Dept. of Marine Bioresource Science

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Assessing The Feasibility and Impacts of Introducing Seaweed Cultivation in Shrimp Farming Ghers/Ponds in Coastal Regions of Bangladesh
(Faculty of Fisheries Chittagong Veterinary and Animal Sciences University Chittagong-4225, Bangladesh, 2025-08) Talapatra, Joy
To assess the feasibility and ecological impacts of introducing seaweed cultivation into shrimp farming systems, a comparative cultivation trial of Gracilaria sp. was conducted from October 2023 to March 2024 across pond and nearshore environments in Cox’s Bazar, Bangladesh. The study employed a total of 18 experimental plots—9 in shrimp ponds (ghers) and 9 in nearshore waters—spanning both surface and bottom layers. In the nearshore environment, cultivation was conducted using floating long-line systems at the surface and off-bottom long-line and off-bottom net systems at the bottom, whereas in pond conditions, floating long-line and floating net methods were applied at the surface, with a broadcast technique used for bottom-layer cultivation. A two-way ANOVA revealed that the biomass production was significantly influenced by both cultivation environment and layer, with nearshore environments yielding substantially higher values (1.47 ± 0.68 kg m⁻²) than ponds (0.19 ± 0.09 kg m⁻²), and greater productivity at the surface (1.04 ± 0.98 kg m⁻²) compared to the bottom layer (0.62 ± 0.52 kg m⁻²). The proximate composition of Gracilaria sp. was also significantly affected by environment and layer, with nearshore and surface-grown seaweeds exhibiting notably higher protein, lipid, ash, and fiber contents compared to pond-cultivated seaweeds, which consistently showed lower nutritional values across all parameters. The amino acid concentrations of Gracilaria sp. were also substantially higher in nearshore grown seaweeds, whereas the effect of cultivation layer remained relatively minor across most amino acids. A total of 50 distinct phytochemical compounds were identified through GC-MS analysis in both pond and nearshore cultivated Gracilaria, with their concentrations showing clear variations based on cultivation environment and layer, reflecting different accumulation patterns under different culture conditions. Among the 13 essential minerals detected, Na, K, Fe, Co, and Cu were more abundant in nearshore-cultivated Gracilaria, whereas Ca, Mn, Se, and Rb were predominantly enriched in pond-grown seaweeds. Among the four identified heavy metals, Cr and Pb showed significantly higher accumulation in nearshore- and pond-grown Gracilaria, respectively, while Cd and Hg levels remained relatively stable across all cultivation conditions. The study also revealed that although the antioxidant levels in Gracilaria remained consistent across cultivation environments, flavonoid content was markedly elevated in nearshore-cultivated seaweeds (192.13 ± 35.50) compared to those grown in ponds (44.07 ± 15.50). The x findings of the study demonstrated that surface based floating net systems could be a promising culture technology for the production of Gracilaria sp. in shrimp farming ghers/ponds in coastal regions of Bangladesh.
Benthic Community Variability at Himchori Beach Point, Cox’s Bazar: In Relations with Sediment Characteristics
(Chattogram Veterinary and Animal Sciences University Chattogram-4225, Bangladesh, 2020-06) Shafikul Alam, Md.
This study was undertaken to know the benthic community of Himchori Beach Point in relations with any differences between a newly deposited muddy beach and adjacent sandy beaches. 15 samples representing muddy and sandy beaches were collected and analyzed following standard methods. A total of 20 macro benthos and 18 micro benthos species were identified. In case of macro benthos, the most dominant species was Mesogastropoda comprising 39.29% in muddy beaches, while Ponderous ark (34.90%) and Pila globosa (35.71%) was dominant species in two sandy beaches. In case of micro benthos, Nephtys (27.27%), Bivalves and Urothoe sp. (40%) and Unionidae (92.30%) was dominant species in muddy and sandy beaches respectively. Both macro and micro benthos distribution showed differences between the newly deposited muddy beach and the sandy beaches in north and south. 10 species of macro benthos out of 20 were found only in the muddy beach and 2 species only in sandy beaches. 13 species of micro benthos out of 18 species were restricted to the newly deposited muddy beach. Contrary to this only one species `Unionidae' was common in sandy beaches. From the differences observed in this study, it can be concluding that the newly deposited beach which visually seems muddy is different from the existing sandy beaches of north and south part of Himchori Beach Point.
Biochemical Profiling of Pond-Cultivated Brine Shrimp (Artemia franciscana) Along the Southeast Coast of Bay of Bengal, Bangladesh.
