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Aquilaria malaccensis Lam., a threatened tree commonly called agarwood, is emerging as one of the most promising commercially important aromatic species in the world. This paper presents the findings on the vegetative and reproductive phenology of Aquilaria malaccensis from the secondary tropical evergreen forest in Cachar district, Assam. The effect of tree phenology and the influence of seasonal drought and environmental variables, especially temperature and precipitation, on various phenophases such as leaf initiation, leaf-fall, flowering, and fruiting were investigated. For this, a quantitative assessment was made at 15-day intervals by tagging 35 trees over a period of two years. Seasonal influence on the phenology of different phenophases was correlated with environmental variables and Spearman's rank correlation coefficient was employed. Leaf initiation was positively correlated with temperature (rs=0.694, p=<0.05), while leaf-fall was negatively correlated with temperature (rs=-0.542, p=<0.05) and rainfall (rs=-0.521, p=<0.05). Flowering (rs=0.713, p=<0.01; rs=0.713, p=<0.01) and fruiting (rs=0.721, p=<0.01; rs=0.775, p=<0.01) were positively and significantly influenced by temperature and rainfall. The study suggests that temperature and rainfall were major determinants of the vegetative and reproductive phenology of A. malaccensis, and any changes in these variables under expected climate change phenomenon may have a profound effect on phenophases of this threatened tree species. [ABSTRACT FROM AUTHOR]

Identification and mapping of the spatial distribution of species is an important aspect of zoogeographical enquiry. The habitats of many species are facing the threat of depletion in increasingly human-influenced environments. This has already led to the extinction of many species in different localities, making understanding the linkages between anthropogenic threats and species distribution of utmost importance. A GIS-based model was applied to gain an overall picture of the potential distribution of Ploceus philippinus (Baya Weaver) in and around Nagaon District in Assam. The used maxent model in the GIS environment gives a highly significant Area Under Curve (AUC) validation statistic of 0.99. Out of the total area of 3,975 km2, 596.86 km2 (15%) is demarcated as a high-potential area. Such predictions are highly useful in assisting in the conservation of threatened species under current and future climatic conditions. [ABSTRACT FROM AUTHOR]

The present paper deals with 25 new records of lichens under 19 genera and 11 families for the state of Assam in India. The newly reported species from Assam are Alyxoria apomelaena, A. culmigena, A. varia, Caloplaca pseudisteroides, Cryptothecia striata, Diorygma rupicola, Dtrinaria papillulifera, Flavoplaca citrina, Graphis sundarbanensis, Herpothallon echinatum, Lecanographa rufa, Letrouiria muralis, Myriotrema clandesrinum, Opegrapha discolor, Parmotrema crinitoides, Phaeophyscia hispidula, Porina eminenrior, P. interstes, P. mastoidella, Pyrenula submastophora, P. thelomorpha, Rinodina oxydata, Synarthonia bicolor, Zwackhia bonplandii, and Z. viridis. Briefdescriptions of these additional lichen taxa from Assam are provided to facilitate their identification. [ABSTRACT FROM AUTHOR]

Mantispa indica (Westwood) is an insufficiently explored species under the family Mantispidae (Neuroptera) with limited understanding. Its presence has been documented in various regions of India and Nepal over time. Nevertheless, a comprehensive examination of its morphometric characteristics has been lacking. This research presents a novel morphological comparison of male and female specimens, accompanied by appropriate illustrations, from two distinct protected areas in Assam, India. [ABSTRACT FROM AUTHOR]

This study was conducted on a continuous 64-km stretch of National Highway (NH) 715, which bifurcates the Kaziranga-Karbi Anglong landscape complex, with Kaziranga National Park on its southern side and North Karbi Anglong Wildlife Sanctuary on the northern side. The survey was carried out from October 2017 to September 2018 via two-way journeys three days a week, with two observers using a motor vehicle at a steady speed of 25-35 km/hour. Roadkill reports of one Large Indian Civet Viverra zibetha and six Small Indian Civets Viverricula indica were collected. Both the species are solitary and nocturnal, and prefer to inhabit secondary landscapes intermingled with human habitation. This stretch of NH 715 forms a crucial passage for wildlife foraging and breeding, and this study reflects the impacts of roads causing wildlife-vehicle collision for two civet species. [ABSTRACT FROM AUTHOR]

