Morphotaxonomical description of six new species of acephaline gregarines infecting oligochaete host.

This communication deals with the morphology, taxonomy and life history of six new acephaline gregarines (Apicomplexa: Gregarinomorphea) of the genus Monocystis Stein (1848), Nematocystis Hesse (1909), Aikinetocystis Gates (1926) and Dirhynchocystis Cognetti de Martiis (1921) from oligochaete hosts. These are Monocystis molnari sp. nov. from Metaphire anomala (Clitellata: Opisthopora: Megascolecidae); Monocystis paneki sp. nov. from Lampito mauritii (Clitellata: Opisthopora: Megascolecidae); Monocystis bulbae sp. nov from Metaphire posthuma (Clitellata: Opisthopora: Megascolecidae); Nematocystis cylindrum sp. nov. from Perionyx excavatus (Clitellata: Opisthopora: Megascolecidae); Aikinetocystis perionyxae sp. nov. from Perionyx excavatus (Clitellata: Opisthopora: Megascolecidae) and Dirhynchocystis drawidae sp. nov. from Drawida nepalensis (Clitellata: Haplotaxida: Moniligastridae). Trophozoites of Monocystis molnari sp. nov. elongated and cylindrical. Gametocysts elliptoid. Oocysts fusiform. Trophozoites of Monocystis paneki sp. nov. elongated and hump like. Gametocysts orbicular. Oocysts fusiform. Trophozoites of Monocystis bulbae sp. nov. elongated and cylindrical. Gametocysts fusiform. Oocysts fusiform. Trophozoites of Nematocystis cylindrum sp. nov. cylindrical. Gametocysts orbicular. Oocysts fusiform. Trophozoites of Aikinetocystis perionyxae sp. nov. cylindrical. Gametocyst ovoid. Oocysts fusiform. Dirhynchocystis drawidae sp. nov. having a capsule like body. Gametocysts orbicular. Oocysts rhomboid.

An annotated list of aseptate gregarine parasites (Protozoa; Apicomplexa; Sporozoa) infecting oligochaete hosts.

Gregarines are mainly coelozoic parasites belonging to the protozoan phylum Apicomplexa. The present communication deals with 137 species belonging to the genera Aikinetocystis Gates, 1926; Apolocystis Cognetii de Martiis, 1923; Dirhynchocystis Cognetii de Martiis, 1921; Enterocystis Tsvetkov, 1926; Nematocystis Hesse 1909; Rhynchocystis Hesse 1909; and Zygocystis Von Stain, 1848. This study was conducted to explore the diversity of gregarine parasites infecting the oligochaete hosts of the world.

Observation on Monocystis kuidongae sp. nov. (Apicomplexa: Eugregarinida) from an Indian earthworm Perionyx excavatus Perrier (Annelida: Oligochaeta).

A survey to know the diversity of endoparasitic protozoan parasites of the earthworms of West Bengal, revealed a new species of the genus Monocystis Stein, 1848, that resides in the seminal vesicle of the earthworm Perionyx excavatus Perrier. Monocystis kuidongae sp. nov. is characterized by ovoidal gamonts (trophozoites) with inconspicuous mucron and measure 69.53-102.25 (86.29 ± 11.48) µm × 24.54-61.35 (35.17 ± 12.82) µm. Shape of the gametocysts are almost rounded and measure 81.80-110.43 (96.11 ± 8.85) µm in diameter. Oocysts are navicular with pointed ends and measure 11.55-12.32 (11.78 ± 0.36) µm × 5.00-5.77 (5.39 ± 0.25) µm.

Description of a new species of Myxobolus Butschli, 1882 from the Cirrhinus mrigala Hamilton, 1822 an edible fish of India.

Myxobolus Bütschli 1882 is an important group of parasitic protozoa infecting a large number of freshwater fish species worldwide. The severity of Myxobolus infection leads to heavy loss in production of fishes. During the survey of the fish parasites, a new species of the genus Myxobolus have been isolated from the gills of a freshwater edible fish Cirrhinus mrigala Hamilton, 1822 from Canning, South 24 Parganas, West Bengal, India which has been described here.

Description of a New Haemogregarine, Haemogregarina sundarbanensis n. sp. (Apicomplexa: Haemogregarinidae) from Mud Turtle of Sundarban Regions, West Bengal, India.

