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C. Dieter Zander - One of the best experts on this subject based on the ideXlab platform.
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Four-year monitoring of parasite communities in gobiid fishes of the southwest Baltic: III. parasite species diversity and applicability of monitoring.
Parasitology research, 2004Co-Authors: C. Dieter ZanderAbstract:The parasite infrapopulations of five goby species (Pomatoschistus minutus, P. pictus, P.microps, Gobiusculus flavescens and Gobius niger) were investigated during spring, summer and autumn of the years 1997-2000. In total, 34 parasite species were found: 17 Digenea, 6 Nematoda, 5 Cestoda, 3 Acanthocephala, 2 Protozoa, and 1 Monogenea. The dominant parasites were the digeneans Podocotyle atomon and Cryptocotyle concavum, which represent different ecological groups in terms of their modes of transmission, either indirectly by prey or directly by larvae. The relationship between the parasite Cryptocotyle concavum and the host P. microps is a special one which results in a mean intensity of several hundred cysts (max. 1,329) which settle in the kidney. The diversity of the parasite component community was highest in autumn, but low in spring and summer, with the exception of P. microps for which high values were already found in spring when direct parasites were disregarded. These results depend on the respective seasonal variation in species, some of which occur in huge numbers in some hosts. The diversity of the prey parasite assemblage is higher in Pomatoschistus microps and Gobius niger than in the whole parasite spectrum; the other hosts present the opposite trend. A combination of the island theory of biogeography as modified for parasite infection with the theory of screens and filters leads to a model which considers three handicaps or distances for parasite colonisation: genetic, phylogenetic and ecological. Long-term investigations, as performed here over a time-span of 4 years, can detect more than 80% of parasite species in single hosts after 3 years, and in the whole goby guild after 2 years. Long-term investigations can be useful for finding rare parasites, in analysing parasite diversity, and for determining the seasonality of parasites.
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Four-year monitoring of parasite communities in gobiid fishes of the south-western Baltic
Parasitology Research, 2004Co-Authors: C. Dieter ZanderAbstract:The parasite infracommunity of five goby species ( Pomatoschistus minutus, P. pictus, P.microps, Gobiusculus flavescens, Gobius niger ) from the south-western Baltic was investigated during spring, summer and autumn of the years 1997–2000. The mean parasite species number in single hosts was high, ranging between 1.1 ( P. minutus ), 2.1 ( P. pictus ) to even 3.3 ( P. microps ). Gobius niger is the only host which lives longer than a year and is infested by almost identical parasites for longer times, i.e. the parasite species composition has greater homogeneity. Most intensity of infestation values peaked in summer and were lowest in autumn; only a few exceptions were found in spring or autumn. Only the Digenea Podocotyle atomon and Cryptocotyle concavum were abundant enough to show a clear seasonal fluctuation in Pomatoschistus minutus, P. pictus and Gobiusculus flavescens . Aphalloides timmi and Apatemon gracilis (Digenea) also attained high intensities in P. microps . These four parasite species and, additionally, Cryptocotyle lingua (Digenea), and Hysterothylacium sp. (Nematoda) can be strongly accumulated from either prey or free-swimming larvae and, thus, decisively influence the structure of the infracommunities. Due to selection by filter mechanisms, rare parasites settle rather by chance after competition with other species. The number of parasite species usually increased significantly with host growth. As many as four parasite species were found at the same time in the intestinal tract microhabitat of Gobius niger and P. minutus ; at most three parasite species were present on the skin and fins or in the body cavity. The level of infection is due to the respective life history patterns and the kinds of prey, which harbour different parasites as intermediate hosts. Additionally, it depends on the time of appearance of goby offspring in the course of the year.
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Four-year monitoring of parasite communities in gobiid fishes of the south-western BalticII. Infracommunity.