(Faculty of Fisheries Chittagong Veterinary and Animal Sciences University Chittagong-4225, Bangladesh, 2025-12) Tasnim, Sadia Halima
Artemia is an essential live feed organism in aquaculture hatcheries, especially during the early larval stages of fish and crustaceans. In Bangladesh, the lack of natural hypersaline environments has led to a complete reliance on imported Artemia cysts, which raises concerns about supply stability, high costs, and long-term sustainability. In response to this challenge, the present study offers a comprehensive evaluation of pond-cultivated Artemia produced along the southeast coast of the Bay of Bengal within integrated salt-farming systems. The research focuses on assessing its nutritional composition, microbial safety, and potential chemical residues to determine its suitability as a sustainable alternative to imported sources. Artemia biomass samples were collected from ten coastal locations in Cox’s Bazar, namely Chowfaldandi, Khamarpara, PM Khali, Choto Moheshkhali, Boro Moheshkhali, Teknaf, Chakaria, Pekua, BSCIC-1, and BSCIC-2, during two distinct cultivation periods: the early production period (January-March) and the late production period (April-June). Biomass yields were comparatively higher during the early production period, particularly at Teknaf, PM Khali, and BSCIC sites which exhibited favorable salinity regimes and stable pond conditions. In contrast, relatively reduced growth and biomass accumulation were observed during the late production period, especially at Chakaria, Khamarpara, and Choto Moheshkhali, likely due to increased environmental stress and salinity fluctuations. Biochemical analysis revealed significant spatial and temporal variation in proximate composition. Artemia cultured during the early production period showed comparatively higher lipid and energy-rich components, while late production samples were characterized by increased ash and fiber content. Fatty acid profiling demonstrated a clear shift between cultivation periods, with higher proportions of short- and medium-chain fatty acids dominating the early period, whereas long-chain polyunsaturated fatty acids, including nutritionally important n-3 and n-6 PUFAs, were more pronounced during the late production period. Amino acid analysis indicated location-specific differences, although essential amino acids remained relatively stable across cultivation periods. Microbiological analyses showed moderate total bacterial loads across sampling sites, with no detection of critical pathogens such as Salmonella, Shigella, or Vibrio cholerae. Antibiotic residue analysis confirmed that all detected compounds were below international safety thresholds, indicating the suitability of pond cultivated Artemia for aquaculture use. Overall, the xvi findings highlight that cultivation period and location strongly influence Artemia nutritional quality, with the early production period offering superior biomass yield and energy content. This study demonstrates the potential of coastal salt ponds in Bangladesh for sustainable Artemia production and provides practical insights for optimizing cultivation timing and site selection.
Biodiversity of Indigenous Ornamental Fishes of Saint Martin’s Island of Bangladesh.
(Chattogram Veterinary and Animal Sciences University Chattogram-4225, Bangladesh, 2021-04) Maksudur Rahman, Md.
Saint Martin’s Island is a unique island in the northern part of the Bay of Bengal. The island is rich in fish biodiversity. There are some ornamental fishes can be found in the island. The demand of ornamental fishes is growing up day by day. The study was done on the assessment of the indigenous ornamental fishes of the island from January 2019 to January 2020. The criterion for the selection of the study area was identifying suitable geographical area for wider variety of ornamental fish biodiversity according to fishermen. Different PRA tools like focus group discussion, personal interview was used during data collection. Shannon Biodiversity index was used for data analysis. Different statistical tools such as Pie chart and Table was used to represent the findings. There are 69 species was recorded under 30 family. The species of Chaetodontida (17%), Terapontidae (10%), Serranidae (7%), Lutjanidae (6%), Pomacentridae (11%), Pomacanthidae (4%), Mullidae (4%), Labridae (8%), Tripterygiidae (4%), Ephippididae (3%), Acanthuridae (3%), and Gobiidae (3%) are abundant family. The Shannon index was found 3.89308. Which indicates the biodiversity of the indigenous ornamental fishes of the island is very good. The study found Shannon’s Equitability (EH) = 0.92. It indicates that this sample has pretty high equitability.
COMPARATIVE STUDY ON GROWTH PERFORMANCE OF GREEN MUSSEL (Perna viridis) CULTIVATED ON RAFT AND LONGLINE IN THE COAST OF BAY OF BENGAL
(Chattogram Veterinary and Animal Sciences University Chattogram-4225, Bangladesh, 2021-04) Ahmed, Sabbir
Green mussel (Perna viridis) is one of the most potential mariculture shellfish species not only in context of Bangladesh but also for the world. Developing of P. viridis culture techniques can be a great source of livelihood for many people. A thorough study on the feasible green mussel culture method in the context of Bangladesh is essential for farmers and investors to adapt this new and non-conventional species for commercial aquaculture farming. Therefore, the main purpose of this study was to compare the growth performance of the green mussel cultivated on raft and longline in the coast of Cox’s Bazar, Bangladesh and investigate the relation of growth with the eco-physiological factors of P. viridis. Raft and long-lines were stationed in the coast of Bay of Bengal near Nuniar Chora, Cox’s Bazar for green mussel culture. Water sampling was done twice a month basis for a period of 13 months from November 2019 to November 2020 and P. viridis were sampled from February 2020 to November 2020 after naturally spat settlement. Collected green mussel samples were brought to the laboratory to measure live weight and shell length for analyzing the growth performance. From the study, the maximum live weight and maximum shell length of P. viridis was found 54.56 g and 12.20 cm, respectively which was cultivated in the raft. There was no significant variation in growth of P. viridis cultivated on longline and raft. The growth increment of P. viridis was higher in August than the other months in both raft and longline culture methods. All the water quality parameters of the two culture sites were suitable for green mussel culture and had influence on the growth of green mussel. However, the study will be helpful for local communities to develop green mussel culture near the coast adjacent to their homestead in Nuniar chora, Cox’s Bazar, Bangladesh.
COMPARATIVE STUDY ON THE PROXIMATE COMPOSITION AND FATTY ACID PROFILES OF LIVER, GONAD AND MUSCLE IN MALE AND FEMALE Plotosus canius.
