Incidence of Trematode Parasites of American Plaice (Hippoglossoides platessoides) of the Scotian Shelf and Gulf of St. Lawrence in Relation to Fish Length and Food

1975 ◽  
Vol 32 (4) ◽  
pp. 479-483 ◽  
Author(s):  
J. S. Scott
Keyword(s):  
Alimentary Tract ◽  
Sea Urchins ◽  
Trematode Species ◽  
Fish Length ◽  
Intermediate Hosts ◽  
Scotian Shelf ◽  
Food Items ◽  
Digenetic Trematodes ◽  
Hippoglossoides Platessoides ◽  
Trematode Parasites

The following digenetic trematodes were found in the alimentary tract of American plaice (Hippoglossoides platessoides) from the Scotian Shelf and Gulf of St. Lawrence: Derogenes varicus, Fellodistomum furcigerum, Lecithaster gibbosus, Stenakron vetustum, Steringotrema ovacutum, Zoogonoides viviparus, Hemiurus levinseni, Otodistomum veliporum (larvae), Podocotyle atomon, Prosorhyncus squamatus.The incidence of several trematode species changed with length of fish and associated changes in the fish’s diet. Incidence of D. varicus and S. vetustum decreased with increase of host length, whereas incidence of R. ovacutum and Z. viviparus increased. Lecithaster gibbosus and S. furciger showed little change in incidence. Correlations between parasite incidence and frequency of occurrence of food items indicated that small crustaceans may be intermediate hosts for S. vetustum and D. varicus; sea urchins may be intermediate hosts for R. ovacutum and brittle stars for Z. viviparus.

Geographic Variation in Incidence of Trematode Parasites of American Plaice (Hippoglossoides platessoides) in the Northwest Atlantic

1975 ◽  
Vol 32 (4) ◽  
pp. 547-550 ◽  
Author(s):  
J. S. Scott
Keyword(s):  
Geographic Variation ◽  
Gulf Of Maine ◽  
Biological Indicators ◽  
Scotian Shelf ◽  
Northwest Atlantic ◽  
Digenetic Trematodes ◽  
Hippoglossoides Platessoides ◽  
Trematode Parasites

The digenetic trematodes Steringotrema ovacutum, Zoogonoides viciparus, Derogenes varicus, Lecithaster gihbosus, Fellodistomum furcigerum, and Stenakron vetustum were common in American plaice (Hippoglossoides platessoides) from the southern Gulf of St. Lawrence, Scotian Shelf, and northeast Gulf of Maine in the summers of 1971 and 1972. Levels of incidence of the trematodes in different areas within the region are compared. Steringotrema ovacutum, Z. viviparus, and F. furcigerum may be useful as biological indicators in plaice in the Northwest Atlantic.

scholarly journals Global warming and temperature-mediated increases in cercarial emergence in trematode parasites

Parasitology ◽  
2005 ◽  
Vol 132 (1) ◽  
pp. 143-151 ◽  
Author(s):  
R. POULIN
Keyword(s):  
Global Warming ◽  
Geographical Distribution ◽  
Climate Models ◽  
Extreme Values ◽  
Geometric Mean ◽  
Effect Of Temperature ◽  
Trematode Species ◽  
Intermediate Hosts ◽  
Cercarial Production ◽  
Trematode Parasites