Parasitology research, 2004Co-Authors: C. Dieter ZanderAbstract:The parasite infracommunity of five goby species (Pomatoschistus minutus, P. pictus, P. microps, Gobiusculus flavescens, Gobius niger) from the south-western Baltic was investigated during spring, summer and autumn of the years 1997-2000. The mean parasite species number in single hosts was high, ranging between 1.1 (P. minutus), 2.1 (P. pictus) to even 3.3 (P. microps). Gobius niger is the only host which lives longer than a year and is infested by almost identical parasites for longer times, i.e. the parasite species composition has greater homogeneity. Most intensity of infestation values peaked in summer and were lowest in autumn; only a few exceptions were found in spring or autumn. Only the Digenea Podocotyle atomon and Cryptocotyle concavum were abundant enough to show a clear seasonal fluctuation in Pomatoschistus minutus, P. pictus and Gobiusculus flavescens. Aphalloides timmi and Apatemon gracilis (Digenea) also attained high intensities in P. microps. These four parasite species and, additionally, Cryptocotyle lingua (Digenea), and Hysterothylacium sp. (Nematoda) can be strongly accumulated from either prey or free-swimming larvae and, thus, decisively influence the structure of the infracommunities. Due to selection by filter mechanisms, rare parasites settle rather by chance after competition with other species. The number of parasite species usually increased significantly with host growth. As many as four parasite species were found at the same time in the intestinal tract microhabitat of Gobius niger and P. minutus; at most three parasite species were present on the skin and fins or in the body cavity. The level of infection is due to the respective life history patterns and the kinds of prey, which harbour different parasites as intermediate hosts. Additionally, it depends on the time of appearance of goby offspring in the course of the year.
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Four-year monitoring of parasite communities in gobiid fishes of the south-western Baltic
Parasitology Research, 2003Co-Authors: C. Dieter ZanderAbstract:The parasite communities of goby species (Teleostei, Percomorphi) from the south-western Baltic Sea were investigated from 1997 to 2000 in three different seasons. In total, 30 parasite species were found in the guild of four goby spp. from Dahmeshöved (Lübeck Bight). The component community of Pomatoschistus minutus comprised 22, Pomatoschistus pictus 20, Gobiusculus flavescens 18 and Gobius niger 14 parasite species, whereas Pomatoschistus microps from the Salzhaff (Mecklenburg Bight) harboured 24 species. The digenean Podocotyle atomon (ingested with prey) and Cryptocotyle concavum (active penetration) were the most common parasites. Cryptocotyle lingua and the nematode Hysterothylacium sp. in Gobius niger as well as the specialists Aphalloides timmi and Apatemon gracilis (Digenea) in Pomatoschistus microps were also very abundant. There were large changes in the parasite communities within the years as well as between the seasons of a year; only Gobius niger presented rather homogeneous communities. The ratio of core parasite species in the hosts was at most 28% ( Gobiusculus flavescens ) and at least 9% ( Gobius niger ). The core species can attain their maximum values at different seasons, which is not only influenced by the parasite but also by the host species. It is concluded that the composition of parasite communities was predominantly determined by the ways of life of the host as well as of the parasite species. Another important factor is the population density of intermediate hosts.
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Alteration of the Metazoan Parasite Faunas in the Brackish Schlei Fjord (Northern Germany, Baltic Sea)
International Review of Hydrobiology, 2000Co-Authors: Verena Kesting, C. Dieter ZanderAbstract:Parasite communities of the inner and middle Schlei Fjord were investigated from 1992 to 1994. Host groups, comprising small-size or young fishes, benthic and planktonic crustaceans, and snails were taken from 4 localities (Selk, Haddeby, Borgwedel and Missunde) of differing salinities (1-8 ‰). The host and parasite fauna turned out to be very sparse, comprising 10 (Selk) to 16 (Missunde) host species of which only 7 and 9, respectively, harboured parasites. Parasites numbered 4 in Selk and 8 in Borgwedel and Missunde, Hysterothylacium sp. (Nematoda) was the only parasite present in all localities. High prevalences were attained by Proteocephalus percae (Cestoda) and Cryptocotyle concavum (Digenea) in Borgwedel and Missunde, whereas in Selk and Haddeby Caligus lacustris prevailed. With the exception of Cryptocotyle concavum intensities were mostly 1, and multiple infestations were rare. On the basis of comparisons with former investigations a faunal impoverishment can be stated during the course of 18 years in the inner Schlei Fjord. Increasing eutrophication causing deep mud layers on the bottoms as well as the ensuing high oxygen deficiencies even in the free water column during summer and autumn can be possible reasons for this phenomenon. As further consequence, the parasite spectrum was reduced to species which have simple developmental cycles and to species which prefer planktonic or suprabenthic, not benthic, hosts. The environment in Missunde with salinities of 6-8 ‰, can be designated as that described by REMANE as an area of species minimum. In former times the parasite communities in Missunde were characterised by a species richness which was in contrast to the abundance of free living organisms.
