Mohammad Abdul Wahed Chowdhury
Department of Zoology, University of Chittagong, Chittagong 4331, Bangladesh
Md. Mizanur Rahman
Department of Zoology, University of Chittagong, Chittagong 4331, Bangladesh
Md. Abdul Gofur Khan
Department of Zoology, University of Chittagong, Chittagong 4331, Bangladesh
Habitat, Factor interaction, Population, ecology, Euphlyctis cyanophlyctis, Frog
Chittagong University Campus, Chittagong
Animal Health and Management
The Chittagong University Campus (CUC) (between 22°27'25.69" and 22°27'26.34" North latitudes, and 91°48'10.12" and 91°48'10.96" East longitudes) is situated in over 1754 acres hilly area. The campus area, due to high elevation, was never affected by flooding. However, the campus has a good number of small perennial lakes and ponds, and several narrow hilly streams. The neighbouring lands of those water bodies frequently turned into temporary wetland because of comparatively greater amounts of rain characteristics of CUC. The summer extends from March to May, and is characterized by dry hot condition interrupted by occasional rains with north western storms and prevailing winds from the south west. The monsoon, last from June to October, is humid and warm, with infrequent thunder storms, with high temperature and wind from the southeast; about 90% of the annual rainfall occurs during this season. The winter season, exist between November and February, is cold and dry with prevailing winds from the north-west, rainfall and humidity are lowest during this part of the year. Three study sites, with different extents of variations in habitat, were chosen considering, also, size, location and availability of frogs. Site 1 (S1), the Science Faculty Lake, is a moderately large (2 acres) perennial water body with an average depth of 0.97 m. Floating and submerged aquatic weeds have luxuriant growth in this lake. Site 2 (S2), the Round Pond, is also a perennial water body with an area of 0.59 acre and a mean depth of 1.9 m. It is frequently used for swimming practice. Due to high banks, runoff water does not enter this pond. The shallow parts support lots of hydrophytes facilitating frog community to inhabit and seek shelter and food. Site 3 (S3), the Forestry Lake, is characterized by an almost flat basin, banks with the gentle slope, and hills on two sides. Total area of the water body is about 1.5 acres, and its mean depth is 1.1 m. The hill slopes have many planted teak trees. The physico-chemical conditions of S1 and S3 are significantly influenced by drainage from the hilly watersheds. Site 1, however, has additional problem from drainage from the laboratories of science departments. Habitat selection of Euphlyctis cyanophlyctis (henceforth abbreviated as Ec) was investigated in relation to six abiotic factors, viz., size and depth of water body, air and water temperature (AT and WT), dissolved oxygen (DO), free carbon dioxide (FCO2) and three biotic factors, viz., plant species richness (PSR), zooplankton species richness (ZSR) and zooplankton density (Zp_den) of three aforementioned water bodies of the CUC. From earlier knowledge and preliminary investigations it is known that Ec is active throughout the year. The study period, extends three practical seasons (summer, rainy and winter) (Ahmed 1968) of Bangladesh, was decided in view of the knowledge that this time includes the pre-breeding and post-breeding periods of the frog species. Temperature was measured instantly by using the mercury thermometer calibrated from 0 to 1100C. Water depth and size were, also instantly, measured by using rope and measuring tape in meter scale. Dissolved oxygen and free carbon dioxide were measured, in the laboratory, by Winkler Modification of the Azide Method and Titrimetric Method, respectively (APHA 2005). The zooplankton analysis was carried out using Sedgwick Rafter counting Cell (APHA 2005). All statistical analyses were done using the SPSS version 17.0. Canonical Discriminant Analysis of the data matrix (10 × 51 [n = 17 × 3 sites]) necessitated further correlations and regressions analyses done separately for each of the water bodies.
Bangladesh J. Zool. 44(1): 133-146, 2016 ISSN: 0304-9027 (print) 2408-8455 (online
Journal