Seasonal abundance of Proteocephalus ambloplitis (Cestoidea: Proteocephalidea) from largemouth bass living in a heated reservoir.

Abstract

Proteocephalus ambloplitis was recovered from largemouth bass inhabiting different thermal regimes, ranging from normal to greater than 10 degrees C above normal, on the Energy Research and Development Administration's (ERDA) Savannah River Plant near Aiken, South Carolina. Possible alterations in the mechanisms initiating plerocercoid migration as proposed by Fischer & Freeman (1969) were noted. According to these authors, a rise in temperature from 4 to 7 degrees C and above stimulated migration of parenteric plerocercoids into the gut. The lowest water temperature recorded for the reservoir for the entire sampling period was 8.0 degrees C. Theoretically, this should have terminated the life-cycle of this tapeworm since migration temperature was never attained. At Savannah River, the appearance of adult tapeworms coincided with a decrease in water temperature, while the appearance of adult tapeworms in Canada was correlated with an increase in water temperature. It is postulated that the decline in water temperature in southern latitudes and the increase in water temperature in northern latitudes initiates the same response, that is, migration of plerocercoids from parenteric to enteric sites where maturation to the adult form ensues.