A Method for Estimating Egg Numbers in Egg Clutches of The Exotic Apple Snail Pomacea maculata Without Affecting Clutch Viability

The exotic apple snail Pomacea maculata appears to be gradually extending its range and increasing its density through much of south Florida. As a consequence, there is increasing interest in understanding its life history. One difficulty encountered in studying P. maculata is that it lays large, multilayered clutches of very small eggs that are impossible to count without disaggregating the egg mass; which results in the loss of viability. Using a previously described dis-aggregation technique, we weighed, dis-aggregated, photographed, and counted 70 egg masses of P. maculata collected from various locations in Lake Okeechobee. Using the resulting mass and egg numbers we developed an algorithm that reliably relates clutch mass to the number of eggs in a clutch, allowing the estimation of the number of eggs in a clutch without impacting the eggs’ viability and paving the way for investigations into studies on fecundity, hatching rate, etc.