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2. Gill parasites of Cephalopholis argus (Teleostei: Serranidae) from Moorea (French Polynesia): site selection and coexistence
- Creator:
- Lo, Cédrik M. and Morand, Serge
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- ectoparasites, Cephalopholis argus, French Polynesia, coral reef fish, microhabitat, spatial distribution, and parasite interactions
- Language:
- English
- Description:
- The distribution and coexistence of gill ectoparasites of 121 specimens of Cephalopholis argus Bloch et Schneider, caught between October 1994 and October 1995, were investigated. Adults of the monogenean Benedenia sp. and copepod Hatschekia sp., the larval caligid copepod Caligus sp. (copepodite and chalimus stages), and praniza larvae of the isopod Gnathia sp. were found. All species were aggregated within the host population. Infracommunities were poor, with only 40.5% of fish infected by two parasite species. Only two individual fish harboured all the parasite species observed at the component community level. Prevalences were less than 50% and mean intensities were low (less than 6 parasites/host). No dominant parasite species were observed in the host population. The spatial distribution of each parasite species was studied on different partitions of the gill arches. Adult parasite stages that are mobile showed much overlap in their distribution, whereas temporarily attached larvae of Caligidae were more site specific. Copepodite and chalimus larvae showed niche restriction that is probably due to gregarious behaviour. Positive associations between caligid larvae reflected intraspecific interaction for site and/or resources. Each of the Caligus sp. larval stages prefers specific sites, as do the adults, which occur exclusively in the buccal cavity of the host. Infracommunities were too poor and too few to induce processes of interspecific competition.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
3. Microhabitat selection of Discocotyle sagittata (Monogenea: Polyopisthocotylea) in farmed rainbow trout
- Creator:
- Rubio-Godoy, Miguel
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Monogenea, Discocotyle sagittata, microhabitat, trout, and Oncorhynchus mykiss
- Language:
- English
- Description:
- Microhabitat preference of the monogenean Discocotyle sagittata (Leuckart, 1842) was determined in late spring and late autumn in rainbow trout, Oncorhynchus mykiss (Walbaum), reared in the Isle of Man, UK. Discocotyle sagittata exhibits a preference for attachment to anterior gill arches: 29% of all worms occurred on gill arch I, 28% on II, 25% on III and 18% on IV. This distribution pattern on the introduced salmonid species is the same as reported for its native European host, the brown trout Salmo trutta (L.). Previous experimental work suggested that invasion is a passive process followed by post-invasion migration to anterior gill arches; the present work provides evidence of equivalent site selection taking place in fishes maintained under conditions promoting continuous reinfection in aquaculture. Migration may be density-dependent, since a significant inverse association was found between the intensity of mature parasites and their proportion on anteriormost gill arch I.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4. The microecology of dactylogyrids (Monogenea: Dactylogyridae) on the gills of wild spotted rose snapper Lutjanus guttatus (Lutjanidae) from Mazatlan Bay, Mexico
- Creator:
- Soler-Jiménez, Lilia C. and Fajer-Ávila, Emma J.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- microhabitat, distribution, Pacific coast, Euryhaliotrema perezponcei, Euryhaliotrematoides sp., Haliotrematoides spinatus, Haliotrematoides plectridium, and Haliotrematoides guttati
- Language:
- English
- Description:
- The spatial distribution and coexistence of monogenean dactylogyrids was assessed on the gills of 63 specimens of wild spotted rose snapper, Lutjanus guttatus (Steindachner), caught in the Mazatlan Bay, Sinaloa, Mexico. Five species are reported: Euryhaliotrema perezponcei García-Vargas, Fajer-Ávila et Lamothe-Argumedo, 2008, Euryhaliotrematoides sp., Haliotrematoides spinatus Kritsky et Mendoza-Franco, 2009, H. plectridium Kritsky et Mendoza-Franco, 2009, and H. guttati García-Vargas, Fajer-Ávila et Lamothe-Argumedo, 2008. All except E. perezponcei and H. guttati represent new geographical records for the Pacific coast. The most prevalent dactylogyrid species was E. perezponcei (100%), H. plectridium and H. spinatus had >80% prevalence, and H. guttati and Euryhaliotrematoides sp. had the lowest prevalence. The mean abundance of H. plectridium and E. perezponcei was close to 60 parasites/fish, whereas Euryhaliotrematoides sp. and H. guttati had the lowest abundance. The dactylogyrid species exhibited a tendency for attachment to gill arch 2: 25% attachment occurring on gill arch 1, 30% on 2, 27% on 3 and 18% on 4, and showed a significant preference for the central sector of the gill (42%). Haliotrematoides plectridium had a preference for attachment to gill arches 2 and 3 and the central sector. Haliotrematoides spinatus tended to settle on the gill arches 2 and 3 and had a preference for the central sector. Euryhaliotrema perezponcei tended to settle on the gill arches 1 and 2 and the anterior gill sector. Euryhaliotrematoides sp. and H. guttati did not show a preference for any gill arch or sector. The intraspecific aggregation was stronger than the interspecific aggregation, indicating that all the dactylogyrid species on spotted rose snapper were aggregated, and there was no evidence of competition among the species.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public