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Factors Influencing Ectoparasitism On Western Fence Lizards (Sceloporus Occidentalis): Host Sex, Testosterone, Reproductive Condition, And Behavior, Nicholas B. Pollock
Factors Influencing Ectoparasitism On Western Fence Lizards (Sceloporus Occidentalis): Host Sex, Testosterone, Reproductive Condition, And Behavior, Nicholas B. Pollock
Master's Theses
Host-parasite relationships are one of the most common symbiotic relationships present in a diverse array of ecosystems. There are numerous factors that impact the dynamics of these relationships. Major factors that can influence the degree of parasitism include host sex, hormonal state, reproductive condition, and behavior. It has been observed in several vertebrate taxa that males have higher ectoparasite intensities than females and males with increased testosterone have increased ectoparasite intensities. One potential reason for these observations is that testosterone concentrations are elevated in males, particularly during the breeding season, and when circulating concentrations increase males become more vulnerable to …
Life History Characteristics Of The Starry Skate, Raja Stellulata, From California Waters, Kelsey James
Life History Characteristics Of The Starry Skate, Raja Stellulata, From California Waters, Kelsey James
Master's Theses
The order Rajiformes, or skates, is a morphologically conservative group that exhibits a wide range of life history characteristics. This inter-species variability warrants species-specific research. This study investigates the age, growth, reproduction, and habitat of the Starry Skate, Raja stellulata, which is endemic to the U.S. West Coast. Age and growth parameters were determined using two preparation techniques: gross sectioning and histological sectioning. The assumption that gross sections deposit one band pair a year was indirectly validated with centrum edge analysis and marginal increment ratio. It was not indirectly validated with histological sections. Age estimates from gross sections ranged from …