http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Development, growth and environmental adaptations in two genetically distinct populations of the eastern oyster, Crassostrea virginica(GMELIN)
Martinez-Bucciantini, Mirella Concepcion.
xiv, 133 leaves : illustrations, maps ; 28 cm.
Development, growth, survival and environmental adaptations of two genetically distinct populations were studied. Broodstock from Offatt's Bayou, Galveston, Texas and the Lower Laguna Madre, Texas, were acclimated and spawned to produce two pure (LL and GG) crosses and their reciprocal hybrids (GL and LG). Larvae from these crosses were raised in 20%o and 40%0 from day 5 post fertilization to settlement. On day 97, one half of the individuals in each cross was transferred to the Laguna Madre and the other half was raised in Offatt's Bayou in Galveston Bay. Gametic incompatibility and/or outbreeding depression between the two populations was apparent. Early larval survival was greatest among the pure crosses. Size differences were apparent between the treatment salinities. Larvae grown at 20%o were larger those grown at 40%o. In general, metamorphic success was greater among larvae grown at 20%o. However, the Laguna Madre pure cross exposed to 40%o as larvae had the highest metamorphic survival rate. There was a strong relationship between larval size and metamorphic success. Survival rates from day 97 to day 249 were higher in the Laguna Madre. Growth rates in Galveston Bay were similar among all crosses, but in the Laguna Madre larval exposures to high and low salinity affected the growth of Laguna Madre pure crosses. Differences were also found among several morphometric parameters. Size variances within crosses and treatment groups were larger in the Laguna Madre than in Galveston Bay and the variance varied with age. Allozyme studies indicated selective mortality at the larval and/or metamorphic stages due to salinity treatment. In the pure Laguna Madre cross, those exposed to 20 and 40%o salinity as larvae differed at the Gpi-2 locus, while the hybrids differed at the Mdh-2 locus. A genetic-environmental interaction among groups was also apparent when I analyzed the correlation between genotypes and morphometric parameters.
by Mirella Concepcion Martinez-Bucciantini.
"Major Subject: Wildlife and Fisheries Sciences".
Issued also on microfiche from University Microfilms Inc.