Occurrence of Protozoan Parasites of Channa Punctatus in Bangladesh

Three species of myxozoa (Henneguya chaudhuryi, Henneguya bengalensis and Myxobolus sp.) and 3 species of ciliophora (Trichodina pediculus, Epistylis lwoffi and Apisoma piscicolum) and two actinosporean stages of myxoza were identified. Some 51.72% of total host fishes which were found infected with at least one of the above mentioned parasites with average load of 95.93±41.53 per infected host. High percentage (98.05) of C. punctatus possessed myxozoan infection and 1.95 had chiliophoran infection. The highest prevalence of parasitic infection was observed in host sample collected from Faridpur district and lowest (33.33%) in fish sample collected from Mymensingh. The association of parasitic infection of H. bengalensis and Myxobolus sp. with study areas was found statistically significant (p=0.024 and 0.049, respectively). Protozoan parasites were most abundant in gills of hosts. Shannon Diversity Index indicated that host fishes were not infested by more parasites and the parasite community was poorly diverged in all study sites. However, Simpson’s Diversity showed that, parasites community was moderately diverged in host fishes collected from Mymensingh district and in rest of the areas parasite community was poorly diverged. Asiat. Soc. Bangladesh, Sci. 46(1): 13-25, June 2020

Using parasites as biological tag for Hilsa shad (Tenualosa ilisha) migration in Bangladesh waters

The study was aimed at following the movement of adolescent Tenualosa ilisha from nursery grounds to feeding and spawning grounds or other type of movements in Bangladesh waters. To accomplish this, data on metazoan endoparasites were used as biological tags for detection of migratory route. A total of 2667 host fishes were collected from eleven sites covering the three different ecological habitats of Bangladesh. Initial selection of parasites as biological tags was executed by using established criteria, primarily on the basis of different level of infection in different habitats. The role of incidental parasites as tags is also discussed. Overall fourteen species under eleven genus of endohelminths were identified from alimentary canal and associated organs of host, only three species of them had satisfied the criteria of being as biological tag. These are cestode parasite Ilisha parthenogenetica and acanthocephalan parasite Acanthosentis indica and Acanthosentis hilsai. Higher prevalence of these parasites at respective sites and the trend of prevalence of infection in size class of host fish demonstrated host‟s anadromous nature and reinforced the belief that the T. ilisha as a whole, migrates from the sea to the rivers via the estuaries and vice versa. Bangladesh J. Zool. 48(2): 243-251, 2020

Comparative study of protozoan parasite communities between Anabas testudineus and Channa punctatus

The study was conducted to determine the comparative occurrence of protozoan parasites of two host species- Anabas testudineus and Channa punctatus. The host fishes were collected from April, 2018 to March, 2019 from freshwater bodies of Mymensingh, Kishoreganj, Faridpur and Jashore districts of Bangladesh. Three species of myxozoa (Henneguya mystusia, Henneguya qadrii and Henneguya acerinae) and four genera/species of ciliophora (Trichodina acuta, Trichodina sp., Epistylis lwoffi and Amphileptus disciformis) in A. testudineus; three genera/species of myxozoa (Henneguya chaudhuryi, Henneguya bengalensis and Myxobolus sp.), three species of ciliophora (Trichodina pediculus, Epistylis lwoffi and Apisoma piscicolum) and a few actinosporean stage of myxoza in C. punctatus were identified. The prevalence of protozoan infections were found higher in A. testudineus (76.19%) compare to C. punctatus (51.72%). However, mean intensity was relatively higher in C. punctatus (95.93 ± 41.53) than that of A. testudineus (71.38 ± 32.26). Myxozoans were clearly dominant group in both hosts. Multiple parasitic infections were higher in A. testudineus. The highest parasitic infection was observed in Mymensingh (100%) and lowest in Jashore (40%) in A. testudineus, whereas it was highest in fish of Faridpur (100%) and lowest in Mymensingh (33.33%) in C. punctatus. Shannon Diversity Indices indicated that the parasite community was poorly diverged in both hosts of all study areas. However, Simpson’s Diversity revealed that, parasites community was moderately diverged in both hosts in Mymensingh and in other study areas they were poorly diverged. Dhaka Univ. J. Biol. Sci. 30(1): 23-34, 2021 (January)

Biochemical response of two fish species of Gobiidae (Gobiiformes) to Cryptocotyle (Opisthorchiida, Heterophyidae) metacercariae infection from the mouth of the river Chernaya (Black Sea)