OBJECTIVE: The aim of this study was to provide a description of a new haemogregarine, Haemogregarina sundarbanensis n. sp., from mud turtles collected from Sundarban regions, West Bengal, India. METHODS: The turtles were collected from fish markets near Canning, South 24-Parganas District, West Bengal. Thin blood films were prepared using the blood drawn from the head and feet. The blood films were then air-dried, fixed in absolute methanol, and stained with Giemsa. RESULTS: The erythrocytic stages could be differentiated into small and large forms. The young gamonts measured 7.896×3.469 µm, microgamonts measured 8.876×4.425 µm, and macrogamonts measured 8.919×4.272 µm. The cytoplasm of the macrogamonts was stained deep blue with Giemsa, and many metachromatic granules are found uniformly distributed. The oval or rounded nucleus was central in position and stained deep red with Giemsa stain, whereas in microgamonts, the nucleus was not at all compact but with a few dispersed chromatin granules. CONCLUSION: The prevalence of infection was found to be 33.3% (5/15). The infected erythrocytes reveal shape alteration, marginal and atrophic nucleus, and were larger than non-parasitized erythrocytes. The cytoplasm of the infected erythrocytes stained darker than that of the uninfected erythrocytes.

On the occurrence of a Haemogregarinae (Apicomplexa) parasite from freshwater turtles of South 24 Parganas, West Bengal, India.

OBJECTIVE: The aim of this study was to investigate Haemogregarine parasites (Apicomplexa: Haemogregarinidae) of freshwater turtles (Lissemys punctata andersoni, Geoclemys hamiltonii) of India. METHODS: Turtles were collected by net from two ponds of South 24 Parganas, West Bengal, India. A small amount of blood was taken from the subcarapacial vein puncture site. The blood smears were prepared and air dried and fixed in absolute methyl alcohol. The slides were stained with Giemsa. RESULTS: Haemogregarine parasites were recorded from the erythrocytes of turtles. Multiple stages of intraerythrocytic gametocytes (microgametocytes, macrogametocytes, early schizonts and mature schizonts) were observed in blood films. CONCLUSION: It was found that only twenty out of the twenty five turtles (80%) were infected with the parasite. The prevalence rate was higher in larger turtles in comparison to smaller ones. It was also found that female turtles had a higher prevalence of infection than males.

Myxobolus leafa sp. nov. (Myxozoa: Bivalbulida) from the gill filament of Labeo bata (Hamilton) from Manipur, India.

OBJECTIVE: The aim of this study was to investigate the gill filaments of Labeo bata in India parasitologically and to describe the new Myxozoa parasite species, Myxobolus leafa sp. nov., which was determined. METHODS: Fish were collected alive from fish farms from Manipur (India). Sporogonic plasmodia were removed with sterile forceps and observed under phase contrast microscope. For permanent preparations, air dried smears were stained with Giemsa after fixation in acetone free absolute methanol. RESULTS: Mature spores of the new species appear as leaf-like structures in valvular or frontal view, tapering at both ends. The anterior end of the spore is broader than the posterior end. Spores measure 15.3-11.8 µm (16.91 ± 1.16) in length and 13.6-15.3 µm (14.15 ± 0.67) in breadth. CONCLUSION: The new gill parasite species, Myxobolus leafa sp. nov., was described from fish in India. The prevalence of the parasite was 3.3% and two stages (cyst and spore) of the parasite existed in its life cycle.

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.

A checklist of the species under the genus Monocystis Von Stein, 1848 (Apicomplexa: Sporozoa: Monocystidae) described from oligochaete hosts.

A checklist of 24 species of the genus Monocystis is presented and includes the salient features of each species, type host and site of infection.

Description of two new species of ectoparasitic Trichodina Ehrenberg, 1830 (Ciliophora: Trichodinidae) from freshwater fishes in the river Ganges, India.

Two new species of the genus Trichodina Ehrenberg, 1838, T. silondiata sp. nov. and T. pangasi sp. nov. from the gills of freshwater fish Silonia silondia (Hamilton 1822) and Pangasius pangasius (Hamilton-Buchanan) respectively from the river Ganges of West Bengal are described here. Wet smears of gills and skins were prepared in the field, air dried and impregnated with Klein's dry silver method. In case of S. silondia (Hamilton 1822) 24 out of 146 host fishes were parasitized on the gills. Infestation rate in case of P. pangasius (Hamilton-Buchanan) was not significant. From a total of 86 examined host fish, only seven were parasitized on the gills. The mean diameters of the body of the specimens of T. silondiata sp. nov. and T. pangasi sp. nov. were 32.7-60.6 (46.4 ± 6.3) µm and 38.9-54.1 (44.9 ± 3.0) µm respectively. Taxonomic and morphometric data for these ectoparasitic trichodinids based on wet silver nitrate impregnated specimens are presented.

Observations on two new species of Myxobolus Butschli, 1882 from minor carps of Tripura, India.