Global warming can affect the world's biota and the functioning of ecosystems in many indirect ways. Recent evidence indicates that climate change can alter the geographical distribution of parasitic diseases, with potentially drastic consequences for their hosts. It is also possible that warmer conditions could promote the transmission of parasites and raise their local abundance. Here I have compiled experimental data on the effect of temperature on the emergence of infective stages (cercariae) of trematode parasites from their snail intermediate hosts. Temperature-mediated changes in cercarial output varied widely among trematode species, from small reductions to 200-fold increases in response to a 10 °C rise in temperature, with a geometric mean suggesting an almost 8-fold increase. Overall, the observed temperature-mediated increases in cercarial output are much more substantial than those expected from basic physiological processes, for which 2- to 3-fold increases are normally seen. Some of the most extreme increases in cercarial output may be artefacts of the methods used in the original studies; however, exclusion of these extreme values has little impact on the preceding conclusion. Across both species values and phylogenetically independent contrasts, neither the magnitude of the initial cercarial output nor the shell size of the snail host correlated with the relative increase in cercarial production mediated by rising temperature. In contrast, the latitude from which the snail-trematode association originated correlated negatively with temperature-mediated increases in cercarial production: within the 20 ° to 55 ° latitude range, trematodes from lower latitudes showed more pronounced temperature-driven increases in cercarial output than those from higher latitudes. These results suggest that the small increases in air and water temperature forecast by many climate models will not only influence the geographical distribution of some diseases, but may also promote the proliferation of their infective stages in many ecosystems.

Helminth parasites of the alimentary tract of the hakes (Merluccius, Urophycis, Phycis: Teleostei) of the Scotian Shelf

1987 ◽  
Vol 65 (2) ◽  
pp. 304-311 ◽  
Author(s):  
J. S. Scott
Keyword(s):  
Alimentary Tract ◽  
Parasite Species ◽  
Gulf Of Maine ◽  
Parasite Prevalence ◽  
Fish Length ◽  
Helminth Parasites ◽  
Scotian Shelf ◽  
High Prevalence ◽  
Merluccius Bilinearis ◽  
Separate Population

Alimentary tracts of the five common hakes of the Scotian shelf (Urophycis chuss, Urophycis tenuis, Phycis chesteri, Merluccius bilinearis, Merluccius albida) were examined for helminth parasites. A total of 29 species was found: 17 Digenea, 4 Cestoda, 6 Nematoda, 2 Acanthocephala. The greatest numbers of species were found in the closely associated U. tenuis (25) and U. chuss (19). Phycis chesteri hosted a moderate number (14) but included 3 digeneans that are typical of deep water (Anomalotrema koiae, Lethadena profunda, Paraccacladium jamiesoni) not found in the other hakes. The merlucciids were characterized by low numbers of parasite species, particularly of digeneans, but showed high prevalence of the host-specific cestode Clestobothrium crassiceps. The effects of geographic distribution, fish length, and depth of capture on parasite prevalence were examined for those parasites that were adequately represented. There was little difference in geographical distribution except in the case of C. crassiceps, in which distribution suggested a separate population of M. bilinearis on the Scotian Shelf from that of the Gulf of Maine. Fish length and depth of capture had little effect on parasite prevalence.

Helminth parasites of the alimentary tract of Atlantic halibut (Hippoglossus hippoglossus L.) and Greenland halibut (Reinhardtius hippoglossoides (Walbaum)) on the Scotian Shelf

1989 ◽  
Vol 67 (6) ◽  
pp. 1476-1481 ◽  
Author(s):  
James S. Scott ◽  
Shelley A. Bray
Keyword(s):  
Parasite Prevalence ◽  
Fish Length ◽  
Atlantic Halibut ◽  
Helminth Parasites ◽  
Intermediate Hosts ◽  
Scotian Shelf ◽  
Greenland Halibut ◽  
Hippoglossus Hippoglossus ◽  
Greenland Halibut Reinhardtius Hippoglossoides ◽  
Reinhardtius Hippoglossoides

Examination of the alimentary tracts of 272 Atlantic halibut (Hippoglossus hippoglossus (L.)) and 71 Greenland halibut (Reinhardtius hippoglossoides (Walbaum)) from the Scotian Shelf yielded a total of 25 helminth parasite species, 23 from H. hippoglossus (16 Digenea, 3 Cestoda, 2 Acanthocephala, 2 Nematoda) and 16 from R. hippoglossoides (11 Digenea, 3 Cestoda, 1 Acanthocephala, 1 Nematoda). Parasite prevalence and intensity were low (< 50% and < 10%, respectively) in both hosts, except for Derogenes varicus and Steganoderma formosum in H. hippoglossus and anisakid nematodes in R. hippoglossoides. Consideration of change in parasite prevalence and mean intensity in relation to fish length and diet suggests fish prey as transport hosts for D. varicus in larger halibuts, and crustaceans as the intermediate hosts for S. formosum before transmission to its principal host, H. hippoglossus. Geographical change in parasite prevalence and intensity was in the form of southwest to northeast clines along the Shelf, probably related to environmental factors. There was no evidence for stock differentiation in either of the hosts based on parasite fauna.

