0000000000016645
AUTHOR
A. M. Bagge
Parasite assemblages of crucian carp (Carassius carassius) – is depauperate composition explained by lack of parasite exchange, extreme environmental conditions or host unsuitability?
Recent studies on parasite communities have considered the factors which contribute to variability in parasite infections among populations of one host species. This paper examined parasite assemblages of crucian carp (Carassius carassius) in a natural set-up of two distinctive environments inhabited by the same host species and differing in respect to composition of other fish species: ponds, where extreme conditions prevent other fish species from occurring and lakes, where crucian carp coexist with other fish species. Our aim was to evaluate the significance of parasite exchange, environmental conditions and host suitability for the depauperate parasite assemblages observed in pond cruci…
Infracommunity level aggregation in the monogenean communities of crucian carp (Carassius carassius).
Aggregation is one of the distinctive features in parasite-host relationships, which has generally been studied at the level of host communities. Parasite aggregation at the infracommunity level may nevertheless be important for intraspecific interactions such as parasite mating success and opportunities for cross-fertilization. In the present paper, we studied the infracommunity aggregation of 3 highly abundantDactylogyrus(Monogenea) species occurring on the gills of crucian carp (Carassius carassius). In line with the previous work on monogenean communities, we observed no competition between the species. At the species level, parasites were distributed unevenly on the gills showing aggre…
Development of monogenean communities on the gills of roach fry (Rutilus rutilus).
The formation and development of monogenean communities on the gills of roach fry was followed in 1992 from early June to October (size range 9 to 47 mm). Roach fry (n=291) were sampled weekly from the small, humic River Rutajoki in central Finland. A further 209 roach fry were reared in a fish farm supplied by water from the river. Four Dactylogyrus species were found: D. nanus, D. crucifer, D. micracanthus and D. suecicus. Other species found on the gills were Gyrodactylus sp. and Paradiplozoon homoion. The first Dactylogyrus juvenile occurred on a 12 mm long fish fry in late June and the first adult (D. nanus) 1 week later in Tank 1. D. nanus was also the most common parasite in the rive…
Experimental study on the influence of paper and pulp mill effluent on the gill parasite communities of roach (Rutilus rutilus)
SUMMARYRoach (n= 81) caught on 23 May, 1992 from oligotrophic, unpolluted Lake Peurunka were kept in cages over a 2-week period before moving half of the fish to nearby Lake Vatia, which is influenced by pulp mill effluents. Before moving the fish gill parasites were examined from 9 fish; 5Dactylogyrusspecies,Gyrodactylussp. andParadiplozoon homoionwere found, the main components of the infracommunities being dactylogyrids. Afterwards, 5 fish from each lake were studied weekly between 1 July and 17 August. Metazoan parasites were recorded from gill arches divided into 4 sections along the dorso-ventral axis.D. crucifer, D. nanus, D. micracanthusandD. suecicusoccurred in both lakes throughou…
Fish population size, and not density, as the determining factor of parasite infection: a case study.
The diversity and abundance of parasites vary widely among populations of the same host species. These infection parameters are, to some extent, determined by characteristics of the host population or of its habitat. Recent studies have supported predictions derived from epidemiological models regarding the influence of host population density: parasite abundance and parasite species richness are expected to increase with increasing host population density, at least for directly transmitted parasites. Here, we test this prediction using a natural system in which populations of the crucian carp, Carassius carassius (L.), occur alone, with no other fish species, in a series of 9 isolated pond…
Interspecific and intraspecific interactions in the monogenean communities of fish: a question of study scale?
SUMMARYMonogenean communities of fish have generally been considered non-interactive as negative interspecific interactions have rarely been reported. Most of the earlier studies on monogenean communities, however, have been conducted not only in systems with relatively low parasite abundances but, more importantly, at study scales where microhabitat-level interactions between the parasites are easily overlooked. We examined the communities of 3 abundant Dactylogyrus (Monogenea) species on the gills of crucian carp (Carassius carassius) by analysing the interactions at the scale of individual gill filaments, where interactions between the species, if any, should most likely take place. Cont…