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Volume 37, Issue 3
Displaying 1-16 of 16 articles from this issue
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Supap Monkolprasit, Tyson R. Roberts1990 Volume 37 Issue 3 Pages 203-208
Published: November 30, 1990
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSA new whiptailed stingray, Himantura chaophraya, is described from three specimens caught in the Mae Nam Chao Phraya of Thailand. The new species, reportedly attaining 500kg or more, belongs to a species group found mainly in fresh water and characterized by large body size, strongly projecting snout, broad but thin oval disc, small eyes, black marginal coloration on ventral surface of disc, very narrow tail base, 158-164 pectoral radials, and 21 spiral valve turns. The species group is known from India, Borneo and New Guinea and probably also occurs in the Mekong River, but the only specimens available in museum collections are from the Chao Phraya and the Mahakam River basin in eastern Borneo (Kalimantan, Indonesia).View full abstractDownload PDF (4542K) -
Yoshihiko Machida1990 Volume 37 Issue 3 Pages 209-214
Published: November 30, 1990
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSA new ophidiid fish, Hoplobrotula badia, is described from a single specimen from the Pacific Ocean off central Japan. This species is distinguished from its congeners by the following combination of characters: snout spine extremely short and blunt, no sensory pore just above anterior nostril, dorsal fin rays 94, anal fin origin below 17th dorsal fin ray, abdominal vertebrae 13, pelvic fin extending well beyond posterior margin of head, and color of head and body uniformly deep brown.View full abstractDownload PDF (5701K) -
Atsushi Fukui, Umeyoshi Yamada, Takakazu Ozawa1990 Volume 37 Issue 3 Pages 215-223
Published: November 30, 1990
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe original description of Arnoglossus yamanakai was unsatisfactory, being based on larval specimens, written in Japanese and without designation of the holotype. In this paper, the lectotype is designated, and types and adult specimens are fully described. In adults, this species is distinguished from other Arnoglossus species by 11 (rarely 12) abdominal vertebrae, slender gill rakers with serrated spinules on the upper margin, and in males, a black band on the distal margin of the anterior part of the dorsal fin. This species is distributed in the East and South China Seas.View full abstractDownload PDF (1228K) -
Kunio Sasaki1990 Volume 37 Issue 3 Pages 224-229
Published: November 30, 1990
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSA Chinese sciaenid species, long identified in both China and Japan as Johnius belangerii (Cuvier, 1830), is now considered to be more correctly named as Johnius grypotus (Richardson, 1846). The species is characterized by a blunt snout, wide interorbital space (8.0-9.7% SL), usually eight anal soft rays, high gill raker number (6-7+1+10-14), and ctenoid scales on the throat.View full abstractDownload PDF (3128K) -
Nobuhiko Taniguchi, Yoshiharu Honma, Kenji Kawamata1990 Volume 37 Issue 3 Pages 230-238
Published: November 30, 1990
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSTo investigate the origin of the freshwater form of the threespine stickleback, Gasterosteus aculeatus, genetic differentiation among local populations of the species was elucidated from isozyme genetic markers of skeletal muscle and liver tissue by means of an electrophoretic method. The mean value of the genetic distance between the freshwater and anadromous forms of this species was very large (D= 0.6746), almost at the level for congeneric species pairs in both freshwater and marine fishes, whereas the mean values of pairs within the respective forms were very small (D=0.0006-0.0015). The level of genetic variability of the freshwater form was distinctly lower than that of the anadromous form. Results suggest that local populations of the freshwater form from northern Japan have been derived monophyletically from a common ancestor which was established before the recent postglacial colonization.View full abstractDownload PDF (905K) -
Ryuzo Fukao, Toshio Okazaki1990 Volume 37 Issue 3 Pages 239-245
Published: November 30, 1990
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSElectrophoretic analyses were made on the two species of Neoclinus, N. nudus and N. okazakii, from Okinawa in addition to the five congeneric species (including N. okazakii) from Shirahama examined in the previous study (Fukao and Okazaki, 1987). In terms of Nei's genetic distance, N. nudus was grouped with N. lacunicola and N. toshimaensis (N. lacunicola species complex) with relatively small values. Recognition of N. okazakii from Okinawa was supported by the present electrophoretic study . The small genetic distance of 0.001 was scored between Okinawa and Shirahama populations of this species.View full abstractDownload PDF (813K) -
Osamu Katano1990 Volume 37 Issue 3 Pages 246-255
Published: November 30, 1990
