Biman Kumar Dutta

Anthelmintic activity of Acacia oxyphylla stem bark against Ascaridia galli.

The anthelmintic activity of the ethanol extract of Acacia oxyphylla Graham ex Bentham (Mimosaceae) stem bark was tested against Ascaridia galli Schrank (Nematoda), the intestinal roundworm of domestic fowl. Different concentrations of the extract (0.5, 1, 2, 5, 10 and 20 mg/mL) were prepared in 0.9% phosphate buffered saline (PBS) with 1% dimethylsulfoxide (DMSO). In vitro treatment of the adult roundworms indicated concentration-dependent efficacy of the plant extract. Similar concentrations of a broad-spectrum antiparasitic drug, albendazole, were used as a standard reference. Control experiments consisted of nematodes maintained in 0.9% PBS with 1% DMSO. Albendazole was significantly effective (P < 0.05) at all concentrations tested in causing mortality of A. galli. However, the plant extract showed concentration-dependent efficacy only at the concentrations of 2, 5, 10, and 20 mg/mL. In order to ascertain the anthelmintic effect, scanning electron microscopy was performed, which indicated devastating structural alterations on the fine topography of A. galli treated with 20 mg/mL of the plant extract, when compared with that of the control specimen. Severe shrinkage of the cuticle, loosening and collapse of the lips, and extensive irregular wrinkles all over the body surface were very distinct on the plant extract-treated nematode. Moreover, high magnification of the cuticle revealed formation of a number of small swellings or blebs, which apparently marked the initiation of disintegration of the entire cuticle.

Ornithochilus cacharensis (Orchidaceae), a new species from India (Assam)

SummaryA new orchid species from Assam, Ornithochilus cacharensis Barbhuiya, B. K. Dutta & Schuit., is described. It differs from the other species in the small genus Ornithochilus (Lindl.) Benth. in floral morphology and in the uniformly red-purple flowers. The taxonomy of the genus is discussed and a key to the known taxa of Ornithochilus is presented.

Student Perceptions of, and Attitudes toward, Bats in Barak Valley, Assam, India

ABSTRACT Bats are commonly found all over the world and provide significant ecosystem services. These animals are facing serious threats due to various anthropogenic activities, including hunting. Additionally, bats are often not particularly well liked due to their non-aesthetic characteristics. A positive attitude to these animals is essential to protect them through appropriate conservation measures involving public intervention. Current high school students are the conservationists of the future, and the extent of support for bat conservation received from this and future generations is dependent upon their attitude toward these animals. It is therefore important to assess their perceptions of bats so that appropriate awareness programs can be devised, and negative attitudes (if any) rectified. The present study aimed to understand this aspect in order to provide inputs for shaping positive attitudes toward bat conservation. The study was undertaken in Barak Valley, Assam, India, where 65 bat colonies had already been recorded. A total of 3,059 high school students from 36 schools situated in their vicinity were questioned using a close-ended questionnaire to determine their perceptions. The responses received were divided among three categories: familiarity with bats, opinion on bats, and attitudes toward conservation, and were ranked on a scale of 10, based on selected aspects. Most students were awarded a score of four, indicating an average knowledge and opinion of bats. These findings suggest that awareness programs are urgently needed in schools to improve the general knowledge of and attitudes toward bats, and to inspire the next generation of bat conservationists.

Human-wildlife Conflict in the Forest Fringe Villages of Barak Valley, Assam, India

Abstract Human-wildlife conflict is a challenge to both mankind and wildlife and is a severe conservation issue. Villages located adjacent to protected forests are the most vulnerable sites as human and wildlife needs intersect each other in these areas. There are 12 reserve forests and one wildlife sanctuary in Barak Valley, South Assam, but no proper study has been undertaken on this aspect in their fringes. In view of this, a close-ended questionnaire survey was conducted to study the problem in such areas of the region. Four main conflict animals, viz., jackal, civet, wild boar and monkey were documented. Some other mammals, including a few endangered species were also found to cause depredation. The outcome is expected to aid conservationists for further study of the problem as well as for the management of wildlife.

An annotated checklist of the Grasses (Poaceae) of Southern Assam

We provide a checklist of grass flora along with the details of life form a ~ 6922 km2 area located in the southern part of Assam (Barak valley). This area harbors 98 grass species belonging to 49 genera of the Poaceae. Subfamily Panicoideae (52 species) had the highest number of species followed by Bambusoideae (25 species), Chloridoideae (13 species), Ehrhartoideae (4 species), Centothecoideae (3 species) and Arundinoideae (1 species), while subfamilies like Anomochlooideae, Aristidoideae, Danthonioideae, Pharoideae, Pooideae and Puelioideae were not represented. The region accounts ca. 32% of the diversity of grass flora of the state of Assam.