(Faculty of Fisheries Chittagong Veterinary and Animal Sciences University Chittagong-4225, Bangladesh, 2025-12) Akter, Fatema
The present study evaluated the proximate composition and fatty acid profile of Plotosus canius with respect to sex in order to understand potential biochemical differences between male and female individuals collected from the south-eastern coastal waters of Bangladesh, including the Kattoli mangrove forest (Chattogram) and the Moheshkhali channel (Cox’s Bazar). Proximate parameters such as moisture, protein, lipid, and ash were analyzed to assess overall nutritional quality, while detailed fatty acid composition including saturated (SFA), monounsaturated (MUFA), and polyunsaturated fatty acids (PUFA) was determined to evaluate the health-related lipid characteristics of the species. Morphometric analysis revealed that males attained greater total length and body weight than females. Length– weight relationship analysis indicated positive allometric growth in both sexes, with regression coefficients (b) of 3.13 for males and 3.28 for females. Proximate composition analysis demonstrated significant tissue- and sex-dependent variations. Muscle protein content was significantly higher in females than males (p < 0.05), whereas liver protein content did not differ significantly between sexes. Hepatic lipid content was markedly higher in males (p < 0.001), while muscle lipid levels showed no significant sex-based variation. Moisture content was significantly higher in male liver tissue, whereas ash content was significantly greater in female liver. Fatty acid profiling revealed pronounced sexual dimorphism across muscle, liver, and gonadal tissues. Female muscle tissue exhibited higher total saturated fatty acids (ΣSAFA), monounsaturated fatty acids (ΣMUFA), and n-6 polyunsaturated fatty acids (PUFA), while male muscle contained higher n-3 PUFA, including eicosapentaenoic acid (EPA). In liver tissue, females showed substantially higher ΣSAFA and ΣMUFA, whereas males displayed elevated n-6 PUFA. Gonadal tissues showed the most distinct differences, with males exhibiting significantly higher ΣSAFA and n-3 PUFA, while females accumulated greater ΣMUFA and selected n-6 PUFA associated with reproductive functions. Atherogenicity index (AI) and thrombogenicity index (TI) varied significantly among tissues and sexes. Liver tissue showed the lowest AI and TI values in both sexes, indicating favorable lipid quality, whereas the highest values were recorded in male gonads. Overall, VIII the findings demonstrate that sex and tissue type strongly influence nutritional composition, fatty acid distribution, and lipid health indices in P. canius. These results provide valuable insights into sex-specific lipid metabolism, reproductive physiology, and the nutritional importance of this species for human consumption and fisheries management in coastal Bangladesh.
Comparison of growth performance and survival of clam Meretrix meretrix in Hapa, Plastic Bag, and Seabed-based culture methods in the southeast coast of Bangladesh
(Faculty of Veterinary Medicine, Chattogram Veterinary and Animal Sciences University, Khulshi, Chattogram-4225, Bangladesh, 2025-08) Kamran, Md Abdul Alim
The Asiatic hard clam Meretrix meretrix represents a valuable bivalve resource in coastal Bangladesh. This study evaluated the growth and survival of Meretrix meretrix cultured over 180 days period (January–June 2024) at two unique coastal sites on the southeast coast of the Cox’s Bazar Reju Khal and Chowfaldondi using four culture systems hapa, floating bag, seabed fencing, and seabed covering. Clam Meretrix meretrix seeds were collected from natural beds and stocked at method-specific densities. Monthly measurements of shell dimensions, total weight, and mortality were recorded alongside key water quality parameters including temperature, salinity, dissolved oxygen, pH, turbidity. Results showed significant differences (p < 0.001) in growth and survival among culture systems and between sites. Hapa culture yielded the highest growth rates across all shell dimensions and total weight, attributed to effective predator exclusion, enhanced water circulation, and improved phytoplankton access. Floating bag systems exhibited the lowest growth and survival, primarily due to severe biofouling by barnacles (Balanus spp.), green mussels (Perna viridis), and oyster spat (Crassostrea spp.) which restricted water flow, reduced oxygen availability, and increased interspecific competition. Seabed fencing and covering systems provided intermediate performance, benefiting from natural substrate conditions but remaining susceptible to partial predator intrusion and environmental variability. Survival rates were highest in fencing at Reju Khal and lowest in floating bags at the same site. Correlation and PCA analyses indicated that dissolved oxygen, salinity, and moderate turbidity were key drivers of growth and survival. These findings demonstrate that suspended hapa systems offer the most favorable conditions for M. meretrix growth, while bottom fencing provides better survival in predator-rich environments. The results highlight the need for site-specific culture strategies that integrate hydrodynamic conditions, fouling management, and predator control to optimize clam mariculture in Bangladesh.
