Population status and feeding behavior of black kite (Milvus migrans) in Dhaka city, Bangladesh

The status and feeding behavior of black kite (Milvus migrans) in Dhaka city were studied from July 2015 to June 2017. Road transects and morning roost-count method were used for population estimation and distribution, whereas focal sampling method was used to study the feeding and foraging behavior. Based on roosting and foraging areas, five transects were selected for population estimation. Moreover, six different feeding areas were selected for identifying various types of consumed food and assessing the feeding behavior of black kite. The black kite population was estimated at (1296±5.87) in Dhaka city. The population density was estimated at 21.8/km2. Among selected five different transects, the recorded population ranged from 108.12±6.70, 8.34%) at S-3 (Mirpur to Ramna Park) to 805±11.88, 62.11% of individuals at S-5 (Gulistan to Demra). The present study revealed that black kites were distributed throughout the study area and the distribution was influenced by availability of food, water and roosting place. Based on the annual records, the highest population (1510±6.92) was found in 2016. Majority of black kites fed on offal and insects in study area. In garbage dumps, the highest rate of feeding was recorded in afternoon followed by in morning and lowest in the noon. Whereas in non-garbage feeding areas, the highest rate was recorded in the morning followed by in the afternoon and lowest in the noon. Among four different foraging strategies, food collection by kites standing on the ground and intraspecific cleptoparasitism was never observed during study period while interspecific cleptoparasitism (against crows) was the highest number (193.67±2.77, 68.43%). Jahangirnagar University J. Biol. Sci. 9(1 & 2): 35-48, 2020 (June & December)

In vitro antioxidant activity of the methanolic extract of leaves of a hill tract plant Begonia roxburghii

The study was designed to investigate the antioxidant activities of the methanolic extract of leaves of Begonia roxburghii by five different in vitro methods namely Folin-Ciocalteu, total flavonoid content, phosphomolybdenum, total reducing power determination, and DPPH scavenging activity. Phenol content (Gallic acid equivalent) was found as 180.40±0.03 mg/g of the dry sample by the Folin-Ciocalteu method. Flavonoid assay method revealed the content of flavonoids (Quercetin equivalent) as 60.43±0.27 mg/g of the dry sample. Total antioxidant capacity of the extract was observed 243.43±0.11 mg/g ( ascorbic acid equivalent) by phosphomolybdenum method. Free radical scavenging activity (measured by the DPPH test) of the methanolic extract was found 158.36±0.22 μg/mL whereas ascorbic acid, the standard, showed 19.53±0.04 μg/mL. The methanolic extract of Begonia roxburghii leaves exhibited positive and linear dose dependent reducing power activity and its activity was comparable to the standard ascorbic acid for a given dose. Phytochemical screening of the extract showed positive results for alkaloids, carbohydrates, flavonoids, glycosides, saponins, steroids, and tannins, which demonstrate definite pharmacological actions on human body. The extract showed negative results for the steroids. Jahangirnagar University J. Biol. Sci. 9(1 & 2): 79-89, 2020 (June & December)

Estimation of accumulated degree hours-based post-mortem intervals in mammalian and avian model

The post-mortem interval (PMI) of a jungle cat (Felis chaus) and a chicken (Gallus gallus domesticus) were estimated as a mammalian and an avian model, respectively. The estimations were performed adopting the Accumulated Degree Hours (ADH) method using blowfly, Lucilia sericata. The required developmental time from oviposition to the 3rd instar larvae of the blowfly species was considered for the determination of PMI in each of the study. The results revealed that the calculated PMI of jungle cat was 5.29 days. On the other hand, the estimated PMI of the chicken was 2.83 days. The difference of these two PMIs in two different models might be due to the variation of temperatures and other related factors in the development of the larvae of the blowfly species. This study might offer a new approach in the medico-legal investigations with a view to resolving homicide as well as other suspected death of animals including wildlife in Bangladesh. Jahangirnagar University J. Biol. Sci. 9(1 & 2): 49-58, 2020 (June & December)

Assessment of status and threats of wild mammals in some selected locations of Dinajpur district, Bangladesh

