A note on Aaptosyax grypus, a very rare, unique cyprinid fish
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Rainboth (1991) described a new cyprinid fish, Aaptosyax grypus, from the Mekong River in Thailand, establishing a new monotypic genus. I was very interested in his figures of the species, which was similar to Chanos chanos in general appearance, and visited the fishermen’s base at Khong Chiam, eastern Thailand, several times from April 1998 to January 1999. Then I obtained a total of ten specimens of A. grypus: two from Khong Chiam and eight from the lower reaches near Khone Falls, Laos. All specimens were adult and larger than 700 mm in standard length (SL). One specimen was obtained in August (Khong Chiam), while the others were all obtained from the end of November to December, which may be the spawning season of the species, when the temperature of the Mekong decreases to 20°C, the coolest period (see “Ecological notes”).
Since Rainboth (1991) first described the superficial characters of A. grypusin detail, little biological information has accumulated for this species (e.g.,...
I wish to give thanks to Dr. Chaiwut Krudpan, who helped me a great deal when collecting specimens. Thanks are also extended to Dr. Katsutoshi Watanabe and Dr. Tsuneo Nakajima, who helped with the preparation of the manuscript.
- Alexander R McN (1962) The structure of the Weberian apparatus in the Cyprini. J Zool Lond 139:451–473Google Scholar
- Alexander R McN (1966) The functions and mechanisms of the protrusible upper jaws of two species of cyprinid fishes. J Zool Lond 149:288–296Google Scholar
- Gaubert P, Denys G, Oberdorff T (2009) Genus-level supertree of Cyprinidae (Actinopterygii: Cypriniformes), partitioned qualitative clade support and test of macro-evolutionary scenarios. Biol Rev 84:653–689Google Scholar
- He S, Liu H, Chen Y, Kuwahara M, Nakajima T, Zhong Y (2004) Molecular phylogenetic relationships of Eastern Asian Cyprinidae (Pisces: Cypriniformes) inferred from cytochrome b sequences. Sci China Ser C Life Sci 47:130–138Google Scholar
- Kottelat M (1996) Aaptosyax grypus. In: IUCN (ed) IUCN Red List of threatened species, version 2010.4. http://www.iucnredlist.org. Accessed 4 Jan 2011
- Phillips JB (1942) Osteology of the sardine (Sardinops caerulea). J Morphol 70:463–500Google Scholar
- Rainboth WJ (1991) Aaptosyax grypus, a new genus and species of large piscivorous cyprinids from the middle Mekong River. Jpn J Ichthyol 38:231–237Google Scholar
- Roberts TR (1993) Artisanal fisheries and fish ecology below the great waterfalls of the Mekong River in southern Laos. Nat Hist Bull Siam Soc 41:31–62Google Scholar