What causes cannibalization-associated suffocation in cultured brown-marbled grouper,Epinephelus fuscoguttatus(Forsskål, 1775)?

Abstract

During culture of grouper, cannibalism is a frequent phenomenon that usually causes economic loss. Grouper culture often requires grading to prevent size-dependent cannibalism. In comparison with orange-spotted (Epinephelus coioides) and giant grouper (E. lanceolatus), failure to swallow prey during cannibalism is frequently observed in brownmarbled grouper (E. fuscoguttatus). The cannibal cannot engulf the entire prey and the two ¢sh ultimately end up dying together. Herein, we attempted to compare morphometric di¡erences among orange-spotted, giant and brown-marbled grouper. We established a cannibal^prey total length (TL) relationship for brown-marbled grouper: TL prey 5 0.71 TL cannibal À1.75. According to the equation, a di¡erence of approximately 50% in TL is a threshold to use for grading the grouper. This value is much larger than that used (30%) in orange-spotted and giant grouper, and this size di¡erence results in a higher incidence of failed cannibalism attempts in brown-marbled grouper. It is our belief that the standard grading method will fail to produce as good an e¡ect in brownmarbled grouper as is seen in orange-spotted and giant grouper. Therefore, in addition to grading, other manipulations such as satiation feeding, nutritional supplementation and optimal stocking densities should be applied to reduce cannibalism of brownmarbled grouper.

How many meals a day to minimize cannibalism when rearing larvae of the Amazonian catfishPseudoplatystoma punctifer? The cannibal’s point of view

“…These scores compare to those of highly cannibalistic species such as barramundi Lates calcarifer (Parazo et al 1991), northern pike Esox lucius (Bry et al 1992;Ziliukiene and Ziliukas 2006), tunas (Sawada et al 2005) and groupers Epinephelus spp. (Hseu et al 2003(Hseu et al , 2004(Hseu et al , 2007. Cannibals of P. punctifer in the present study never consumed prey as large as allowed by their mouth dimensions, possibly because stomach capacity was limiting.…”

“…It is not frequent that cannibals or piscivores prefer prey as large as possible, because suffocation is frequent when the prey is slightly too large, especially in species with spiny fin rays that prevent regurgitation (Eurasian perch Perca fluviatilis, Brabrand 1995; brownmarbled grouper Epinephelus fuscoguttatus, Hseu et al 2007). …”

Do cannibalistic fish forage optimally? An experimental study of prey size preference, bioenergetics of cannibalism and their ontogenetic variations in the African catfishHeterobranchus longifilis

“…In the context of cannibalism, there have been several reports of situations following size-grading in aquaculture facilities where inexperienced cannibals suffocated while attempting to ingest prey that were excessively large relative to their ingestion capacities (Brabrand 1995;Hseu et al 2007), whereas such situations were never observed prior to size-grading. These observations suggest that individual experience in cannibalism can impact on prey size selectivity as well.…”

“…In larger fish, the victims are swallowed whole and cannibalism is governed by specific morphological restrictions (reviews in Hecht and Pienaar 1993;Folkvord 1997;Baras and Jobling 2002;Baras 2013). Information on the allometric variations of mouth and body dimensions has been used often to predict the occurrence or risk of cannibalism (Hecht and Appelbaum 1988;Brabrand 1995;Hseu et al 2003Hseu et al , 2004Hseu et al , 2007Hseu and Huang 2014). In some cases, cannibalistic fishes have been found to ingest siblings near the maximal possible size (e.g., largemouth bass Micropterus salmoides, Johnson and Post 1996; redtail catfish Hemibagrus nemurus, Baras et al 2013), whereas this "maximalistic" behaviour is infrequent with other types of piscivory (Juanes 1994(Juanes , 2003Juanes et al 2002).…”

Induced breeding and larval rearing of Surubí, Pseudoplatystoma fasciatum (Linnaeus, 1766), from the Bolivian Amazon

“…Cannibalism is frequent among cultured fish larvae, especially in piscivorous species, which develop a wide gape and oral teeth at a precocious age (Baras & Jobling 2002). Among the factors that govern the impact of cannibalism in fish, size heterogeneity is probably the most striking one (Qin & Fast 1996; Kestemont, Jourdan, Houbart, Melard, Paspatis, Fontaine, Cuvier, Kentouri & Baras 2003; Hseu, Huang & Chu 2007; Mandiki, Babiak, Krol, Rasolo & Kestemont 2007). Other factors that modulate cannibalism, either directly or indirectly through an increase in size heterogeneity, include the feeding environment, rearing density, water temperature, light regime and intensity (Boeuf & Le Bail 1999; Appelbaum & Kamler 2000; Kestemont et al 2003).…”