Short Communication Odonata of eastern Bangladesh with three new records for the country

For Focus, Scope, Aims, Policies and Guidelines visit https://threatenedtaxa.org/index.php/JoTT/about/editorialPolicies#custom-0 For Article Submission Guidelines visit https://threatenedtaxa.org/index.php/JoTT/about/submissions#onlineSubmissions For Policies against Scientific Misconduct visit https://threatenedtaxa.org/index.php/JoTT/about/editorialPolicies#custom-2 For reprints contact <info@threatenedtaxa.org> Short Communication Odonata of eastern Bangladesh with three new records for the country


Short Communication
Odonata of eastern Bangladesh with three new records for the country M. Kawsar Khan 1977;Chowdhury & Akhteruzzaman 1983;Chowdhury & Mia 1989;Chowdhury & Mohiuddin 1993;Noruma & Alam 1995;Chowdhury & Mohiuddin 2011;Khan 2015a,b). Among these, 76 species from seven families are reported from the northeastern region (Khan 2015b). On the other hand, 90 species are reported from the southeastern region (Chowdhury & Mohiuddin 2011). The checklist of the eastern region, however, is not comprehensive and many prospective habitats are yet to be explored.
The eastern region of Bangladesh is situated in the Indo-Burma biodiversity hotspot and is rich with diverse floral and faunal communities. This region has a few semi-evergreen forests and wildlife sanctuaries enriched with numerous streams and waterfalls. In addition to that, there are many marshes and lakes that provide ambient habitats for odonates. Despite being a suitable habitat for Odonata fauna, there is a lack of studies annotating the order of the eastern region to date. Moreover, the previous research initiatives left many potential habitats to survey. The current study is a comprehensive approach for the documentation of the Odonata diversity of the eastern region of Bangladesh.

Study area
The odonates were surveyed from the entire Sylhet Division and five districts of Chittagong Division, namely, Bandarban, Cox's Bazar, Chittagong, Khagrachari, and Rangamati, of Bangladesh ( Fig. 1). In the northeastern region that is administratively under Sylhet Division, odonates were surveyed in Khadimnagar National Park, Tilagar Eco Park, Shahjalal University of Science and Technology campus, Satchari National Park, Lawachara National Park, and Madhobpur Lake. On the other hand, in the southeastern region that is administratively under Chittagong Division, odonates were surveyed in the Chittagong University campus, Kaptai National Park, Bariadhala National Park, and many streams and waterfalls in the areas associated with Chittagong, Khagrachari, and Bandarban districts.

Specimen collection and identification
During the survey, potential habitats like marshes, ponds, streams, streams associated with forest patches, and temporary watersheds created during the monsoon were scanned thoroughly from 09.00hr to 16.00hr. In the field, the species were photographed using a Canon 600 DSLR camera fitted with a 55-250 mm telephoto zoom lens. The specimens were captured using an insect-sweeping net and brought into the Department of Biochemistry and Molecular Biology, Shahjalal University of Science and Technology, Sylhet, Bangladesh, for further identification and deposition. In the laboratory, the specimens were examined under the microscope and identified based on the available identification keys provided by Fraser (1933Fraser ( , 1934Fraser ( , 1936 and Asahina (1993). The odonates were classified according to Dijkstra et al. (2013). The collected specimens are stored in my personal collection in the department of Biochemistry and Molecular Biology department in the Shahjalal University of Science and Technology, Bangladesh.

Results
A total of 75 species from nine families belonging to 45 genera were recorded from the eastern region of Bangladesh (

Odonata of eastern Bangladesh Khan
male is black; orange and red colours are absent in the thorax; narrow straight blue ante-humeral stripe present, inferior is two third of the superior, tip of the superior is wide apart. This species was previously known from India, Laos, Myanmar, Thailand, and Vietnam (Fraser 1933;Hamalainen & Pinratana 1999;Cuong & Hoa 2007) Prodasineura autumnalis (Fraser, 1922 Prodasineura autumnalis is superficially similar to P. verticalis and P. sita; however, they can be distinguished by the unmarked black thorax and the white-tipped inferior anal appendages (Image 1C). The females are found close to males and can be distinguished by their blue ante-humeral stripe (Image 1D). The species was previously known from China, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Singapore, Thailand, and Vietnam (Fraser 1933;Vick 1989;Hamalainen & Pinratana 1999;Wilson & Reels 2003;Orr 2005;Cuong & Hoa 2007;Wilson 2005;Tang et al. 2010). The present record extends its distribution to Bangladesh.

