Temperature and salinity effects on postembryonic development of the neotropical calanoid Boeckella poopoensis Marsh, 1906 (Crustacea, Copepoda)

Abstract

ABSTRACT Because temperature and salinity affect life cycle of copepods, the aim was to determine the influence of both factors upon postembryonic development ofBoeckella poopoensis. Bioassays with 5, 10, 20, 30, and 35 g/Lat 15° and 22°C were carried out. At 15°C, specimens needed 21-26 days to complete its development in the four lower salinities, but did not pass from naupliar stages in 35 g/L. At 22°C complete development fluctuated from 13 (5, 10, and 20 g/L) to 22 and 41 days (30 and 35 g/L). The greatest mortality was registered at higher salinities, especially at 15°C, as lower metabolism may not have contributed sufficient energy for osmoregulation. Though it is a halotolerant species, low temperatures could reduce its tolerance, suggesting that this factor would limit its distribution in South America (nowadays up to 43°S). Changes in these conditions due to global warming could allow its advancement to the South.