Bangladesh Journal of Zoology

Temperature effects on the reproductive performance of Aedes aegypti (Diptera: Culicidae) mosquitoes in Dhaka City, Bangladesh

Afroza Sultana — 2024-04-01

Abstract not available

Bangladesh J. Zool. 51(3): 361-369, 2023

Challenges of exotic fishes invading the native waters of Bangladesh

Md Niamul Naser — 2024-04-01

Abstract Not abilable

Bangladesh J. Zool. 51(3): 231-232, 2023

Morphometrics and Truss-networking distances among three species of croaker (Johnius borneensis, Johnius argentatus and Johnius belangerii) from Bangladesh coast of the Bay of Bengal

Sanjoy Kumar Modak — 2024-04-01

Morphometric features are efficiently used for the differentiation of species and long-term management of fish populations. Truss analysis is a frequently used taxonomic method as well as a stock identification tool to dissimilitude the morphologically similar species. Using landmark-based truss networking techniques following 18 morphometric lengths, 10 meristic counts, and 23 truss-network distance, the morphological variation of three croaker species viz. Johnius borneensis, Johnius argentatus, and Johnius belangerii were examined from Bangladesh coast. Data were analyzed and visualized through univariate ANOVA, canonical discriminate function analysis (DFA), and principal component analysis (PCA). Results found that the first DFA was responsible for 80.6% & 81.1%, whereas the second DFA was responsible for 19.4% & 18.9% variations among three species for the morphometric and truss-distances, respectively. In addition, 14 out of 18 morphometric and 12 out of 23 truss-network measurements were significantly different (p < 0.05) among means of three species. 1^st PCA found 70.76% & 64.49% explained variations and 2^nd PCA displayed 12.8% & 11.5% explained variations respectively for morphometric and truss distances. The findings of the study demonstrates that J. borneensis and J. belangerii are highly morphologically similar and J. argentatus is completely distinct which might be due to their physiological and genetic variations. The present study might be helpful in differentiating species and managing existing stocks of marine fish. Further studies regarding the molecular characterization of the Cytochrome c oxidase subunit I (COI) gene could confirm the genetic variations among these species.

Bangladesh J. Zool. 51(3): 233-251, 2023

Identification of key habitats and conservation threats of the Ganges River dolphin (Platanista gangetica) of Bangladesh

M Abdul Aziz — 2024-04-01

Ganges River Dolphins (Platanista gangetica) are known to inhabit all major river systems in Bangladesh. However, comprehensive spatial records for this globally endangered aquatic mammal are notably scarce nationwide. Furthermore, their habitats are increasingly threatened due to excessive utilization of aquatic resources and their habitats by the growing human population. To allocate limited resources in safeguarding high-priority dolphin habitats, we conducted field surveys and arranged stakeholder consultations to identify key dolphin habitats and the conservation threats they face across Bangladesh. Through this process, we have identified 14 river segments as high-priority winter habitats for Ganges River Dolphins. These dolphins encounter both direct and indirect threats within their habitats. Direct threats include entanglement and occasional intentional killing for traditional medicinal purposes and as fish attractants. Indirect threats leading to habitat degradation comprise the construction of dams and barrages for upstream water extraction, increasing industrial pollution in river waters, overfishing, and alterations to river morphology caused by siltation and sedimentation. The heavy reliance of local communities on dolphin habitats, coupled with a lack of widespread awareness and insufficient conservation efforts, pose significant challenges to the future survival of Ganges River Dolphins in Bangladesh.

Bangladesh J. Zool. 51(3): 253-266, 2023

Pollinator Diversity and Plant-Pollinator Interactions in the Puthia Upazila of Rajshahi District, Bangladesh

Md A Alim — 2024-04-01

From September 2021 to August 2022 a study was carried out to assess the species diversity and abundances of pollinators and plant-pollinator interactions in Puthia Upazila of Rajshahi District, Bangladesh. A total of 3284 individuals were recorded, in which 109 species of 87 genera were identified as belonging to 49 families and 12 orders under three classes (Insecta, Aves and Mammalia). The relative abundance of insects and non-insect pollinators was 91.57% and 8.43%, respectively. A maximum of 32 species (relative abundance, RA= 32.70 %) was observed in the order Lepidoptera and minimum in the order Chiroptera (1 species; RA= 0.09 %). The most abundant family was Apidae (n= 267, RA= 8.12%) and the most dominant species was Eurema hecabe (n= 95, RA= 2.89%) (Family: Pieridae, Order: Lepidoptera). Based on number of individuals (n), the status of pollinators: 25 species were very common, 29 species were common, 18 species were fairly common, 21 species were rare and 16 species were very rare. A total of 51 flowering plants were documented that were visited by the pollinators, of which 32 were crop plants and 19 were non-crop flowering plants. Among them, the flowers of Orangeberry (Glycosmis pentaphylla) received the greatest number of pollinator species, i.e., 55. Overall, 79 species of recorded pollinators visited non-crop flowering plants, 65 species visited crop plants, and 35 species were common in both. According to the obtained individuals, the Shannon (H') and Simpson (1-D) diversity indices were 4.41 and 0.99, respectively. The Berger-Parker dominance (d) and Pielou's evenness index (J') were 0.03 and 0.94, respectively, while the Margalef (D_Mg) and Menhinick (D_Mn) species richness indices were 13.34 and 1.90, respectively. The present study is the first report to offer baseline abundance and diversity of main pollinator groups in agroecosystems and provide data for a checklist of the variety of pollinators in the Puthia Upazila, Rajshahi, Bangladesh.