Tranmission pattern differences of miracidia and cercariae larval stages of digenetic trematode parasites

2016 ◽  
Vol 61 (4) ◽  
Author(s):  
Michael R. Zimmermann ◽  
Kyle E. Luth ◽  
Gerald W. Esch
Keyword(s):  
Abiotic Factors ◽  
Field Studies ◽  
Life Cycles ◽  
Digenetic Trematode ◽  
Snail Species ◽  
Intermediate Hosts ◽  
Complex Life Cycles ◽  
Larval Stages ◽  
Digenetic Trematodes ◽  
Trematode Parasites

AbstractDigenetic trematodes have complex life cycles involving multiple hosts and free-living larval stages. Some species have 2 lar-val stages that infect snails, with miracidia and cercariae using these molluscs as first and second intermediate hosts, respec-tively. Although both larval stages may infect the same snail species, this is accomplished using different chemical cues and may be influenced by different biotic and abiotic factors. Significant differences in the infection patterns of these parasitic stages regarding host size and density were observed in 2 separate field studies. The prevalence of sporocysts/rediae and mean abundance of

Occurrence of alimentary tract helminth parasites of pollock (Pollachius virens L.) on the Scotian Shelf

1985 ◽  
Vol 63 (7) ◽  
pp. 1695-1698 ◽  
Author(s):  
J. S. Scott
Keyword(s):  
Alimentary Tract ◽  
Helminth Species ◽  
Fish Length ◽  
Fish Diet ◽  
Helminth Parasites ◽  
Scotian Shelf ◽  
Or Groups ◽  
Marine Parasites ◽  
Anisakid Nematodes ◽  
Support Evidence

Examination of the alimentary tracts of 456 pollock (Pollachius virens L.) revealed the presence of 15 helminth species or groups representing four phyla. Prevalence ranged from 76.6 in anisakid nematodes to negligible levels (<1.0) in some other species, with "ubiquitous" marine parasites Derogenes varicus, Hemiurus levinseni, anisakid nematodes, and Echinorhynchus gadi showing highest values. Changes in prevalence were related to a change from a largely crustacean diet to a largely fish diet with increasing fish length. Differences in prevalence of the more common parasites between the central and southwestern Scotian Shelf support evidence for separate pollock populations in the two areas.

scholarly journals A re-evaluation of the occurrence of freshwater molluscs in the Kruger National Park

Koedoe ◽  
1998 ◽  
Vol 41 (1) ◽  
Author(s):  
K.N. De Kock ◽  
C.T. Wolmarans
Keyword(s):  
Species Diversity ◽  
National Park ◽  
Kruger National Park ◽  
Intermediate Hosts ◽  
Freshwater Molluscs ◽  
Freshwater Mollusc ◽  
Mollusc Species ◽  
Trematode Parasites

Most of the previous records of the freshwater molluscs from the Kruger National Park date back prior to and up to 1966. On account of several droughts between 1966 and 1995 it was decided to do a survey of the freshwater mollusc population in 1995 to evaluate the effect of these droughts. The traditional mollusc intermediate hosts were also screened for trematode parasites to establish whether or not they were infected. No infected molluscs were found. Eight of the 19 species reported up to 1966 were not found during the 1995 survey. Three new mollusc species were collected in 1995. The consequences of the drought are clearly visible when the species diversity found in the dams in the 1995 survey, is compared to what was previously recorded.

