Effects of density, starvation and size difference on aggressive behaviour in juvenile yellowtails (Seriola quinquevadiata)

Abstract

SummaryEffects of density, starvation, and size difference on aggressive behaviour in juvenile yellowtails Seriola quinqueradiata (Temminck and Schlegel) were investigated. When fish were acclimated to densities at 1, 2, 4, 8, and 16 fish L -1 , frequencies of aggressive behaviour per fish decreased significantly. Under the starvation of 0, 4, 8, 12 and 24 hours, the highest aggression was observed at 24 hours, while aggression showed same levels between 0 to 8 hours. According to pair match test among three groups of different size from one batch (TL mm; 16.6±2.0, 21.1±2.1, and 29.7±4.9), the highest aggression was observed in the most size different group, whereas others showed the same levels. Therefore, in view of the three investigated parameters, aggressive behaviour was concluded to be starvation-and size-dependent but negatively density-dependent in the yellowtail. Synthesizing all relevant results, including abiotic factors such as light condition, a practical method to reduce the mortality caused by aggressive behaviour in the yellowtail culture is presented.

Sampling effort required to obtain repeatable average size estimates of juvenile fish

“…The CV W values for the 9 cohorts studied (30 to 55%) were comparable to the CV W values reported for other species at a similar life stage (Folkvord & Otterå 1993, Sakakura & Tsukamoto 1998, Baras et al 2000, Imsland et al 2009); therefore, the sample size estimates from the current study can act as a guideline for researchers who would like some assurance that they have adequately sampled juvenile populations in order to gain a repeatable average size measurement.…”

Effect of Initial Stocking Density on Larviculture Performance of the Ocellate Puffer, Takifugu rubripes

“…Cannibalism is an important issue in the rearing of larvae and juvenile fish and is not only observed in rearing of ocellate puffer (Kurata 1975; Folkvord 1991; Smith and Reay 1991; Folkvord and Otterå 1993; Ruzzante 1994; Mélard et al 1996; Sakakura and Tsukamoto 1996, 1998, 2002; Watanabe et al 1996; Yagi 1996; Hseu 2002; Liao and Chang 2002). When cannibalism was observed in previous studies, its occurrence was influenced by stocking density (Mélard et al 1996; Sakakura and Tsukamoto 1998; Hseu 2002). Also, we assumed that higher densities caused earlier occurrence of cannibalism and higher mortalities in the present study (Table 1; Fig.…”

“…We did not find any evidences why more fishes died in the initial densities of 15 and 20 larvae/L, especially all fishes died in one tank of both initial densities. Sakakura and Tsukamoto (1998) suggested that high stocking density in yellowtail juvenile suppressed the aggressive tendency of fish per individual. It is possible that a similar phenomenon occurred in this study.…”

Production Characteristics and Body Composition of Florida Pompano Reared to Market Size at Two Different Densities in Low‐Salinity Recirculating Aquaculture Systems

“…Although both positive and negative relationships between stocking density and various fish production indices have been documented, the latter is usually the case, as shown by the results of density studies conducted on a variety of marine finfishes, including Atlantic salmon Salmo salar (Refstie and Kittelsen 1976;Soderberg et al 1993), gilthead seabream Sparus aurata (Canario et al 1998), red porgy Pagrus pagrus (Maragoudaki et al 1999), Atlantic halibut Hippoglossus hippoglossus (Bjö rnsson 1994), California halibut Paralichthys californicus (Merino et al 2007), European seabass Dicentrarchus labrax (Paspatis et al 2003), common sole Solea solea (Howell 1998;Schram et al 2006), white-spotted rabbitfish Siganus canaliculatus (El-Sayed et al 1995), estuary grouper Epinephelus salmoides (Teng and Chua 1979), turbot Scophthalmus maximus (Howell 1998;Irwin et al 1999;Ma et al 2006), Atlantic cod Gadus morhua (Lambert and Dutil 2001;Björnsson and Olafsdottir 2006), silver hake Merluccius bilinearis (Helser and Almeida 1997), amarillo snapper Lutjanus argentiventris (Guerrero-Tortolero et al 1999), and yellowtail Seriola quinqueradiata (Sakakura and Tsukamoto 1998). The presence of an inverse relationship between stocking density and production performance may be attributed to one or more of a suite of factors, including competition (Brett 1979;Helser and Almeida 1997;Irwin et al 1999), formation of hierarchic structures and agonistic behaviors (Keenleyside and Yamamoto 1962;Refstie and Kittelsen 1976;Brown et al 1992;Howell 1998), space limitation (Björnsson 1994;Ewing et al 1998), and suboptimal water quality (Kindschi and Koby 1994;Zoccarato et al 1994;…”