Illustrated redescription of a colourful bug Urolabida histrionica (Westwood 1837), along with comments on bionomics, is presented for the first time from an Indian population. The host plant for this bug was identified as Ficus hispida L. f. (Moraceae). [ABSTRACT FROM AUTHOR]

Fish constitute a major component of diet for the people of northeastern India and one of the main food items for most people in Assam. But fishes are facing serious risks due to parasitic infestations which deteriorate the food value and also leads to fish mortality. The present study aims to investigate the occurrence of helminth parasites in some selected fishes of the species Mystus tengara, Channa punctata, and Trichogaster fasciata collected from Deepor Beel, Guwahati, Assam. Trematode parasite species have been recorded from Trichogaster fasciata. The recovered trematode is Clinostomum complanatum belonging to the family Clinostomatidae. The present study incorporates the morphological, morphometric, and scanning electron microscopy studies of the prevailing parasite. This study is the first report on the occurrence of helminth parasites in the edible freshwater fishes collected from Deepor Beel. [ABSTRACT FROM AUTHOR]

Indian Institute of Technology - Guwahati (IITG), Assam, is an ecologically rich campus hosting different species of birds, butterflies and mammals. It accommodates several migratory and resident species of birds across different seasons. However, information is scanty on avian diversity with respect to the different habitats of the campus. Therefore, the present study attempts to gain insight into avian diversity with respect to habitat heterogeneity by considering the species presence-absence dataset collected for three years (2017-2020). A multivariate Beta (β) diversity analysis is carried out for the IITG campus constituted of five primary habitats, viz., secondary growth, eco-forest, water bodies, swampy-marshy area, and constructions. Of 152 bird species observed in the IITG campus, the highest number is reported from secondary growth, followed by eco-forest. The multivariate analysis shows that the average β-diversity for the IITG campus is approximately equal to 79%, which is in accordance with another published study. These observations are examined in light of hypotheses and phenomena documented in the literature, such as habitat heterogeneity hypothesis, niche-based hypothesis and anthropogenic impact on habitats. The study also establishes that the IITG is among the educational institutes and campuses that host many migratory bird species. Lastly, based on the outcomes of β-diversity analysis, it is suggested that the conservation effort for avian species in the campus should be directed towards individual habitats uniformly. [ABSTRACT FROM AUTHOR]

Gibbon Wildlife Sanctuary (GWLS) in the Jorhat District of Assam in northeastern India is rich in primate diversity with seven species. The plains alluvial semi-evergreen forest patches with high canopy cover support a variety of fauna. In October-November 2008, we carried out a survey to estimate the population status of Bengal Slow Loris (Nycticebus bengalensis) in GWLS, a species for which little data are available in India, and whose conservation status has only recently been changed from Data Deficient to Vulnerable. We estimated population abundance of 0.18 loris individuals/km using recce-survey transects' method in GWLS. [ABSTRACT FROM AUTHOR]

A study spanning 3.7 years on the butterflies of Gibbon Wildlife Sanctuary GWS (21km2), a semi-evergreen forest, in Jorhat District of Assam, northeastern India revealed 211 species of butterflies belonging to 115 genera including 19 papilionids and seven 'rare' and 'very rare' species as per Evans list of the Indian sub-continent (Great Blue Mime Papilio paradoxa telearchus; Brown Forest BobScobura woolletti; Snowy Angle Darpa pteria dealbatahas; Constable Dichorragia nesimachus; Grey Baron Euthalia anosia anosia; Sylhet Oakblue Arhopala silhetensis; Branded Yamfly Yasoda tripunctata). The butterflies showed a strong seasonality pattern in this forest with only one significant peak during the post monsoon (September-October) when 118 species were in flight inside the forest which slowly declined to 92 species in November-December. Another peak (102 species) was visible after winter from March to April. Species composition showed least similarity between pre-monsoon (March-May) and post-monsoon (October-November) seasons. The number of papilionid species were greater from July to December as compared from January to June. The findings of this study suggest that the pattern of seasonality in a semi-evergreen forest in northeastern India is distinct from that of the sub-tropical lowland forest in the Himalaya. Favourable logistics and rich diversity in GWS points to its rich potential in promoting 'butterfly inclusive ecotourism' in this remnant forest. [ABSTRACT FROM AUTHOR]