John W Lewis - One of the best experts on this subject based on the ideXlab platform.
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Epidemiological studies on intestinal helminth parasites of rural and urban red foxes (Vulpes vulpes) in the United Kingdom
Veterinary Parasitology, 1995Co-Authors: D.t. Richards, S Harris, John W LewisAbstract:Abstract An epidemiological study of intestinal helminths in 843 foxes ( Vulpes vulpes ) from southern England revealed the presence of 13 parasite species: five nematodes— Toxocara canis (prevalence 55.9%), Toxascaris leonina (1.5%), Uncinaria stenocephala (68.0%), Trichuris vulpis (0.5%) and Capillaria aerophila (0.2%); four cestodes— Taenia pisiformis (13.8%), Taenia hydatigena (2.5%), Echinococcus granulosus (0.1%) and Dipylidium caninum (3.8%); two trematodes— Brachylaima recurva (2.9%) and Cryptocotyle lingua (2.3%); two acanthocephalans— Prosthorhynchus transversus (0.7%) and Macracanthorhynchus catulinus (0.1%). Trichuris vulpis, Brachylaima recurva, Macracanthorhynchus catulinus and Prosthorhynchus transversus are new host records for the UK. Results are discussed with reference to variations in the diets of urban and rural foxes and to their potential as reservoir hosts for helminths of medical and veterinary importance.
Arne Skorping - One of the best experts on this subject based on the ideXlab platform.
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Transmission of Cryptocotyle lingua cercariae in natural environments: a field experiment
Journal of Fish Biology, 1998Co-Authors: Dag Atle Lysne, Arne Skorping, Willy HemmingsenAbstract:Atlantic cod were kept at two different depths in three cages placed at increasing distance from a rocky shore where natural infections of the digenean Cryptocotyle lingua occurred in the snail Littorina littorea. During a 6-month period the fish kept at 0–2 m accumulated significantly more parasites than those kept at 2–4 m. Distance from the shore did not affect infection rates. We conclude that host location behaviour of cercariae influences the infection pattern under natural conditions, and that transmission from snail to fish can take place over large areas of coastal waters.
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Regulation of infrapopulations of Cryptocotyle lingua on cod
Parasitology, 1997Co-Authors: Dag Atle Lysne, Willy Hemmingsen, Arne SkorpingAbstract:To study the infection dynamics of metacercariae of the digenean Cryptocotyle lingua, wild living Atlantic cod, Gadus morhua, were caged for 18 months close to the shore. Here they were exposed to naturally occurring transmission stages of the parasite. First, both the abundance and the variance to mean ratio of metacercariae increased, but during the second half of the study the abundance levelled out, and the variance to mean ratio showed a significant decrease. Host mortality was negligible throughout the study. Based on the relationship between pigment spots and metacercariae observed by skin digestion, there was no indication of density-dependent parasite mortality. We conclude that the infrapopulations of metacercariae on the caged cod probably were regulated by density-dependent host responses acting against the cercariae.
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Pepsin digestion reveals both previous and present infections of metacercariae in the skin of fish
Fisheries Research, 1995Co-Authors: Dag Atle Lysne, Willy Hemmingsen, Arne SkorpingAbstract:In the present study we first counted the pigmented spots that surround Cryptocotyle spp. metacercariae in the skin of fish. Thereafter we digested the skin and counted the parasites. It was then possible both to quantify the present infections and to estimate the number of metacercariae that had died recently.