Bangladesh J. Zool. 51(3): 267-287, 2023

Molecular identification and genetic diversity of ten Pierid butterflies based on mitochondrial COI gene

Muhammad Sohe Abedin — 2024-04-01

The IUCN Bangladesh has documented a total of 31 species belonging to the Pieridae family in Bangladesh. There is currently limited knowledge regarding the genetic diversity and molecular relationships among these butterflies. The present investigation involved the generation of mitochondrial COI (mtCOI) gene sequences for ten species of butterflies belonging to the Pierid family. After that, BLAST analysis showed 96% to 100% similarity, and then the sequences were submitted to NCBI’s GenBank. MEGA10 and BioEdit were used to identify a 584 bp COI gene fragment with 179 variable sites and 128 parsimony-informative sites. The COI sequences' average base compositions were 38.56% T, 17.12% C, 30.18% A, and 14.12% G. While a significant AT bias (68.74%) existed among the Pierid species. The genetic distance between ten Pierid species was assessed using the Kimura 2-Parameter (K2P) algorithm, and the nucleotide differences ranged from 0.00172% to 0.24261%. Afterwards, the Maximum Likelihood (ML) method was used to construct a phylogenetic tree using ten sequences of Pierid species. These species belongs to two subfamilies, Pierinae and Coliadinae in Bangladesh. On the tree, the Pierinae subfamily of Pieridae formed a paraphyletic arrangement whereas the Coliadinae subfamily was shown to be monophyletic. The data analyses support the following relationships between the two subfamilies as follows: [(Appias + Leptosia) + (Pieris + Appias) + (Delias) + (Eurema + Catopsilia) + (Pareronia)]. This supported the theory that Pierinae and Coliadinae are sister taxa. Nonetheless, Pareronia hippia remains outside the main Pierinae group, requiring further study to resolve this issue. Finally, these studies generated ten mtCOI gene sequences that have the potential to serve as valuable references for the accurate identification of Pierid species. In addition, this result could be used in the future to reveal the subfamily relationships within the Pieridae taxonomic classification.

Bangladesh J. Zool. 51(3): 289-299, 2023

Identification of Orissa frog Fejervarya orissaensis from Bangladesh based on 16s and 12s rRNA genes

Hafisha Khatun Anee — 2024-04-01

In this study, we attempted species-level identification of frog specimen collected from Faridpur district of Bangladesh beyond it’s location outside Orissa, India. Specimen was identified morphologically at genus level as Fejervarya sp. belonging to the family Dicroglossidae using finger formula F3>F4>F1=F1 where F denote as toe finger. From the study two nucleotide sequences of 16S and 12S rRNA genes were obtained which contained 508bp and 408bp respectively. The Sequences were submitted to Gene Bank database with the accession number OQ231604 and OQ240197 for 16S and 12S rRNA gene sequences. Furthermore, the 16S rRNA gene sequence was used as molecular bar-code for the identified Orissa frog F. orissaensis species from Bangladesh. GC content of partial 12S and 16S rRNA genes have been calculated as 44% and 45% respectively. For 16S rRNA gene sequence there was no intra specific divergence. Whereas the inter specific polymorphic divergence were calculated 4.13% and 6.3% when the collected Orissa frog F. orissaensis was compared with that of F. iskandari and F. kupitzi, respectively. In case of 12S rRNA gene intra specific divergence was found 2.45% where the inter specific divergence were 4.41% and 6.86% when the collected Orissa frog F. orissaensis was compared with that of F. iskandari and F. limnocaris, respectively. Maximum likelihood tree also indicates that our sample Orissa frog formed a monophyletic group with F. orissaensis in both the cases of 16S and 12S rRNA genes and thus can be concluded as closely related. Therefore, the collected specimen was identified to be belonging to Fejervarya orissaensis which would be first report from Bangladesh outside Orissa, India.

