Correlations of Heavy Metal Concentrations in Alligator Eggs with Reproductive Parameters
D.M. Metzer; E.J. Skoch; H.F. Percival; P.T. Cardekhac
Marine Mammal Research Lab, John Carroll University, University
Heights, OH; Florida Cooperative Fish and Wildlife Research Unit; College of Veterinary
Medicine, University of Florida, Gainesville, FL
Abstract
Approximately 30 alligator eggs were collected for metal analysis from
17 to 30 nests selected at random from each of the 6 largest lakes or collection areas in
Florida. Thirty eggs from nine nests were collected at a productive area in Louisiana and
served as controls. Thirty eggs were randomly collected from each of 4 alligator farms (where
diet was approximately known) for a comparison. The following reproductive parameters for
nests from each lake were determined: clutch size, clutch mass, egg size, deviation of egg
from spheroidal shape, egg major/minor axis ratios, egg yolk percent, egg white percent, egg
shell percent, egg membrane percent, egg fertility, embryonic death rate, developmental stage
of the dead embryo, and hatching yield. Hatchling vigor was determined for each lake. Egg
white and yolk were separated from each egg and digested by a cold acid technique.
Concentrations of As, Cd, Cu, Fe, Ni, Pb, and Zn were determined for the egg white and yolk
of each egg by means of a flame atomic absorption spectrophotometer. Mean value and the range
of metal concentrations for eggs from each lake were determined and correlated with
reproductive parameters determined for the lake.