title: Feeding behaviour, swimming activity and boldness explain variation in feed intake and growth of sole (Solea solea) reared in captivity.
abstract: The major economic constraint for culturing sole (Solea solea) is its slow and variable growth. The objective was to study the relationship between feed intake/efficiency, growth, and (non-) feeding behaviour of sole. Sixteen juveniles with an average (SD) growth of 2.7 (1.9) g/kg(0.8)/d were selected on their growth during a 4-week period in which they were housed communally with 84 other fish. Selected fish were housed individually during a second 4-week period to measure individual feed intake, growth, and behaviour. Fish were hand-fed three times a day during the dark phase of the day until apparent satiation. During six different days, behaviour was recorded twice daily during 3 minutes by direct observations. Total swimming activity, frequency of burying and of escapes were recorded. At the beginning and end of the growth period, two sequential behavioural tests were performed: "Novel Environment" and "Light Avoidance". Fish housed individually still exhibited pronounced variation in feed intake (CV = 23%), growth (CV = 25%) and behavior (CV = 100%). Differences in feed intake account for 79% of the observed individual differences in growth of sole. Fish with higher variation in feed intake between days and between meals within days had significantly a lower total feed intake (r = -0.65 and r = -0.77) and growth. Active fish showed significantly higher feed intake (r = 0.66) and growth (r = 0.58). Boldness during both challenge tests was related to fast growth: (1) fish which reacted with a lower latency time to swim in a novel environment had significantly higher feed intake (r = -0.55) and growth (r = -0.66); (2) fish escaping during the light avoidance test tended to show higher feed intake (P<0.1) and had higher growth (P<0.05). In conclusion, feeding consistency, swimming activity in the tank, and boldness during behavioral tests are related to feed intake and growth of sole in captivity.
authors: Aquaculture and Fisheries Group, Wageningen University, Wageningen, The Netherlands. julia.mas@wur.nl
authors: Julia
authors: J
authors: Mas-Muñoz
authors: Hans
authors: H
authors: Komen
authors: Oliver
authors: O
authors: Schneider
authors: Sander W
authors: SW
authors: Visch
authors: Johan W
authors: JW
authors: Schrama
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D005247:Feeding Behavior / Q000502:physiology; D005412:Flatfishes / Q000254:growth & development* / Q000502:physiology*; D013550:Swimming / Q000502:physiology