Two experiments were conducted to study the influence of salinity and desiccation on the development of first-stage larvae in eggs of Eustrongylides ignotus. In cultures of low salinities (0, 10, and 20 parts per thousand [ppt]) 54% to 60% of the eggs contained first-stage larvae by day 90, but no development occurred in the eggs incubated in seawater (40 ppt). Development of eggs in cultures that were exposed to sunlight and allowed to dry down was ca. 1%, whereas 57% to 62% development occurred in cultures maintained in deionized water.