Effect of body size heterogeneity on the aggressive behavior of larvae of matrinxã, Brycon amazonicus (Characiformes, Bryconidae)

Abstract

Brycon amazonicus is a native Amazonian fish that is important for aquaculture in South America. Larval mortality is high in this species in intensive breeding systems due to aggressiveness among larvae. The present study investigated experimentally the effects of body size heterogeneity on the aggressive behavior and survival of B. amazonicus during the early stages of larval development. Two treatments (larvae groups with homogeneous and heterogeneous body size) were evaluated throughout early larval stages tested at six time points: 12, 24, 36, 48, 60 and 72 hours after hatching (HAH). Two experiments quantified, respectively, aggressive interactions and mortality rates among larvae at each time point. The frequency of aggressive interactions exhibited by the less aggressive larvae in each replicate was higher in the homogeneous size treatment. Aggressiveness was higher at 12 HAH, decreasing thereafter, and increasing again at 72 HAH. The mortality rate significantly increased with the larval stage, and was higher in the homogeneous than in the heterogeneous sized groups. Our results showed that aggressiveness in B. amazonicus larvae is affected by size variability and larval development stage. This knowledge about larval behavior is important to develop measures to improve larval health and survival in intensive production systems for this species.

Stocking density in Colossoma macropomum larviculture, a freshwater fish, in recirculating aquaculture system

“…It is also important because, in spite of C. macropomum being an omnivorous species, larger animals were found attacking and eating smaller animals. Heterogeneity in size is considered one of the central problems in aquaculture (Carvalho et al., 2018) when smaller fish are consumed by larger fish (Baras, 1998; DeAngelis et al., 1980; Hecht & Appelbaum, 1988). Studying B. amazonicus , Carvalho et al.…”

“…Studying B. amazonicus , Carvalho et al. (2018) highlighted the importance of understanding social behaviour in order to propose effective measures to manipulate biotic and abiotic factors to reduce aggression and mortality in larval stages. Another factor to be considered may be nutrition, and it is important to search for diets that meet the requirements of larvae in order to avoid this problem (Toledo‐Solís et al., 2020), since the tested densities did not affect survival.…”

Does transcriptome of freshly hatched fish larvae describe past or predict future developmental trajectory?

“…Larvae from different families diverged mainly in growth-related traits, which probably influenced their cannibalistic behavior and development. Growth depensation has been commonly observed in many other fish species [28,33,34] and has always been considered a relevant determinant and predictor of fish survival since it can lead to aggressiveness and mortality. Furthermore, within a cohort of fish larvae, while aspects such as feeding behavior and swim bladder inflation rate tend to show a relatively homogenous pattern, differences become apparent in regard to growth quality between siblings, leading to variations in size.…”

Can turbid water and refuges with aquatic macrophytes increase the survival and growth of Brycon amazonicus larvae?

“…Brycon amazonicus is noted for being a fish of economic importance and has potential in aquaculture in Brazil and other South American countries (Muller, Villacorta-Correa & Carvalho, 2019) due to it being well accepted in the consumer market, and for having good growth performance (Zaniboni-Filho, Reynalte-Tataje & Weingartner, 2006;Gomes & Urbinati, 2010). However, one of the main difficulties for large-scale production is the low survival rate due to its aggressive behavior and cannibalism (Carvalho et al, 2018), which can result in more than 90% mortality during larviculture (Bernardino et al, 1993;Romagosa et al, 2001).…”