The status of mammals in Dinajpur district was studied from October 2016 to November 2017. For inventory and assessment of wild mammal’s belt-transect sampling, box trap survey, mist netting, night survey and questionnaire survey methods were used. A total of 22 species of mammals belonging to 11 families and 5 orders were recorded. Of the recorded species 8 were rodents, 1 hare, 1 shrew, 7 bats and 5 carnivores. Muridae appeared as the largest family containing 8 species. A total of 9 species (41%) were recorded as “very common”, 6 species (27%) “common”, 4 species (18%) “uncommon”, and 3 species (14%) “rare”. Among all the mammalian species, 41% (9 species) were nocturnal, 14% (3 species) crepuscular, 37% (8 species) metaturnal and 9% (2 species) diurnal. On the other hand, 55% (12 species) of mammals were terrestrial, 9% (2 species) arboreal, 32% (7 species) aerial and 4% (1 species) aquatic mammals. Of all the recorded species, 32% (7 species) were herbivores followed by 27% (6 species) carnivores, 5% (1 species) opportunists while frugivores and insectivores were 18% (4 species) each. About 19% (4 species) of the known species are nationally threatened comprising of Endangered (5%), Vulnerable (5%) and Near Threatened (9%) and Least Concern (81%). Based on the habitats, 14 species (64%) were recorded from forests, 7 (31%) from homestead vegetation’s and 1 (5%) species from wetlands. A good number of individuals (n=12) of the nationally threatened Bengal Fox (Vulpes bengalensis) were found in the study area and two mammal species, Indian Hare (Lepus nigricollis) and Large Indian Civet (Viverra zibetha) have been locally facing the threat of extirpation. The mammalian diversity in the natural forests (64%) was higher than that of the other habitats. Different anthropogenic threats, especially hunting by ethnic Santal people (frequency of observation 24 times, impact point 4), exist in the study area. The major proposed actions for the study area are habitat restoration, increase public awareness and conflict management. Jahangirnagar University J. Biol. Sci. 9(1 & 2): 21-34, 2020 (June & December)

Effect of Ashwagandharishta on the lipid profile of male and female rats

The effect of Ashwagandharishta on the lipid profile and chronic toxicity of both male and female Albino rats were observed for 51 days. Our results demonstrate that the treatment of the plant extract failed to exhibit any statistically significant change (increase/ decrease) in the serum cholesterol (Total), high density lipoprotein (HDL), low density lipoprotein (LDL) and triglyceride of the male rats. But the female rats showed highly (p<0.01) and very highly (p<0.001) significant decrease in the serum cholesterol (Total) levels of the medium and high dose treated groups respectively. Regarding HDL, ASG showed statistically significant decrease at low (p <0.05), medium (p<0.01) and high (p<0.001) dose treated female rats. The LDL level of the medium dose treated female rats were statistically significant (p <0.05). The serum Triglyceride decreased significantly at low (p<0.01) and high (p <0.05) dose treated female rats. Jahangirnagar University J. Biol. Sci. 9(1 & 2): 59-68, 2020 (June & December)

Floristic composition and plant species diversity in and around the brickfield areas of Savar-Dhamrai region of Dhaka district

This study has confirmed the occurrence of a total of 181 species of vascular plants under 133 genera and 51 families and estimates the plant species diversity in and around the brickfield areas of Savar-Dhamrai region of Dhaka district. Of these, six species were pteridophytes, 175 were Angiosperms, and 144 species were economically important. Five families, composed of six species, belonged to Pteridophyta, 40 families, consist of 128 species, to Magnoliopsida (dicotyledons) and six families, comprised of 47 species, to Liliopsida (monocotyledons). Total of 161 species were herbs, 14 were shrubs, and only six were trees. Asteraceae with 14 species and Poaceae with 24 species were the largest family in Magnoliopsida and Liliopsida, respectively. Amaranthus L., Persicaria (L.) Mill., Solanum L. and Lindernia All. with four species each were appeared as the best representative genera in Mangoliopsida, while Cyperus L. with five species in Liliopsida. The species composition and diversity of abandoned brickfields were found to be higher than those of functional brickfields. A total of 42 (23.20%) species were common in both abandoned and functional brickfields of this region. Species composition in the abandoned brickfields of Savar and Dhamrai was mostly similar (64.15%). This study suggests to control and monitor the brickfields under the respective authorities to favor the formation and regeneration of natural vegetation in their neighboring areas. Jahangirnagar University J. Biol. Sci. 9(1 & 2): 91-108, 2020 (June & December)

Comparative karyomorphological analysis of two varieties of Brassica campestris from Bangladesh