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe relationships among body length, gonad and body weights and secondary sexual characters of the dark chub, Zacco temmincki, were analyzed with reference to their variations. Both condition factor and gonosomatic index (GSI) greatly increased in the pre-mating season. Body size was positively correlated with GSI value for females, except in post-spawning periods, but negatively correlated or uncorrelated for males. Individual variation (CV) of both condition factor and GSI value also increased in the pre-mating and mating seasons. Breeding color and pearl organs on the head developed in both sexes all the year round, and most conspicuously in males in the mating season. Pearl organs on the anal fin only developed in males in the mating season. The development of these secondary sexual characters neither necessarily indicated sexual maturation nor a high potential for reproduction, but was greatly associated with large body size. Breeding color was believed to function as a signal showing the development of pearl organs and body size, pearl organs on the head as a weapon in conspecific aggressive encounters and pearl organs on the anal fin as a tool for burying eggs in spawning behavior.View full abstractDownload PDF (1237K) -
Koji Kobayashi, Katsumi Suzuki1990 Volume 37 Issue 3 Pages 256-264
Published: November 30, 1990
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe present paper deals with gonadal formation and sex succession based on histological observations in the wrasse, Cirrhilabrus temmincki Bleeker, from Suruga Bay. Gonads of the present species are in the undifferentiated stage in young fish ranging from 11.4 to 19.5mm TL. In fish ranging from 21.1 to 40.4mm TL, gonads begin to differentiate initially into ovaries, forming an early ovarian cavity of the parovarian type and no evidence is found for the existence of any primary male. Reproduction takes place from June to September. The minimal size of sexual maturation is thought to be about 50mm TL for females and about 88mm TL for males. The androgenic transformation generally starts after the completion of female's reproductive function and these females thus change sex rather slowly. Several intersexual gonads are found both before and after the reproductive season. Although the intersexual form which shows the normal course of protogynous sex succession is found after the reproductive season, a few fish change sex previous to the reproductive season from female to male but their gonads seem to function only as female during this season. On the other hand, a group which is formed only of young or small transitionals and secondary males is obtained in April. The role and significance of this occurrence in hermaphroditism are discussed. C. temmincki is established as a monandric and dimorphic species. All the fish which show the terminal phase are secondary males, but the others which show the initial phase form a complex consisting of females, transitionals, and secondary males. A marked elongation of the second ventral ray is seen only in males as the result of a positive correlation with body growth.View full abstractDownload PDF (10767K) -
Jun Kita, Yasuo Itazawa1990 Volume 37 Issue 3 Pages 265-272
Published: November 30, 1990
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThree-dimensional structure of the vascular system of the rainbow trout (Oncorhynchus mykiss (=Salmo gairdneri)) spleen was studied under a scanning electron microscope using mainly corrosion casts. The specialized vessels related to the periarterial lymphatic sheath and lymphatic nodules which are seen in the mammalian spleen were not found in the rainbow trout. A major trunk artery simply gave off arterioles toward the subcapsular region. Termination of arterial capillaries in reticular meshwork, i.e. open circulation, was clearly observed. Arterioles infrequently showed sphincter-like constrictions which probably regulated blood flow through the organ. Reticular meshwork, which appeared in the cast as clusters of granular resin masses, was considered to be an important site for erythrocyte storage. At the subcapsular region the collecting veins, which showed a plate-like structure and lay on the reticular meshwork, gathered into veins which in turn went straight into the inside of the organ and joined a major trunk vein. These veins running from the reticular meshwork to a larger vein were considered to aid the rapid drainage of erythrocytes from the reticular meshwork at times of urgent need, such as during periods of strenuous exercise.View full abstractDownload PDF (14876K) -
Sho Tanaka, Yoshihisa Shiobara, Syozo Hioki, Hidenao Abe, Genjirou Nis ...1990 Volume 37 Issue 3 Pages 273-291
Published: November 30, 1990
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSAn analysis of the reproductive biology of the frilled shark, Chlamydoselachus anguineus, was made on the basis of a collection of 264 specimens from Suruga Bay, Japan. This species is caught mainly from December to July. Almost all specimens were mature. The frilled shark appears to segregate by size and reproductive stage. Males mature below 1, 100mm total length (TL), while females reach sexual maturity between 1, 400 and 1, 500mm TL. Males have active testes throughout the year. Females do not have a defined reproductive season. Ova emerge through each ovulation pore on the ovarian epithelium at a size of 230-250g, and only enter the right oviduct. Ovarian eggs do not continue to develop during gestation. Egg capsules are shed when embryos reach between 60 and 80mm TL. Young are born at a size of about 550mm TL and 380g body weight. Litter size ranges from 2 to 10, with a mean of 6. Late stage embryos may receive nutrients from the mother. The intervals of ovulation seem to be about two weeks. The ovulation season in each female extends over a few months. The early embryonic development is slow. The gestation period appears to last at least three and a half years. The encapsulated embryos maintained in artificial conditions grow at a rate of between 10 and 17mm per month for a period up to 134 days.View full abstractDownload PDF (6475K) -
