Seasonal Distribution and Ecology of Three Caryophyllaeid Cestode Species Infecting White Suckers in SE New Hampshire

Abstract

The caryophyllid species found in 423 Oyster River and 350 Bellamy River white suckers were Glaridacris catostomi Cooper 1920; G. laruei Lamont 1921; and Isoglaridacris bulbocirrus Mackie- wicz 1965 (Cestoda: Caryophyllaeidae). The prevalence and mean intensity of G. catostomi and G. laruei in Oyster River hosts were highest in spring 1975 and 1976 and in winter 1976-1977, and corresponded to the collection and examination of large suckers that had moved into the Oyster River sampling area. The mean intensity of G. catostomi in Bellamy River hosts was highest in spring 1975 and 1976. In the same hosts, the mean intensity of I. bulbocirrus was highest in spring 1975 and 1976, fall 1975, and winter 1976-1977. Isoglaridacris bulbocirrus and G. laruei were nonseasonal in prevalence and mean intensity in Oyster and Bellamy River suckers, respectively. Glaridacris catostomi and I. bulbocirrus occurred in the anterior intestinal area of white suckers col- lected from both localities. Glaridacris laruei was found throughout the intestine, but the majority of worms occurred in the posterior intestinal area. In Oyster River suckers, there was evidence that intra- specific competition occurred by G. catostomi and G. laruei. The mean size of gravid worms of these species decreased as the population density of each increased in their respective intestinal areas. As parasite intensity decreased, mean size increased. The significant correlation coefficients calculated be- tween the prevalence and/or mean intensity of each cestode species with fish length were all positive. Male and female white suckers had similar prevalences and mean intensities of each species. The state of New Hampshire is a new locality record for G. catostomi, G. laruei, and I. bulbocirrus.