Bangladesh J. Zool. 51(3): 301-313, 2023

Predatory competence of Danio rerio (Cypriniformes: Cyprinidae) and Poecilia reticulata (Cyprinodontiformes: Poeciliidae) as biocontrol agent of Aedes larvae (Diptera: Culicidae) under the laboratory condition

Tanjina Akter — 2024-04-01

Predatory potential of Zebrafish, Danio rerio (Cypriniformes: Cyprinidae) and Guppy, Poecilia reticulata (Cyprinodontiformes: Poeciliidae) were evaluated to control Aedes mosquito larvae and thereby manage dengue epidemics in a sustainable, and eco-friendly manner. Under laboratory conditions, size-matched fish of each species were introduced into separate plastic containers containing 2 liters of tap water and 100 third instar larvae of Aedes. In addition, different prey combinations were used to assess the comparative predation potential of the fishes. Mosquito prey preferences were assessed using Manly’s preference index. Over 24-hours of laboratory conditions, a significant difference (p<0.05) between the predatory efficiency of the studied fish species was reported where the predatory efficiency of D. rerio was higher than that of Po. reticulata. D. rerio showed significantly (p<0.05) higher predation efficiency and prey preference for 2nd instar larvae and pupae of Aedes than Po. reticulata on the presence of alternative prey. Based on predation efficiency and prey preference, this study suggests that indigenous Danio rerio can be evaluated as an alternative species to exotic Poecilia reticulata in biological control for more eco-friendly, cost-effective sustainable management of Aedes mosquitoes.

Bangladesh J. Zool. 51(3): 315-327, 2023

Morphometric evaluation of Aedes aegypti (Linnaeus, 1762) and Culex quiquefasciatus (Say, 1823) (Diptera: Nematocera: Culicidae) of different metamorphosis stages

Kazi Ashrufa Hasna — 2024-04-01

Morphometric comparison of Aedes. aegypti and Culex. quiquefasciatus larval instars and pupae were done through the measurements of total body length, length of head, thorax and abdomen as well as length and width of different external body parameters. From linear regression of the data from different larval instars showed that the important morphological features were the size of the head, thorax and abdomen of the Ae. Aegypti and Cx. Quinquefasciatus. They increased significantly with the advanced metamorphosis stages (p≤0.05). Size of the external larval organs viz. antennae, comb spine, siphon, anal papilla were also significantly (p≤0.05) increased during stages of metamorphosis.

Bangladesh J. Zool. 51(3): 329-343, 2023

NLRC5 expression profile in the oviduct of laying hens and its changes following estradiol treatment in induced molting hens

A M Abdel Mageed — 2024-04-01

The innate immune defense system is initiated by recognizing components of microorganisms by different families of receptors such as TLRs and the intracellular NLR family. Among the NLR family, NLRC5 recognizes pathogenic components of microorganisms. The current study aimed to determine the expression profile of NLRC5 in the mucosal tissue of the oviduct of laying hens and to examine the effects of oviduct regression and estradiol benzoate (EB) on its expression. In this study, we used two groups of laying and molting hens. The molting group was treated by receiving a single dose of sesame oil or estradiol benzoate through intramuscular injection. To examine the histological differences in the oviduct between laying, molting, and estradiol-injected groups, Tissue samples from all segments of the oviduct of all groups were fixed in formalin and stained with hematoxylin and eosin. To observe the profile of NLRC5 gene and the effects of estradiol treatment, RNA was obtained from the surface epithelium and lamina propria of the whole segments of the oviduct of normal laying hens, and mucosal tissue of magnum, isthmus, uterus, and the vagina of molting groups. Both mucosal surface epithelium and lamina propria expressed NLRC5. The expression of NLRC5 was higher in the molting than in the laying group, and it was lower in the EB group. These results suggested that NLRC5 may have a role in recognizing pathogens invading the oviduct of laying and molting hens, and its expression is changed in association with oviduct growth.

Bangladesh J. Zool. 51(3): 345-359, 2023

Invasive Suckermouth catfishes (Siluriformes: Loricariidae) in Bangladesh wetlands: A review on the present status and challenges

Md Masud Rana — 2024-04-01

The suckermouth catfish (SMF) is an invasive species in Bangladesh that has had a huge negative impact on ecosystems including rivers, lakes and wetlands. Several SMFs had been introduced as aquarium fish in the early 80‘s. The first report of this fish in Bangladesh was recorded in 2008; more recently, it has been banned in September 2022 due to its alarming adverse impact on flora and fauna of inland waterbodies. This review explores the complex ecological, economic, and social dynamics triggered by several species of SMFs. The information on SMF‘s rapid proliferation, adaptability, and destructive capacity on inland waterbodies were underscored, as well as the resulting challenges significant to the indigenous aquatic flora and fauna, habitats, and livelihoods of the wetland-dependent communities. However, the eradication of SMFs from inland waterbodies would be a major challenge. Moreover, a cautious yet prospective plan for either exploitation or eradication, along with inflexible ecological safeguards, are recommended. Technological supports such as environmental DNA (eDNA) techniques, together with the integration of image processing, machine learning, and robotics, may be favorably used in detecting the presence of SMFs. Additionally, identifying habitat, distribution, and hotspot should be considered for needful action. This review highlights a multifaceted narrative of SMF in Bangladesh, emphasizing a complex balance between ecological conservation, economic gains, and technological innovations. Therefore, the illustrated information of SMFs could be helpful to enhance the current knowledges which may lead our nation towards ecological resilience and sustainable harmony against future aquatic invasions. This review suggests advanced action plan and collaboration among different fisheries stakeholders, government authorities and policy makers for eradication or sustainable management of SMFs in inland waterbodies.

Bangladesh J. Zool. 51(3): 371-396, 2023