Culture potential of green mussel based on bio-physical variables and food availability in Rezu Khal, Cox’s Bazaar
(A thesis submitted in the partial fulfillment of the requirements for the degree of Master of Science in Marine Bio-resources Science Department of Marine Bio-resources Science Faculty of Fisheries Chittagong Veterinary and Animal Sciences University Chittagong-4225, Bangladesh, 2018-06) Sultana, Afroja
ABSTRACTS Bivalve aquaculture is an important source of affordable animal protein for coastal community. The success and sustainability of this industry is highly influenced by the suitability of the environment in which it is being carried out. The present study was carried out to evaluate whether it would be possible to culture green mussel Perna viridis in Rezu Khal, Cox’s Bazar. In this study, site suitability of Rezu Khal for green mussel farming was evaluated based on the year-round variations of physico-chemical water quality parameters, and quantitative and quantitative abundance of plankton community. Five Stations were selected chronologically from upstream to downstream at specific interval of distance. The water and plankton samples were collected from these five Stations of the Rezu Khal on monthly interval from April 2017 to March 2018. The results showed that most of the physico-chemical water quality parameters (temperature, dissolve oxygen, pH, turbidity and dissolved nutrients such as nitrite, nitrate, phosphate and ammonia) in all Stations were considered as suitable for green mussel culture. The water depth was moderate in Stations 4 and 5, and very low in other Stations for green mussel culture. Salinity fluctuation (2 to 34.5 ppt) was also a major issue in all Stations of Rezu Khal for green mussel culture. In Rezu Khal, a total of 59 genera of phytoplankton and 16 genera of zooplankton were identified, and their abundance was varied from 15.4×103 to 37.5×103 cells/L depending on the seasons and the Stations. The phytoplankton community was mostly dominated by Bacillariophyceae (83% of the total phytoplankton count) with Skeletonema and Coscinodiscus as the dominant genera. After taking all the water quality parameter qualitative and quantitative abundance of plankton, the station 1 and 2 (located on the upstream) less recommended for green mussel culture and station 3, 4 and 5 (located on the downstream) exhibited medium site capability rating point. In conclusion, downstream Stations (3, 4 and 5) of Rezu Khal are capable and moderately suitable for green mussel farming.
DETERMINATION OF PHYTOPLANKTON SINKING RATE IN NORTHERN BAY OF BENGAL: COMPARATIVE STUDY OF SEASONAL CARBON ABSORPTION
(Chattogram Veterinary and Animal Sciences University Chattogram-4225, Bangladesh, 2021-04) Acharjee, Mishu
Seasonal carbon flux via “Biological pump” associated with phytoplankton sinking rate were measured conducting this research during monsoon((August 2019) and winter (January 2019).It was done in the Northern east part of Bay of Bengal included three stations (Teknaf,Patenga and Bashbaria). Sinking rate was determined by homogeneous sample method SETCOL. Phytoplankton community was dominant by Bacillariophyceae, Dinophyceae and Chlorophyceae and ten dominant species. The average value found in Bashbaria was 2.62 ± 0.28 m/d (monsoon) and 1.89 ± 0.48 m/d (winter), in Patenga was 2.30 ± 0.15 m/d (monsoon) and 2.56 ± 0.57 m/d (winter), in Teknaf was 2.40 ± 0.06 m/d (monsoon) and 2.33 ± 0.09 m/d (winter).No significant correlation were found between phytoplankton sinking rate and most of the environmental parameters. During this study average total c arbon flux was varied from 5.69 ± 0.61 to 3.99 ± 1.02 mg C/m-2d-1 in Bashbaria, 9.07 ± 0.61 to 8.24 ± 1.84 mg C/m-2d-1 in patenga and 19.20 ± 2.66 to 14.69 ± 1.37 mg C/m-2d-1 in Teknaf during monsoon and winter chlorophyll-a and Total carbon showed strong correlation with carbon flux. Two way ANOVA results Showed that variations in Carbon flux and phytoplankton sinking rate among 3 stations and 2 seasons and depth were significant (p<0.05) and PCA showed that there was a close correlation among Carbon flux,Chl-a and Total carbon but no correlation with sinking rateThis study provides an understanding the seasonal carbon export in the water column by dominant marine phytoplankton with an association of phytoplankton sinking.Teknaf coast is the prime contributor of daily carbon export from surface to the bottom among three stations and during monsoon this contribution is higher than winter Because of higher phytoplankton abundance than the other two stations.
Distribution and Captive Breeding of Barnacle: A Potential Live-Feed for Enhancement Blue Economy
(Faculty of Fisheries Chittagong Veterinary and Animal Sciences University Chittagong-4225, Bangladesh, 2025-08) Bhowmik, Pranta
Barnacles (Cirripedia: Thecostraca) are sessile marine crustaceans with vital ecological and economic significance across global coastal ecosystems, yet their diversity, biology, and aquaculture potential remain unstudied in Bangladesh. The first integrative investigation into the morphological identification, spatial distribution, reproductive biology of acorn barnacles along the seven intertidal zones- Chowfaldandi (CD), Dorianagor (DN), Raju Khal (RJ), Inani (IN), Paturtek (PT), Teknaf (TC), and Sha Porir Dwip (SP) with upper and lower strata along the southeastern coast of Bangladesh was done. Additionally, it reports the first feeding trial comparing barnacle nauplii (BN) and barnacle meat (BM) with polychaetes (PO), Artemia (AN), and commercial feed (CF), tested on both tilapia (Oreochromis mossambicus) fry and shrimp (Litopenaeus vannamei) post-larvae, to evaluate their potential as larval feed for marine fish and crustaceans. Twelve acorn barnacle species from three families and six subfamilies were identified across seven intertidal sites, with distribution patterns strongly influenced by tidal strata, substrate type, and local habitat characteristics. The coastline predominantly comprised sandy habitats. In the upper stratum, the highest mean density in 15×15 cm2 sampling site was recorded at IN (2085.4 ± 1161.8), while the highest mortality occurred at PT (389.1 ± 312). In the lower stratum, IN and SP exhibited the highest barnacle densities, although IN also reported the greatest mortality. Moreover, barnacle attachment was markedly higher on artificial