Some aspects of salinity and temperature stress on Neanthes arenaceodentata Moore

Abstract

Organismic functions of Neanthes arenaceodentata Moore were studied in response to thermosaline stresses. Capacities for chloride ion concentration, osmoconcentration and body volume regulation were first considered. Chloride ion and osmoconcentrations of the coelomic fluid in relation to the environment were examined at room temperature. The chloride concentration of the coelomic fluid varied directly with that of the environment and was maintained at a hypo-chloride concentration. The osmoconcentration of coelomic fluid followed a conformity response, but was slightly and significantly hyperosmotic. Body volume regulation was studied under factorial conditions and the ratio of body water to wet weight was found to vary between 0.8 and 0.9 suggesting that the environment influenced its capacity for body volume regulation. Salinity and temperature affected the steady state levels of oxygen consumption of N. arenaceodentata. Size exhibited an endogenous effect and the positive size coefficient (b = 0.51) was found insensitive to treatments. Thermal sensitivity occurred at optimal salinity, but at the lower salinities, other factors were affecting respiratory rates. No difference of oxygen consumption was attributed to sex.