15 MORPHOLOGICAL DEVELOPMENT OF HATCHERY-REARED LARVAL AND JUVENILE MEKONG GIANT CATFISH PANGASIANODON GIGAS Yushiro Kinoshita 1 , Viseth Hav 1,2 , Fumihito Akishinonomiya 3 , Yasuhiko Taki 4 and Hiroshi Kohno 1* ABSTRACT Morphological development of Pangasianodon gigas was described for hatchery-reared 111 larvae and juveniles of 3.41–65.5 mm in body length (BL) sampled from day 0 to day 35. BLs of larvae and juveniles on day 0 were 3.87±0.30 (mean±SD) mm, reaching 22.1±0.53 mm RQ GD\ DQG PP RQ GD\ 1RWRFKRUG WLS ÁH[LRQ EHJDQ LQ WKH VPDOOHVW ODUYD RI PP %/ DQG WKH FRPSOHWHO\ ÁH[HG QRWRFKRUG WLS ZDV HYLGHQW LQ VSHFLPHQV RI DERXW mm BL. Melanophores were scarcely developed in the yolk sac larvae smaller than 7.13 mm BL DQG VWDUWHG DSSHDULQJ RQ PDQ\ ERG\ SDUWV LQ WKH ÁH[LRQ ODUYDH ² PP %/ 7KH MXYHQLOH VWDJH VWDUWHG DW PP %/ DW ZKLFK SRLQW VRPH RI WKH ERG\ SURSRUWLRQV UHODWLYH WR %/ ZHUH in the process of developmental change, while others had reached peak or constant values. The results were compared with those of such confamilial species as Pangasianodon hypophthalmus, Pangasius bocourti and Pangasius larnaudii. Key words: Pangasiidae, morphology, ontogeny, developmental stage INTRODUCTION 7KH 0HNRQJ JLDQW FDWÀVK Pangasianodon gigas, a species of the siluriform family 3DQJDVLLGDH LV RQH RI WKH ZRUOG·V ODUJHVW IUHVKZDWHU ÀVKHV DWWDLQLQJ DERXW P LQ WRWDO OHQJWK and 300 kg in body weight (SMITH 5AINBOTH +OGAN, 2004). This species is endemic to the Mekong River basin (RAINBOTH +OGAN 3OULSEN ET AL., 2004), occurring sporadically in the main channels of the Mekong River and its tributaries in Thailand, Lao PDR and Cambodia at present (HOGAN, 2013). Due to the deterioration of habitat FRQGLWLRQV DQG LQVXIÀFLHQW VWRFN PDQDJHPHQW IRU WKH ÀVK LWV QDWXUDO SRSXODWLRQ KDV GHFOLQHG VWHHSO\ +OGAN ET AL. 3OULSEN & VIRAVONG 0ITCHELL & BRAUN +OGAN, 3OULSEN ET AL )ROESE & PAULY 7KHUHIRUH WKH ÀVK LV QRZ FDWHJRUL]HG as “critically endangered” in IUCN Red List (IUCN, 2014), and its international trade is FRQWUROOHG E\ WKH &RQYHQWLRQ RQ ,QWHUQDWLRQDO 7UDGH LQ (QGDQJHUHG 6SHFLHV RI :LOG )DXQD DQG )ORUD &,7(6 OLVWHG LQ $SSHQGL[ , &,7(6 7KH 'HSDUWPHQW RI )LVKHULHV RI WKH _________________________________________ 1 Laboratory of Ichthyology, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan 2 )LVKHULHV $GPLQLVWUDWLRQ 0LQLVWU\ RI $JULFXOWXUH )RUHVWU\ DQG )LVKHULHV &DPERGLD 3 7RN\R 8QLYHUVLW\ RI $JULFXOWXUH )XQDNR $WVXJLVKL .DQDJDZD -DSDQ 4 1DJDR 1DWXUDO (QYLURQPHQW )RXQGDWLRQ .RWREDVKL 6XPLGDNX 7RN\R -DSDQ * Corresponding author. E-mail: [email protected]5HFHLYHG $SULO DFFHSWHG -XO\ NAT+IST. BULL. SIAM SOC. 61(1): 15–27, 2015
13
Embed
MORPHOLOGICAL DEVELOPMENT OF HATCHERY-REARED · PDF fileMORPHOLOGICAL DEVELOPMENT OF HATCHERY-REARED LARVAL AND JUVENILE MEKONG GIANT CATFISH PANGASIANODON GIGAS ... Pangasius bocourti
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
15
MORPHOLOGICAL DEVELOPMENT OF HATCHERY-REARED LARVAL AND JUVENILE MEKONG GIANT CATFISH
PANGASIANODON GIGAS
Yushiro Kinoshita1, Viseth Hav 1,2, Fumihito Akishinonomiya 3, Yasuhiko Taki 4 and Hiroshi Kohno 1*
ABSTRACT
Morphological development of Pangasianodon gigas was described for hatchery-reared
111 larvae and juveniles of 3.41–65.5 mm in body length (BL) sampled from day 0 to day 35.
BLs of larvae and juveniles on day 0 were 3.87±0.30 (mean±SD) mm, reaching 22.1±0.53 mm
mm BL. Melanophores were scarcely developed in the yolk sac larvae smaller than 7.13 mm BL
in the process of developmental change, while others had reached peak or constant values. The
results were compared with those of such confamilial species as Pangasianodon hypophthalmus,