Pycnocaris chagoae Bruce 1972
Creators: name: Prakash, Sanjeevi
name: Babu, Idrees
name: Gopi, Mohan
name: Kumar, Thipparamalai Thangappanpillai Ajith
name: Balasubramanian, Thangavel
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Gnathophyllidae
Pycnocaris
Pycnocaris chagoae

description: Pycnocaris chagoae Bruce, 1972
(Figs. 1, 2)
Pycnocaris chagoae Bruce, 1972: 50 –64, Figs. 1 –7; Bruce, 1973: 108; Bruce, 1983: 107, Fig. 1.
Material examined. 1 ovigerous female (tl 8.3 mm, cl 4.2 mm, partly dissected), 1 subadult female (tl 6.2 mm, cl 2.6 mm) India, Lakshadweep, east side of Agatti Island, 10o50’39.75”N 72o11’16.23”E, rocky intertidal, on Labidodemas sp. leg. S. Prakash & M. Gopi, 1 February 2011 (MBRC /ZSI M1-08).
Diagnosis. Small sized gnathophyllid shrimp, body stout, glabrous, slightly depressed, dorsally convex and ventrally flattened. Rostrum short, stout, without dentition, extending almost to the frontal margin of the second article of antennal peduncle (Fig. 2 A). Carapace broadened posteriorly; hepatic and supra-orbital spines absent; antennal spine small, acute, submarginal. Abdominal somites broad, flattened; pleura of the first three somites well developed. Eyes well developed, each with a small accessory pigment spot. Antennular peduncles stout, exceeding the rostrum by the two distal articles. Third maxilliped with an operculiform endopod; medial margin with dense overlapping setae (Fig. 2 B). First pereiopod moderately slender, palm of the chela stout, slightly compressed, tapering distally, fingers strongly compressed (Fig. 2 C); second pereiopods subequal, chela robust, smooth, palm slightly compressed (Fig. 2 D). Ambulatory legs robust; dactylus of third pereiopods stout, strongly compressed, biunguiculate; propodus somewhat compressed (Fig. 2 E). Telson narrow, tapering distally, with straight lateral margins; two pairs of marginal spines present on distal half; posterior margin with two pairs of spines, mesial spines stouter and longer (Fig. 2 F). Uropods without disterolateral spine and diaeresis (Fig. 2 G).
Color pattern. Creamy white or pale yellow, with bright red markings on the chelipeds and ambulatory pereiopods (Figs. 1 A–C), similar to the description in Bruce (1973).
Host. The Lakshadweep specimens were associated with Labidodemas sp., an individual of 19.3 cm total length, of whitish colour with brown podia tips ventrally (Fig. 1 A).
Distribution. Presently known only from the Indian Ocean: Chagos Archipelago; Diego Garcia Island; India: Lakshadweep (Laccadive Archipelago).
Remarks. The discovery of Pycnocaris chagoae in Lakshadweep constitutes the first record of this species in India, and also the first record outside its type locality in the Chagos Archipelago. The present material agrees well with the description of Bruce (1972), except for the presence of two pairs of marginal spines on the distal half of the telson versus four pairs in the type material (cf. Bruce 1972, fig. 4e). The non-ovigerous specimen from Lakshadweep is tentatively considered as a subadult female because of the absence of an appendix masculina on the second pleopod (but see Bruce 1983 for alternative explanation).
description: Published as part of Prakash, Sanjeevi, Babu, Idrees, Gopi, Mohan, Kumar, Thipparamalai Thangappanpillai Ajith & Balasubramanian, Thangavel, 2011, Discovery of the shrimp Pycnocaris chagoae Bruce, 1972 (Decapoda: Caridea: Gnathophyllidae) in the Lakshadweep Archipelago, India, pp. 66-68 in Zootaxa 2998 on pages 66-67, DOI: 10.5281/zenodo.205342