Metacercariae of Cryptocotyle are among the most numerously recorded trematode parasites in the estuarine biocenoses of the Azov-Black Sea basin. These parasites can massively affect body surface, gills and fins of host fishes including gobiids. However, information on the influence of Cryptocotyle metacercariae on the physiological and biochemical status of gobies is extremely limited. Biochemical response of two fish species of Gobiidae - grass goby Zosterisessor ophiocephalus (Pallas, 1814) and mushroom goby Ponticola eurycephalus (Kessler, 1874) to Cryptocotyle spp. metacercariae infection at the mouth of River Chernaya (Black Sea) was investigated. Activities of superoxide dismutase, catalase, peroxidase, glutathione reductase, glutathione-S-transferase, alanine transaminase, aspartate transaminase, level of thiobarbituric acid-reactive substances were measured as parameters of biochemical response. The findings of this study demonstrate interspecific differences in fish response to parasite infections. High infection leads to an intensification of lipid peroxidation and a weakening of antioxidant protection in the muscles of mushroom goby but activation of the antioxidant enzyme system in the muscles of grass goby. The results show a greater resistance of grass goby to the infection when compared with mushroom goby.

Vertical limits of host infestation by gnathiid isopods (Isopoda: Gnathiidae) parasitic on Caribbean coral reef fishes

Parasites play significant roles in the function of ecosystems and can make up a large proportion of overall biomass. Yet, fundamental aspects of their ecology are often understudied relative to other organisms. Gnathiid isopods are the primary ectoparasites of fishes in coral reef ecosystems. While some studies have investigated their host-detection capabilities, the means by which they seek hosts are largely unknown. Gnathiids are benthic and live on the bottom, and all collection efforts involving live hosts have thus far involved traps set at or near the reef substrate. We investigated the distance gnathiids will travel vertically in the water column to attach to a fish host. The majority of gnathiids collected were at or less than 1 m above the reef substrate, and gnathiids were collected in serially diminishing numbers at 2 and 3 m above it. No gnathiids were collected from any fish hosts set more than 3.5 m above the reef substrate. Results suggest that gnathiids will actively seek host fishes in situ and will travel further from their benthic habitat than previously known. By swimming into the water column, gnathiids can exploit larger, highly-mobile fishes, which can serve as a major source of dispersal.

Taxonomy of Piscian Cestodes of Freshwater fish: A cladistic model of Morphotaxonomic Study of Rare Tapeworm from the Dehradun Region (U.K.), India

The current experimental study has been conducted to analyze cladistic taxonomic aspects of the piscian cestode parasites including its morphological characters. Freshwater fishes caught on the spot at selected sampling stations with the help of local fishermen and collected for tapeworm investigations. Freshwater catfish Clarias batrachus (Linnaeus, 1758)[3] collected from Dehradun sampling stations and examined for tapeworm parasites as per experimental design. The collected fishes were brought to the Parasitology laboratory for experimental study and morphological as well as anatomical facts investigation. Parasites obtained from infected host fishes kept intact in 5% formalin for further investigation. Ten cestode (tapeworm) parasites were found from its infested Intestine. The morphological study of tapeworms indicates that parasitic diversity is accessible within the Ganga river at Dehradun (U.K.) region. Morphotaxonomic characterization reported as - H, butterfly flap shaped ovary, testes numerous and well developed, vitelline follicle - cortical and medullary. This study provides an overview of the piscian tapeworm parasites of some freshwater fishes inhabiting the Ganga river

A Study of Parasitic Copepod Infesting Two Freshwater Fish Populations (Cyprinus carpio and Abramis brama) from Beni-Haroun Dam (Mila) North-East of Algeria

Copepods are one of the main fish ectoparasites, commonly known among the parasitism world, due either to their special adaptive capacity or to induce stress in aquatic organisms, as well as the parasitism result is overall a physiological rate affecting the survival of host. This study was, therefore, aimed to investigate the ectoparasite copepods, infesting 277 fishes including 135 of Cyprinus carpio (Linnaeus, 1758) and 142 of Abramis brama (Linnaeus,1758), collected from Beni-Haroun dam (Mila, northeast Algeria). The fishes were subjected to some morphometric measurements and gill dissections and the harvested parasites were afterwards stored and identified. The parasitic indices were determined to examine the effect of size, sex, season and microhabitat on the parasitic infestation by using χ2 test. The gill examination of individuals of the two host fishes led to harvest 135 copepods, including 127 individuals from Cyprinus carpio belonging to five species (Ergasilus sieboldi, Ergasilus briani, Neoergasilus japonicus, Neoergasilus longispinosis and Lernaea cyprinacae) and 8 individuals from Abramis brama belonging to the two species: Ergasilus sieboldi and Ergasilus briani, and hence Cyprinus carpio is the most infested species than Abramis brama. This study also revealed that the parasitic index values were high in C. carpio (P=53.00%; A=3.7; I=6.93) compared to A. brama (P=12,0.5%, A=0.12, I=1.00) during autumn, since no effect on infestation was noticed during winter. The statistical analysis has revealed the effect of season on parasitic copepod infestation in the two fish species (χ2Obs =30,959 > χ20.05 = 7,815, ddl =3), Since there was no effect due to the microhabitat and sex.