Tilapia tilapinevirus, known worldwide as tilapia lake virus (TiLV), is a single-stranded RNA virus that belongs to the Amnoonviridae family. The virus attacks the fish species’ external and internal organs, such as the eyes, brain, and liver. Syncytial cells develop in the liver cells of infected fish, which are characterized by widespread hepatocellular necrosis and karyolytic nuclei. It is a highly infectious virus that spreads both horizontally and vertically. Despite these devastating complications, there is still no cure or vaccine for the virus. Therefore, a vaccine based on epitopes developed using immunoinformatics methods was developed against TiLV in fish. The putative polymerase basic 1 (PB1) gene was used to identify immunodominant T- and B-cell epitopes. Three probable epitopes were used to design the vaccine: CTL, HTL, and LBL. Testing of the final vaccine revealed that it was antigenic, non-allergenic, and has improved solubility. Molecular dynamics simulation revealed significant structural compactness and binding stability. Furthermore, the computer-generated immunological simulation indicated that immunization might stimulate real-life immune responses following injection. Overall, the findings of the study imply that the designed epitope vaccine might be a good option for prophylaxis for TiLV.

The present research focuses to examine the meristic and landmark-based morphometric variations of barred spiny eel Macrognathus pancalus from four populations namely Dhakuria beel , Jessore (DBJ); Bohnni boar , Gopalgonj (BBG); the Arial kha river, Madaripur (AKRM) and the Nabaganga river, Jhenidah (NRJ) in Bangladeshi freshwaters. Six meristic counts were compared among four populations and significant differences were observed in number of caudal fin rays and number of pelvic fin rays in all meristic characters. The truss protocol was used in the present study based on six general morphometrics and fifteen truss measurements. Univariate statistics showed that five (standard length (SL), upper jaw length (UJL), lower jaw length (LJL), head depth (HD) and inter orbital (IO)) of six morphometric and eleven truss networks ( viz. 2-3, 3-4, 5-6, 6-7, 7-8, 1-8, 2-8, 3-8, 3-7, 4-7 and 5-7) among fifteen truss measurements differed significantly. Cannonical discriminate function analyses were conducted among samples and the populations were fully intermingled. Pooled within-group correlation showed morphometric and landmark measurements; the first discriminant function (DF) accounted for 79%, the second DF accounted for 15.9% and third DF accounted for 5.1% of group variability. An euclidian dendrogram was prepared based on morphometric and truss measurements in four populations, where two clusters were mainly formed, in which first cluster formed by NRJ population was fully separated, and the second cluster was formed by two populations of AKRM and DBJ. Additionally, a subcluster BBG was formed with AKRM. On the basis of morphometric and truss measurements, 68.8%, 83.6%, 55.6% and 80% of original grouped cases were correctly classified in NRJ, AKRM, DBJ and BBG, respectively. These results specify the presence of different stocks of fish from four aquatic habitats. This study is highly significant for proper conservation and effective management of M. pancalus populations as well as for the scientific community for further research.

Aim: Landmark-based truss network system was applied to examine the morphometric and meristic differences among four different populaces of Macrognathus aculeatus namely; Dhakuriabeel, Jashore (DBJ); Arial Kha River, Madaripur (AKRM); Nabaganga River, Jhenaidah (NRJ); Kopotakkha River, Jashore (KRJ) in Bangladesh. Methodology: Completely 80 samples of M. aculeatus were collected (20 individuals from each population) for this study. Six meristic characters, 6 morphometric characters and 15 truss-based morphometric characters were measured for one-way analysis of variance (ANOVA) and Tukey-HSD post hoc test. Discriminant function analyses were also performed by using morphometric and truss-based morphometric characters to detect potential characters responsible for population separation. Results: ANOVA results revealed significant differences among three meristic characters, 6 morphometric and 10 truss-based morphometric characters. By using both morphometric and truss dimensions, the first discriminant function analysis (DFA) resulted for 46.3%, the second DF resulted for 36.6% and the third DF resulted for 17.1% among-group variability. The populations were clearly aggregated among four populations in the discriminant space. Considering the morphometric and truss measurements, 100%, 94.4%, 91.7% and 84.2% of unique grouped cases were appropriately classified in KRJ, AKRM, DBJ and NRJ, respectively. In Euclidian dendrogram, where first cluster formed by AKRM and second cluster formed by two populations DBJ and NRJ and finally KRJ formed another sub cluster with DBJ. Interpretation: The baseline information derived from the present study would be useful for appropriate conservation of M. aculeatus populations as well as for the researchers for further investigation.

