Date of Degree
John R. Waldman
Pokay M. Ma
Robert E. Schmidt
Little is known about the ecology of the clam shrimp, Caenestheriella gynecia. Caenestheriella gynecia was first discovered in 1939 in a single pool in Oxford, Ohio. Schmidt and Kiviat (2007) reported four new localities of C. gynecia in New York and New Jersey, three within the Hudson Valley of New York and one in northeastern New Jersey. Caenestheriella gynecia may have originated from a very small founder population due possibly to unusual dispersal vectors from its natural range to the west, in Ohio. Egg samples and hatched individuals were obtained from all study sites and specimens were raised in the lab to estimate several growth and survivorship traits. In the field, puddle habitats were observed between the months of May and August where water quality parameters (i.e., dissolved oxygen, temperature, conductivity and pH, and nutrient composition) were recorded. Genetic comparisons across the study sites were made using nuclear DNA sequencing and random amplified polymorphic DNA (RAPD) analysis. The results of this study presented a wide range in the hydro-chemical and physical characteristics of the ephemeral pools in which C. gynecia seem to tolerate.
Morphologically, New Jersey and Massachusetts populations possessed meristics counts within the range of those discovered by Mattox in 1950. However, I recommend the placement of the New York population within the Cyzicus genus as their meristic measurements fell outside the range for Caenestheriella. RAPD results revealed the presence of more than one clone in puddles containing C. gynecia although mtDNA sequencing did not reveal any genetic variation within or among populations. The lack of males within C. gynecia's population and low levels of genetic variability support the clonal nature of a strictly parthenogenetic species. These investigations provide a substantial extension of fundamental knowledge of this poorly understood species.
Orridge, Jonelle, "Genetic, Morphological and Ecological Relationships Among Populations of the Clam Shrimp, Caenestheriella gynecia" (2011). CUNY Academic Works.