The pattern of giant nuclei in neoechinorhynchus rutili acanthocephala neoechinorhynchidae
Amin, O.M.; Gunset, M.
Transactions of the American Microscopical Society 111(1): 65-69
The pattern of giant nuclei was studied in 300 specimens of Neoechinorhynchus rutili collected from carp, Cyprinus carpio, from the Macha Lake fishpond system, Czechoslovakia. The giant hypodermal, lemniscal, and cement gland nuclei usually were spheroid or ovoid in prereductive stages, elongate or lobulated in reproductively active adults, and spheroid postreproductive adults; the latter stage was rarely encountered. Reproductive activity extends well beyond the season(s) during which gravid females are recovered in the field. Structural changes of giant nuclei were associated with the initiation and retention of the reproductive state of N. rutili. This pattern is similar to that reported for three other species of Neoechinorhynchus and thus may be of common occurrence in neoechinorhynchid acanthocephalans. Moreover, the pattern in N. rutili sows some overlap of stages and abbreviation of the postreproductive stage similar to the pattern of Neoechinorhynchus robertbaueri, which has a short lifespan (2-4 months) in its fish definitive host and a brief reproductive period.