The Indian river shad, Gudusia chapra, is a well-known species of potamodromous fish belonging to the Clupeidae family. The main focus of this study is to state the sex ratio, growth pattern, length-length relationship, form factor, Fulton’s condition factor and relative weight of G. chapra harvested from the Rupsha River (south-west Bangladesh). Altogether 300 specimens (male=166 and female=134) were harvested with the help of commercial fisher folks on seasonal basis (summer, rainy and winter) during 2022. Body weight and length of individual specimen were recorded with digital balance and measuring board. Total length varied between 12.7 to 16.5 cm for males and 13.0 to 17.3 cm for females. Further, body weight ranged between 15.82 to 42.48 g for male and 18.36 to 46.65 g for female. As a whole, both sexes revealed positive allometric growth pattern (b>3.00). Moreover, the length-length relationships were found highly correlated for both sexes. The estimated form factor was 0.0087 indicated fusiform body shape for G. chapra population. The mean Fulton’s condition factor was recorded close to 1 indicated a pleasant health condition for this species. Further, mean relative weight revealed a sound ecological atmosphere regarding prey-predator status. The research outcomes would be helpful to execute a sound management policy in the Rupsha River and connected ecosystem in the south-west Bangladesh.

The intraspecific morphological variations of the butter catfish, Ompok bimaculatus has been assessed from two fish farms viz., Chanchra Fish Farm, Jashore (CFFJ) and Fish Seed Complex, Khulna (FSCK) and two natural wetlands viz., Bohni beel, Gopalganj (BBG); Dakatia beel, Khulna (DBK) in the south-western part of Bangladesh. A total number of 80 samples were collected comprising 20 individuals from each sampling location. Five meristic characters, 18 morphometric characters and 21 truss-based morphometric characters were measured respectively. Meristic, morphometric and truss-based morphometric characters were exposed to one-way analysis of variance followed by Tukey-HSD post-hoc test at 5% significance level. Significant differences were observed in two meristic characters viz., CFR and PevFR, and five morphometric and four truss morphometric characters. However, morphometric and truss measurements showed highly intermingled among four populations in discriminant functions (DFs) analysis and discriminant space as well. DFs showed that 6-7, PrDL, HL, PSDL, 1-2, 4-6, FL, ED, 3-9, 5-6, SnL and 4-5 characters contributed 62.8% in first DF, while 2-9, HD, 1-9, 2-3, 2-6, 3-6, 3-4, LAB, 3-8, 9-10, IO and MXBLR characters contributed 20.6% in second DF, and the remaining characters contributed 16.6% in third DF. In cluster analysis, two distinct clusters were made, where BBG demonstrated a solitary group, and FSCK and CFFJ jointly shaped alternative clusters, while the DBK population found a subgroup with CFFJ. These results postulate the occurrence of intermingling populations of this species from four aquatic habitats. These morphological discrepancies play an important role in establishing proper decisions in order to achieve appropriate management and conservation as well as mass seed production for their future sustainability.

The present study focuses to examine the meristic and morphometric variations of Ompok pabo from three populations namely Bergobindapur baor (BB), Bhairab River (BhR) and Kopotakho River (KR) in Bangladeshi freshwaters using the landmark-based truss network analysis. Truss protocol used in the present study based on seven general morphometrics and eight landmarks points constructed by interconnecting them to form total 16 truss measurements. Meristic counts were compared among three populations and no significant differences were observed in non-parametric Kruskal Wallis test. Univariate statistics (ANOVA) showed 5 [standard length (SL), post-orbital length (PsOL), maximum body depth (MBD), length of left barbel (LLB) and length of right barbel (LRB)] of seven morphometrics measurement and 8 (2-3, 3-4, 6-7, 2-7, 2-6, 3-6, 3-5, 2-8) of the 16 truss measurements significantly differed to varying degrees (p<0.05, p<0.01, p<0.001) among samples. Cannonical discriminant function analyses were done among the samples and the populations were fully separated. In case of both morphometric and truss measurements, the first and second discriminant function (DF) accounted for 76.3% and 23.7% respectively in group variability explaining 100% of the total among group variability. A dendrogram was drawn for the three populations of BB, BhR and KR based on the morphometric and truss measurements where two clusters were mainly formed in which BB and BhR formed one cluster and KR formed a separate cluster. The preliminary information derived from the present study may be useful to manage and conserve of O. pabo populations in three aforementioned ecological niches.