Effects of ambient colour on colour preference and growth of juvenile rainbow trout Oncorhynchus mykiss (Walbaum)

Abstract

Colour preference of individual juvenile rainbow trout Oncorhynchus mykiss was tested at 1 and 12°C, and also at 12°C after a 42 day growth experiment under white, blue, green, yellow or red ambient colour. All experiments were carried out under controlled laboratory conditions and the preference was assessed by the location of the fish in a preference tank with four chambers. Rainbow trout showed a preference for blue and green at 1°C and for green at 12°C. After the growth experiment the fish reared in blue tanks preferred blue and green but green was the most preferred colour for the fish reared in green, yellow and red tanks. Yellow and especially red chambers were avoided, irrespective of the ambient colour during the growth trial. The final mass of fish reared in the red aquaria was significantly smaller than that of the fish in green tanks. In addition, when the data of the preference tests were correlated with the data of the growth experiment using mean values of the four tested colours, a very good linear relationship was observed between the preference (i.e. visit frequency in coloured compartments) and growth rate as well as food intake. When considering the results both from the preference and growth trials it is suggested that green is the best environmental colour for rearing juvenile rainbow trout while rearing in a red environment cannot be recommended.

<b>Behavioral profile of <i>Macrobrachium rosenbergii</i> in mixed and monosex culture submitted to shelters of different colors

“…According to Luchiari and Pirhonen (2008), knowledge on the effects of the colors on the farmed aquatic animals is still very restricted. Studies on the effect of environmental coloration may contribute to improve the culture environment and increase productivity.…”

“…Its territorial behavior (KARPLUS et al, 1992) among members of the same species, with the loss of the queliped, its main attack and defense organs (MARIAPPAN;BALASUNDARAM, 1999). In natural environment, the crustaceans live under fissures, burrows, stones or gastropod shells that protect specimens during agonistic encounters in intra and interspecific interactions (GARVEY et al, 1994).…”

“…for the animals to recognize the details of the environment . Some studies have demonstrated the influence of color in the biological processes of crustaceans and other aquatic animals (MARIAPPAN; BALASUNDARAM, 1999;VOLPATO et al, 2004;PIRHONEN, 2008;LUCHIARI et al, 2012).…”

“…Several studies have been conducted on the efficiency of shelters for the prawns M. rosenbergii (MURTHY et al, 2012), Macrobrachium nobilli (MARIAPPAN;BALASUNDARAM, 1999) and Macrobrachium australiense (LAMMERS et al, 2009). Current paper evaluates the occupation frequency of shelters for M. rosenbergii in male monosex, female monosex and mixed cultures, and analyzes the behavioral activities of the prawn in environments that offer different color shelters during light and dark phases.…”

Untitled

“…Conversely, excessively high LI can cause severe retinal damage, as reported in European sea bass Dicentrarchus labrax (L., 1758), Atlantic cod Gadus morhua (L., 1758) and Atlantic salmon Salmo salar (L., 1758) (Vera & Migaud, 2009) and increased aggressiveness in African catfish Clarias gariepinus (Burchell 1822) (Britz & Pienaar, 1992). Different TWC induce a variety of responses in relation to growth (Luchiari & Pirhonen, 2008), survival (Raghavan et al, 2013), aggression (Hoglund, Balm, & Winberg, 2002), stress response (Rotllant et al, 2003;Papoutsoglou, 2005), behaviour and feed acceptance (Strand, Alanara, Staffan, & Magnhagen, 2007). The LI and TWC can influence fish survival (Brannas, Alanara, & Magnhagen, 2001) and inflation of larva swim bladder (MartinRobichaud & Peterson, 1998), and optimal TWC is associated with lower incidence of mouth deformities (Cobcroft, Shu-Chien, Kuah, Jaya-Ram, & Battaglene, 2012).…”