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Extracellular Calcium Concentration Affects Infectivity of Ichthyophthirius (Ciliophora) Theronts
Author(s) -
EWING MARGARET S.,
HEFLER CAROL,
KOCAN KATHERINE M.,
STEBLER ELAINE
Publication year - 1991
Publication title -
the journal of protozoology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 0022-3921
DOI - 10.1111/j.1550-7408.1991.tb04426.x
Subject(s) - calcium , extracellular , biology , infectivity , ichthyophthirius multifiliis , andrology , zoology , anatomy , microbiology and biotechnology , immunology , fish <actinopterygii> , medicine , fishery , virus
Tomonts and their theront offspring of the hymenostomatid fish parasite Ichthyophthirius multifiliis were exposed to calcium levels from 0 to 0.8 mM Ca 2+. The survival and reproductive rates of tomonts in the absence of extracellular calcium were not significantly different from rates of tomonts provided calcium. Theronts that developed in the absence of calcium, however, were not infective for Ictalurus punctatus even when the extracellular magnesium concentration was doubled. Theronts that developed in 0.10 mM Ca 2+ were infective (0.77 trophonts/mm 2 of pectoral fin) to essentially the same extent as theronts provided 0.33 mM Ca 2+. Infectivity of those provided 0.8 mM Ca 2+ was 1.79 trophonts/mm 2 of fin, similar to that of theront controls. Theronts deprived of extracellular calcium as they developed contained significantly fewer secretory mucocysts than did theronts provided 0.1 to 0.8 mM Ca 2+ although no significant differences among groups occurred with respect to abundance of crystalline or differentiating mucocysts. Theronts deprived of extracellular calcium also had swollen or enlarged mitochondria and abnormal crystalline mucocysts.