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Volume 30, Issue 1
Displaying 1-11 of 11 articles from this issue
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Akihisa Iwata1983 Volume 30 Issue 1 Pages 1-9
Published: May 15, 1983
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe cottid fish genus Vellitor is represented in Japan and Korea by two species, V. centropomus (Richardson) and V. minutus sp.nov. The genus is characterized by the strongly compressed and deep body, the large acute head, the slender caudal peduncle and by the absence of spines and cirri on the dorsal surface of head. V. minutus is distinguished from V. centropomus by the number of pectoral fin rays (V. minutus, 18-20: V. centropomus, 13-16) and shape of this fin (V. minutus, rounded: V. centropomus, bilobate). The two species show clear isolation in their habitat preferences.View full abstractDownload PDF (1476K) -
Ronald Fricke, Heiko Brunken1983 Volume 30 Issue 1 Pages 10-14
Published: May 15, 1983
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSA new species of cottid fish, Stlengis mesembrinus collected from Indonesia, is described. It is distinguished from other species of this genus by its lateral line scale row of 29 scales, the additional row of 9 small dorsal scales, its large eye, its eight spines in the first dorsal fin, 13 rays in the second dorsal fin, 10 anal fin rays, and by its color pattern (e. g., first dorsal fin translucent, with several irregular darkish streaks). The present species is compared with the Japanese members of Stlengis and with the species of Antipodocottus known from the Tasman Sea and New Zealand; the origin of the present species is discussed.View full abstractDownload PDF (3448K) -
Uday Raj, Johnson Seeto1983 Volume 30 Issue 1 Pages 15-17
Published: May 15, 1983
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSPlectranthias fijiensis, a new anthiine fish species from Fiji is described and illustrated from a single specimen.This species is distinguished from other members of the genus by possessing some branched pectoral rays, preopercle edge without serrae or spines, snout without scales dorsally or laterally, and some canine teeth in both jaws.View full abstractDownload PDF (469K) -
Mamoru Yabe1983 Volume 30 Issue 1 Pages 18-26
Published: May 15, 1983
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSMarukawichthys pacificus captured from the Emperor Seamount Chain in the central North Pacific is described as a new species in the family Ereuniidae.It is the second species of the genus Marukawichthys and closely related to M. ambulator Sakamoto, from which it differs in having a narrower interorbital space, longer upper jaw, chin with smooth skin, greater number of gill rakers and vertebrae, and uniformly dark brown body color.This species is the first cottoid to be recorded from the Emperor Seamount Chain.View full abstractDownload PDF (1372K) -
Kenji Mochizuki, Shojiro Fukui1983 Volume 30 Issue 1 Pages 27-36
Published: May 15, 1983
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSUpper jaw teeth of Sicyopterus japonicus are examined regarding their shape, development and replacement.The fish has a row of functional teeth and ca. 23 rows (31 mm SL) to ca. 40 rows (85 mm SL) of replacement teeth on their upper jaw. Replacement teeth shift their position in the gum with development, and at the last stage of their development a small bone is formed at the base of each tooth. Replacement teeth with the small basal bones completed move downward in the gum and set firmly on the premaxillary to become functional teeth. Old functional teeth replaced by new ones are gradually resorbed in the tissue of the upper jaw in the process of entering into a crevice of the premaxillary, and finally completely disappear. This resorption suggests that there is a possibility of the reuse of their components to produce new teeth. This replacement occurs every 9.2 days when the fish size (SL) increases 0.12 mm per one day (1.1 mm per 9.2 days). The fish probably needs tooth replacement frequently and resorption of the teeth because the upper jaw teeth wear out rapidly when feeding by scraping algae from the surface of stones with its teeth.View full abstractDownload PDF (11041K) -
Masanobu Matsuoka, Tamotsu Iwai1983 Volume 30 Issue 1 Pages 37-46
Published: May 15, 1983
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSAdipose fins of 33 species belonging to the Salmoniformes, Cypriniformes, Siluriformes and Myctophiformes were studied. Cartilaginous structure was found in the base of the adipose fin in 14 species of the Salangidae, Osmeridae, Plecoglossidae, Myctophidae and Neoscopelidae.In the Osmeridae, the cartilaginous structure can be divided into two types: a rather large slender cartilage observed in Spirinchus, and a small pear-shaped cartilaginous structure observed in Thaleichthys, Osmerus and Hypomesus. The former is similar to that of the Salangidae. The latter is similar to the cartilage of the Plecoglossidae in shape and location. In the Myctophidae and Neoscopelidae, cartilage and chondroid tissue are ventrally inserted in the underlying muscle layer, and different from the cartilaginous structure found in three families of the Salmoniformes in morphological characters.