substrates, particularly on concrete (1373.08 ± 1031.6), compared to both natural (stone, mollusk shell and mangrove) and other artificial surfaces (wood, bamboo, and plastic). Species such as Amphibalanus amphitrite and Chthamalus moro were widespread, while others like commercial Austromegabalanus psittacusfrom PT and Tetraclita squamosafrom IN showed localized occurrence, highlighting potential biogeographic and ecological specificity. Moreover, the genera Amphibalanus and Chthamalus were the most dominant. Morphometric analyses of most abundant A. amphitrite revealed a strong relationship between width of basis (WB) and length of basis (LB)(R² = 0.8786, p<0.01). Length–weight regression models indicated highly significant allometric relationships, with xii barnacle weight (WT) basis length (R² = 0.8983) and basis width (R² = 0.8884). The embryo fecundity of A. amphitrite barnacles (basal length: 0.801 ± 0.356 cm) was 6,359 ± 2,160 embryos per individual. This species has a year-round mature gonadal activity and embryo stage-4h (ready to release), with peak development during pre-monsoon to monsoon months. After successful induced breeding of barnacle, nauplii were reared in hatchery conditions using microalgae cultured in cost-effective media. Nauplii containing six planktonic stages (stage-Ⅰ to stage-Ⅵ) prior to settlement, lasted for 13 days. On 30 days feeding trial, Oreochromis mossambicus fry fed with where BN exhibited significantly higher growth across multiple metrics, including final length, final weight, net weight gain, daily weight gain, percent weight gain, and specific growth rate compared to AN fed and CF feed fry. The CF group consistently showed the lowest performance, while Artemia-fed fry showed moderate growth for those growth parameters, with no statistically significant variation in condition factor and survival. The 30-day feeding trial on Litopenaeus vannamei post-larvae, BM diet also showed significantly higher (p<0.001) growth (total length, total weight, muscle weight, head weight, and head length ) and survival than other diets. . Successful induced breeding and hatchery rearing of Amphibalanus naupliiand their demonstrated efficacy as live feed in finfish and shrimp trials highlight barnacles as a promising alternative feed source in aquaculture. This research not only fills a major knowledge gap in Bangladesh’s marine invertebrate biology but also offer insights for advancing sustainable aquaculture, optimizing hatchery inputs, and enhancing blue economy of Bangladesh through underutilized marine invertebrates.
ENHANCING SCENARIOS OF LAND USE LAND COVER CHANGE OF MOHESHKHALI AND KUTUBDIA ISLAND, BANGLADESH
(Chattogram Veterinary and Animal Sciences University Chattogram-4225, Bangladesh, 2021-04) Humaira Ahmed Koly, Sayeda
Land Use / Land Cover (LULC) refers specifically to the categorization or designation within a particular time frame of human activities and natural elements on the landscape based on established scientific and statistical methods of analysis of suitable source materials. This study describes the Kutubdia Island and the Moheskhali Island Land use/Land cover analysis and the most likely causes of spatial land changes from 2001 to 2019. Moderate Resolution Imaging Spectroradiometer (MODIS), Sentinel and Landsat8 OLI imageries were used for land cover change analysis. Using remote sensing, nine distinct land classes with their related physical characteristics were identified and quantitative analysis was summarized in this study in order to find out the changes of each land class over the last 19 years. The most troubling situation occurred in the field of land-class mangrove forest, which decreased about of 21.38 sq. km in Kutubdia and 61.65sq.km in Moheshkhali from 2001 to 2019. At the same time period, the dramatic rise in salt fields was found which are about 27.52sq.km in Kutubdia and 8.88sq.km in Moheshkhali. For proper planning and management of Kutubdia Island and Moheshkhali Island, the outcome of this particular analysis may be useful. Those LULC maps will play a significant and key role in planning, management and monitoring programmers at local, regional and national levels. For the safety of Moheshkhali Island, further mangrove planting is strongly recommended in newly developing tidal flats as it falls into a strong cyclonic zone in the Bay of Bengal.
Gametogenic cycle with seasonal variation of Perna viridis in Moheskhali Channel, Bangladesh
(Chattogram Veterinary & Animal Sciences University, 2019-06) Noor, Aysha Rahi
Green mussel (Perna viridis) is one of the most potential mariculture shellfish species not only in context of Bangladesh but also for the world. A thorough study on the reproductive biology of P. viridis and determination of the accurate spat collection time is essential to develop the green mussel culture technology. Therefore, the main purposes of this study was to determine dynamics of the gonadal development accurately through histology, and to find how condition index (CI) is linked with the spawning of the green mussel. Twenty green mussel were collected each month from November 2017 to October 2018 from Moheskhali Channel, Chawfaldandi, Cox’s Bazar. Collected samples were brought to the laboratory to measure body length, body weight, muscle weight, and dry weight. The general reproductive condition of the population were assessed by calculating mean gonadal index (GI). From the histological analysis, the sex ratio of male and female was found tas 1:0.93 and no evidence of hermaphroditism in P. viridis were documented. There was a significant relationship between length and weight where R² value was found to be 0.92, indicating a positive correlation between this parameters. The male CI value was relatively higher than female. The highest value of female and male GI were observed to be 2.1 and 2.4 in the month of January and February, respectively, and a minor increase was observed in the month of June. GSI (gonadosomatic index) value was found to be generally higher in male than female. The study confirmed that the spawning of green mussel occurred twice in a year with major spawning season from November to March and a very minor spawning during the month of June to July. However the study will be helpful for naturally occurring green mussel stock management and to develop future aquaculture aspect in Moheskhali Channel.