Megalogomphus smithii (Selys, 1854) (Image 1E)
Megalogomphus smithii was previously known from Assam, India, which is adjacent to the northeastern region of Bangladesh. Considering the similarity of habitats, this species was predicted to be present in Bangladesh too (Fraser 1934). I recorded this species based on one male collected from the Khadimnagar National Park, Sylhet, Bangladesh (24.951 0 N & 91.918 0 E, 56m), on 10 April 2015 (ODO-013). The lengths of the abdomen and hindwing in males are 53-55 mm and 42-44 mm, respectively. This species has a prominent M-shape marking in the thorax and can be easily distinguished from the other members of the genus by its yellow-marked black legs.

Discussion
In the current study, the Odonata fauna of the eastern region of Bangladesh was documented. A total of 75 species from 45 genera was recorded. Among them, three species and one genus were recorded A total of 65 species belonging to eight families were recorded from the northeastern region. On the other hand, 52 species belonging to seven families were documented from the southeastern region. Among the 75 recorded species, 41 species were commonly recorded from the northeastern and southeastern regions. Twenty-three and 11 species were uniquely recorded from the northeastern and southeastern regions, respectively. Coenagrionidae and Libelluidae were the best-represented zygopteran and anisopteran families with 15 and 33 species, respectively. Similarly, in the southeastern region, Coenagrionidae and Libelluidae were the best-represented zygopteran and anisopteran families with 11 and 27 species, respectively.

Calicnemia imitans Lieftinck, 1948 (Image 1A,B)
Calicnemia imitans is one of the most abundant species of odonates in the southeastern hilly streams of Bangladesh. They prefer streams associated with shady bushes for perching. This is the third recorded species of this genus from Bangladesh after C. eximia and C. pulverulans. I recorded this species based on the two male specimens collected from the Alutila Cave, Khagrachari, Chittagong (23.085 0 N & 91.956 0 E, elevation 281m), on 02 June 2015 (specimen registration number ODO-008 and ODO-009). The length of the male abdomen is 29-31 mm and that of the hindwing is 20-22mm. This species can be distinguished by its body colouration and anal appendages. The ground colour of Table 1 Regional checklists are indicators of the diversity, distribution range, and population fragmentation of a particular faunal community. Hence, updating regional checklists on a regular basis is a good practice to understand the conservation status of a species. In the current study, three species, Agriocnemis clauseni, Pseudagrion spencei, and Tramea Virginia, are newly added to the odonata fauna of the northeastern region of Bangladesh. In addition to that, the current study extended the distribution range of a few previously recorded species. The distribution range extension and new habitat allocation are particularly important to assess the global and national status of species. In the current study, the distribution range of two globally data deficient species is extended. Among them, Macrogomphus robustus was previously recorded from Lawachara National Park, Maulavibazar (Chowdhury & Mohiuddin 2011). The present record extends its distribution further north to the Khadimnagar National Park, Sylhet. The other data deficient species, Megalogomphus smithii, was previously known from China, India, and Indonesia. The present study reported this species for the first time within the geographical area of Bangladesh. The individual number of this two data deficient species recorded from the current study is very low and thus long-term studies are essential to assess their population trends and distribution range.

. A list of the Anisoptera and Zygoptera species recorded in the current study from eastern Bangladesh. The species newly discovered from Bangladesh are indicated with asterisks (*). The species present in a particular area are shown by tick sign (√) and the species absent are shown by cross mark (X).
In conclusion, the diverse Odonata fauna and newly recorded species of the eastern region indicate that the area may accommodate hitherto unknown species. Moreover, the current study suggests that more longterm surveys are required to annotate the Odonata fauna of Bangladesh to estimate their current status and to determine their conservation needs.