Pasiphaea alcocki ( Wood-Mason & Alcock 1891 )

Kuberan, G., Chakraborty, Rekha Devi, Purushothaman, P. & Maheswarudu, G., 2018, Record of the deep sea shrimp Pasiphaea alcocki (Wood-Mason & Alcock, 1891) (Crustacea: Decapoda: Pasiphaeidae) from the southwestern coast of India, Zootaxa 4532 (4), pp. 597-600: 598-599

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Pasiphaea alcocki ( Wood-Mason & Alcock 1891 )


Pasiphaea alcocki ( Wood-Mason & Alcock 1891)  Fig. 1View FIGURE 1 (A–G)

Parapasiphae alcocki Wood-Mason & Alcock 1891: 196  (Type locality: Arabian Sea, 1732 m).

Phye alcocki Wood-Mason, 1892  : pl. 3-fig. 5.

Pasiphaea (Phye) Alcocki Wood-Mason & Alcock 1893  ; Alcock & McArdle 1901,pl.52,fig. 6.

Pasiphaea  alcocki— De Man 1920, p.6; George & Rao 1966, p. 328; Mohamed & Suseelan 1973, P. 619; 1985: pl. 8- fig 8-

10; Hayashi, 2006a: 197, figs. 1, 2A-P, 3A-E; Komai et al., 2012 (figs. 4, 21B, C).

Material examined: Specimens deposited in the Marine Biodiversity Referral Museum at Central Marine Fisheries Research Institute: Arabian Sea, (ED. Sakthikulangara, off Kollam8°56'60.78"N / 76°32'34.27"E, Kerala, India, 200–300 m depth, November 2013, 3 males (CL 20-23 mm) with TL 78 mm.

Diagnosis: Body laterally compressed. Rostrum with postfrontal spine strongly elevated. The carapace of the dorsal midline is most bluntly carinate in the anterior half; branchiostegal tooth sub marginal exceeding well beyond anterolateral margin; antennular peduncle long with a pointed stylocerite reaching anterior margin; 3 rd maxilliped as long as scaphocerite. First to fifth abdominal somite rounded dorsally; the sixth somite bluntly carinate dorsally. Telson shorter than the sixth somite shallowly grooved in dorsal midline; posterior margin deeply forked, each terminal margin with 8-10 spines including prominent one located at a posterolateral angle. 1 st pereiopod overreaching scaphocerite by about half of its chela, its merus armed with 2-3 spines on posterior margin, 2 nd pereiopod slightly longer than 1 st, merus armed with 10-11 spines; carpus of 1 st and 2 nd legs very short, 3 rd to 5 th pereiopods slender; uropod long, subequal, extending beyond telson (modified from Komai et al. 2012).

Coloration: Body almost entirely transparent with some scattered red chromatophores and eyes dark brown.

Remarks: The present specimens agrees with the description provided by ( Alcock & McArdle 1901; Suseelan 1985; Hayashi 2006a; Komai et al. 2012). Pasiphaea alcocki  is widely distributed in the Indian Ocean, Bay of Bengal, 922 fathoms: Gulf of Mannar, 406 fathoms: Arabian Sea, off the Sind coast, 947 fathoms: southern region of Cochin, Off Alleppey in 185 fathoms (Alcock 1901; George & Rao 1966; Suseelan 1985). In the present study, the specimen was obtained in the lesser depth range of 200-300 m from the southern region of Quilon bank, off Kollam along the Arabian Sea. Earlier, three species under the genus Pasiphaea  named P. sivado ( Risso 1816)  , P. unispinosa ( Wood-Mason, 1892)  and P. alcocki ( Wood-Mason and Alcock, 1891)  are recorded. These species differ from each other in the following characters: carapace not carinate dorsally in P. sivado  , merus of 1 st pereiopod unarmed, that of 2 nd pereiopod armed with a single spine on the posterior border in P. unispinosa  and merus of 1 st pereiopods armed with 3-4 and 12-14 spines in the 2 nd pereiopod in P. alcocki  from Indian Exclusive Economic Zone (EEZ) as described in the earlier records. But in the present material P. alcocki  , all three male specimens showed 2-3 spines on the merus of 1 st pereiopod and 10-11 spines on the merus of 2 nd pereiopod ( Fig. 1View FIGURE 1, E-F). Moreover, presence of a mid-dorsal carina on the carapace forms an important character of this species particularly in the present male specimens, while ( George & Rao 1966) in a female specimen such carina was not examined ( Suseelan 1985) but however one female specimen with distinct carina extending clearly extends to almost the posterior border of the carapace was reported.

The gene sequences obtained were deposited in GenBank (COI: MG748565View Materials; 16S DNA: MG748566View Materials). The nine species of COI and twenty two species of 16S including one intraspecies sequences of P. alcocki  are retrieved from NCBI database. COI: P. sivado  ( KP759488View Materials & JQ306265View Materials), P. telacantha  ( KP759492View Materials), P. multidentata  ( JQ305978View Materials, FJ581855View Materials & KF931036View Materials), P. planidorsalis  ( KP759483View Materials), P. sirenkoi  ( KP759484View Materials), P. tarda  ( DQ882139View Materials, JQ305981View Materials & AF125439View Materials), P. merriami  ( MF197272View Materials), P. pacifica  ( DQ882135View Materials) and P. hoplocerca  ( JQ306169View Materials). 16S: P. sivado  ( MF279526View Materials & KP725631View Materials), P. telacantha  ( KP725635View Materials), P. multidentata  ( MF279519View Materials), P. planidorsalis  ( KP725624View Materials), P. levicarinata  ( MF279517View Materials & GQ131899View Materials), P. japonica  ( MF279516View Materials), P. sirenkoi  ( MF279525View Materials & KP725625View Materials), P. merriami  ( MF197216View Materials & EU868700View Materials), P. mclaughlinae  ( MF279518View Materials), P. americana  ( MF279511View Materials), P. acutifrons  ( MF279508View Materials), P. sinensis  ( MF279524View Materials), P. diaphana  ( MF279512View Materials), P. aequus  ( MF279509View Materials), P. falx  ( MF279514View Materials), P. romenskyi  ( MF279522View Materials), P. gelasinus  ( MF279515View Materials), P. scotiae  ( MF279523View Materials), P. orientalis  ( MF279520View Materials), P. pseudacantha  ( MF279521View Materials) and P. exilimanus  ( MF279513View Materials). The level of interspecific divergence was observed for COI and 16S sequence, P. alcocki  exhibited high genetic distance range of 18.5% to 27.9% with COI, while with 16S sequences the genetic distance was a comparatively lesser range of 7.4% to 26.4%. Pasiphaea sirenkoi  which showed minimum genetic variation (16S: 7.4% & COI: 18.5%) with the present isolate, P. alcocki  among all the species retrieved. Morphologically, the present specimen showed 10-11 spines on the merus of the 2 nd pereiopod and P. sirenkoi  differed by having 1 spine ( Fig. 1View FIGURE 1, C, F). Intraspecies divergence among P. alcocki  (16S: MF279510View Materials) showed a genetic distance of 21.2%.














Pasiphaea alcocki ( Wood-Mason & Alcock 1891 )

Kuberan, G., Chakraborty, Rekha Devi, Purushothaman, P. & Maheswarudu, G. 2018

Parapasiphae alcocki

Wood-Mason, J. & Alcock, A. 1891: 196