Amalendu Chatterjee

A new species of the genus Discolaimus Cobb, 1913 (Qudsianematidae: Dorylaimida) from West Bengal, India with revised key to the genus

A new species of dorylaimid nematode, collected from rhizospheric soil of banana plantation (Musa paradisiaca L. cv. Kanthali) in Paschim Medinipur district of West Bengal, India is being described and illustrated. Discolaimus dhanachandi n. sp. comes close to D. affinis Loof, 1964 and D. elegans Sauer and Annells, 1985. But differs significantly in having large odontostyle, spear aperture occupying more than half of its length, prerectal and rectal length less than anal body width, asymmetrical ovary and slightly longer tail than anal body diameter. Besides, D. dhanachandi n. sp. differs from D. affinis in the values of c and V, and from D. elegans in the values of a, b and c. Species key of the genus Discolaimus is also provided.

Coomansinemoides wasimi n. gen., n. sp. (Nematoda: Dorylaimida) From West Bengal, India

Coomansinemoides wasimi n. gen., n. sp. was collected from the soil around the roots of guava. The new genus is characterized by moderate labial sclerotisation, double guiding ring, moderately narrow odontostyle with wide aperture, smaller expanded portion of pharynx, amphidelphic reproductive system, and dissimilar tail shape in female and male. Due to the moderate labial sclerotisation and the relatively anterior position of the second pair of pharyngeal gland nuclei, the new genus has been included in the subfamily Thornenematinae. It comes closest to the genus Coomansinema, distinctly differing in having very minute labial sclerotisation, smaller and narrower odontostyle with wider aperture, shorter odontophore, smaller expanded part of pharynx, the shape of cardia and also in having different female tail shape. Coomansinemoides n. gen. is also related to Mesodorylaimus, but can be differentiated on the basis of larger stylet aperture, double guiding ring, smaller expanded part of pharynx, and by the position of second pair of pharyngeal gland nuclei which is typical of the subfamily Thornenematinae.

Actus shamimi n. sp. (Nematoda: Mononchida) from the Andaman and Nicobar Islands, India, with a key to the species of Actus Baqri & Jairajpuri, 1974

A new predatory nematode species, Actus shamimi n. sp., is described and illustrated. Actus shamimi n. sp. is characterised by medium body length, buccal cavity barrel-shaped with apex of dorsal tooth located at ca 80% from base of cavity and 3-6 subventral denticles present in each latero-subventral row, cardia triangular in shape, amphidelphic gonad with longer oviduct, vagina very short and with distinct pars refringens vaginae containing cuboidal sclerotised pieces, tail elongate-conoid, slightly arcuate ventrally with three caudal glands and prominent terminal spinneret opening. It is similar to A. baqrus but has a smaller body length; absence of advulval papillae and shorter tail. It also differs from A. neocaledonensis in the position of the dorsal tooth apex, length of tail and presence of caudal glands and spinneret. The new species also differs from A. conoidus in the larger buccal cavity; lower lip height; lower c′ value and in having a sphincter at the oviduct-uterus junction; and from A. minutus and A. salvadoricus by longer body, longer buccal cavity, presence of a much more anteriorly located dorsal tooth and much higher c value. The genus Actus is reported for the first time from the Andaman and Nicobar Islands, India. A key to species in the genus is provided.

Studies on soil and plant parasitic nematodes associated with banana in West Midnapur, West Bengal, India

During a taxonomic survey from March 2004 to February 2006, a total of 46 species of soil and plant parasitic nematodes, associated with banana plantations (Musa paradisiaca L. cv. Kanthali) have been encountered from different localities of Paschim Medinipur district of West Bengal, India. Of these, 29 species belonging to 21 genera were recorded under the order Dorylaimida and 17 species belonging to 11 genera were under the order Tylenchida. Most of the species are represented through female sex. The typical plant parasitic nematode genus Helicotylenchus Steiner, 1945 holds maximum number of species.