Energy Reserves in Male Three-Spined Stickleback, Gasterosteus aculeatus L. (Pisces, Gasterosteidae): Annual Variation and Relation to Reproductive Aggression
The aims of this project were to investigate the annual variation in energy reserves in males of a Scottish population of three-spined stickleback, Gasterosteus aculeatus and to relate this to their body condition and major life history events such as gonad maturation and breeding. Another aim of this study was to examine the association between energy reserves and reproductive aggression in the male sticklebacks. The work concentrated on estimations of energy sources (viz. glycogen, lipids and protein) in the different body compartments (viz. liver, gonad and carcass) of the fish over one complete year. The resulting observations were related to changes in body size, condition factor, somatic condition factor, hepatosomatic and gonadosomatic indices. The study involved regular monthly collection of sticklebacks from November 1985 to October 1986 from the River Kelvin in Glasgow. Samples collected during the months of August to December consisted fish of two different age categories namely the newly hatched young of the year and adult fish which had failed to breed. The 1+ adults survived until their second winter after which no fish of this age category were encountered in the sample. Fish were killed by immersing in liquid nitrogen and stored at -7
