セジロハゼの生活史

• Main Authors: 塩垣 優, 道津 喜衛
• Format: Report
• Language: Japanese
• Published: 長崎大学水産学部 1972
• Subjects: Snyder; Copepods; Rotifer
• Online Access: http://hdl.handle.net/10069/30890; https://nagasaki-u.repo.nii.ac.jp/?action=repository_uri&item_id=8164; https://nagasaki-u.repo.nii.ac.jp/?action=repository_action_common_download&item_id=8164&item_no=1&attribute_id=18&file_no=1

The gobiid fish, Clariger cosmurus Jordan and Snyder, is a elongate 3-spined goby, growing to 40mm in full grown size, and inhabiting along the coast of Japan. It lives among gravels and stones lying in tidal zones and tide pools on the rocky shore. It feeds on crustaceans comprising gammarids, copepods and mysids. The squamations of the fish varied by individual and the squamation patterns were divided into 4 types as shown in Fig.2. Three egg masses deposited on the underside of the stones lying in the rocky shore of Nomozaki (Lat. 32° 35.3' N, Long. 129° 45.5' E) were collected in April 1972. The egg number of the egg masses ranged from 99 to 159. Each egg mass comprised the eggs in the same developmental stage. In one spawning, the male parent guarding over the egg mass was collected from the nest below the stone. The eggs were demersal adhesive ones and short club shaped and ranged from 2.73 to 3.00mm in long axis and 0.91 to 1.02mm in short axis. The yolk was orange yellow in color. The newly hatched larvae each provided with 32 to 34 myomeres ranged from 4.25 to 4.45mm in total length. The larvae numbering about 200 hatched out from the egg masses collected were kept in a plastic vessel of 30 liters and reared for 68 days. They were first fed with the rotifer, Brachionus plicatilis and next with the mixture of the nauplii of the brine shrimp, Artemia salina, the planktonic copepods from the sea and the splash copepod, Tigriopus japonicus. One of the larvae grew to an 18.0mm young during the rearing period in the vessel. In the course of the rearing experiments, the larvae first spent the planktonic life for about 40 days and entered into bottom life at the early juvenescent stage of about 11mm long. From the examination of the collected specimens, it seemed that the fish in Nomozaki grew to the mature length of over 30mm in a year and the spawning period there extended from late March to late June.