On 16-2-'94 a female Hump - back dolphin Sousachinensis (Osbeck)measuring 2.235 mm and weighing 80 kg was accidently caughtin drift gillnet off Tuticorin. When the dolphin was cut openeda foetus measuring 250 mm was obteilned from i

Arumugam, G

Balasubramanian, T S

Chellappa, M

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ISSN 0254-380 X ICAR No. 138 MARINE FISHERIES INFORMATION SERVICE JUNE - JULY 1995 ^m^^mmmmmmmmmmm$mmmi^^^^a^^^^^^^m s^mhmmmm UMGmUm^ W ^ T ^ S i ^ ^ ^ TECHNICAL AND f ^ F r T H : 3 f ^ 5 T ^ c ^ EXTENSION SERIES %7^cr F i iT^ TUTT¥Q^ CENTRAL MARINE FISHERIES ar^duT^ TT¥e:Tr? RESEARCH INSTITUTE ^f^^, I^TcT COCHIN, INDIA INDIAN COUNCIL OF AGRICULTURAL RESEARCH A NOTE ON THE FOETUS OF THE HUMP-BACK DOLPHIN FROM TUTICORIN COAST, GULF OF MANNAR* Very few reports are available on the foetuses of dolphin. On 16-2-'94 afemale Hump - back dolphin Sousachinens(s (Osbeck) measuring 2.235 mm and weighing 80 kg was accldently caught in drift gillnet off Tuticorin. When the dolphin was cut opened a foetus measuring 250 mm was obteilned from it (Fig. 1). The foetus was more or less a perfect replica of the adult dolphin except that it possessed the umbllcal cord. The beak of the foetus was at 152° to trunk, eyes opened, teeth not sprouted but tender teeth gums were clearly visible, dorsal fin emd caudal fluke well developed, genital and anal opening far apart, umbllcal cord robust, 150 mm long with papillae like processes arranged in rows, body uniformly light brown, few black patches on vertical side, skin very delicate and tender and bristles absent on beak. Morphometric measurements of the foetus are given in Table 1. Fig. 1. The foetus of dolphin Sousa chinensis. TABLE- 1. Morphometric measurements fmrn/o/Sousa chinensis off Tuticorin Tip of upper Jaw to notch of fluke 250 Tip of upper Jaw to centre of eye 43 Tip of upper Jaw to apex of melon 41 Tip of upper Jaw to angle of gape 30 Tip of upper Jaw to external auditory meatus 51 Centre of eye to angle of mouth 15 Centre of eye to external auditory meatus 15 Centre of eye to centre of blowhole 26 Tip of upper Jaw to blowhole 40 Tip of upper Jaw to anterior insertion of flipper 60 Tip of upper Jaw to tip of dorsal fin 175 Tip of upper Jaw to mid point of umbllcus 126 Tip of upper Jaw to geniteil aperture 154 Tip of upper Jaw to centre of anus 170 Length of flipper (anterior insertion to tip) 45 Length of flipper (axilla to tips) 30 Width of flipper (maximum) 16 Height of dorsal fln 15 Width of fluke (tip to Up) 54 Length of umbilical cord 150 Number of bristles on the beak Absent Angle of the beak to the trunk 152° Weight 240 gm Sex Female * Prepared by G. Ammugam, T.S. Balasubramaniam and M. Chellappa, Tuticorin Research Centre of CMFRI, Tuticorin - 628 001. 14 Lai Mohan (1982) estimated the age of foetus of 241 mm of T. adimcus as 2'/2 month, that of 91 mm foetus to be about 1 month and the 471 mm foetus of S. plumbea as 5'/j month old. By comparing the size of the present foetus of S. chinensis it is presumed that the age would be between 2V2 - 3 month old. Based on the gestation period and the age determined for the foetus, the mating season of S. chinensis is likely to be during October - November as a 2'/2 - 3 month old foetus was collected during February along the Tuticorln coast. But this could be confirmed beyond doubt if only some more reports are avEillable on this aspect. Such endangered animals have to be protected. Fishermen should be educated to save such entsmgled specimens by releasing them back Into the sea. OBSERVATIONS ON A WHALE SHARK RHBVODOJV TYPUS SMITH CAUGHT AT ATHANKARAI ALONG THE PALK BAY COAST, TAMIL NADU* On 26.10.92 a large specimen of whale shark Rhinodon typus Smith was caught in a shore-seine at Athankarai in live condition but died the next day. The net was badly damaged by the whale shark. As there was no demand for its flesh, the fish was cut into pieces and buried near the sea shore. The morphometric measurements of the whale shark (cm) are given below: Body characters Measurements (cm) Total length (tip of snout to tip of caudal fin) 1,022 Tip of snout to origin of pectoral fin 204 Tip of snout to centre ridge 35 Length of pectoral fln 210 Tip of snout to first gill opening 148 Tip of snout to last gill opening 217 Length of upper caudal fluke 225 Length of lower caudal fluke 129 Head length 240 Width of head Tip of the snout to eye Length of mouth opening Eye diameter Eye length Tip of snout to spiracle Length of spiracle Width of spiracle Height of first dorsal fln Tip of snout to caudal fluke Height of first gill opening Height of second gill opening Height of third gill opening Height of fourth giU opening Height of fifth giU opening Weight Sex 224 65 145 4.5 6.5 95 4.5 3.3 153 822 81 94 87 80 60 5 t Male ' Reported by C. Kaslnatban and N. Ramamoorthy, Regional Centre of CMFRI, Mandapam Camp - 623 520. 15 

A note on the foetus of the hump-back dolphin from Tuticorin coast, Gulf of Mannar

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A note on the foetus of the hump-back dolphin from Tuticorin coast, Gulf of Mannar

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