| Budget Amount *help |
¥3,620,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥120,000)
Fiscal Year 2007: ¥520,000 (Direct Cost: ¥400,000、Indirect Cost: ¥120,000)
Fiscal Year 2006: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2005: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2004: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Research Abstract |
The early ontogeny of macrourid fishes was poorly known, since eggs and larval forms have been rarely collected and identified. In this study, the author carried out deeper sampling in the water column and DNA analyses for species identification. Thereby the following was clarified.
1. The ontogeny of two species, Coryphaenoides marginatus and Caelorinchus kishinouyei, development of pelagic eggs, morphology of yolk-sac larvae, pelagic larvae and juveniles, were described.
2. The pelagic larvae and/or juveniles of Ventrifossa garmani, Caelorinchus sp., and two types (Macrourid genus sp. 1 and sp. 2) were described.
3. The morphological characters are remarkably different among the pelagic larvae (juveniles) of Coryphaenoides marginatus, Caelorinchus kishinouyei, and Ventrifossa garmani. These differences are corresponded to neighbor joining tree based on the nucleotide sequences of the 16S rRNA gene from macrourid adult fishes.
4. The overall distance of vertical migration of Coryphaenoide
… More
s marginatus seems to be 100-700 m, judging from the pelagic larval and adult collections. The pelagic larvae of C. marginatus do not seem to be particularly specialized for pelagic life. The less specialized morphologies (for a pelagic life style) apparent during early ontogeny of the present species seem to be related to the narrower ontogenetic migration range. However, the relationship between larval morphological specialization and ontogenetic migration is not clear in macrourids as some pelagic larvae of other shallower-dwelling species have a remarkably elongate caudal region and elongate first dorsal and pelvic fm rays.
5. In addition to the knowledge of macrourid fishes, the pelagic juvenile of Halargyreus johnsonii (Gadiformes : Moridae)and the larvae and juvenile of Polymetme elongata (Stomiiformes : Phosichthyidae) were described, being not known to date.
As part of this study, the author established the towing method in the epibenthic layer (less than 10m above seafloor) of the upper continental slope of Suruga Bay (depth between 200 m and 900 m). Thereafter, the ontogeny of the deep benthic fishes will be made clear by this method. Less
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