The effects of salinity and temperature on the development and survival of fish parasites

Abstract

In brackish water the variety of marine and freshwater parasite species is considerably reduced. The distribution in brackish water of most marine endoparasites is restricted by the salinity tolerance of their hosts, most of the parasite species are more tolerant than their hosts. The influence of salinity and temperature on nine species has been examined; first stage larvae of Contracaecum aduncum develop in 0-32%, salinity; CryptocotyZe lingua proved to be infective at salinities down to 4%,. The greatest resistance was found in Anisakis larvae from herring Clupea harengus, which survived for more than half a year. Parasites in the fish intestines appear to be unaffected by changing water salinities, as the osmolarity in the intestines stays nearly constant. Marine ectoparasites (Acanrhochondria depressa, Lepeophtheirus pectoralis) survive about three times longer than freshwater species (Piscicola geometru, Argulus foliuceus) when salinity is 16%,. High temperature increases the effects of adverse salinities on parasites. There is evidence that none of these ectoparasitic species can develop within the range of 7-20%, salinity.

Richness and Diversity of Helminth Communities In the Japanese Grenadier Anchovy, Coilia nasus, During Its Anadromous Migration In the Yangtze River, China

“…However, H. tenuis on the gills and E. coiliae in the stomach were absent from Anqing, the locality most distant from the estuary. Osmotic pressure in stomach changed easily with the water salinity outside the fish, and the ectoparasite was stenohaline; i.e., Argulus foliaceus could survive about 2 wk (Mö ller, 1978). Thus, the absence of H. tenuis and E. coiliae at the Anqing locality was due to the unstable osmotic pressure in stomach and the stenohalinity of ectoparasites.…”

“…and the acanthocephalan Neoechinorhynchus salmonis in intestine were observed between the host sockeye salmon (O. nerka) smolts held in freshwater or saltwater (Bailey et al, 1989). In freshwater at 10 C, the endohelminth Anisakis larvae when removed from the host and the nematode cysts in vitro can survive more than 2 mo (Mö ller, 1978). However, H. tenuis on the gills and E. coiliae in the stomach were absent from Anqing, the locality most distant from the estuary.…”

“…in intestine. The constant mean abundance among the 3 localities perhaps was due to the stable osmotic pressure condition in intestine of their hosts (Mö ller, 1978) and the strong salinity tolerance of endohelminths. Larvae of A. crassus, a nematode in swimming bladder of their hosts, survived up to 100 days in freshwater, 70 days in 50% seawater, and 40 days in 100% seawater (Kirk et al, 2000).…”

“…Although some Anisakis spp. larvae with high salinity tolerance survived for more than half a year in freshwater, some survived less than 3 mo (Mö ller, 1978). In a previous study, the prevalence and mean abundance of marine parasites in the anadromous fish C. nasus decreased when spawning was completed in freshwater and returned to the Yangtze Estuary (Li et al, 2011).…”

Population biology of Allocreadium lobatum Wallin, 1909 (Digenea: Allocreadiidae) in the creek chub, Semotilus atromaculatus, mitchill (Osteichthyes: Cyprinadae), in a Nebraska Creek, USA

“…The fact that changes were found that differed from previous studies may have to do with factors such as pH and conductivity that were not measured in this study. Additionally, temperature may have effects on the rate of development, life expectancy, and infection rate of the parasite (Bauer 1959, Kennedy 1975, Chubb 1977, Evans 1977, Möller 1978.…”