Uranoscopus crassiceps Alcock, 1890

Pradhan, Alakesh, Maji, Debarghya, Mahapatra, Bijay Kali & Mishra, Subhrendu Sekhar, 2019, First report of stargazer Uranoscopus crassiceps (Alcock, 1890) (Perciformes: Uranoscopidae) from Digha coast, India, Records of the Zoological Survey of India 119 (1), pp. 91-94 : 91-93

Uranoscopus crassiceps Alcock, 1890

1890. Uranoscopus crassiceps Alcock, Ann. Mag. Nat. Hist. (Ser. 6) 6 (33): 205 (Type locality: Off Madras coast, India, 18°30’N, 84°46’E) .

Material and Methods

Fishes are collected mainly from commercial trawlers. After collection of specimens, photograph was taken and then preserved in 5% formaldehyde. Taxonomic identification of the specimen was based on the original description ( Alcock 1890), and the redescription of the species from Oman ( Fricke et al., 2013) and other standard literatures. Measurements and counts of the examined specimens follow Fricke et al. (2013). All the measurements were done by Mitutoyo digital calliper to the nearest 0.01 mm ( Table 1) and photographs taken by Sony DSC-W800 camera. Fishes are deposited in the Zoological Survey of India, Kolkata. In this paper, specimens collected from off the northeast coast of India are presented as a new record from Dighacostal waters.

Material: ZSI/F11925/2, 1 ex., 147.31 mm SL, Locality: Mohona, Digha (21º 37′ 48′′N and 87º 32′ 45′′E), 12-09- 2016, Dr.B. K. Mahapatra.

Comparative material: ZSI F 12788, 1 ex. (Holotype),

133.75 mm SL, off Chennai coast, India, 04-03-1890, F.W. Alcock .

Diagnostic Characters: D V + iii, 11; A i,13; P i,17; V I,5. Head large and flattened; dorsal and lateral surfaces almost entirely encased in minutely sculptured bones; anterior part of body broad, depressed, but tapering and compressed posteriorly. Head length 2.44 times in SL; body depth 4.56 times in SL. Eyes large, directed dorsally; its diameter 7.62 times in HL. Interorbital fossa semicircular, longer than broad, including posterior half of interorbital space and its length 14.66 in SL. Mouth large, protactile, strongly oblique, with fringed lips; teeth in jaws small, conical, in two series; one series of widely separated caniniform teeth on premaxillary and dentary; nostrils with short tubiform valve. Humeral spine obliquely directed upwards; lower edge of operculum with 5 spines; 2 pairs of short, forwardly directed spines under head. Scales arranged in 52 oblique rows, breast and belly naked. Tubiform scales embedded along lateral line. Lateral line positioned dorsally, bending down on caudal peduncle to continue in an extension of the central two caudal-fin rays, extending along the basal one-third of those rays. First dorsal fin with 5 spines, 1-4 th is well developed, connected by membranes and 5 th one is rudimentary, covered by skin; second dorsal fin segmented and unbranched; anal fins fleshy and thickened. Pectoral fin broad, dorsoposterior margin truncate with 1 unbranched and 17 soft rays, anal fin with 13 soft rays and caudal fin distally convex. Pelvic fins situated on isthmus with 1 feeble spine and 5 soft rays. Single pair of basipterygial processes widely separated. Joints of head bone elements marked by deep channels. Post-interorbital knobs absent. Two occipital lobes developed.

Dorsal parts of head and body brown, belly, thorax and pectoral-fin base white, eyes dorsally blackish brown, laterally yellowish green. Two pale brownish bands are at the first dorsal fin base and other one is at the second dorsal fin ray base near to caudal peduncle. First dorsal fin black, base of first and second spines reddish brown, fourth membrane white. Rays of second dorsal and anal fins yellowish brown, membranes translucent. Caudal fin rays dark brown, membranes in dorsal half dusky. Upper half of pectoral fin slightly transparent, lower half greyish brown. Pelvic fin whitish brown. In preserve condition head and body dorsally dark brown, laterally brown, ventrally white with light brown shades. Yellowishbrown, and greyish-brown shades band on dorsal half no longer visible.

Distribution: Indian Ocean: off northern Somalia, and southern Yemen (Gulf of Aden) ( Norman, 1939); Oman (Arabian Sea) ( Fricke et al., 2013); India: east coast and southwest coast. In India, it has been reported from Tamil Nadu ( Alcock, 1890; Barman et al., 2011), Odisha ( Barman et al., 2007) and off Southwest coast of India in the Indian EEZ ( Sidharthan et al., 2017).

Remarks

The counts and measurements agree with the Holotype, range of larger adult specimens described by Fricke et al. (2013) and that of Sidharthan et al. (2017). The head is slightly bigger (2.44 in SL) compared to the proportion observed by Fricke (2.7-2.9 in SL) and slightly smaller than that of Alcock (2.34 in SL). According to Fricke et al. (2013), U. crassiceps and U. guttatus from the southern Red Sea and eastern India have a similar body colouration, but U. crassiceps is distinguished from U. guttatus by narrower head width (1.07-1.10 vs. 1.4 % head length), absence of post-interorbital knobs (present in U. guttatus ), and 41- 54 lateral scale rows (55 in U. guttatus ). The only other species of this genus occur along the coastal region of West Bengal and Odisha is Uranoscopus cognatus Cantor which can be distinguished from U. crassiceps in having three pair of short forwardly directed spine under head (vs two pairs) and yellow coloured caudal fin (pale in preservation) against dark brown caudal fin in U. crassiceps .