Fish Biology RSS
Stock enhancement (SE), or the release of cultured fish into the wild to support native fisheries, has been used since the late nineteenth century. The goal of SE typically is to overcome the phenomenon of recruitment limitation (Munro and Bell 1997, Doherty 1999) in which the natural supply of juveniles fails to reach the carrying capacity of the habitat even though there may be sufficient numbers of spawning adults; however, it is also possible to supplement wild stocks without regard to the level of recruitment to simply support increased fishing pressure (Lorenzen 2005).
Today we’re breaking down endotherms vs. ectotherms, specifically as it pertains to fishes and how they deal with thermoregulation. The prefix endo- means ‘internal’ or ‘within’ and the prefix ecto- means ‘external’ or ‘outside’. The suffix therm- means ‘heat’. In fish speak, and biology speak in general, an endotherm is an organism that generates heat within its own body. In colloquial terms, we know these animals as warm-blooded. Ectotherms are just the opposite in that they cannot generate heat from within their own bodies (i.e., cold-blooded), and must rely on external heat sources for body temperature regulation (e.g., the sun).
The caudal fin is the culprit for every heart wrenching snapped line and straightened hook. The caudal fin is the reason we fishermen enjoy fishing – the thrill of the fight. We are addicted to the caudal fin. Dive in with us and explore species-specific evolutionary adaptations of the caudal fin, and how they are used.