Tripura is a north-eastern state of India with a total geographical area of 10,491 sq.km. Labeo bata, L. calbasu, L. gonius of the genus Labeo Cuvier and Cirrhinus reba of genus Cirrhinus Oken are the most popular and commercially important native minor carps of the state. During a detailed survey on the protozoan parasites of the minor carps of Tripura, two new species of myxozoan (Myxozoa: Bivalvulida) parasites Myxobolus tripurensis sp.n. and Myxobolus potularis sp.n. were encountered on the gill filaments of the host fishes. Distinctive characteristics of the plasmodia and the spores have been described.

Observations on the histopathological changes caused by myxosporidian infections in minor carps.

Myxozoan infections result in large scale histopathological features depending on various factors. Earlier studies on pathological changes caused by myxozoan infections in piscine hosts have been reported from different localities. This study is based on the histopathological features caused by the members of genera Myxobolus Bütschli, 1882 and Thelohanellus Kudo, 1933 in the gill and fin tissues of commercially significant minor carps, Labeo calbasu and Labeo gonius of the genus Labeo collected from the four different districts of the north-eastern Indian state of Tripura (latitude 22°51'-24°32'N and longitude 90°10'-92°21'E) spanning over a total geographical area of 10,491 km(2).

Description of Rhynchocystis silvae sp. nov (Apicomplexa: Eugregarinida) from Metaphire peguana Rosa (1890) of Dhaka, Bangladesh.

OBJECTIVE: Biodiversity studies in search of endoparasitic acephaline gregarines of earthworms revealed a new species under the genus Rhynchocystis Hesse, 1909. METHODS: The species has been obtained from the seminal vesicles of the earthworm, Metaphire peguana. The parasite was identified using standard methodology. RESULTS: Gamonts are solitary, elongated with a conical, enlarged head and blunt posterior end. The mature gamont measures 419.90- 430.95 (425.05±4.70) µm in length and the width at the widest portion is 44.2-50.83 (47.88±2.85) µm and 15.47-17.68 (16.50±1.14) µm in the posterior end. The nucleus is elongated and positioned at the posterior end. The nucleus measures 17.68-22.01 (19.74±1.95) µmx11.05- 15.47 (13.40±1.95) µm. The measurement of the mucron is 13.26-17.68 (15.47±1.86) µmx17.68-22.1 (19.44±1.71) µm. Gametocysts are ovoid with two unequal sized gametocytes. The gametocyst measures 95.03-97.24 (96.20±1.14) µmx77.35-81.77 (79.56±1.86) µm. Large and small gametocytes measure 57.46-61.88 (59.81±1.76) µmx70.72-75.14 (72.48±1.71) µm and 30.94-37.57 (34.47±2.74) µmx61.88-66.3 (64.38±1.84) µm respectively. Oocysts are biconical, measuring 11.05-15.47 (12.81±1.71) µmx6.63-8.84 (7.70±1.20) µm. CONCLUSION: A new gregarine parasite species is described.

Apolocystis cognetti sp. nov. (Apicomplexa: Monocystinae) a new aseptate gregarine species from the earthworm Amynthas hawayanus (Annelida: Oligochaeta) from West Bengal, India.

During the course of surveys of endoparasitic aseptate gregarines in Darjeeling district of West Bengal, India, seminal vesicles of Amynthas hawayanus (Rosa 1891) found to be infested with a new species of the genus Apolocystis (Cognetti de Martiis 1923). Trophozoites are spherical or rounded and without any polar differentiation. Diameter of the trophozoite ranges from 65.4 to 126.7 (91.8 ± 17.5) µm. Nucleus diameter measures 12.2-20.4 (14.4 ± 2.2) µm. Gametocyst is round and measures 73.6-110.4 (93.3 ± 14.0) µm and contains two unequal gametocytes. Oocyst measures 7.7-10.7 (9.5 ± 0.9) µm × 3.8-5.3 (4.6 ± 0.4) µm.

Occurrence of Trichodinid Ciliophorans (Ciliophora: Peritrichida) in the freshwater fishes of the river Churni with description of Trichodina glossogobae sp. nov. in West Bengal, India.

Between January 2011 and March 2011 occurrence of trichodinid ciliophorans were studied in the freshwater fishes of the river Churni. The biodiversity survey revealed presence of a new species of the genus Trichodina (Ehrenberg 1830) infesting Glossogobius giuris (Hamilton-Buchanan). Another freshwater fish Labeo bata (Hamilton 1822) were found to be infested with two species of the genus Tripartiella Lom 1959: Tripartiella bulbosa (Davis 1947) Lom 1959 and T. copiosa Lom 1959. Adhesive disc size of the new Trichodina species is small measuring 30.6-46.9 (36.2 ± 3.9) µm in diameter. The centre of the disc is finely granular and transforms into dark when impregnated with silver. The overall prevalence of this species is 15.6% (12/77). Tripartiella bulbosa and T. copiosa are very small sized ciliophorans, measuring 16.7-23.8 (20.6 ± 2.2) µm and 15.2-22.4 (19.7 ± 1.9) µm in diameter, respectively.

