MOLLENHAUER, M.A.; BIESIOT, P.M.*; PERRY, H.M.; Univ. Southern Mississippi, Hattiesburg; Univ. Southern Mississippi, Hattiesburg; USM’s Gulf Coast Research Laboratory, Ocean Springs, MS: A Biochemical Analysis of Developing Eggs and Larvae of the American Horseshoe Crab Limulus polyphemus from Delaware Bay and the Gulf of Mexico

The American horseshoe crab Limulus polyphemus ranges along the Atlantic and the Gulf of Mexico coasts of North America. Although horseshoe crab eggs are an important resource for migrating shorebirds along Delaware Bay, nothing is known about the nutritional quality of these eggs during embryonic development or whether there are geographic differences in egg composition. Freshly fertilized horseshoe crab eggs were collected from New Jersey, Florida and Mississippi and were reared in the laboratory. Samples were taken at successive developmental stages (stages 1�21) through hatching and the first two larval instars (stages 22�23). Changes in biochemical composition correlated with the process of morphogenesis and the energy requirements for embryonic molting. Protein remained relatively unchanged, indicating a sparing for morphogenesis. Lipid remained relatively unchanged through stage 18, followed by a gradual decline through stage 22. Carbohydrate increased initially, and then followed a pattern similar to lipid. Ash was low throughout most of embryonic development, increased after the second embryonic molt, declined at hatching and increased again in the second instar larva. Patterns of yolk composition and rates of yolk utilization for embryonic and larval horseshoe crabs were generally similar regardless of collection location, except for significantly higher ash in New Jersey embryos. This study provides basic information about L. polyphemus reproduction and embryonic development in the Gulf of Mexico and may provide useful data for shorebird management.