Meeting Abstract

101.2  Thursday, Jan. 7  Immunohistochemical and Histological Analyses Indicating the Presence of SCP-like Neuropeptides in Larval Crassostrea virginica (Bivalvia) ELLIS, IE*; KEMPF, SC; Auburn University; Auburn University ellisir@auburn.edu

The Eastern oyster Crassostrea virginica is an important species within both estuarine ecosystems and the aquaculture industry. Investigating how the larval nervous system affects larval behaviors, such as settling, could reveal information to aid in the restoration of declining populations and aquaculture practices. Although a few immunohistochemical studies have been conducted, there has been no documentation to date identifying the location of small cardioactive peptides (SCPs), a common neuropeptide in molluscan larvae. In this study, larvae at the D-hinge, umbo, and pediveliger life stages were purchased from the Dauphin Island oyster hatchery. SCP-like neuropeptide analyses were conducted using two techniques: 1) labeling of SCP neuropeptides via a Diaminobenzidine kit and then embedding the larvae in Epon 812 for histological examination or 2) immunohistochemical labeling to visualize SCP-like neuropeptides using a laser-scanning, confocal microscope. Progressive development of the central nervous system of C. virginica, along with investigations of the presence and location of SCP-like neuropeptides were examined. Here, we found SCP labeling at the D-hinge stage, indicating that this neuropeptide is present in the early larval stages of development. Additionally, SCP labeling becomes more predominant as development continues towards competency. Nerve processes containing SCP were found throughout the central nervous system loop, which includes 3 paired ganglia: the cerebro-pleural, pedal and visceral ganglia. At the pediveliger stage, SCP-like neuropeptides were found in 1-2 and 2-3 neuron cell bodies within the cerebral and visceral ganglia respectively.