タチウオ類の1新種, Lepidopus calcarの記載を行った.本種はハワイ海嶺のコラハン海山の水深270～350mのところから採集され, 強いトゲ状の啓鰭第2棘を有することで他のLepidopus属魚類 (成魚) と区別できる.本種の脊椎骨数と背鰭鰭条数はL.caudatus (Euphrasen) のものより少なく, L.xantusi Goode et BeanおよびL.dubius Parin et Mikhailinのものよりも多い.
Opisthocentrus ocellatus (Tilesius, 1811), a stichaeid species attaining a size of about 22 cm TL, is known north from Kamchatka, Sakhalin and Peter the Great Bay south to Wonsan, Korea and Japan.In Japanese waters it has been recorded from Hokkaido, Mutsu Bay, Aomori Pref., Sado Island, Niigata Pref, and Himi, Fukui Pref.In Mutsu Bay, this species inhabits shallow waters from inshore Zostera beds to depths of 30-50 m.From Hokkaido specimens have been collected from depths of more than 300 m.Mature males have a conspicuous nuptial coloration and greatly prolonged dorsal spines along the entire length of the fin except for the posteriormost 7-12 pungent spines.In the stomach of specimens collected from Zostera beds in Mutsu Bay, gammarids, caprellids, small limpets and ostracods are mainly found.In the bay the spawning season extends from early December to mid January, when the water temperature falls to 5°-10°C. In spawning experiments carried out in December, 1978 and January, 1979 in an aquarium, spawnings took place in empty scallop shells, in a horizontal hole of a concrete block, or under a net set on the bottom at dark corners of the aquarium.In all of the five spawnings observed, females encircled their egg masses and guarded them until the eggs hatched.In natural grounds, 5-6 m deep, at Moura, Mutsu Bay, egg masses were found in narrow cavities under stones on muddy sand bottoms.The egg masses were guarded by females in the same manner as in the aquarium.The eggs are spherical and translucent, 1.89-2.01 mm in diameter.Eggs adhere to each other at their adhesive points and form an egg mass.The yolk is colorless and contains a large light yellow oil globule and many small ones.A white cloudy substance surrounds the large oil globule.In the rearing experiment in 1979, larvae hatched from natural egg masses were reared for 35 days in a vessel.Newly hatched prolarvae were 9.0-10.0 mm TL.In about 23 days they absorbed yolk and grew to 12.7 mm TL.Young fish, 33.0-40.0 mm TL, were collected from Zostera beds at Shirasu, Mutsu Bay with a small trawl-net in late May, 1979.The fish grows to 6-11 cm TL in one year and matures at a size of about 10cm TL in both sexes.Life span of the fish is two years or, in a few cases, three years.
Morphological development of jack mackerel, Trachurus japonicus (Temminck et Schlegel) is described from 196 specimens reared from eggs to juveniles in the laboratory at Tosa City, Japan.The egg is spherical in shape, and of moderate size, 0.87-0.90mm in mode.It is characterized by a light brownish oil globule, 0.17-0.22mm in diameter, and a narrow perivitelline space.During the late stages of embryonic development, the oil globule becomes situated rather close to the head, and on hatching is immediately under the forward part of the head.Hatching takes place about 40 hours after fertilization at water temperatures 20-22°C. The newly hatched larvae are 2.3-2.5mm in total length, with 18-21 (8-10+10-11) myomeres.The most characteristic feature of the larvae is the extension of the anterior end of the yolk sac beyond the anterior margin of the head.On the 4th day after hatching the body reaches approximately 3mm in length, and the yolk material has been absorbed. During the early postlarval stage, the caudal rays, the base of 2nd dorsal and anal fins begin to develop, the body attaining a length of about 6mm.The preopercular spines appear for the first time in the 7th day when the larvae reach about 3.4mm in length, and increase in size and number during larval development.During the late postlarval stage, the body is elongated to approximately 13mm in length.The 1st dorsal and pelvic fins are becoming evident at the end of this stage, the 29th day after hatching. Soon after reaching the early juvenile stage, the preopercular spines become less conspicuous and have almost disappeared at the end of this stage.Small scutes developed along the lateral line can be observed in individuals as small as 19mm in length.Both the scutes and body scales are well developed in individuals longer than 26.5mm in length.At the late juvenile stage, complete number of rays is present in the pectoral and caudal fins.The juveniles attain about 55mm in length at the end of this stage, about 60 days after hatching.
A total of 70 larvae and juveniles of Cryptacanthodes bergi (Cryptacanthodidae, Blennioidei) were collected by a fish larva net towed off the east coast of Aomori Pref.in the northwestern Pacific Ocean.The larvae and juveniles, measuring from about 15 to 31.5 mm TL, were collected at the sea surface from March to June, mainly by night hauls.In a 18.0mm TL postlarva, the body is elongated and compressed.The anus opens a little ahead of the midpoint of the body.The eyes and pectoral fins are large.The body is densely pigmented along each myotome except for the abdomen and caudal peduncle.Along the middorsal line, there is a longitudinal white area which is wider anteriorly.The myotome count is 74 (24+50).In a 30.0mm TL juvenile, the body is much elongated and compressed, and the eyes and pectoral fins are relatively small.The lower jaw protrudes beyond the upper jaw and forms a wry mouth.The pelvic fins are absent.Head sensory canals are not well developed and have some outer openings. A gravid female, collected on Oct.6, 1977, from muddy bottom at a depth of 50-60m in Mutsu Bay off Aomori City, has 249 maturing orange yellow eggs measuring 1.7 to 2.2mm in diameter.Its ovary is a single type. A similarity in the distribution of melanophores between larvae of C.bergi and Zaprora silenus (Zaproridae) was detected.