A specimen of Lactarius lactarius 330 mm total length was recorded from

a drift net catch at Pamban (Gulf of Mannar). The largest specimen of this

species recorded so far had only 23 rays in the anal fin as against 72-28 rays

in the normal specimens

Shanmugavelu, C R

CMFRI Digital Repository

ON THE LARGEST SPECIMEN OF BIG-JAWED JUMPER, LACTARIUS LACTARIUS (SCHNEIDER) C. R. SHANMUr;HAVELU Central Marine Fisheries Research Institute; Regional Centre, Mandapam Camp A specimen of Lactarius lactarius 330 mm total length was recorded from a drift net catch at Pamban (Gulf of Mannar). The largest specimen of this species recorded so far had only 23 rays in the anal fin as against 72-28 rays in the normal specimens. Lactarius lactarius is quite common along the south eastern coast of India and fairly large numbers are landed by trawl and drift nets. It is re-ported to attain a size of 250-280 mm (Appa Rao, 1966; Day, 1889; Munroe, 1955; Weber and de Beaufort, 1931). During the course of the investigation on the biology of this species the author came across many speqimens ranging from 300-330 mm in total length. The largest specimen measuring 330 mm in total length obtained on 26-8-1967 (C.M.F.R.I. F-86|232 e) from a drift net operated in the Gulf of Mannar (Pamban) at a depth of 22 metres showed an interesting variation in the number of anal rays and a brief description of the specimen is given below. Total length 330 mm; Standard length 267 mm; Height of body 3.47 in T.L. (2.81 in S.L.); Length of head 3-47 in T.L. (2.81 in S.L.); Length of snout 4.13 in head; Eye diameter 4.52 in head, slightly less than snout. The largest specimen resembled a normal specimen in all the morpho-metric and meristic characters except the number of anal rays. In the anal fin only 23 rays were noticed whereas a normal specimen possesses 27-28 rays. The arrangement of the first 16 rays in the anal fin is normal with their usual basal articulation with the pterygiophores. The 17th ray, which is slender and small, is free in the anal membrane without articulation to the pterygiop-hore. A large gap measuring 13 mm was noticed between the 17th and the succeeding anal ray. Although the anal membrane is entire at this region no rays are seen. Except for this anamoly the shape and size of the anal fin is normal. The absence of a few anal rays in the middle of the fin is probably due to some minor injury to the fin at this region. The 17th ray reveals partial regeneration but the missing 4 or 5 rays have failed to regenerate. NOTES 24S A reduction in the number of rays in the anal fin of this species has been noticed by Day ( 1 8 8 9 ) . H e remarks that in many specimens taken in Malabar the anal rays were invariably 26, but amongst several taken in Madras there were in all instances 28. So far as the author is aware this appears to be the first instance where a reduction in the number of anal rays due to com-plete absence of few rays in the middle of the fin has been noticed. The author is grateful to Dr. R. V. Nair, Deputy Director for helpful suggestions in the preparation of this note. APPA RAO, T . 1966. Indian J. Fish., 13:334-349. DAY, F . 1889. Fauna of British India, Fishes, 2:195-196. MUNROE, I. S. R. 1955. The Marine And Freshwater Fishes of Ceylon. 122 pp. WEBER, M . AND L. F . D E BEAUFORT. 1931. The Fishes of Indo-Australian Archipelago, 6:306-308. ON THE OCCURRENCE OF THE DEEP SEA STING RAY, UROTRYGON DAVIESI WALLACE IN INDIAN WATERS R. V. NAIR AND R. SOUNDARARAJAN Central Marine Fisheries Research Institute; Regional Centre, Mandapam Camp The deep sea sting-ray, Urotrygon daviesi Wallace, caught off Mandapam in the Gulf of Mannar, is recorded for the first time from the Indian waters. A detailed description of the fish, based on a young female, 534 mm in length, is given. Till recently no representative of the family Urolophidae was known from the Indian Ocean and the rays of this family were restricted in their distribution to the Pacific and Western Atlantic Oceans- The occurrence of the family in the Indian Ocean was reported for the first time by Wallace (1967) when he described Urotrygon daviesi, a new species, trawled off Lim-popo River mouth, Portuguese East Africa. According to him this species is not common even in the type locality in Portuguese East African waters and 

Largest specimen of big-jawed jumper,

Lactarius lactarius (Schneider)

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Largest specimen of big-jawed jumper, Lactarius lactarius (Schneider)

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