Probir K. Bandyopadhyay

Observation on prevalence of ectoparasites in carp fingerlings in two districts of West Bengal.

The present study has been carried out to find out the prevalence of ectoparasites of carp fingerlings during different months of the year 2008–2009. Four groups of ectoparasites viz. myxozoan, ciliophoran, monogenean and crustacean were recorded from 400 fingerlings of Rohu (Labeo rohita), Catla (Catla catla), Mrigal (Cirrhinus mrigala), Bata (Labeo bata), Common carp (Cyprinus carpio) and Lata (Channa punctatus) collected from different ponds of Nadia and Hooghly district of West Bengal from June 2008 to May 2009. The highest prevalence (51.66%) of infection has been recorded in ciliophorans and the lowest was in crustacean (17.5%) between the months of December and February. The highest ectoparasitic prevalence (36.85%) was recorded during winter season (December–February) while the lowest prevalence (9.16%) recorded during rainy season (June–August).

Studies on Trichodinid and Chilodonellid Ciliophorans (Protozoa: Ciliophora) in the Indian freshwater and estuarine fishes with description of Trichodinella sunderbanensis sp nov and Trichodina nandusi sp nov.

A comprehensive icthyoparasotological survey among estuarine and freshwater fishes of West Bengal, India revealed Trichodinella sunderbanensis sp. nov. and Trichodina acuta Lom, 1961 from an estuarine fish Mystus gulio (Hamilton, 1822) from the Vidyadhari river; Trichodina nandusi sp. nov. from a freshwater fish, Nandus nandus (Hamilton-Buchanan); Chilodonella hexasticha (Kiernik, 1909) Kahl, 1931 from freshwater fishes Labeo rohita (Hamilton, 1822); and Cyprinus carpio Linnaeus, 1758 from the Rupnarayan river. Taxonomic description of all the species based on wet silver nitrate impregnation method along with additional comments based on scanning electron microscopic descriptions of T. nandusi sp. nov. are also provided in this paper. Prevalence rate, morphometric parameters and comparisons with closely related species are also discussed.

Observations on two new species of Monocystis Stein, 1848 (Protozoa: Apicomplexa: Monocystidae) Monocystis darjeelingensis sp.n. and M. ranaghatensis sp.n. from earthworms (Annelida: Oligochaeta) of West Bengal, India

Surveys of acephaline gregarines infesting earthworms from Senchal of Darjeeling and Ranaghat of Nadia districts of West Bengal, India revealed the occurrence of two new species of Monocystis Stein, 1848. Monocystis darjeelingensis sp.n. was found in the coelomic fluid of the earthworm Amynthus robusta Perrier, 1892 from Senchal, Darjeeling, and M. ranaghatensis sp.n. in the seminal vesicles of the earthworm Eutyphoeus valtoni (Michaelsen) from Ranaghat. Trophozoites of M. darjeelingensis sp.n. are cylindroid in shape: 210.0-273.0 (231.0 ± 2.0) × 84.0-140.0 (98.0 ± 1.8) μm; spherical gametocyst: 147.0-163.0 (156.0 ± 0.4) μm; navicular oocyst: 15.4-18.0 (17.0 ± 1.0) × 8.0-9.0 (8.2 ± 0.5) μm. Trophozoites of M. ranaghatensis sp.n. are napiform, having a nearly spheroid to ellipsoid or ovoid body, 119.0-167.0 (124.0 ± 11.0) × 57.0-84.0 (62.0 ± 1.9) μm with a prominent tail like structure at the posterior end and ellipsoidal nucleus, 9.022.0 (12.0 ± 0.4) × 9.0-13.0 (10.0 ± 1.5) μm. Gametocysts are egg-shaped, measuring 95.0-124.0 (105.0 ± 0.9) μm. Oocysts are biconical, measuring 7.6-10.1 ( 9.3 ± 1.1) × 4.1-5.6 (4.5 ± 1.3) μm.

Observations on two new species of Nematocystis Hessé, 1909 (Protozoa: Monocystidae) from earthworms (Annelida: Oligochaeta) of West Bengal, India

Surveys of acephaline gregarines from Nadia district (23°N, 88.5°E) of West Bengal, India revealed the occurrence of two new species of Nematocystis Hesse, 1909; Nematocystis gardenica sp.n. and Nematocystis kalyaniensis sp. n. in the seminal vesicles of earthworms, Amynthas diffriengens (Bairds, 1809) and Amynthas hawayanus (Rosa, 1891), respectively. Trophozoites of Nematocystis gardenica sp. n. are elongate, nematode-like and have parallel sides with pointed tips. Dimensions of trophozoites ranged from 110 to 1320 (505.0 ± 12.0) μm. Dimensions of gametocysts ranged from 140 to 166 μm and the small biconical sporocysts have varying dimensions of 11.0−12.6 μm × 4.0 μm. Trophozoites of Nematocystis kalyaniensis sp.n. are solitary, elongate, nematode-like but have nearly equal bulb-like swellings at two ends, one of which lodges the nucleus. Dimension of trophozoites ranged from 246 to 1232 (565.0 ± 21.0) μm. Dimensions of gametocysts ranged from 120 to 155 μm. Sporocysts are biconical with dimensions of 8.5−11.4 × 5.0 μm.

