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2. Component population study of Acanthocephalus tumescens (Acanthocephala) in fishes from Lake Moreno, Argentina
- Creator:
- Rauque, Carlos A., Viozzi, Gustavo P., and Semenas, Liliana G.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Acanthocephalus tumescens, Patagonian freshwater fishes, host status, component population, and suprapopulation
- Language:
- English
- Description:
- Seasonal samples of all fish species from Lake Moreno were taken in order to determine the presence of paratenia, to evaluate the status of the hosts and to characterise the transmission of Acanthocephalus tumescens (von Linstow, 1896) at the component population level. Prevalence, mean abundance, mean intensity, numbers of gravid females, relative abundance of the different fish species, relative output of eggs and relative flow rates for each host species were computed. Acanthocephalus tumescens showed low host specificity, successfully parasitizing six out of eight fish species present in the lake. No paratenic infection was registered. If prevalence, mean abundance, and number of gravid females are considered, host species can be placed in a continuum from the most to least suitable as follows: Galaxias platei Steindachner, Diplomystes viedmensis (Mac Donagh), Oncorhynchus mykiss (Walbaum), Salvelinus fontinalis (Mitchill), Percichthys trucha (Cuvier et Valenciennes) and Galaxias maculatus (Jenyns). However, when parasite flow rates and egg output were calculated, including relative abundance of each fish species, the continuum was rearranged as follows: P. trucha, O. mykiss, G. platei / G. maculatus, S. fontinalis and D. viedmensis. The first four species would be the main contributors to the population of A. tumescens in this lake, P. trucha being the major one. Different regulatory and non-regulatory mechanisms are suggested.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
3. Myxidium biliare sp. n. (Myxozoa) from gall bladder of Galaxias maculatus (Osmeriformes: Galaxiidae) in Patagonia (Argentina)
- Creator:
- Viozzi, Gustavo P. and Flores, Verónica R.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Myxidium biliare, Myxosporea, Galaxias maculatus, fish, Patagonia, and Argentina
- Language:
- English
- Description:
- Myxidium biliare sp. n., a new myxosporean species parasitizing the gall bladder of Galaxias maculatus (Jenyns), in Patagonia, is described. Its coelozoic plasmodia were floating free in the bile. Spores are fusiform 13.7 ± 0.9 µm long and 6.9 ± 0.6 µm wide, with rounded ends in frontal view and slightly pointed ends in sutural view; shell with ridges and sinuous sutural line. Both maximum prevalence and maximum percentage of immature plasmodia occurred in summer. In winter the prevalence and the percentage of immature plasmodia fell to their lowest values. Prevalence was independent of host sex but increased with host length. Prevalence in 15 Patagonian Andean lakes (situated from 39°25'S to 41°30'S) ranged between 4.2% and 70%.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4. Post-cyclic transmission in Acanthocephalus tumescens (Acanthocephala: Echinorhynchidae)
- Creator:
- Rauque, Carlos A., Semenas, Liliana G., and Viozzi, Gustavo P.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- post-cyclic transmission, Acanthocephalus tumescens, Oncorhynchus mykiss, and Galaxias maculatus
- Language:
- English
- Description:
- The aim of this study was to investigate the post-cyclic transmission of Acanthocephalus tumescens (von Linstow, 1896) from Galaxias maculatus Jenyns to Oncorhynchus mykiss (Walbaum). Wild G. maculatus naturally infected with A. tumescens were fed to cultured rainbow trout, which were sacrificed at the second, third and fourth weeks post infection. Normally attached male and female acanthocephalans were recovered alive from the intestine of rainbow trout. Parasites survive at least four weeks post infection, growing and attaining full sexual maturity. Prevalence and mean intensity generally decreased after infection. A. tumescens is the eighth acanthocephalan species in which post-cyclic transmission has been proven.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public