This article presents data on canopy use by a group of Western Hoolock Gibbons Hoolock hoolock inhabiting the Inner-line Reserve Forest in Barak Valley, Assam, India. The study was carried out from December 2011 to November 2012. The group consisted of an adult male, an adult female with an infant and one sub-adult male, with a home range of approximately 55ha. Data was collected on the canopy height and canopy use by the gibbons. A total of 3,648 observations were recorded during the study period. Canopy height used by the gibbons was found to be within the range of 5m and 30m and most of the activities were observed between 6m and 25m. A maximum use of canopy height in different activities was recorded between 11-15 m and a minimum was recorded from 1-10 m and above 25m respectively. While using various levels of canopy, most of the activities were performed on small branches near the periphery, and least on the trunks of the trees. Canopy height and canopy use during different activities varied significantly among the type of activities and also among different age-sex classes. No activities were observed on the ground. [ABSTRACT FROM AUTHOR]

Analysis of diversity, distribution and endemism of the family Rubiaceae for southern Assam has been made. The analyses are based on field observations in the three districts, viz., Cachar, Hailakandi and Karimganj, as well as data from existing collections and literature. The present study records 90 taxa recorded from southern Assam, four of which are endemic. Chassalia curviflora (Wall.) Thwaites var. ellipsoides Hook. f. and Mussaenda keenanii Hook.f. are rediscovered after a gap of 140 years. Mussaenda corymbosa Roxb. is reported for the first time from northeastern India, while Chassalia staintonii (H.Hara) Deb & Mondal is reported as a new record for Assam. [ABSTRACT FROM AUTHOR]

Oreichthys cosuatis (Hamilton, 1822) was believed to be a monotypic genus widely distributed throughout India, Myanmar and ranging up to Thailand. Though the genus Oreichthys was known to have an incomplete lateral line, certain studies showed that there are species possessing a complete lateral line, as well as a much higher lateral line scale count. One such species is described here as a new species, Oreichthys andrewi, which can be distinguished from its congeners by the possession of a complete lateral line; 30+1 scales in the longitudinal series; ½ 4 / 1 / 2 ½ scales in the transverse row; 9 predorsal scales and bright yellow pelvic fins. [ABSTRACT FROM AUTHOR]

The article discusses a study to determine the occurrence of Mesostoma tetragonum or Turbellaria in the Deepar wetlands of Assam, India. It relates the origin of the freshwater turbellarians and the growth of their population. Results of the study reveal that there were no previous record of occurrence of Mesostoma tetragonum in Deepar wetland as had appeared from other works.

Plankton samples collected from Deepor Beel, a Ramsar site of India, during August 2008-July 2010, revealed six rare and interesting Cladocera belonging to four genera of the family Chydoridae. The globally important elements include the Australasian Disperalona caudata; the Asian Kurzia (Rostrokurzia) brevilabris; the Indo-Malayan Alona macronyx; and Leydigiopsis curvirostris which is known to occur elsewhere in North and South America. Kurzia (Rostrokurzia) brevilabris is a new record from India while Alona guttata tuberculata, A. macronyx and Coronatella anodonta are new records from Assam. The documented species are briefly diagnosed and comments are made on their distribution. [ABSTRACT FROM AUTHOR]

The article discusses a study on freshwater testate amoebae (Protozoa: Rhizopoda), in a Ramsar site in Assam, India. It states that a stereoscopic binocular microscope was used to sort out different species while a Leica DM 1000 image analyzer was used to identify the Rhizopoda species. It also mentions the ratio of several species of the class Lobosea and Filosea and concludes that the Rhizopoda richness of Deepor Beel exceeds the number of species observed from other freshwater biotopes.

