Lice of five wild bird species, of diversified feeding habits and phylogeny viz., Sturnus contra, Acridotheres tristis, A. fuscus, Pycnonotus cafer and Streptopelia chinensis – have been investigated between 2014 and 2018 from the Chittagong University Campus and adjoining areas. A total of six lice species, viz., Menacanthus eurysternus (Burmeister), Sturnidoecus sturni (Clay), Bruelia zohrae (Ansari), Myrsidea kathleenae (Hellenthal and Price), Columbicola turturis (Uchida) and Nitzschiella lativentris (Uchida), were identified and described. Among them, five were strictly host specific – S. sturni (in S. contra), B. zohrae (in A. fuscus), M. kathleenae (in P. cafer), C. turturis (in S. chinensis), and N. lativentris (in S. chinensis). The remaining species, M. eurysternus, had wide specificity – occurring in all the three sturnid species investigated, i.e., S. contra, A. tristis and A. fuscus. Closely related hosts were found to share similar parasite species whereas unrelated host possess completely different lice species. Of the five hosts, three (S. contra, A. fuscus, and Streptopelia chinensis) were found to be infested by two lice species each, whereas, A. tristis and P. cafer hosted by a single lice species each. Bangladesh J. Zool. 50 (1): 51-66, 2022

For proper conservation measures and to elucidate coexistence mechanism of sympatric herbivore, we assessed the temporal foraging and ranging patterns of the Axis axis (spotted deer) and feral and/or semi domesticated Bubalus bubalis (buffalos) in the Nijhum Dweep National Park (NDNP) of Bangladesh. We have collected the data by day long scan sampling method for 12 months. We found that spotted deer and buffalos, respectively, spent 50.34% and 36.41% of their total day time in foraging. To avoid clash with the larger sized buffalos in the grazing ground, the spotted deer choose a slightly different time for grazing. At least three foraging peaks were found for spotted deer, whereas, buffalos showed two foraging peaks in a day. More importantly, spotted deer relied more on browsing for their food collection although they are natural gazer, whereas, buffalos relied more on their natural grazing habit for food collection. Spotted deer spent most of their time inside the forest and forest edges, whereas, buffalos mostly spent their time in the open grazing grounds. The range of total distance moved (TDM) per day for spotted deer and buffalos was 1.56 to 2.67 km and 1.02 to 3.30 km, respectively. The total area ranged (TAR) per day were 0.23 km2 to 0.8 km2 for spotted deer and 0.03 km2 to 0.35 km2 for buffalos. Although, these two parameters varied seasonally for both species, only in case of TAR of spotted deer the variation was statistically significant ( P < 0.05 ). We conclude that because of the presence of a larger sympatric herbivore, the spotted deer did some alterations in their temporal foraging and ranging pattern (TFRP) to survive in the small island which has very limited resources for their existence and survival.

Population dynamics of the mullet species, Rhinomugil corsula, was studied, using FiSAT-II program, with the length-frequency data of 2480 fish specimens. The asymptotic length (L∞) and growth coefficient (K) of this fish were estimated to be 31.4 cm and 1.0/year, respectively. The instantaneous rate of natural mortality (M), fishing mortality (F) and total mortality (Z) were estimated to be 1.73, 1.20 and 2.93, respectively. The recruitment pattern of the species was prolonged with two peaks, major peak during June to December and a minor peak during January to April. The L25, L50 and L75 were found to be 8.61, 10.42 and 12.23 cm, respectively. The relative yield per recruit (Yʹ/R) and biomass per recruit (Bʹ/R) were 0.751 and 1.731, respectively. The value of exploitation (E) was found to be 0.41 which indicated that R. corsula was not over fished (E > 0.50) in the study area. The maximum exploitation (Emax) value was 0.55. The growth performance index (ϕ´ = 2.99) of R. corsula in the Sitakunda coast of the Bay of Bengal was found to be moderate. Bangladesh J. Zool. 47(2): 305-314, 2019

This study deals with the length-weight relationship and relative condition factor (Kn) of 2480 specimens of Rhinomugil corsula (Hamilton, 1822), ranging from 3.5 cm to 29.5 cm total length and 0.40 g to 235.34 g weight, sampled monthly for two years period from March 2016 to February 2018 from the Sitakunda Coast of the Bay of Bengal, Bangladesh. Arithmetic form of equations for length (TL) and weight (W) of fish showed curvilinear relationships in male: W=0.0081TL3.016, female: W= 0.0083TL3.058 and combined sex: W=0.0076TL3.052, while logarithmic scale showed linear relationships in male: LogW=-2.122+3.016LogTL, female: LogW=-2.09+3.058 TL and combined sex: LogW=-2.121+3.052TL. In all the cases the coefficient of correlations between length and weight were positive and highly significant (P<0.01). The regression coefficient ‘b’ values were found to be 3.01±0.11, 3.06±0.12 and 3.05±0.12 for male, female and combined sexes, respectively for two years period together. When ‘t’ test was done, the growth was found to be isometric in case of male and combined sex and positive allometric in case of female. The relative condition factor (Kn) varied from 1.0003-1.009, 1.001-1.008 and 1.001-1.008, respectively, for male, female and combined sex in 2016-17, whereas 1.001-1.007, 1.003-1.006 and 0.992-1.008 respectively in 2017-18. The Kn values were always around ‘1’ or a little bit more than ‘1’ for length groups as well as monthly, indicating the excellent growth and robustness of fish due to favorable environmental condition prevailing in the habitat of the fish, in the Sitakunda coast of the Bay of Bengal. Bangladesh J. Zool. 49(1): 91-103, 2021

A total of 65 specimens of Rhinomugil corsula (Hamilton, 1822), measuring from 8.1 cm to 28.9 cm in total length, collected from the Sitakunda coast of the Bay of Bengal, were used for the morphometric analysis during the period between March 2016 and February 2018. Twenty seven morphometric characters were selected and studied during the investigation period. The regression equations – both arithmetic and logarithmic – between the total length (TL) and 21 morphometric characters, and head length (HL) with five morphometric characters related to the head, were determined. The value of coefficient of correlation ‘r’ for each relationship was calculated and t-test for each ‘r’ value was also done. The relationships of the various measurements of the body with the total length – and head length with the five relevant characters -of R. corsula from the Sitakunda coast of the Bay of Bengal showed linear relationships, which were highly significant (P<0.01). The ranges of ‘b’ values 0.967 to 1.346 in case of the relationships between TL and 21 relevant characters, whereas 0.906 to 1.236 in case of the relationships between HL and 5 relevant characters. These values differ insignificantly (P>0.01) with typical value b=1 indicating isometric relationships among the characters. Bangladesh J. Zool. 49 (2): 229-241, 2021