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The distribution of Cryptocotyle spp. metacercariae in the skin of caged Atlantic cod (Gadus morhua)
Journal of Fish Biology, 1994Co-Authors: Dag Atle Lysne, Willy Hemmingsen, Arne SkorpingAbstract:In caged Atlantic cod (>40cm), Cryptocotyle spp. metacereariae were concentrated on the dorsal surface, but relatively scarce on the fins. Behaviour and mechanical forces probably affect this distribution.
Thomas Lang - One of the best experts on this subject based on the ideXlab platform.
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Spatial distribution of grossly visible diseases and parasites in flounder (Platichthys flesus) from the Baltic Sea: a synoptic survey
ICES Journal of Marine Science, 1999Co-Authors: Thomas Lang, Vello Kadakas, Stig Mellergaard, Werner Wosniok, K. NeumannAbstract:Information on prevalences of grossly visible diseases and parasites of flounder (Platichthys flesus) from the Baltic Sea is presented for 11 sampling areas on a transect from the Mecklenburg Bight to the Gulf of Finland. Among the 3008 flounder examined, highest overall prevalences were observed for lymphocystis (14.4%) and acute/healing stages of the skin ulcer disease (5.9%). The prevalences of liver neoplasms >2 mm in diameter (0.4%), skeletal deformities (0.6%), and fin rot/erosion (0.5%) were low. The only externally visible parasite recorded was Cryptocotyle concavum (28.2%). The results of a multivariate statistical analysis reveal that the diseases are influenced by a variety of host-specific (length, age, sex) and area-specific (salinity, temperature) factors as well as their interactions. By calculating the expected prevalence for a standardized fish population for each area and disease, the extent of area-specific effects not attributable to host-specific factors was estimated.
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Diseases and parasites of Baltic cod (Gadus morhua) from the Mecklenburg Bight to the Estonian coast.
ICES Journal of Marine Science, 1999Co-Authors: Stig Mellergaard, Thomas LangAbstract:During the 1994 BMB/ICES Sea-going Workshop “Fish Diseases and Parasites in the Baltic Sea”, the prevalences of skin ulcers, pseudobranchial swellings (X-cell disease), skeletal deformities, and the parasites Cryptocotyle lingua and Lernaeocera branchialis were recorded in cod in 11 areas from the Mecklenburg Bight in the southwest to the Estonian coast in the northeast of the Baltic Sea. Prevalences were highest in the western part, except for skeletal deformities, which were highest in the central part. The spatial distribution of pseudobranchial swellings, C. lingua and L. branchialis appeared to be restricted to areas with salinity above 8. Skin ulcers were mainly observed in German waters, while skeletal deformities were most abundant in the Polish, Russian, and Lithuanian coastal zones.
D.t. Richards - One of the best experts on this subject based on the ideXlab platform.
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Epidemiological studies on intestinal helminth parasites of rural and urban red foxes (Vulpes vulpes) in the United Kingdom
Veterinary Parasitology, 1995Co-Authors: D.t. Richards, S Harris, John W LewisAbstract:Abstract An epidemiological study of intestinal helminths in 843 foxes ( Vulpes vulpes ) from southern England revealed the presence of 13 parasite species: five nematodes— Toxocara canis (prevalence 55.9%), Toxascaris leonina (1.5%), Uncinaria stenocephala (68.0%), Trichuris vulpis (0.5%) and Capillaria aerophila (0.2%); four cestodes— Taenia pisiformis (13.8%), Taenia hydatigena (2.5%), Echinococcus granulosus (0.1%) and Dipylidium caninum (3.8%); two trematodes— Brachylaima recurva (2.9%) and Cryptocotyle lingua (2.3%); two acanthocephalans— Prosthorhynchus transversus (0.7%) and Macracanthorhynchus catulinus (0.1%). Trichuris vulpis, Brachylaima recurva, Macracanthorhynchus catulinus and Prosthorhynchus transversus are new host records for the UK. Results are discussed with reference to variations in the diets of urban and rural foxes and to their potential as reservoir hosts for helminths of medical and veterinary importance.