From host–parasite systems to parasitic systems: Interactions of littoral mollusks of the genus Littorina with their trematode parasites

The last twenty-five years have witnessed an increasing output of significant work in this country on the trematode parasites of a number of wild birds, including aquatic species. These studies, which are mostly faunistic, and can be said to have commenced in 1926, when Bhalerao (1926) described from Burma (then a province of India) the flukes of the house crow, deal primarily with a large number of representative species of nearly twenty families of Digenea. Of these families, species assignable to the Clinostomidae Lühe, 1901, the Cyathocotylidae Poche, 1926, the Cyclocoelidae Kossack, 1911, the Diplostomidae Poirier, 1886, the Echinostomatidae Poche, 1926, the Notocotylidae Lühe, 1909, the Opisthorchiidae Braun, 1901, and the Strigeidae Railliet, 1919, were encountered in a survey conducted to assess the nature of helminthic infections in wild aquatic birds of the Mathura area.

Download Full-text

The Nematode and Acanthocephalan Parasites of the Sheathbill, Chionis alba (Gmelin), at Signy Island, South Orkney Islands and a summary of host parasite relationships in the Sheathbill

Journal of Helminthology ◽

10.1017/s0022149x00003928 ◽

1969 ◽

Vol 43 (1-2) ◽

pp. 59-67 ◽

Cited By ~ 5

Author(s):

N. V. Jones ◽

I. C. Williams

Keyword(s):

Orkney Islands ◽

British Antarctic Survey ◽

Signy Island ◽

South Orkney Islands ◽

Host Parasite ◽

Trematode Parasites

We have previously reported on the cestode and trematode parasites of the Sheathbill at Signy Island (Jones & Williams 1967, 1968, 1969) and conclude with an account of the nematodes and Acanthocephala. Our previous reports were based on specimens obtained from 13 Sheathbills collected at Signy Island in July and October, 1965 by Mr. Charles Howie, British Antarctic Survey. In addition to these we have examined a further 12 Sheathbills taken at Signy Island in March, 1967. We are greatly indebted to Mr. E. A. Smith, Senior Biologist, British Antarctic Survey, for arranging the collection and transport of the latter material.

Download Full-text

The trematodes of groupers (Serranidae: Epinephelinae): knowledge, nature and evolution

Parasitology ◽

10.1017/s0031182002001671 ◽

2002 ◽

Vol 124 (7) ◽

pp. 23-42 ◽

Cited By ~ 31

Author(s):

T. H. CRIBB ◽

R. A. BRAY ◽

T. WRIGHT ◽

S. PICHELIN

Keyword(s):

Marine Fishes ◽

Major Determinant ◽

Eastern Pacific ◽

Host Switching ◽

Geographical Proximity ◽

Review Of The Literature ◽

West Pacific ◽

The World ◽

Host Parasite ◽

Trematode Parasites

Groupers (Epinephelinae) are prominent marine fishes distributed in the warmer waters of the world. Review of the literature suggests that trematodes are known from only 62 of the 159 species and only 9 of 15 genera; nearly 90% of host–parasite combinations have been reported only once or twice. All 20 families and all but 7 of 76 genera of trematodes found in epinephelines also occur in non-epinephelines. Only 12 genera of trematodes are reported from both the Atlantic–Eastern Pacific and the Indo–West Pacific. Few (perhaps no) species are credibly cosmopolitan but some have wide distributions across the Indo–West Pacific. The hierarchical ‘relatedness’ of epinephelines as suggested by how they share trematode taxa (families, genera, species) shows little congruence with what is known of their phylogeny. The major determinant of relatedness appears to be geographical proximity. Together these attributes suggest that host-parasite co-evolution has contributed little to the evolution of trematode communities of epinephelines. Instead, they appear to have arisen through localized episodes of host-switching, presumably both into and out of the epinephelines. The Epinephelinae may well be typical of most groups of marine fishes both in the extent to which their trematode parasites are known and in that, apparently, co-evolution has contributed little to the evolution of their communities of trematodes.

Download Full-text

Infection with cerebral metacercariae of microphallid trematode parasites reduces reproductive output in the gammarid amphipodGammarus insensibilis(Stock 1966) in UK saline lagoons

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315417000662 ◽

2017 ◽

Vol 98 (6) ◽

pp. 1391-1400 ◽

Cited By ~ 1

Author(s):

Andrew R. Gates ◽

Martin Sheader ◽

John A. Williams ◽

Lawrence E. Hawkins

Keyword(s):

Reproductive Output ◽

Early Stage ◽

Infection Intensity ◽

Dry Weight ◽

Experimental Conditions ◽

The United Kingdom ◽

Specialist Species ◽

Host Parasite ◽

Trematode Parasites

Saline lagoons are priority habitats in the United Kingdom supporting several protected specialist species. One specialist, the amphipodGammarus insensibilis, is infected with behaviour-altering microphallid trematodes such asMicrophallus papillorobustus. In saline lagoons around the coast of England (Gilkicker and Lymington–Keyhaven on the Hampshire coast and Moulton Marsh in Lincolnshire) there is variation in the prevalence of this parasite in the gammarid populations (0 at Salterns in the Lymington–Keyhaven lagoon system to 98% at Gilkicker). Infection intensity ranged from 0 to 20 metacercariae in individual amphipods. Higher infection intensity can alter the shape of the amphipod's head. Under experimental conditions respiration rate is significantly reduced in infected animals and reproductive output (expressed as early stage embryos mg g dry weight−1) is significantly lower in infected females. It is important to consider the role of host–parasite interactions in order to understand the ecology of specialist lagoon species such asG. insensibilisand their lagoon habitats.

