Abstract
SUMMARYFreshwater shrimp,Palaemonetes paludosus, infected by the bopyrid isopod,Probopyrus pandalicola, occurred as far as 33 km upstream in many coastal rivers and canals throughout Florida. Free-swimming isopod larvae and the intermediate copepod host,Acartia tonsa, were collected in the plankton of the Wakulla River, and it appeared that cryptoniscus larvae swam at least as far as 13 km upstream to infect the definitive shrimp host after leaving the copepod in brackish water. In the Wakulla River infection levels ranged from 87·5 to 100%. In contrast, at McBride's Slough infection levels fluctuated from 0·9 to 93·2%. In the St Marks River the frequency of infected shrimp gradually increased from 0% upstream to 96%, 6 km further downstream. A significantly greater percentage of female than male hosts were infected, but only females of size classes less than 31 mm long had a greater frequency of infection. FemaleP. pandalicolawere greatly under-dispersed (coefficient of dispersion (s2/x¯) less than 1) throughout the host population; 99·6% of the infected hosts carried only 1 female parasite. Control ofP. pandalicolaat the infrapopulation level is probably accomplished by some mode of intraspecific competition, and control at the suprapopulation level occurs through an upstream limitation of the transmission range of the cryptoniscus larval stage. Host–parasite interactions appear to be unstable.
Publisher
Cambridge University Press (CUP)
Subject
Infectious Diseases,Animal Science and Zoology,Parasitology
Reference82 articles.
1. Probopyrus pandalicola: Discontinuous ingestion of shrimp hemolymph
2. The American land and fresh-water isopod Crustacea;Van Name;Bulletin of the American Museum of Natural History,1936
3. Thompson S. M. (1977). Vascular plant communities and environmental parameters under tidal influence on the Wakulla and St Marks Rivers, Florida. M.S. thesis, Florida State University.
4. Note on Cyproniscus ovalis n. sp. a new cryptoniscan parasite (Epicaridea, Isopoda) found on Cypridina hirgendorfi;Shiino;Annotationes Zoologicae Japonenses,1942
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