25'05"N, 92°27'06"E, 741 m; the two additional specimens were reported in 1894 from the Bay of Bengal off Madras; 12°50'N, 81°30'E, 869 m and off Goa; 15°29'N, 72°41'E, 1023 m].

Acanthephyra fimbriata .— Chace 1986, fig. 2l, 4l, 51, 6j, 9c.

Material examined. Kalamuku fish landing center, off Cochin (9°59'02.91"N; 76°14'33.14"E), 1♂ (CL: 30 mm), 200–300 m at depth, during 18 th November 2015; Sakthikulangara (off Kollam8°56'60.78"N; 76°32'34.27"E), 3♂ (CL 26–28 mm), depth at 200–350 m, during 3 rd February 2015. Voucher specimen accession number, CMFRI: ED.5.9.5.1.

Characters of specimen from off Kerala Rostrum as long as carapace, overreaching antennal scale, dorsal margin armed with 4 teeth on base, ventral margin armed with 1 tooth; carapace smooth,without carina on the entire lateral surface; antennal spine present, branchiostegal spine with strong carina, sharp carina extending posteriorly nearly to branchial region; exopod of third maxilliped and all pereopods neither foliaceous nor rigid; abdomen smooth, dorsally carinate on somites 2–6, somites 3–6 with posteromesial tooth, third somite not deeply excavate either side of median tooth, pereopods are not slender. Telson with strong dorsal midline, with 3 dorsolateral spines (Modified from Chace 1986).

Coloration: Body is entirely reddish and orangish in the abdominal region.

Remarks: A. fimbriata is similar to A. armata , but different in the carapace with strong carina supporting branchiostegal spine to branchial region and abdomen with posterior margin of 3 rd pleura not distinctly excavate either side of the posteromedian tooth ( Chace 1986). The present specimens concede well with the earlier descriptions ( Alcock & Anderson 1894; Chace 1986) without any dissimilarity. In this study, only male specimens were obtained from the southwest off Kerala between depths of 200 and 350 m, but the previous records of this species was off Madras, Bay of Bengal (BOB, 869 m) and Goa, Arabian Sea ( AS, 1023 m) at higher depths. The distributional records of this species are limited to Gulf of Aden, Andaman Sea, Bay of Bengal, Laccadive Sea, and Arabian Sea: off Goa and Philippines occurring between 412–1785 m ( Chace 1986).

The gene sequence obtained from the present specimen was deposited in GenBank (Accession no’s: COI, MF627725 View Materials , MF627726 View Materials , KU055638 View Materials , KU055639 View Materials ; 16S, KU055642 View Materials , KU055643 View Materials ). The sequence lengths are 540 and 407 bp for cytochrome c oxidase I (COI) and 16S rDNA genes, respectively. The present specimen sequences was compared with the NCBI sequences of the genus Acanthephyra was obtained from the GenBank ( Table. 1). The level of intraspecies genetic divergence was 3% with COI and 0.3% in 16S between the Indian and Philippines samples (COI: KP076185 View Materials ; 16S: KP075895 View Materials ) while it showed 100% similarity within the Indian material (COI: KT222917 View Materials , KT222918 View Materials , MG029405 View Materials ; 16S:KP372713). Interspecies genetic divergence (COI: 17.5–20.9% & 16S: 5.2–9.5%) between the present specimen and 14 species of Acanthephyra sequences collected from NCBI was depicted in Fig.2 View FIGURE 2 & Fig.3 View FIGURE 3 . COI sequence divergences of less than 3% are generally considered to be intraspecific in decapod crustaceans ( Darling 2011; Vergamini et al. 2011; Yang et al. 2016).