Download Full-text

An efficient photograph-based quantitative method for assessing castrating trematode parasites in bivalve molluscs

Parasitology ◽

10.1017/s0031182020001213 ◽

2020 ◽

Vol 147 (12) ◽

pp. 1375-1380 ◽

Cited By ~ 1

Author(s):

Joshua I. Brian ◽

David C. Aldridge

Keyword(s):

Reproductive Capacity ◽

Bivalve Molluscs ◽

Intensity Of Infection ◽

Important Species ◽

Gonad Tissue ◽

Digenean Trematode ◽

Host Parasite Interactions ◽

Reproductive Response ◽

Host Parasite ◽

Trematode Parasites

AbstractParasitic castration of bivalves by trematodes is common, and may significantly reduce the reproductive capacity of ecologically important species. Understanding the intensity of infection is desirable, as it can indicate the time that has passed since infection, and influence the host's physiological and reproductive response. In addition, it is useful to know the developmental stage of the trematode, to understand trematode population trends and reproductive success. However, most existing methods (e.g. visually estimating the degree of infection) to assess intensity are approximate only and not reproducible. Here, we present a method to accurately quantify the percentage of bivalve gonad filled with digenean trematode tissue, based on small squashes of gonad tissue rapidly photographed under light microscopy. A maximum of 15 photographs is required to determine the percentage of the whole gonad occupied by trematodes with a minimum of 90% confidence, with smaller mussels requiring fewer. In addition, the stage of trematode infection can be assessed because full sporocysts, spent sporocysts and free cercariae are clearly distinguishable. Although variation exists in the distribution of trematodes in gonad tissue, and thus in the estimate of percentage of the gonad filled with trematodes, this method represents a marked improvement on current coarse assessments of infection which typically focus on binary presence/absence measures. This technique can be used to facilitate a more sophisticated understanding of host–parasite interactions in bivalves, and can inform the conservation and reproductive biology of environmentally crucial species.

Download Full-text

Cockle as Second Intermediate Host of Trematode Parasites: Consequences for Sediment Bioturbation and Nutrient Fluxes across the Benthic Interface

Journal of Marine Science and Engineering ◽

10.3390/jmse9070749 ◽

2021 ◽

Vol 9 (7) ◽

pp. 749

Author(s):

Anaïs Richard ◽

Xavier de Montaudouin ◽

Auriane Rubiello ◽

Olivier Maire

Keyword(s):

Intermediate Host ◽

Parasite Species ◽

Nutrient Fluxes ◽

Sediment Reworking ◽

Biogeochemical Fluxes ◽

Time Period ◽

Second Intermediate Host ◽

Host Parasite ◽

High Parasite ◽

Trematode Parasites

Trematode parasites are distributed worldwide and can severely impact host populations. However, their influence on ecosystem functioning through the alteration of host engineering behaviours remains largely unexplored. This study focuses on a common host parasite system in marine coastal environments, i.e., the trematode Himasthla elongata, infecting the edible cockle Cerastoderma edule as second intermediate host. A laboratory experiment was conducted to investigate the indirect effects of metacercarial infection on sediment bioturbation and biogeochemical fluxes at the sediment water interface. Our results revealed that, despite high parasite intensity, the sediment reworking and bioirrigation rates, as well as nutrient fluxes, were not impacted. This finding was unexpected since previous studies showed that metacercarial infection impairs the physiological condition of cockles and induces a mechanical obstruction of their feet, thus altering their burrowing capacity. There are several explanations for such contrasting results. Firstly, the alteration of cockle behavior could arise over a longer time period following parasite infection. Secondly, the modulation of cockle bioturbation by parasites could be more pronounced in older specimens burying deeper. Thirdly, the intensity of the deleterious impacts of metacercariae could strongly vary across parasite species. Lastly, metacercarial infection alters cockle fitness through an interaction with other biotic and abiotic environmental stressors.

Download Full-text

The Pathogenesis of Experimental Mycotic Encephalitis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010006369x ◽

1969 ◽

Vol 27 ◽

pp. 356-357

Author(s):

James A. Swenberg ◽

Adalbert Koestner ◽

R.P. Tewari

Keyword(s):

Electron Microscopy ◽

Pathogenetic Mechanisms ◽

Host Parasite

Previous investigations of pathogenetic mechanisms in mycotic encephalitis have been restricted to light microscopic and mycologic approaches. In this study, electron microscopy was utilized to determine the mode of vascular penetration and the cellular and subcellular host-parasite interrelationships in brains of mice infected with Oidiodendron kalrai. This newly isolated fungus was selected because of its ability to consistently produce encephalitis with gross and microscopic lesions similar to those observed in naturally occuring mycoses.

Download Full-text

Examination of Schistosome Cercariae and Schistosomules by Scanning Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100062154 ◽

1969 ◽

Vol 27 ◽

pp. 50-51

Author(s):

D. Johnson ◽

P. Moriearty

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

High Resolution ◽

Light Microscopy ◽

Surface Structure ◽

Extensive Study ◽

Scanning Microscopy ◽

Host Parasite ◽

Conventional Electron Microscopy ◽

Scanning Electron

Since several species of Schistosoma, or blood fluke, parasitize man, these trematodes have been subjected to extensive study. Light microscopy and conventional electron microscopy have yielded much information about the morphology of the various stages; however, scanning electron microscopy has been little utilized for this purpose. As the figures demonstrate, scanning microscopy is particularly helpful in studying at high resolution characteristics of surface structure, which are important in determining host-parasite relationships.

Download Full-text