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Volume 17, Issue 2
Displaying 1-6 of 6 articles from this issue
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Gareth J. Nelson1970 Volume 17 Issue 2 Pages 61-66
Published: July 15, 1970
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSGill arches of salangids, despite certain embryonic features, resemble those of argentinids in having an elongate basihyal and basihyal tooth plate.The arrangement of basihyal teeth in Argentina is in a distinctive pattern, found also among galaxiids, osmerids and salmonids, suggesting that these groups are more closely related among themselves than to esocoids.A relationship between osmerids and stomiatoids is not supported by gill-arch structure.View full abstractDownload PDF (898K) -
Hiroya Takahashi1970 Volume 17 Issue 2 Pages 67-73
Published: July 15, 1970
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSFour immature adults of goldfish, Carassius auratus, were found having ovaries with vestigial testicular tissue.The ovaries were provided with a hypertrophied germinal layer along the inner margin of ovigerous lamellae where oocyte development reaching the primary yolk stage was normally proceeding.The hypertrophied germinal layer was composed of irregularly arranged, large clusters of gonial cells of transitory sizes and clusters of gametogenetic cells presumed to be spermatocytes in respect to their sizes and cytological characteristics.A mitotic division of germ cells was frequently detectable in the gonial cell clusters, while it was hardly seen in oogonial patches of normal ovaries at a comparable stage of oogenesis.Furthermore, repeated occurrence of cell division defined as the first meiosis made it possible to assure that the unusual gametogenesis carried on in the hypertrophied ovarian germinal layer was the spermatogenesis in its nature.The spermatogenesis appeared to fail to progress into spermiogenesis, and was thought to end in degeneration as a result.View full abstractDownload PDF (6275K) -
Kenichiro Kyushin1970 Volume 17 Issue 2 Pages 74-79
Published: July 15, 1970
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe eggs of Gymnocanthus herzensteini were fertilized and cultured for the study of their embryonic and larval development.The eggs were demersal and adhesive.The yolk was light orange in color with a single large oil globule, sometimes accompanying a few small oil globules, and contained a mass of many small granular materials.Melanophores and xanthophores appeared on the embryonal body after the mid-stage of embryonic development, but not on the yolk and oil globule.Hatching occurred between 42 and 49 days after fertilization at the water temperature 5.5°-6.8°C.
The newly hatched larvae averaged 5.83 mm in body length with 41-43 pairs of somites.The prominent characteristic of larvae lay in the pigmentation pattern of melanophores and xanthophores on the nape, the crown of the head, the body cavity, and especially on the ventral margin of the tail portion.After thirty-nine days, the larvae reached an average body length of 7.84 mm.The pigmentation pattern remained essentially unchanged except the appearance of melanophores on the lower jaw and the opercle region.Various body parts were measured to examine the changes in body form in the larval stage.View full abstractDownload PDF (815K) -
Osame Tabeta1970 Volume 17 Issue 2 Pages 80-81
Published: July 15, 1970
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESS -
Seiro Kimura1970 Volume 17 Issue 2 Pages 82-83
Published: July 15, 1970
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe author observed two large specimens of the non-migratory char, Salvelinus leucomaenis (Pallas).exhibited in Oisawa Natural Museum, Nishikawa-cho, Yamagata Prefecture.These fishes are mature males measuring 55 and 58 cm in total length and were captured in Deya River.an upper reach of Aka River which flows into the Japan Sea, in October, 1959 and 1966.These specimens seem to be the largest of the fluvial char, which have been, so far, considered to reach a length of 40cm at the largest.View full abstractDownload PDF (2651K) -
Muneo Okiyama, Waichi Tomi1970 Volume 17 Issue 2 Pages 84-85
Published: July 15, 1970
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSA reversed ambicolorate flatfish was first described from the Japanese waters, on the basis of a flathead flounder, Hippoglossoides dubius, from the Japan Sea.This probably represents the first record of such complicated association of the morphological anomalies in flatfishes as the reversal of side, the ambicoloration and the unusual optic chiasma.It is noteworthy that the known ambicolorate flatfishes with complete reversal of side are restricted to the allied two genera, i.e., Hippoglossoides and Hippoglossus. Certain association of the unusual optic chiasma and the complete reversal of side was also suggested.View full abstractDownload PDF (1866K)
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