Seasonal population dynamics and maturation of Neoechinorhynchus pungitius (Acanthocephala: Neoechinorhynchidae) infecting brook stickleback, Culaea inconstans, from Sioux Creek, Wisconsin, U.S.A.

Abstract

Seasonal population dynamics and maturation of the acanthocephalan Neoechinorhynchus pungitius from brook stickleback (Culaea inconstans) were investigated. Stickleback were collected monthly at Sioux Creek, Wisconsin from April 1981 to May 1982 (excluding December, January, and February). Forty-seven percent (292/620) were infected with N. pungitius, which exhibited seasonal periodicity in prevalence, mean intensity, and maturation. Prevalence and mean intensities were lowest in summer and increased through autumn owing to recruitment of juvenile and immature worms. Prevalence and mean intensity reached their peaks by April and May, and N. pungitius infrapopulations were composed primarily of mature worms. Egg production began in May and continued throughout early summer. Neoechinorhynchus pungitius males appeared shorter lived than females, as the June and July infrapopulations were comprised mostly of females. Prevalence and mean intensity of N. pungitius increased as brook stickleback length increased. There was no significant difference between numbers of male and female fish infected or between mean intensity and host sex.

Prevalence and histopathology of Neoechinorhynchus curemai Noronha, 1973 (Acanthocephala: Neoechinorhynchidae) in Prochilodus lineatus Valenciennes, 1836 from Volta Grande Reservoir, MG, Brazil

“…By the other hand, an amplitude of variation about 1% to 100% prevalence of N. cylindratus in a several fish species in the Silver Lake and Tichigan Lake at South-eastern Wisconsin was observed (Amin, 1986). Nevertheless, Lasee (1989) related 47% prevalence of N. pungitius from brook stickleback collected in the Sioux Creek, Wisconsin. In Brazil, Brasil-Sato & Pavanelli (1999) observed 39.3% prevalence of N. pimelodi from P. maculatus during the studied period in the São Francisco River, Mi-nas Gerais State.…”

The natural history of Echinorhynchus bothniensis Zdzitowiecki and Valtonen, 1987 (Acanthocephala) in a high Arctic lake

“…In acanthocephalans displaying seasonality, adult sex ratios often become more female-biased over the course of a season, suggesting that females survive longer than males (e.g. Tedla and Fernando 1970, Valtonen 1980, Brattey 1988, Lasee 1989. This probably explains the over-representation of females of E. bothniensis in our fish samples.…”

Advanced development of the cystacanths of Neoechinorhynchus beringianus (Eoacanthocephala: Neoechinorhynchidae) living in intermediate hosts

“…Many authors have noted a category of females with compact ovaries in populations of Neoechinorhynchus species on various continents while studying the seasonal cycles of worms in definitive hosts. Among them are N. rutili in Europe (Moravec, 1984;Lassière, 1989), N. qinghaiensis Liu, Wang et Yang, 1981in Asia (Yang Tingbao, Liao Xianghua, 2001), N. pungitius Dechtiar, 1971 in North America (Lasee, 1989) and N. pimelodi Brasil-Sato et Pavanelli, 1998in South America (Brasil-Sato, Pavanelli, 1999. Given all these, one can conclude that ovarian division into balls at the cystacanth stage in species in which the infective larva have unfragmented ovaries should be considered as advanced development of the parasites.…”