Search

The ontogeny of Ilisha elongata was reviewed, and their early distribution was examined because information on the early life history of this species is limited. Revision in ontogeny revealed several unique characteristics to this species, such as two chorions in the egg and a more anterior pelvic bud (fin) position. These characteristics contrast strikingly with the clupeid fishes, suggesting that this species belongs to the Pristigasteridae and not to the Clupeidae. Data from ichthyoplankton collected in March, May, July and November suggest that I. elongata spawned just off river mouths in summer and attained peak spawning in June. The larvae with elliptical eyes migrated inside the rivers, where the waters were more turbid. Thus, the spawning and nursery grounds of I. elongata almost entirely overlapped with those of the clupeid Sardinella zunasi both temporally and spatially, which may result in larval competition between the two species. [ABSTRACT FROM AUTHOR]

The article presents a study which provides a distributional information and descriptions of larval development in Doederleinia berycoides in the coastal waters of Niigata in the northern Japan Sea. The ontogenic development of D. berycoides such as the appearance of distinctive melanophores on the rostral tip, isthmus, throat is cited. It is inferred that the larvae of the species disperse to a wide extend from near-shore to offshore waters during their pelagic phases.

The influence of pelagic larval duration (PLD) and egg type dispersal capabilities of 35 demersal and pelagic-spawning tropical fish species is examined in relation to their abundance on the temperate coasts of Japan. The PLDs of pelagic spawners were significantly longer than those of demersal spawners, and a high occurrence of pelagic spawners on the temperate coasts suggests that these fishes are more easily transported to temperate coasts than demersal spawners. For demersal spawners, the common species on the temperate coasts had significantly longer PLDs than the rare species; this suggests that PLD is a major factor influencing the distribution patterns of tropical demersal spawners on temperate coasts. Moreover, a negative correlation between PLD and the abundance of some species of pelagic and demersal spawners suggests the presence of reproductively active fishes in northern subtropical and even in temperate waters. [ABSTRACT FROM AUTHOR]

Abstract  Reproductive biology and morphology of eggs and early larvae of the sicydiine goby Stiphodon percnopterygionus were investigated on Okinawa Island, southern Japan. Spawning season was estimated as being from May to December. Standard length at maturity was approximately 20 mm in both sexes, and batch fecundity was approximately 1000–10 000 per female. The egg masses, guarded by the male, were laid on the undersurface of stones in freshwater. The pyriform eggs had long- and short-axis diameters of 0.54–0.58 mm and 0.49–0.50 mm, respectively. Newly hatched larvae (1.20–1.32 mm notochord length: NL) were poorly developed, with large yolk sacs and unopened mouths. Three days after hatching (1.87–2.05 mm NL), eyes were fully pigmented and mouths were opened. [ABSTRACT FROM AUTHOR]