Research Product

Procedures for static 96-hour bioassays utilizing grass shrimp larvae, Palaemonetes sp., are outlined here. The grass shrimp is an obvious bioassay choice for several reasons. Three species of the genus, P. pugio, vulgaris, and intermedius, are common inhabitants of estuaries along the Gulf and Atlantic coasts of the United States. They are easy to collect and maintain in the laboratory. Field populations are usually quite large, allowing greater numbers to be brought into the laboratory for testing. By manipulating environmental conditions of temperature and photoperiod, it has been possible to induce spawning in the laboratory, opening the way to laboratory cultures of genetic uniformity. Developing larvae are also available throughout the year for testing with these methods. Larval stages of the three species are hardy and easy to culture in the laboratory. Developmental stages have been described for all species, and salinity-temperature optima are known for the larval development of P. vulgaris. Developing larvae have demonstrated a susceptibilty to polychlorinated hydrocarbons greater than adults or juveniles.