Hierarchical status and colour preference in Nile tilapia (Oreochromis niloticus)

Abstract

We studied the colour preference of isolated Nile tilapia (Oreochromis niloticus) and whether previous residence or body size can affect environmental colour choice. In the first phase, a cylindrical tank was divided into five differently coloured compartments (yellow, blue, green, white and red), a single fish was introduced into the tank and the frequency at which this fish visited each compartment was recorded over a 2-day study period. An increasingly larger fish (approx +2 cm in length each time) was then added into the tank on each of days 3, 5 and 7 (=four fish in the tank by day 7), and the frequency at which each fish visited the different compartments of the tank was observed twice a day to obtain visit frequency data on the differently sized fishes. This experiment was replicated six times. In the first phase, the solitary fish established residence inside the yellow compartment on the first and second days. Following theintroduction of a larger fish, the smaller fish was displaced from the occupied compartment. Nile tilapia possibly shows this preference for yellow as a function of its visual spectral sensitivity and/or the spectral characteristics of its natural environment. Moreover, body size is an important factor in determining hierarchical dominance and territorial defence, and dominant fish chose the preferred environmental colour compartment as their territory.

A history-based method to estimate animal preference

“…Colour preference for fish has been demonstrated by several studies; however, most studies demonstrate one preference for the entire sample of fish30404142. These studies, however, used a small number of daily tests (usually 1 to 4 tests), whereas we used 10 successive days of testing.…”

“…We used the fish Nile tilapia, Oreochromis niloticus (L.), in background colour choice tests. This species has been described to prefer yellow light (2-day test30), and some colours have been demonstrated to affect its behaviour31323334 and physiology323435.…”

Effects of tank colour on feeding, growth and stress responses of young taimenHucho taimen(Pallas, 1773)

“…The colour red seems to have negative effects on the growth and behaviour of several fish species (Ruchin, ; Luchiari et al., ; Rahnama et al., ). However, there were no significant differences in growth among all treatments in this study.…”

“…Young H. taimen seemed to preferred a yellow environment, while red was better for zebrafish, Danio rerio (Spence and Smith, ); blue for barramundi (Ullmann et al., ); and yellow for Nile tilapia, Oreochromis niloticus (Luchiari et al., ).…”

Overlap of Home Ranges of Resident and Introduced Southern Rock Lobster after Translocation

“…Color is frequently a secondary sexual characteristic used to demonstrate fitness or aggression, as it signals better health (Ressel and Schall, 1989;Olson and Owens, 1998), higher reproductive performance (e.g., access to mates, Evans and Norris [1996]; sperm velocity, Janhunen et al [2009]), and better access to critical resources (Luchiari et al, 2007) in a large range of taxa. In the study species, J. edwardsii, size and morph were not indicative of any dominance hierarchy, and a previous study demonstrated that size and color did not influence survival in translocated SP J. edwardsii compared with resident LRs (Green and Gardner, 2009).…”