Maximum prey size estimation of longtooth grouper, Epinephelus bruneus, using morphological features, and predation experiments on juvenile cannibalism. (4th July 2014)

• Record Type: Journal Article
• Authors: Inoue, Nariaki; Satoh, Jun; Mekata, Tohru; Iwasaki, Takashi; Mori, Koichiro
• Is Part Of: Aquaculture research. Volume 47:Number 2(2016)
• Page Start: 605
• Page End: 611
• Publication Date: 2014-07-04
• Subjects: Cannibalism -- Epinephelus bruneus -- mouth size -- logistic regression model -- aquaculture; Aquaculture -- Periodicals; Fishery management -- Periodicals; 639.8
• DOI: 10.1111/are.12519
• Languages: English
• ISSNs: 1355-557X

Abstract

Abstract: In fish culture, cannibalism, which induces critical damage, is separated into two types: type I, which occurs in early larval stages when size heterogeneity is low; and type II, which starts in later larval and/or early juvenile stages following type I when size heterogeneity is high. In type II, the cannibal's maximum prey size is limited by its gape size relative to the prey fish body size. Ratios of prey to cannibal body size changes are associated with allometric factors and feeding behaviour with growth. In a previous study on grouper, the maximal prey size was estimated morphologically (i.e., the relationship between gape size and body height). This method is very simple and useful; however, it does not consider allometric factors and feeding behaviour changes; therefore, it probably causes a large estimation error. To overcome this, we present a new method for estimating maximal prey size to determine the size ranges for size grading of longtooth grouper, Epinephelus bruneus, juveniles using predation experiments. It is shown that grouper type II cannibalism is affected by two factors; in early juvenile stages by morphology and in later (TL over 50 mm) by prey size selectivity.