Gonadal Histological Study of Oyster (Crassostrea sp) Collected from the South-East Coast of Bangladesh
(Chattogram Veterinary & Animal |Sciences University, 2022-10) Nahar, : Nasrin
The edible oyster (Crassostrea sp.) is one of the world's most promising mariculture shellfish species which is bound in the coastal belt of Bangladesh especially along the Cox’s Bazar coast. For development of oyster culture technology, understanding the reproductive biology of Crassostrea sp is required. The objective of this study is to use histology to properly identify the dynamic characteristics of gonadal development process. The study was conducted during March 2018 to February 2019 and a total of 240 oysters were taken from the Moheskhali Channel, Cox's Bazar. The collected samples were analyzed for total length, total weight, shell length and width, gonad weight and wet tissue weight. Length-Weight relationships showed negative allometric growth (b<3) GSI (gonadosomatic index) and histological analysis were done to determine the reproductive cycle. GSI value was found to be generally higher in female than male. The percentage of the male was 30% where the female was 70%. The study confirmed that the spawning of Crassostrea sp. occurred twice during one year study from March 2018 to February 2019. In case of males, two peaks were reported during June and November, whereas, for females, July and December indicated as peak mature stage. The finding of this study would be beneficial for managing naturally occurring oyster stocks and developing future aquaculture aspects in the coastal belt of Bangladesh
Growth and biochemical profiling of indoor nursery cultured Gracilaria sp. under different salinity conditions
(Faculty of Fisheries Chittagong Veterinary and Animal Sciences University Chittagong-4225, Bangladesh, 2025-12) b, Nusrat
In Bangladesh, seasonal salinity variability and seed limitations constrain open-water cultivation of Gracilaria sp., while indoor land-based nursery systems can be a controlled, year-round solution for sustainable year-round source of quality seedlings to increase large-scale cultivation, which enhances food security, meet nutritional demands, and generates income for coastal communities. This study evaluated the feasibility of indoor nursery culture of Gracilaria sp. by examining salinity-driven effects on growth performance and biochemical composition. Six nutrient media (Provasoli’s Enriched Seawater (PES), Von Stosch (VS), and Bosfoliar® Aktiv (BF), PES+VS, PES+BF, and VS+BF) at six concentrations (1.0–3.5 mL/L) were tested to identify the most effective medium which was 2.5mL/L PES+VS. The optimal medium (PES+VS) and dose (2.5mL/L) were subsequently evaluated under six salinity levels (5, 10, 15, 20, 25 and 30 ppt) using a 12:12 h light–dark photoperiod. Growth performance, biochemical composition, antioxidant activity, anthocyanin content, flavonoid activity, functional groups (FTIR), mineral content, and phytochemical profiles (GC–MS) were analysed. Salinity significantly influenced growth, biochemical traits, mineral accumulation, and phytochemical composition of Gracilaria sp. under indoor nursery conditions (p < 0.001). In the aquarium system, SGR and DGR increased from (3.12 ± 0.09) % day⁻¹ and (3.17 ± 0.1) % day⁻¹ at 5 ppt to maxima of (4.44 ± 0.16) % day⁻¹ and (4.54 ± 0.17) % day⁻¹ at 30 ppt, while biomass more than doubled (3.68 ± 0.22) g L⁻¹ to (7.57 ± 0.65) g L⁻¹. Tank culture showed similar trends, with peak biomass at 30 ppt (65.67 ± 3.06 g tank⁻¹). Antioxidant capacity remained stable at 5–20 ppt (~2.1 mg 100 g⁻¹) but declined sharply at ≥25 ppt, whereas flavonoid content peaked at moderate salinity (212.32 ± 6.01) mg 100 g⁻¹ at 10 ppt. Anthocyanin content was highest under low salinity (61.12 ± 0.22 mg 100 g⁻¹ at 5 ppt) and decreased with increasing salinity. FTIR analysis confirmed the consistent presence of polysaccharides, proteins, phenolic hydroxyls, alkenes, and halogenated compounds across treatments, with stronger hydrogen-bonded OH features at higher salinities. Thirteen essential minerals and four heavy metals were detected, with iron (up to 1006.50 ± 26.16 mg kg⁻¹) and lead (253.10 ± 9.76 mg kg⁻¹) showing significant enrichment at 30 ppt. GC–MS profiling identified 62 phytochemicals, with nitrogenous metabolites (40.32%) dominating and higher salinity favouring sulphur-containing, heterocyclic nitrogen, and terpenoid compounds. Overall, optimized indoor nursing of Gracilaria sp. offers a viable year-round seed supply strategy to extend farming cycles and promote sustainable seaweed mari-culture in Bangladesh.