Two varieties of the oilseed plant viz. Brassica campestris var. Tori-7 and Brassica campestris var. BARI Sarisha-9 were karyomorphologically investigated following orcein staining. Presence of “Round Pro-chromosome Type” of interphase nuclei and “Continuous Type” of prophase chromosomes indicating that both Tori-7 and BARI Sarisha-9 were originated from common ancestor. Moreover, both the varieties were found to possess 2n=20 chromosomes with almost similar range of length i.e.; 0.90±0.04-2.51±0.05μm for Tori-7 and 0.99±0.06-2.60±0.06μm for BARI Sharisha-9. The total length of 2n chromosome complement was recorded as 29.61±0.76μm for Tori-7 and 29.75±0.80μm for BARI Sharisha- 9 where a slight gradual decrease of chromosomal length was observed in both cases. Average chromosomal length, range of individual chromosomal length, relative length and centromeric index of both varieties were more or less similar. Karyotype symmetry index and Karyotype asymmetry index indicating the symmetric nature of both varieties. All metacentric chromosomes were found in Tori-7 representing strictly symmetric karyotype. Beside metacentric, 2 sub-metacentric chromosomes were found in BARI Sharisha-9 representing almost symmetric karyotype. Thus the two varieties of Brassica campestris -were plants of primitive nature. However, BARI Sharisha-9 can be considered comparatively advanced than Tori-7 based on different cytogenetical features. Therefore, the compilation of these karyomorphological information will be useful for authentic identification and characterization of the two varieties of Brassica campestris which are very basic and important information for breeding in crop improvement programme. Jahangirnagar University J. Biol. Sci. 9(1 & 2): 69-77, 2020 (June & December)

Three new Angiospermic (Orchidaceae) records from Bangladesh

Coelogyne schwadtkii Danell., Cleisostoma williamsonii (Rchb.) Garay. and Phalaenopsis difformis (Wall. ex Lindl.) Kocyan & Schuit. of the family Orchidaceae collected from southeast part of the country have been reported here as new angiospermic records for Bangladesh flora. Detailed critical examination of the specimens of these species has been made to confirm their taxonomic identification. Detailed taxonomic description with flowering time, ecology, geographical distribution, illustration and photographs of each species has been provided. Jahangirnagar University J. Biol. Sci. 9(1 & 2): 123-132, 2020 (June & December)

Quality and shelf-life extension of refrigerated (4°C) Spotted snakehead (Channa punctata) using γ-radiation and food-grade preservative

Investigations were carried out to evaluate the effect of gamma radiation (1.0 and 1.5 kGy) and food-grade preservative (2% potassium sorbate) on the shelf-life of refrigerated (4°C) Spotted snakehead, Channa punctata (Bloch, 1793). Quality assessments were evaluated by sensory (OS), chemical (TV), microbial (TBC and TCC) analyses. Based on control panel, OS was shown to be gradually decreased with the storage time. Irradiated and potassium sorbate treated samples were found acceptable (edible) up to 28 and 21 days, respectively of storage period. TV were lower in irradiated samples with dose of 1.5 kGy compared to other samples. Though microbial load of each of the irradiated samples were within the acceptable limits up to 28 days but 1.5 kGy dose was found more effective. Gamma radiation in combination with good refrigeration could be most effective treatment for the shelf-life extension and microbiological quality improvement for snakehead preservation. Moreover, this preservation technique may be applicable for other fish species to enhance food safety for public health issues. Jahangirnagar University J. Biol. Sci. 9(1 & 2): 1-12, 2020 (June & December)

Analysis of heavy metal contents in some commercial turmeric samples available at Dhaka, Bangladesh

Nowadays, the use of spices and other herbs have extensively increased due to their medicinal values all over the world. However, the monitoring of heavy metal contamination in spices has also been increased in recent years. A study has been conducted to determine the concentration of eight heavy metals such as Lead (Pb), Cadmium (Cd), Chromium (Cr), Arsenic (As), Zinc (Zn), Iron (Fe), Copper (Cu) and Manganese (Mn) in mainly three different types of turmeric samples (Curcuma longa). The turmeric samples analyzed were (i) Unpacked bulk powder available at three different local markets in Dhaka (ii) Packed and marketed by three branded companies, and (iii) Raw turmeric directly collected from different local farmlands. The samples were analyzed using Atomic Absorption Spectroscopy (AAS). The concentration of most of the heavy metals were found within the limit recommended by WHO (6.0000 ppm) except lead (12.3469 ppm) in unpacked-3 bulk sample. This study also showed the concentration of heavy metals were present in a lower amount in packed power samples compared to unpacked bulk powder samples. The result of this analysis would be helpful for public awareness in consumption of different spices. The concerned authorities who are responsible for monitoring and regulating the food chain in the market in our country may also get a great message about heavy metal contamination of spices. Jahangirnagar University J. Biol. Sci. 9(1 & 2): 13-20, 2020 (June & December)