Terry J. Donaldson1990 Volume 37 Issue 3 Pages 292-301
Published: November 30, 1990
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSCourtship and spawning behavior of the lizardfish Synodus dermatogenys (Synodontidae) was observed at Wing Beach, Saipan, Mariana Islands. This species displayed lek-like behavior in that males aggregated for courtship at a definite site just before sunset and engaged in male-male aggressive interactions prior to and after the arrival of females for courtship.Male-male interactions continued at the site during courtship bouts with females and after spawning had been completed. Females made multiple (1-3) spawnings each night that lek-like behavior was observed. These spawnings began as a paired pelagic ascent but became multi-male group spawnings as additional males (2-7) joined the pair in the water column. Paired spawning occurred only when two individuals, a male and female, were present at the courtship site. Females spawned only once a night when paired spawnings occurred.View full abstractDownload PDF (6835K) -
Makoto Sakurai, Akinobu Nakazono1990 Volume 37 Issue 3 Pages 302-307
Published: November 30, 1990
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe parturition of 4 Ditrema temmincki females (153-162mm TL, 1 year old), captured off Tsuyazaki (130°29'E, 33°47'N), northern coast of Kyushu, Japan, was observed in the aquarium using VTR from May 20 to 26, 1985. The 4 female released 6, 8, 8, and 10 embryos, respectively, within 1 or 2 days during the daytime. Of these, 29 were born alive and 3 dead. Just before and at parturition, respiration of the female became frequent and 2 white spots appeared on the female's side. At the initial phase of parturition of living embryos, the caudal fin appeared first from the gonopore. Within a minute to several hours, the caudal peduncle protruded and the embryo (51.4-58.2mm TL) slipped out. It was also observed that several embryos were released successively at intervals of several seconds to about 10 minutes. The three dead embryos, 1 of which was degenerating, were extruded headfirst. The young formed an aggregation and fed immediately after birth. Female parents swam indifferently from their young and did not show parental care. Observations on metamorphosis of embryos taken out from the female revealed that the embryos just before parturition had ruddy body color and large fins with a developed capillary system and spatulate extensions at their margins. These embryonic features disappeared within 1 or 2 days after embryos were transferred into seawater.View full abstractDownload PDF (5184K) -
Masayoshi Maehata, Yoshikazu Nagata, Masanari Matsuda, Hiromitsu Akiya ...1990 Volume 37 Issue 3 Pages 308-313
Published: November 30, 1990
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe Biwa-sheatfish, Parasilurus biwaensis Tomoda, is endemic to Lake Biwa, and is the largest species of the Japanese silurid fishes. From 23 June to 17 July, 1988, the reproductive behaviour of this fish was investigated during night-time on the rocky shores in the south of the lake. Spawning occurred frequently during midnight following heavy rain. The behavioural patterns observed were as follows: A female first searches for a spawning site, with a male following behind. Immediately the female stops, the male first places his head under that of the female and then, by bending his body towards her anal fin, positions himself such that his tail is towards the end of the female's snout. From this position the male then begins to wrap his tail around the head of the female, gradually winding his body tighter and moving along the body of the female until positioned at the centre of her body. The male then winds his body tightly around the dorsal side of the female's abdomen for 20-30 seconds. The female then shakes her head from side to side several times, and orientates her body downward. This behaviour causes the male to become separated from the female. Immediately after separation, the female releases a large number of eggs, and circles around with the male following on the inside. Although gamete release by the male was not actually observed, it seems likely that the eggs are fertilized during such circling. After circling, the pair turns round twice violently, causing the eggs to become widely scattered. The pair, then swim away with the female in the lead. Reproductive behaviour of the Biwa-sheatfish was compared with that of the Japanese sheatfish, Parasilurus asotus Linnaeus, in temporary waters around paddy fields. Some differences in reproductive behavioural traits were recognized between the two species.View full abstractDownload PDF (3101K) -
Yoshihiko Machida, Suguru Ohta1990 Volume 37 Issue 3 Pages 314-317
Published: November 30, 1990
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESS -
Seishi Kimura, Yoshimi Kohno, Yoichi Tsukamoto, Muneo Okiyama1990 Volume 37 Issue 3 Pages 318-320
Published: November 30, 1990
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESS -
Vicente Gomes, Phan Van Ngan, Maria José de Arruda Campos Rocha ...1990 Volume 37 Issue 3 Pages 321-323
Published: November 30, 1990
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESS
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