On the occurrence of a gregarine parasite (Apicomplexa: Eugregarinorida) from the seminal vesicles of earthworms (Annelida: Oligochaeta) of Bangladesh.

In a survey of the endoparasitic acephaline gregarines in the Satkhira district of Bangladesh, seminal vesicles of earthworm, Metaphire posthuma were found to be infested with a new species of the genus Enterocystis Tsvetcov 1926, Enterocystis elongatum sp. nov. The new species is elongated and measures 55.3-87.8 (67.7 ± 10.3) µm in length and 33.2-37.8 (35.7 ± 1.6) µm in width. Nucleus ovoid and measures 4.4-8.8 (6.6 ± 2.2) µm in length and 4.4-6.6 (5.3 ± 1.1) µm in width. Gametocyst with two unequal sized gametocytes and measures 88.4-101.7 µm (97.9 ± 4.8) µm in length and 77.6-95.0 (86.9 ± 7.7) µm in width. Oocysts ellipsoidal and measure 13.7-19.9 (16.7 ± 2.6) µm in length and 6.6-8.8 (7.6 ± 1.1) µm in width. Prominent association or syzygy is present in life cycle.

Nematocystis vinodae n. sp. (Protozoa, Apicomplexa, Eugregarinida), a monocystid gregarine from Eutyphoeus nicholsoni (Beddard).

OBJECTIVE: Biodiversity studies in search of endoparasitic acephaline gregarines revealed a new species under the genus Nematocystis Hesse, 1909. METHODS: The species has been obtained from the seminal vesicles of the earthworm, Eutyphoeus nicholsoni (Beddard). RESULTS AND CONCLUSION: Gamonts of this species are solitary and bear a perfect nematoid appearance with smoothly curved terminals, especially in mature forms. Mature gamonts measure 245.40-302.66 (270.68±18.86) µm in length and 20.45-26.58 (24.54±2.10) µm in width. Nucleus is rounded or slightly ovoidal, 20.45-24.54 (22.69±1.74) µm in diameter. Gametocysts are almost rounded, measuring 77.71-85.89 (82.82±2.69) µm in diameter. Oocysts are navicular, measuring 7.70-8.47 (8.24±0.36) µm x 4.23-4.62 (4.50 ±0.18) µm.

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).

Observation on Monocystis constricta n. sp. (Protozoa: Apicomplexa: Monocystidae) from an Indian earthworm, Eutyphoeus quaripapillatus Michelsen, 1907.

A biodiversity survey of aseptate gregarines in earthworm hosts in the Calcutta district of West Bengal State revealed the existence of a new species of aseptate gregarine under the genus Monocystis Stein, 1848. The monocystid gregarines obtained from the earthworm host, Eutyphoeus quaripapillatus Michelsen, 1907 have been identified as a new species. The mucron was indistinct. The gamonts are elongated, ovoid, have a hood like structure at the anterior end and measure 150.1-212.4 (188.1+/-2.1) micromx66.1-112.1 (72.3+/-1.1) microm. The gametocysts are ellipsoid and measure 92.3-136.3 microm (111.2+/-2.1)x78.3-114.4 microm (82.6+/-3.6) microm. Prominent syzygy was apparent. Oocysts are navicular, measuring 14.1-22.3 (18.1+/-3.2) micromx9.1-15.2 (11.9+/-1.1) microm.

A new species of Henneguya, a gill parasite of a freshwater fish Anabas testudineus (Bloch) affected with ulcerative disease syndrome from Manipur, India.

A new species of Henneguya parasitizing tissues affected by the ulcerative disease syndrome of a freshwater fish Anabas testudineus (Bloch) from Khiodum and Pumlen lakes of Manipur state is described. Of the fishes examined 75% were found to be infested with this myxozoan parasite. Mature spores of the new species are elongated, biconvex, and oval with bluntly rounded anterior end and gradually tapering posterior end with a caudal prolongation, measuring 12.6-15.4 (14.0+/- 1.1) microm in length. Length of the caudal prolongation is 11.2-12.6 (11.7+/- 0.6) microm. The width of the spores is 5.6-7.0 (6.3+/- 0.5) microm. The length of the polar capsules is 5.6-6.3 (5.5+/- 0.3) microm.