Larvae and Juveniles of Three Japanese Common Gobiid Fishes Reared in Vessels

摘要

Rearing experiments of larvae and juveniles of three Japanese common gobiid fishes, Acentrogobius pflaumi (BLEEKER), Acentrogobius gymnauchen (BLEEKER) and Acanthogobius lactipes (HILGENDORF) were carried out at the Fisheries Experimental Station of Nagasaki University which is situated at Nomozaki near Nagasaki City, Kyushu in 1971 and 1972. The larvae of A. pflaumi newly hatched out from an egg cluster collected from Nomo Bay in Nomozaki were reared in a 30-liter plastic vessel containing sea water at a temperature varying from 26 to 28℃. They were first fed with the rotifer, Brachionus plicatilis and successively fed with nauplii of Artemia sp., the splash copepod, Tigriopus japonicus, wrigglers and chopped clam meat as they grew larger. The newly hatched larvae, ranging from 2.6 to 2.8mm TL, grew to youngs of about 10mm in one month and changed their habits from the planktonic life to the benthic life. The larvae of A. gymnauchen newly hatched out from egg clusters laid in an aquarium were also reared in 30-liter vessels. The larvae, ranging from 1.9 to 2.1mm TL at hatching, were first fed with planktonic larvae of the oyster, Crassostrea gigas and then fed with the rotifer. They were reared for 36 days at the temperature of about 27℃, and the largest one of them grew to a 8.3mm juvenile, but it was still in the planktonic life in the vessel, while a 9.5mm young in a benthic life was collected from a tide pool in Nomozaki. The larvae of A. lactipes newly hacthed out from egg clusters collected from Tameshi near Nomozaki were reared in a vessel of same size as above mentioned at the water temperature varying from 22 to 27℃. The larvae, ranging from 3.6 to 3.7mm TL at hatching, were first with the rotifer and successively fed with Artemia nauplii, the splash copepod and other planktonic copepods collected as they grew larger. The larvae were reared for 38 days and grew about 13mm youngs and they entered from the planktonic life into the benthic life.