Plankton samples collected from two sampling stations of Deepor Beel (a Ramsar site in Assam, northeastern India) between November 2002 and October 2003, reveal 110 and 100 species of Rotifera, exhibit monthly richness ranging between 43-65 (56 ± 6) and 38-60 (52 ± 7) species and record 48.9-88.1 and 53.1-89.7% community similarities respectively. Rotifera (231 ± 60 and 198 ± 70 n/l) comprise between 48.7 ± 6.1 and 42.6 ± 4.1% of zooplankton abundance at station I and II respectively, and follow trimodal annual patterns with peaks during winter. Brachionidae (90 ± 43, 79 ± 39 n/l) > Lecanidae (45 ± 13, 29 ± 9 n/l) form important quantitative components of Rotifera while Asplanchnidae > Synchaetidae > Trochosphaeridae are other notable families. Lecane > Brachionus > Keratella > Asplanchna > Platyias contribute notably to temporal variations of the rotifers. Asplanchna priodonta, Keratella cochlearis, Platyias quadricornis, Lecane leontina, Polyarthra vulgaris, Keratella tropica and Brachionus falcatus are important species. Analysis of variance comparisons indicate significant temporal variations in richness and abundance of Rotifera between stations and months.The rotifer communities exhibit higher species diversity, higher evenness, lower dominance and lack of quantitative dominance of any individual species. The present results show no definite periodicity of richness and abundance of this group, families or species. Individual abiotic factors register limited influence on richness and abundance while multiple regression exhibits higher cumulative influence of ten abiotic factors on these parameters at both sampling stations. [ABSTRACT FROM AUTHOR]

A new species of the genus Badis Hamilton is described from Dibru River, Dibrugarh, Brahmaputra basin in Assam, India. The species has the following combination of characters: a conspicuous black blotch covering the superficial part of the cleithrum above pectoral fin base, a small oval-shaped black blotch on the middle of caudal fin, two predorsal bones, interorbital width 9.9-15.0, upper jaw length 6.1-6.9, lower jaw length 7.1-8.3 and orbital diameter 7.6-9.4 % SL. The species differs from its nearest congeners, B. badis, B. kanabos and B. tuivaiei by the absence of dark black or brown vertical bars on sides. A key to species of Badis of India is provided. [ABSTRACT FROM AUTHOR]

Plankton samples collected from two sampling stations of Deepor Beel, an important floodplain lake of Assam and a Ramsar site of India, revealed 51 species of Microcrustacea and showed qualitative dominance of Cladocera (45 species). Microcrustacea comprised a significant quantitative component (45.6 ± 5.8 and 50.8 ± 4.5 %) of zooplankton and exhibited bimodal and trimodal annual patterns with peaks during winter. Cladocera > Copepoda are important quantitative groups. ANOVA registered significant variation in species richness and abundance of Microcrustacea over time and between stations. Richness and abundance were inversely correlated with water temperature and rainfall, and positively correlated with specific conductivity and dissolved oxygen. Multiple regression registered significantly higher cumulative effects of ten abiotic factors on these two parameters. Our results are characterized by higher species diversity, higher evenness and lower dominance of Microcrustacea and show lack of distinct quantitative importance of individual species. [ABSTRACT FROM AUTHOR]

An assessment of human-elephant conflict was carried out in the fringe villages around Manas National Park, Assam during 2005-06. The available forest department conflict records since 1991 onwards were also incorporated during analysis. Conflict was intense in the months of July-August and was mostly concentrated along the forest boundary areas, decreasing with distance from the Park. Crop damage occurred during two seasons; paddy (the major crop) suffered the most due to raiding. Crop maturity and frequency of raiding were positively correlated. Single bull elephants were involved in conflicts more frequently (59%) than female herds (41%), while herds were involved in majority of crop raiding cases. Of the single elephants, 88% were makhnas and 11.9% were tuskers. The average herd size recorded was 8 individuals, with group size ranging up to 16. Mitigation measures presently adopted involve traditional drive-away techniques including making noise by shouting, drum beating, bursting fire crackers and firing gun shots into the air, and using torch light, pelting stones and throwing burning torches. Kunkis have been used in severe cases. Machans are used for guarding the crops. Combinations of methods are most effective. Family herds were easily deflected, while single bulls were difficult to ward off. Affected villagers have suggested methods like regular patrolling (39%) by the Forest Department officials along the Park boundary, erection of a concrete wall (18%) along the Park boundary, electric fencing (13%), simply drive away (13%), culling (11%) and lighting the Park boundary during night hours (6%). Attempts to reduce conflict by changing the traditional cropping pattern by introducing some elephant-repellent alternative cash crops (e.g. lemon and chilli) are under experiment. [ABSTRACT FROM AUTHOR]