Characterization of Pseudomonas aeruginosa PB112 (JN996498) isolated from infected Labeo bata (Hamilton) by 16S rRNA gene sequence analysis and fatty acid methyl ester (FAME) analysis

In this study, a total number of fifteen moribund Labeo bata were collected from Hooghly, Purba Medinipur, and South 24 Parganas districts of West Bengal, India. The lesions and hemorrhages were recorded at the base of the fins or on the skin due to bacterial infection. Isolation and pure culture of the causative agent were made in the laboratory. The 16S rRNA gene sequence of the bacterial isolate PB112 has been deposited in the NCBI GenBank and was assigned the accession number JN996498. The GC and AT contents of the 16S rRNA gene sequence (JN996498) were 54.22 and 45.78%, respectively. Based on the biochemical properties, 16S rRNA gene sequence analysis and fatty acid methyl ester (FAME) analysis, the causative bacteria were identified as Pseudomonas aeruginosa.

On the occurrence of a myxozoan parasite, Thelohanellus anilae sp. n. from a fresh water fish of India.

A new species of the genus Th elohanellus Kudo, 1933 is described from the gills of Labeo rohita. Th elohanellus anilae sp. n. occurs in two morphometrically dissimilar forms which are described as microspore and macrospore of the same species.

First record of ectoparasitic African Trichodinids (Ciliophora: Peritrichida) in a cichlid fish Oreochromis mossambicus (Peters 1852) from the Churni river system, West Bengal, India

Oreochromis mossambicus (Peters 1852) and Oreochromis niloticus niloticus Linnaeus, 1758 are two popular freshwater fishes introduced from Africa to India. There are many records of different species of trichodinid ectoparasites infesting wild and cultured cichlids in Africa, but no such study has been conducted on this parasitic group in India. The fishes Oreochromis mossambicus and Oreochromis niloticus niloticus were investigated for the occurrence of trichodinid ciliophorans. Oreochromis mossambicus was found positive for two species, viz., Trichodina centrostrigeata Basson, Van As & Paperna, 1983 and Paratrichodina africana Kazubski & El-Tantawy, 1986. Oreochromis niloticus niloticus was found not to be infested with any species of trichodinid ciliophorans, although, interestingly, Paratrichodina africana was first discovered in this host fish. Comparative descriptions and prevalence of these two above-mentioned species are presented.

Studies on histopathological alteration of three major organs of the goldfish, Carassius auratus L., of India due to myxozoan infection with special reference to scanning electron microscopic observation

Severe infections by the protozoan parasite belonging to the genera Myxozoa are causing serious problems in ornamental fish reared in breeding farms. Histopathological study is being used for diagnosis of the severity of diseases. Myxozoan infections result in large scale histopathological damages in different fish tissues. No information is available regarding the histopathological changes of goldfish due to infection with myxozoans. The present study deals with the histopathological changes of the gill, fin, and skin of goldfish, infected with myxozoan parasites along with an ultrastructural study using scanning electron microscope. Several histological alterations have been observed in goldfish, like tissue damage, epithelial hyperplasia, necrosis, anoxia, localized lymphocytic infiltration, excess mucus, cellular necrosis, and epithelial proliferation. The present study revealed the invasion intensified by the occurrence of morphological lesions in the gill, skin, and fin exposed to Myxosporidia, which may lead to respiratory insufficiency in fish and even cause mass mortality.

Seasonal incidence of protozoan parasitic infestation in ornamental fishes of West Bengal, India

The communication, dealing with the prevalence of protozoan parasites of the ornamental fish of West Bengal. During the study more than five hundred fish have been examined from five districts namely, Nadia, Hooghly, Howrah, North 24-pargana and South 24-pargana of West Bengal during pre-monsoon, monsoon and post-monsoon season. The study reveals that the intensity of infection is more in case of ciliate parasites. The highest ectoparasitic infection has been recorded during post-monsoon season, i.e. from November to February, followed by the pre-monsoon period while the lowest infection was recorded during monsoon i.e. from July to October which may lead to the conclusion that environmental factors are responsible for spreading infection.

First report of some known Trichodinella epizootica Šramek-Hušek, 1953, and Tripartiella Lom, 1959 from the cultured Oranda Gold Fish ( Carassius auratus auratus ) in India

Trichodiniasis of fishes cause economic losses in the fish industry through mortality and decrease growth rate. Very few studies of these ectoparasites have been made in India. A comprehensive icthyoparasotological survey in some ornamental fish farms of different parts of India has been done since March 2014-May 2015. During the study these trichodinid parasites have been identified from the gills of Oranda Gold Fish (Carassius auratus auratus L.). They are Trichodinella epizootica, Tripartiella viz. Tripartiella bulbosa, Tripartiella copiosa and Tripartiella obtusa. All these parasites have been recorded for the first time from the gills of Oranda Gold Fish (Carassius auratus auratus L.) in India i.e. The paper deals with the diversity and description of ciliophorans parasites of ornamental fish.