Behavior and Ethology Commons^™

The Fish Assemblages Inside And Outside Of A Temperate Marine Reserve In Southern California, John T. Froeschke, Larry G. Allen, Daniel J. Pondella Ii

Daniel Pondella

The purpose of this investigation was to evaluate the effect of a small marine reserve (established 1988) on a temperate rocky reef fish assemblage at Santa Catalina Island, California. Fish surveys on SCUBA were conducted at two reserve and two non-reserve sites from October 2002 to January 2004. Sites were similar in fish density, species richness and biomass of the entire fish assemblage. However, the adult densities of two important fishery species, California sheephead (Semicossyphus pulcher; 7.6 0.5 and 5.5 0.4/100 m2 inside versus outside) and kelp bass (Paralabrax clathratus; 3.6 0.4 and 2.9 0.4 inside versus outside), were significantly …

Divergence In Thyroid Hormone Concentrations Between Juveniles Of Marine And Stream Ecotypes Of The Threespine Stickleback (Gasterosteus Aculeatus), Jun Kitano, Sean C. Lema

Sean Lema

Background: Hormones regulate the expression of multiple phenotypic traits. Therefore,

divergence in hormone concentrations may lead to evolutionary changes in the coordinated

physiological and behavioural traits that comprise an organism’s integrated phenotype. Adults

of marine ecotypes of threespine stickleback (Gasterosteus aculeatus) have higher concentrations

of the thyroid hormone thyroxine (T4) than adults of stream-resident ecotypes (Kitano

et al., 2010). Thyroid hormones are well-established mediators of osmoregulation and migratory

behaviours in fish, and the difference in T4 concentrations indicates that changes in thyroid

hormone signalling may underlie the evolutionary and ecological divergence of migratory and

non-migratory ecotypes.

Questions: Is the variation …