Variations in condition and body constitution in a tropical estuarine fish with year-round recruitment

Abstract

Fish condition (Fulton's K) and the abundance of biochemical constituents (water, protein, lipid and carbohydrate) of juveniles of the tropical estuarine fish, Ambassis vachelli, were monitored over a 15 month period. Fulton's K and biochemical constituents of juveniles recruiting into the adult habitat varied significantly throughout the study. Correlations between Fulton's K and all biochemical measures were weak, with a maximum correlation of 0.1379 (with protein abundance). Significant differences in condition and body constitution of individuals suggest that juveniles recruiting into the adult habitat are not in equal condition and therefore survivorship and success may vary within and among cohorts. Temperature (and salinity) display greater variation in tropical estuarine waters than in other tropical waters and are likely to play a role in determining recruit condition and body constitution. However, the exact role of physical parameters in determining condition and body constitution of fishes is still unknown.