Taxonomy and Osmoregulatory Capacity in Non-native Herichthys Cichlid Fishes in the Gulf Coast Region

A special Aquaculture Seminar will be presented by Ronald Oldfield, Senior Instructor, Case Western University Department of Biology. He will present Taxonomy and Osmoregulatory Capacity in Non-native Herichthys Cichlid Fishes in the Gulf Coast Region. This seminar will be held in 333C and hosted by Konrad Dabrowski.

The Rio Grande Cichlid, Herichthys cyanoguttatus, has been introduced to several sites in the southern US. Herichthys cf. cyanoguttatus specimens sampled in Louisiana had an obliquely oriented mouth, a rounded ventral profile, and larger iridescent spots than those in Texas. I determined their taxonomic identity not to be H. cyanoguttatus but H. carpintis, a species more often found in estuarine environments. Surprisingly, I found little difference in osmoregulatory capability between the two species, indicating that we should not expect differences in range expansion between the two species based on salinity.

Broadly stated, the goal of my research is to study the origin and conservation of biodiversity. I study the evolution of social behavior, with a focus on mating systems. Why do some males and females form monogamous social bonds to care for their offspring, whereas others might try to mate with as many partners as possible? I use cichlid fishes from Central America as a model system to answer this question. Using the knowledge of the evolutionary relationships among species, it is possible to identify the causes and mechanisms underlying evolutionary transitions in behavior. Methods currently used involve behavior, ecology, anatomy, endocrinology, and systematics and taxonomy. The research justifies the conservation of threatened fish species and their habitats. Also, monogamy and polygamy are issues that humans struggle with in their everyday lives, so the research has important implications beyond fish conservation.

I also study behavioral ecology of local Ohio fishes in order to contribute to the conservation of native biodiversity.