SEMINAR: MBF602 Cheryl Chan Friday 01-21-11, 1 pm S/A 103

["Cheryl" <kchan@rsmas.miami.edu>]

Acute copper toxicity mechanisms in blue crab, Callinectes sapidus at different salinities

 

Abstract

 

The interactions between salinity and acute toxicity of copper in euryhaline teleost are determined by Na⁺ gradients across the gill. However, there is limited information regarding acute copper toxicity in euryhaline invertebrates such as crustaceans at different salinities. Blue crabs are strongly euryhaline, of sufficient size for physiological measurements and as such well suited for the study of copper toxicity at different salinities. Blue crabs were acclimated to different salinities for one week after which water and hemolymph samples were collected to determine Na⁺ gradients and thus the Na⁺ equilibrium potential (Ep). In addition, the gill transepithelial potential (TEP) was measured. The electrochemical (ECp) Na⁺ gradients of blue crabs across a range of salinities were obtained from the calculated Ep and measured TEP. Results showed that the hemolymph osmolarity and ion concentrations increased with increasing salinity and that TEP decreased. From these observations, the magnitude of the gill ECp of blue crabs increase with decreasing salinity illustrating a greater need for active Na⁺ transport at lower salinities compared to SW. Based on this analysis higher sensitivity to acute copper toxicity is expected at lower salinities, an expectation which is currently being tested.

 

Cheryl Chan

 

B.S. Zoology, Universiti Sains Malaysia (2002)

M.Sc Aquatic, Universiti Sains Malaysia (2006)

Entered Ph.D. program in fall of 2008

 

Advisor: Martin Grosell