As far as it was observed, no cartilaginous structure was detected in the adipose fin of fishes belonging to the families Salmonidae, Retropinnidae, Prototroctidae, Aulopodidae, Synodontidae and Chlorophthalmidae, suborders Argentinoidei and Characoidei, and the order Siluriformes.View full abstractDownload PDF (10853K) -
Hiroshi Kohno, Yasuhiko Taki, Yoshimitsu Ogasawara, Yoshioki Shirojo, ...1983 Volume 30 Issue 1 Pages 47-60
Published: May 15, 1983
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDevelopmental sequences of characters concerned in swimming and feeding functions were investigated in the laboratory-raised larvae of Pagrus major. The finfold of early larvae was completely separated at 6.50 mm in notochord length (NL). The vertical fins developed earlier than the paired fins; the formation of dorsal, anal and caudal fin-supports and fin-rays started by 5.90 mm NL and their principal adult complements were attained by 6.50 mm NL, whereas an adult complement of fin-rays was attained at 9.40 mm NL in the pectoral fins and not attained by 10.15 mm NL, the largest size we examined, in the pelvic fins.In the vertical fins the development of the caudal fin preceded that of the dorsal and anal fins.The flection of the notochord end started at around 5.00 mm NL and was completed at about 6.50 mm, at which the angle of flection was 40°-50°. The body became increasingly deep in relation to NL up to about 6.50 mm NL, after which the depth maintained an almost steady ratio to NL. These pat-terns of development suggest that the larvae of P. major shift their mode of swimming from less active larval movement to active caudal propulsion at sizes between 5.00 mm and 6.50 mm NL.
As for feeding-related characters, the premaxillae appeared at 4.35 mm NL and came to occupy most of the upper jaw margin as in adults at about 7.00 mm NL. The formation of teeth started earlier on the upper and lower pharyngeals than on the premaxillae and dentaries. How-ever, a more or less abrupt increase in number of teeth occurred at about 7.00 mm NL irrespec-tive of regions. Observations on these characters indicate that the larvae of Pagrus major change their mode of feeding from swallowing to biting at sizes between 5.00 mm and 7.00 mm NL.
Incorporating these findings and our observations on the behavior of larvae, three stages may be recognized according to the mode of swimming and feeding in Pagrus major larvae. They are: 1) the early stage with less active swimming and feeding by swallowing prey (to about 5.00 mm NL); 2) the transitional stage (to about 6.50-7.00 mm NL); and 3) the advanced stage with swimming by caudal propulsion and feeding by biting prey (about 6.50-7.00 mm NL and larger).View full abstractDownload PDF (4484K) -
Tetsuo Kuwamura1983 Volume 30 Issue 1 Pages 61-71
Published: May 15, 1983
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSReproductive ecology and ethology of Apogon notatus were studied in the shallow coastal waters of Shirahama and Sakura-jima, southern Japan. Male/female pairs began to separate from large aggregations as early as two months before the beginning of the spawning season. The pair stays at its home site during the daylight hours of each day, attacking and chasing other conspecifics approaching it. The female often displays “warping” to her male partner, but the latter exhibits no active display. In the early morning of the day of spawning, the female initiates the prespawning process, and after “parallel-circling” by the pair an egg mass is spawned in the parallel position between 11: 00 and 15: 00.The male takes the egg mass in his mouth within a few seconds after spawning.External fertilization occurs in the male's mouth within a few minutes after spawning, during the “rapid-circling” by the female.Both conspecifics and other fishes often interfere with the spawning process.Causal factors in the spawning process of A. notatus and the sex of the egg-incubating parent in Apogonidae are discussed.View full abstractDownload PDF (4892K) -
Kazumasa Uematsu, Takashi Hibiya1983 Volume 30 Issue 1 Pages 72-80
Published: May 15, 1983
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSWe examined histologically the reproductive ducts of thirteen species of teleosts and found distinct striated muscle fasciculi surrounding the reproductive duct and the ureter only in both sexes of chum salmon, Ayu, carp and goldfish.Although the musculature, unlike the sphincter of mammals, are not tubi-form, their ventral (in salmon) or ventral and dorsal (in Ayu) gaps are filled with dense connective tissue, or the two ducts are enclosed with the fasciculi and the intestinal wall, which are connected with each other with loose connective tissue (in carp and goldfish).Furthermore, muscle fibers run circularly around the two ducts.These arrangements imply a possibility that it acts as a sphincter of the ureter usually and as that of the reproductive duct during the spawning season.In other fishes, most of which are more advanced teleosts than the above four species of fishes, the sphincter-like musculature was not found, but other presumptive sphinctering structures exist.Considering our results, sphinctering mechanisms for the two ducts are assumed to have changed several times with the evolution of the teleosts and the musculature found in the present four species of fishes is probably one of the most primitive systems.View full abstractDownload PDF (15096K) -
Shoichi Suga, Yasuhiko Taki, Koji Wada1983 Volume 30 Issue 1 Pages 81-93
Published: May 15, 1983
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSFluoride concentration in the teeth of 78 perciform species from both marine and freshwater environments was investigated by means of quantitative analysis using electron microprobe.In almost all the species examined, the fluoride concentration was more than 2.0 in enameloid and less than 0.6 % in dentin and bone.This level of concentration in the enameloid is almost equal to that in the enameloid of balistoid species and much higher than in the enameloid of tetraodontoid species and the cypriniform Cyprinus carpio (less than 0.2 %).The fluoride concentration in the perciform enameloid showed no siginificant difference associated with salinity conditions of the habitats of these fishes, and between zoogeographical positions in the case of freshwater forms, i.e., primary, secondary and vicarious freshwater species.There is no correlation between the fluoride concentration in the enameloid and the shape and size of teeth which show diverse morphological adaptation.
These facts suggest that the fluoride concentration in enameloid is related to phylogeny of the fishes rather than the fluoride concentration in environmental water, and that the evolution of chemical composition of fish enameloid is independent of the morphological adaptation of teeth.View full abstractDownload PDF (15566K) -
Yasuo Itazawa, Tatsusuke Takeda, Ken-ichi Yamamoto, Teruo Azuma1983 Volume 30 Issue 1 Pages 94-101
Published: May 15, 1983
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (961K)
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