|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1996 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1995 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1994 : ¥900,000 (Direct Cost : ¥900,000)
Genus Apristurus is a group of deep sea catsharks, and the taxonomy of the genusis is extremely confusing with poorly known species, and many undescribed species which have been either published or unpublished.
Nominal species were taxonomically analyzed, comparing with data of type specimens, which were directly taken by the present author. Thirty one species were recognized as distinct at present. In addition, quite many undescribed species were found from the world oceans. External and internal examination, and morphometric and meristic character analyzes suggested the presence of three subgroups within the genus. All the species were assigned to one of the three groups. First groups, the long-snouted group is characterized by long snout before nostrils, and contains two species, A.herklotsi and A.longicephalus. Second group, short-snouted spongiceps group is characterized by short upper labial furrow and less number of spiral valves. This contains 20 species, like A.atlanticus, A.platyrhynchus, A.laurussoni, A.parvipinnis, etc. Third group, short-snouted brunneus group has longer upper labial furrow and more number of spiral valves, with 9 species, such as A.fedorovi, A.profundorum, and A.kampae. Taxonomic treatments of these groups were left unsolved, until the phylogenetic consideration of the carcharhiniform sharks. Some of the newly found undescribed species are in press, or will be published in the suitable journals.