The effect of ration on behaviour, food consumption and growth in juvenile greenback flounder (Rhombosolea tapirina: Teleostei)
Shelverton, PA and Carter, CG, The effect of ration on behaviour, food consumption and growth in juvenile greenback flounder (Rhombosolea tapirina: Teleostei), Journal of the Marine Biological Association of the United Kingdom, 78, (4) pp. 1307-1320. ISSN 0025-3154 (1998) [Refereed Article]
This study examined the relationships between food ration, intra- and interindividual variation in food consumption, observed behaviours and the growth of individual juvenile greenback flounder (Rhombosolea tapirina: Teleostei) held singly and in groups. Agonistic, feeding and neutral behavioural units were identified and described using video records and focal sampling. Agonistic behaviour, including nipping and pushing, were infrequent and accounted for <5% of behavioural units. The influence of food ration upon agonistic behaviour was investigated using three groups of six flounder offered either a low, medium or high food ration. The total number of agonistic behaviours recorded in each group did not differ significantly (P > 0.05) suggesting food ration had little influence upon the total number of agonistic behaviours performed. Single flounder showed less intra- and less interindividual variation in day-to-day food consumption than in groups of six. Variation in food consumption increased with increasing food ration in single and in groups of flounder. Significant positive correlations between food consumption, intraindividual variation in food consumption and specific growth rate provided indirect evidence for the presence of feeding hierarchies. The small contribution made by agonistic behaviour to the total number of behaviours recorded for each group suggests exploitation competition, as opposed to interference competition, was the dominant competitive mechanism employed by juvenile greenback flounder.