No abstract

The parasite fauna of the stone loach (Barbatula barbatula) was investigated monthly from May to December 2001. Four parasite species were recorded: Gyrodactylus spp. (Monogenea), Tylodelphys clavata (Digenea), Proteocephalus sagittus (Cestoda), and Raphidascaris acus (Nematoda). The changes in the seasonal dynamics of parasite infection were investigated throughout the 8 months. The potential effect of the reproductive investment of the host, measured by gonad mass and gonado-somatic index (GSI), on the parasite infection was tested against the prediction that, during periods of high reproductive investment (beginning of the breeding period or forming gonads after breeding), the fish are more susceptible to parasite infection. Differences between parasite loads between genders were also hypothesized. Seasonal differences in infection were observed for all parasite species studied. The values of GSI showed a pattern of energy accumulation in the pre-reproductive period and at the beginning of breeding, a decrease during breeding, and an increase in the post-breeding period. A similar pattern was observed for parasite abundance, a strong or weak increase in spring and/or autumn and a decrease during summer (July and August). Positive correlations between the abundance of Gyrodactylus spp. and R. acus and both gonad mass and GSI were found in females after eliminating the effect of fish weight. Our results suggest that stone loach females are more susceptible to parasite infection in periods of higher reproductive investment. The main factor determining the infection of T. clavata was fish size. The abundance of P. sagittus was positively correlated with GSI in the total fish sample with no detectable effect of sex or fish weight. The increase in cestode infection in spring supports the hypothesis that the parasite life cycle could by synchronized with the beginning of host reproduction, probably induced by increasing fish hormone levels in the spring.

ABSTRACT:In parrots (Psi�aciformes), seven nematode species of genus Ascaridia have been found so far, both in wild birds and in birds in captivity. Five species are specific for parrots: Ascaridia hermaphrodita, A. sergiomeirai, A. ornata, A. nicobarensis and A. platyceri. Two species: A. galli and A. columbae, that infect gallinaceous and columbiform birds, respectively, were found also in parrots. On the basis of data from the literature and our own observations the taxonomy, synonyms and list of definite hosts of these nematode species were reviewed. The morphometrical features of nematode species were compiled and a determination key was added.

No abstract

Three out of 18 examined common mole-rats (C'~1ptoniys sp., karyotype 2n = 58) from Zambia were infested with cestodes (Inc.rniic.cip.s~~~fi.1. t t i~i r l u~~~~c . c~i i e t l s i s and an undetermined specics) and a nematode (Protospiruru ,murico/n). Four out of 14 examincd Zambian giant mole-rats (Cryy~o/nys ineclzoici) hostcd cestodes (Raillictincr ( R . ) sp. and an undcterniined species) and nematodes (ProioqJiruru inuricoki, Cupilluriu sp.). Heliniiiths and circumstances of findings tire briefly described. N o ectoparasites were found. The influences of subtcrranean and social way of life and feeding habits upon occurrence of parasites i n mole-rats are discussed. Burrow conditions and social behaviour seem not to favour inkslation by parasites. lntroductionThe family Bathyergidae includes five genera of subterranean rodents, all endemic to the subSaharan African region. Among them the genus C r J y r o q s (common or Gray's mole-rat) is exceptional in several aspects. Unlike other bathyergids, the genus Crlptonzjis is widely distributed (from Ghana to the Cape Province in South Africa) and eurybiomic. Honeycutt ct ul.(1 991), in their revision of taxonomy of bathyergids, have recognized seven species of Crjptonij3.v.