NATURAL SPAWNING AND SCALING UP OF LIVE SUCKER SHARK Echeneis naucrates IN CAPTIVITY
Echeneis naucrates commonly known as live sucker shark, one of the most common remoras found around the tropical and subtropical waters.This fish belongs to the family Echeneidae. The live sucker sharks (1Male:1Female) were maintained in the marine aquarium for a few years and the fishes were well acclimatized to the tank. They exhibited courtship and breeding behavior during the middle of June 2018, and within one week the female started laying eggs. During the courtship, male accompanied female to the surface repeatedly and within 10 minutes eggs and milt were released simultaneously. Fertilized eggs so obtained via the volitional spawning hatched out within 65 hrs of spawning. Water quality parameters in the spawning tank were within the optimum range, temperature 270C, pH-7.5 and Salinity- 35-37ppt. Approximately, 2760 eggs were spawned by the female fish on the first day of which 85% hatched out. The eggs are large sized (2.5mm), transparent and pelagic in nature and clearly visible to naked eye. The fish is a batch spawner and spawned continuously for 26 days. The fishes had shown a diel spawning periodicity, every day at the evening time. The fecundity of the fish was estimated to be 68000. Observations were recorded from the eggs to the larval stages of sucker shark with special emphasis on the development of sucker. The size of the newly hatched larvae ranged from 8.6 mm-9 mm. Sucker development started from 8 DPH onwards when the fish attained a total length of 17-19mm and caudal fin was largest in its ratio of total length. Disc development was completed on 19 DPH (32mm TL) and juvenile started to lie on its abdomen and continue this posture until its attachment life starts. The larvae were successfully reared for 40 days till it reached 42 mm SL. This is the first report of natural spawning and larval rearing of live sucker shark in captivity from Indian waters.
