Osame Tabeta

A pre-leptocephalus larva of Conger myriaster (family Congridae) collected from Suruga bay, Central Japan

One specimen of leptocephalus larva, measuring 16.0 mm in total length, was collected from the northern part of Suruga Bay (34°56′N, 138°39′E) by the T/V Bosei Maru II of Tokai University on November 7, 1982. This larva is identified asConger myriaster because of having melanophores under the eye, simple gut with melanophores, 142 total number of myomeres and the position of the last vertical blood vessel at the 52nd myomere. Judging from the body length, appearances of teeth and fins, and disposition of the anus, the present larva belongs to the preleptocephalus stage. The presence of this early larva in this area suggests that one of the spawning grounds ofC. myriaster exists in or near Suruga Bay in autumn.

The Glass Eel

During metamorphosis from the leptocephalus larva to glass eel, which occurs before entering freshwater, eel larvae undergo marked changes in the somatic structures from the leaflike shape of the leptocephalus to the adult-like shape of the glass eel. “Glass eel” is defined here a developmental stage from the end of metamorphosis in the leptocephalus to the beginning of pigmentation (stage VA-VI A; Tesch 1977). Following this stage the young eels are called “elvers” (Tesch 1977). The glass eels and elvers are regarded as the same category at times when they are variously referred to as glass eels, elvers, and juveniles, and are often undistinguishable in the literature.

Pufferfishes and Recent Pufferfish Fisheries in Cheju Island, Korea.

A total of 15 species of pufferfishes belonging to the five genera were recognized in the collections of the Cheju National University Museum (CNU), Ocean Research Institute (CNU), the National Cheju Fisheries Laboratory, and the Cheju Folklore and Natural History Museum, and at the Cheju Fish Market, fish culture ponds, and pufferfish restaurants in April 1992. Lagocephalus gloveri, L. wheeleri, Takifugu reticularis, Diodon liturosus, and Arothron firmamentum were the additional species to the pufferfish fauna of the island. The pufferfish catch in Cheju Is. (1, 166t) stood first in total pufferfish catch in Korea (5, 230t) in 1991. They consisted mainly of T. xanthopterus (ca. 94%), followed by T. rubripes and T. chinensis (ca. 4%) and Lagocephalus spp. (ca. 2%). Almost all of T. xanthopterus were caught with long line in the East China and Yellow Seas in early summer and autumn, while T. rubripes and T. chinensis were caught with long line in the waters around Cheju Is. from autumn to winter.

Distribution and ecology of the swellfish Lagocephalus lunaris (Bloch et Schneider) in the East China SEA.

Over 500 samples of the toxic swellfish Lagocephalus lunaris (BLOCH et SCHNEIDER) were taken with pair trawlers and large-and medium-sized purse seiners in the shallower waters less than 200m depth south of 32°N in the East China Sea in 1980-1985. Examination of the gonads indicated that the spawning season was in the early summer in the southern and continental side of the Sea and the spawning fish were more than two years old. The fish reached about 18cm BL at the end of the year, about 25cm in one year and about 30cm BL in two years from their birth based on their size frequencies. Swellfish less than 20cm BL formed more than 90% of the total catch with the pair trawlers and concentrated in the central area of the Sea between Octo-ber and December in 1983. The swellfisb were inferred not to be schooling in the fishlng ground. The catch with pair trawlers varied from year to year; the prominent occurrence, which was less than 1 ton, was in April 1983-March 1984. The location of capture of the sewllfish L. lunaris differed mazkedly from the fishing ground of the swellfish L. gloveri which is the main catchable stock of the genus Lagocephalus in the Sea.