The morphology of a rather rare parasitic copepod was studied. Ismaila monstrosa Bergh, an endoparasitic copepod was found in the nudibranch, Antiopella fusca, at Coos Bay, Oregon. Many anatomical features were found, ...

Sexual selection can influence the mating system of an organism through multiple mechanisms. These mechanisms result in variation in reproductive success among individuals, and include scramble competition, endurance ri ...

A primary goal of population genetics is to identify the role of microevolutionary forces in producing observed patterns of molecular and phenotypic variation. I conducted four studies in the northern leopard frog, Ran ...

Recruitment of larvae from the plankton is an important determinant of community structure in marine systems. In populations of many marine species, recruitment determines the basic demographic parameters of immigratio ...

The gonadal steroids, testosterone and estradiol, are known to be important modulators of neuronal functions and behaviors in most vertebrate species. These steroid hormones also elicit changes in neuropeptide synthesi ...

In nature, animals survive threats by responding physiologically and behaviorally in ways that are appropriate to the situation. Which responses are appropriate depend on the animals' surroundings and current physiologic ...

Osmotic and ionic regulation was studied in the Dungeness crab, Cancer magister, after acute exposure to a range of five salinities from 25% to 125% sea water (100% = 32%). Blood, urine and muscle tissue were sampled ...

Postcopulatory sexual selection—sperm competition and cryptic female choice—has become a major area of research over the past 40 years. Within this field there are many outstanding questions at every level of analysis, f ...