HABITAT SUITABILITY MAPPING FOR DIFFERENT CULTURE SYSTEMS OF SEAWEED ALONG THE ENTIRE COASTAL AND MARINE TERRITORY OF BANGLADESH: GENERALIZED ADDITIVE MODELLING FOR SPATIAL PREDICTION
(Chattogram Veterinary & Animal Sciences University, Khulshi,Chattogram, 2023-08) Tasnim, Rahanuma
Seaweeds are shallow-water, photosynthetic marine macroalgae that have economic value in the food, cosmetics, pharmaceutical, and biofuel/bioplastics industries as well as play a significant ecological role in providing food and habitat for organisms. Although seaweed cultivation is well-advanced in many Asian nations, Bangladesh's seaweed sector is still in its infancy due to multi-dimensional technological, social, and environmental challenges, including a lack of a site suitability map along its entire coastal and marine territorial area. Therefore, we used the Generalized Additive Model (GAM) to develop habitat suitability mapping for different farming systems of seaweeds by using the in-situ production data and associated environmental factors of 180 culture plots of four species (Gracilaria sp., Enteromorpha intestinalis, Ulva lactuca, and Hypnea musciformis) at five culture sites. Besides in situ measurement data, satellite observations and model simulations were also used to gather the necessary data. The GAM analysis revealed that seven explanatory variables jointly explained 78%, 76%, and 79% of the variability in seaweed data from off-bottom long-line, off-bottom net, and floating long-line culture systems, respectively. The model also discovered that TSS is the primary driver for the off-bottom net culture systems and floating long-line system, while salinity is the major driver for the off bottom long-line culture system. The predicted habitat suitability mapping displayed that the predicted suitable areas (50-100%) for floating long-line culture systems are significantly larger (1850 km2 ) than off-bottom long-line and off-bottom net culture systems (380 km2 ). The highly suitable areas (>75% probability) for off-bottom long line and off-bottom net culture systems are restricted to only the southeast coast, more specifically for the sandy bottom areas of the Moheshkhali channel and surrounding areas. The floating long-line culture system is found to be the most suitable for seaweed farming along the entire coast (except Meghna and adjacent estuaries of the central region) of Bangladesh. Since Bangladesh is keen to increase the commercial cultivation of seaweed, this study may provide a crucial tool for achieving the blue economy goal by providing information on habitat suitability maps along the entire coastal and marine territory areas of the country.
Heavy M etal a nd M icrobial C learance of R aft cultivated G reen M ussels Perna viridis from T he S outheast C oast of T he Bay of Bengal: Salinity and S ize D riven D epuration S trategies for S eafood S afety
(Faculty of Fisheries Chittagong Veterinary and Animal Sciences University Chittagong-4225, Bangladesh, 2025-12) Jahan, Sabrina
Maintaining the microbial and chemical safety of tropical bivalves is diff icult beca use estuarine environments are often heavily contaminated and post harvest purification processes are not yet fully understood. This study offers the first detailed assessm ent of depuration performance in the green mussel Perna viridis ) from Ban gladesh, f ocusing on the roles of salinity, depuration duration, and mussel size in reducing microbial contamination and heavy metal loads. Depuration experiments were carried out fo r 72 hours using a static fill and drain system with UV sterilized, filter ed seawate r at salinities ranging from 15 to 30 ppt and across three size categories (small, medium, and large). Pathogenic bacteria were identified and quantified through selective culture methods followed by PCR confirmation, while ten trace metals (Cr, Mn, Fe, Ni , Cu, Zn, As, Se, Hg, Pb) were analyzed using Energy Dispersive X ray Fluorescence (EDXRF). Statistical analysis using generalized linear mixed effects models demonstrated that depuration time (p < 0.001) and its interaction with salinity signifi cantly aff ected microbial reduction. Complete removal of Salmonella Shigella Escherichia coli , and Vibrio cholerae was achieved within 48 72 hours at salinities of 25 ppt or higher . Larger mussels showed more efficient microbial clearance, likely due to greater fi ltration efficiency. The removal of heavy metals varied among elements, with notable decreases observed for Fe (43.2%), Cu (43.1%), Zn (33.0%), Pb (50.4%), Cr (56.6%), and Hg (41.0%). In contrast, Ni, As, and Se remained largely unchanged, possib ly due to strong binding within tissues and limited biological regulation. Although total arsenic levels slightly exceeded recommended safety limits, concentrations of most metals de clined to well below international standards. Overall, depuration for 72 h ours at sa linities between 25 and 30 ppt effectively improves both microbial and chemical safety of P. viridis , establishing a practical post harvest depuration strategy for shellfis h harvested from tropical estuaries.
i Morphometric Variation of Hilsha Shad (Tenualosa ilisha) from Different Aquatic Population of Bangladesh
(Chattogram Veterinary & Animal Sciences University, 2019-06) Barun Kanti Roy, Barun Kanti
The morphometric character plays an important role in management of Hilsha shad in the aquatic habitat of Bangladesh. Fish samples were collected from 6 regions as Kuakata (Sea), Meghna Estuary (ME), Meghna River (MR), Lower Padma River (LPR), Upper Padma River (UPR), Upper Jamuna River (UJR) of Bangladesh. Landmark-based morphometric characters were examined to evaluate the population status and variation among these six regions. The observed characters suggest that there are morphologic differences among the Hilsha fish due to their geographical distribution, availability of food, difference in various water quality parameters, and also for their variation in habitats. The discriminant functions analysis (DFA) showed an overlapped in all the stocks of T. ilisha. Discriminant functions 1, 2, 3, 4 and 5 accounted for 47.3%, 24.6%, 12.7%, 9.1% and 6.3% of the variation which indicates variation among the stocks. The principal component 1 to 5 accounted for 27.16%, 20.08%, 13.17%, 8.136% and 6.616% of variation. Wilk’s Lambda test also indicates highly significant characteristics among stock. The discriminant function analysis showed that 93.05% original grouped populations correctly classify their populations whereas in the cross-validation test exhibited 86.23% correctly classify their populations. Discriminant function scores of sample centroids; MR was isolated in truss distance and combination of all morphometric characters. The Biplot analysis showed that the maximum diversified populations were UPR, Sea and MR and much variation has seen in HL and D3-9 for morphometric and truss distances. For the first and second principal component maximum contribution in variance were in D2-9, D3-9 and HL. Dendogram analysis also displayed that the individual Hilsha population of ME was the greater homogeneity with LPR and UJR and UPR and MR showed the higher heterogeneity. In future this research finding will be help policy makers to initiate future policy and researchers for the management and conservation of Hilsha population. Nevertheless this research requires further effort in particular, the integration of molecular methods which may help to realize on the taxonomy of Hilsha.
