Durga P. Haldar

First record of Chilodonella hexasticha (Kiernik, 1909) Kahl, 1931 (Ciliophora: Chilodonellidae) infesting a freshwater fish Nandus nandus (Hamilton)from gangetic West Bengal, India

West Bengal, situated in the eastern part of the country, is one of the most beautiful and important states of India. In a developing country like India, fish is one of the cheapest sources of protein and West Bengal contributes a major portion of the total fish production. Fishery development represents a vital sector in West Bengal. The degree of success in this sector depends to a great extent on the advancement of fish parasitology research, as it is evident that the increase of fish yields can only be achieved from healthy fish stock. During an investigation (July 2001 - December 2002), a protozoan ectoparasite, Chilodonella hexasticha (Kiernik, 1909) Kahl, 1931, was found on the gills of a freshwater fish Nandus nandus (Hamilton). This finding is very important for the fishery sector, as this parasite causes the disease chilodonellosis, which leads to mass mortality. The present paper deals with the morphology, systematics, seasonal incidences and prevalence of C. hexasticha.

Description of a new species, Myxobilatus anteronippus sp. n., and synopsis of Indian species of the genus Myxobilatus Davis, 1944 (Myxozoa: Myxosporea: Bivalvulida)

A new histozoic species of the genus Myxobilatus Davis, 1944 (Myxozoa: Myxosporea: Bivalvulida), Myxobilatus anteronippus sp. n., is described from pectoral, dorsal and tail fins and operculum of an estuarine fish Taenioides cirratus (Blyth). The present species is unique in having polar capsules with unequal dimensions with a nipple or knob like structure present at the anterior extremity of each polar capsule, the shell valves are devoid of any striations. A synopsis of Indian species of the genus Myxobilatus Davis, 1944 including a total of six species is also provided.

Two new species of Unilobus Théodoridès, Desportes and Jolivet, 1984 (Apicomplexa: Conoidasida) parasitizing tenebrionid beetles along with the remarks on the genus and its family status.

Summary. This paper deals with the morphology and life history of two new species of septate greganines (Apicomplexa: Conoidasida: Gregarinidae) of the genus Unilobus Theodorides, Desportes & Jolivet, 1984, obtained from two tenebrionid beetles of West Bengal, India. These are Unilobus gonocephali n. sp. from Gonocephalum sp. (Insecta: Coleoptera: Tenebrionidae) and Unilobus scleroni n. sp. from Scleron irregulate (Insecta: Coleoptera: Tenebrionidae). Total length of U. gonocephali varies from 200–467 μm. Gametocysts spherical, 410 μm in average diameter, dehisces through 7–9 sporoducts. U. scleroni is comparatively smaller, total length varies from 61–232 μm. Gametocyst spherical with average diameter 350 μm, dehices through 10 to 12 sporoducts. The two new species share traits which defi ne the genus such as the absence of epimerite, expanded protomerite and late association. These two described species are not only different from the previously described species, but also oocysts (= spores) entirely different from each other in characters like measurements, number of sporoduct and in host range. This communication also confi rmed the validity of the genus Unilobus Theodorides, Desportes & Jolivet, 1984 and its placement under the family Gregarinidae Labbe, 1899.

Description of Two New Species of Phleobum Haldar and Chakraborty, 1974 along with a Major Taxonomic Revision of the Genus

Summary. Two new species of Phleobum (Apicomplexa: Eugregarinida: Hirmocystidae) are described from adult grasshoppers in Kalyani, India. Phleobum globuloepimeritum n. sp. is described from Oxya hyla hyla (Insecta: Orthoptera: Acrididae) and Phleobum elliptica n. sp. from Atractomorpha crenulata (Insecta: Orthoptera: Pyrgomorphidae). In P. globuloepimeritum, the trophozoites are solitary, orangecoloured, have a maximum length of 352 µm with a hyaline globular epimerite and the protomerite in satellite is characteristically flanged. The gametocyst is orange, orbicular, averaging 300 × 250 µm in size, dehiscing through a pore after 50 h. The oocysts are uniformly smooth, ellipsoidal, measuring 9 × 5 µm. In P. elliptica trophozoites are also solitary, orange-coloured, having a maximum length of 157 µm with triangular epimeri tes. The protomerite flange is typically a bowel-shaped collar. The gametocyst is yellow-orange, ellipsoidal, averaging 240 × 165 µm and dehisces through a pore after 72 h, releasing smooth-walled, ellipsoidal, uniformly shaped oocysts measuring 5 × 3 µm. The two new species share traits, which define the genus such as: gamonts in association, satellites with characteristic flange and gametocysts dehiscence through a single pore. The epimerite of P. globuloepimeritu m is hyaline and globular, which is unique among members of the genus. The gametocyst of P. elliptica is notably ellipsoidal. Basing on observation on all the described and present two species, generic characters of the genus Phleobum have been redefined. The genus is also transferred from the family Didymophyidae to the family Hirmocystidae as the gametocysts in all the species of Phleobum dehisce through a pore.

Two new species of the genus Quadruspinospora Sarkar et Chakravarty, 1969 (Apicomplexa, Conoidasida) from grasshoppers (Insecta, Orthoptera)

Descriptions of structures and life histories of two new species of septate gregarines (Apicomplexa, Conoidasida) are given. These are: Quadruspinospora cloptoni sp. nov. and Quadruspinospora caudata sp. nov. from the midguts of Oxya hyla hyla Serville and Gesonula punctiformes (Stal.) (Insecta, Orthoptera, Acrididae), respectively. Trophozoites of Q. cloptoni attain a maximum length of 944 μm and their epimerites are either a simple knob or cauliflower-like without any digitiform process; gamonts are solitary and, spherical gametocysts, 390 μm, release ovoid oocysts by a simple rupture, the latter being provided with four characteristic spines, two at each pole. Trophozoites of Q. caudata are much smaller, 578 μm in maximum length, and the epimerite in this gregarine is short and cone like. Spherical gametocysts, 365 μm, also dehisce by a simple rupture releasing ovoid oocysts having four typical spines, characteristic of the genus Quadruspinospora Sarkar et Chakravarty, 1969. The validity of Quadruspinospora as a distinct genus is discussed.

Two new species of Hirmocystis Labbé, 1899 (Apicomplexa: Conoidasida) from Coleopteran and Lepidopteran insects in India.

This study records the descriptions of the structures and life cycles of two new species of Hirmocystis Labbe, 1899 (Apicomplexa: Conoidasida), H. cleorinis sp. n. and H. corcyris sp. n., from a coleopteran insect, Cleorina sp. and larvae of a lepidopteran, Corcyra cephalonica, respectively.