Fecundity of the American Plaice, Hippoglossoides platessoides (Fabr.) from Grand Bank and Newfoundland Areas

1964 ◽  
Vol 21 (3) ◽  
pp. 597-612 ◽  
Author(s):  
T. K. Pitt
Keyword(s):  
Egg Production ◽  
Fish Length ◽  
Northern Slope ◽  
Southern Slope ◽  
Ovary Weight ◽  
Length Relationship ◽  
Relationship Of ◽  
Hippoglossoides Platessoides

Fecundity estimates were made on a total of 140 mature American plaice from the southern and northern slopes of the Grand Bank and from St. Mary's Bay. Log–log relationships were established between fecundity and fish length, gutted and gilled weight, age, and ovary weight. No differences were found to exist between the fecundity–length relationship of plaice from the three areas, but there is a suggestion that within areas there may be annual differences in egg production. At comparable ages plaice from the southern slope of the Grand Bank are larger in size and produce more eggs than those from the northern slope and St. Mary's Bay.

Trematode Populations in the Atlantic Argentine, Argentina silus, and Their Use as Biological Indicators

1969 ◽  
Vol 26 (4) ◽  
pp. 879-891 ◽  
Author(s):  
J. S. Scott
Keyword(s):  
Biological Indicators ◽  
Reciprocal Relationship ◽  
Intermediate Hosts ◽  
Length Frequency ◽  
The West ◽  
Low Level ◽  
Mean Size ◽  
Mature Fish ◽  
Plankton Feeders ◽  
Trematode Parasites

The trematode parasites Lecithophyllum botryophorum, Derogenes various, Hemiurus levinseni, and Lampritrema nipponicum were found in Argentina silus off Nova Scotia and Newfoundland. Changes in the length-frequency distribution in the population of L. botryophorum at different times of the year reflected changes in parasite recruitment and were used tentatively to estimate the life span of the parasite.Hemiurus levinseni had a high intensity and incidence in very young fish, decreasing to a low level in mature fish; L. botryophorum had the reciprocal relationship; and D. varicus was intermediate in incidence and had a low level of intensity in fish of all sizes. These results were related to the occurrence of the intermediate hosts of the parasites and to the movement of A. silus to deeper water as it increases in size. The intensity of infestation with L. botryophorum increased from south to north. Seasonal variation in recruitment, with a peak immediately after spawning, was reflected in the intensity of infestation, mean size, and percentage of immature specimens of L. botryophorum.The young A. silus are midwater plankton feeders and the mature fish change to a diet that incorporates a high proportion of the crustacean intermediate host of L. botryophorum, probably an amphipod. There is no parasitological evidence of separate populations of A. silus in the west Atlantic.

Trematodes and snails: an intimate association

2004 ◽  
Vol 82 (2) ◽  
pp. 251-269 ◽  
Author(s):  
Anne E Lockyer ◽  
Catherine S Jones ◽  
Leslie R Noble ◽  
David Rollinson
Keyword(s):  
Evolutionary History ◽  
Intermediate Hosts ◽  
Molecular Approaches ◽  
Complex Interactions ◽  
Intimate Association ◽  
In Vitro Cell Cultures ◽  
Medical Burden ◽  
Insight Into ◽  
Trematode Parasites

Trematode parasites share an intimate relationship with their gastropod intermediate hosts, which act as the vehicle for their development and transmission. They represent an enormous economic and medical burden in developing countries, stimulating much study of snail–trematode interactions. Laboratory-maintained snail–trematode systems and in vitro cell cultures are being used to investigate the molecular dialogue between host and parasite. These dynamic and finely balanced antagonistic relationships, in which parasites strongly influence the physiology of the host, are highly specific and may occasionally demonstrate co-speciation. We consider the mechanisms and responses deployed by trematodes and snails that result in compatibility or rejection of the parasite, and the macroevolutionary implications that they may effect. Although for gastropods the fossil record gives some insight into evolutionary history, elucidation of trematode evolution must rely largely upon molecular approaches, and for both, such techniques have provided fresh and often surprising evidence of their origins and dispersal over time. Co-evolution of snails and trematodes is becoming increasingly apparent at both cellular and population levels; the implications of which are only beginning to be understood for disease control. Untangling the complex interactions of trematodes and snails promise fresh opportunities for intervention to relieve the burden of parasitic disease.

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