クメ　マナブ   Manabu Kume   久米　学    所属   石巻専修大学  理工学部    職種   准教授
言語種別	英語
発行・発表の年月	2020/10
形態種別	研究論文（学術雑誌）
査読	査読あり
標題	Gut morphometry represents diet preference to indigestible materials in the largest freshwater fish, Mekong giant catfish (Pangasianodon gigas)
執筆形態	未選択
掲載誌名	Zoological Science
出版社・発行元	ZOOLOGICAL SOC JAPAN
巻・号・頁	37(5),pp.444-449
著者・共著者	Ayano Medo,Hideaki Nishizawa,Ayako Yokoyama,Manabu Kume,Yasushi Mitsunaga,Nobuaki Arai,Hiroyuki Yamane,Koki Ikeya,Thavee Viputhanumas,Hiromichi Mitamura
概要	The Mekong giant catfish Pangasianodon gigas is one of the largest freshwater fish, measuring up to 3 m in total length. This study was designed to determine the feeding habits of P. gigas to better understand how the fish achieve their large body size. We compared the relationship between gut length (GL) and total length (TL) among related species in superfamily Bagroidea, order Siluriformes (Pangasianodon hypophthalmus and Hemibagrus nemurus) in the Kaeng Krachan reservoir, Thailand. The mean relative gut length (RGL = GL / TL) of P. gigas was 3.50, showing that they have relatively long guts, with values more similar to those of omnivorous P. hypophthalmus (RGL = 3.70) than to those of carnivorous H. nemurus (RGL = 0.92). In the allometric relationship (i.e., log(10) GL = log(10) a + b log(10) TL), the slope close to 1 for P. gigas (b = 1.07) has been widely observed in carnivores, while P. gigas has a greater intercept of the linear equation than P. hypophthalmus and H. nemurus, resulting in a similar GL of P. gigas to omnivorous P. hypophthalmus at approximately 35 cm in TL. Moreover, GL of P. gigas at 150 to 250 cm in TL showed great variations (RGL = 1.35-6.32). The variation in RGL for P. gigas seemed to result from a poor nutritional state. In conclusion, P. gigas is suggested to feed on indigestible materials such as plants, algae, and sediments, and potentially experience fasting in a reservoir.
DOI	10.2108/zs200047
ISSN	0289-0003