Influence of Depth and Site-specific Ecological Factor on Shell Morphometrics and Coloration in Green Mussels (Perna viridis)
(Faculty of Fisheries Chittagong Veterinary and Animal Sciences University Chittagong-4225, Bangladesh, 2025-08) Fatema Eti, Kanij
The green mussel (Perna viridis) is a commercially valuable bivalve with strong aquaculture potential in Bangladesh. This study examined how water depth and site-specific ecological factors influence shell morphometrics and coloration in P. viridis. A total of 450 mussels were cultured at three depths (0.5 m, 1.0 m, and 1.5 m) across three coastal sites Khurushkul, Moheshkhali, and Chowfaldandi. Monthly monitoring of water quality was conducted throughout the study from October 2024 to March 2025. Shell shape and size variations were assessed using geometric morphometric techniques, while shell coloration was analyzed through RGB, HSV, and CIELAB color models. The results revealed significant differences in shell morphology and pigmentation across both site and depth. Mussels from Chowfaldandi displayed broader shells, while those from Khurushkul had a more streamlined form, reflecting local water dynamics. Deeper-dwelling mussels tended to develop rounder, more inflated shells, possibly as an adaptation to calmer, low-light environments. Coloration also varied notably: darker green pigmentation was observed in mussels from shallow depths and from Moheshkhali, likely associated with higher chlorophyll a concentrations and clearer water. In contrast, mussels from Chowfaldandi showed paler shells, potentially due to reduced light penetration and limited food supply. These findings demonstrate how environmental conditions shape key shell traits in P. viridis, offering insights for site and depth selection to enhance growth and shell quality in aquaculture. Shell morphology and pigmentation serve as valuable indicators for assessing habitat suitability and environmental quality.
LAND-SEA INTERACTIONS IN THE FRAMEWORK OF MARITIME SPATIAL PLANNING: COX’S BAZAR COAST, BANGLADESH
(Chattogram Veterinary and Animal Sciences University Chattogram-4225, Bangladesh, 2021-04) Nazmul Hasan Forhad, Md.
An effective maritime spatial planning cannot be achieved and prepared without proper examining the uses and activities between the land and sea. Land-Sea Interaction (LSI) through marine spatial planning framework provides clear concept about inter management conflicts among the present uses and activities and most possible recommendation for minimizing conflicts which helps to make a balance between the ecological and economical status. This research was carried out in three major islands of southeastern Bangladesh coast of named Kutubdia, Moheskhali, and Saint Martin in Cox’s Bazar district during 2019-2020. This study is very essential for significant to determine the elevation level of these regions and take necessary steps in future to protect and development those regions and explore the blue economy in Bangladesh.Using the Suttle Radar Topography Mission (SRTM) satellite data with a 30 m resolution Digital Elevation Model (DEM) processing procedure was performed for understanding the contour profile to make a decision about the elevation height of these regions with the help of software QGIS 3.6.1, ArcMap 10.5 and ArcView 10.6. There were about 225 interaction issues found between the coastal land uses and maritime spatial uses through matrix analysis whereas land-sea interactions were characterized of which 79 without conflicts,61 weak conflicts, 60 strong conflicts interaction were found. The maximum elevation was 14 m, 75 m, and 28 m which covered approximately 0.36, 0.2, and 0.004 area of Saint Martin, Moheshkhali, and Kutubdia, respectively. To enhance sustainable uses and activities, conflict should be reduced through pollution minimizing, well maritime spatial planning, and maintenance of existing laws and regulations.
MARKETING CHANNEL AND VALUE CHAIN ANALYSIS OF BOMBAY DUCK (Harpadon nehereus) AND SEA BASS (Lates calcarifer) IN CHATTOGRAM AREA OF BANGLADESH
(Chattogram Veterinary and Animal Sciences University Chattogram-4225, Bangladesh, 2021-04) Mohammed Abdulah, Siam
Fishes are a highly perishable food commodity that requires rapid and smooth supply to the consumers. For the commercially important fishes, it is necessary to make the fishes to be supplied, ensuring good quality, to the consumers at the right time and right place. To achieve these conditions, a well-structured marketing system is required for each fish species. The present study was conducted to investigate the marketing channel and value chain of two commercially important marine fish species in the Chattogram area, Bangladesh. The studied species were Bombay duck, Harpodon nehereus and Sea bass, Lates calcarifer. A total of three types of markets were investigated in the present study which were primary, secondary, and retail markets. For this investigation, a total number of 120 people, fishermen and intermediaries, were interviewed. In the case of Bombay duck, 4 intermediaries were found to be involved in the marketing chain whereas, for Sea bass, 5 intermediaries were found. It is believed that this intermediary group makes a huge profit which makes the prices of fishes to become very high in the final consumer market. The marketing margin for Bombay duck and Sea bass were 38% and 35%, respectively. Fishermen share in consumer purchase price were 86%, 73% and 62% in case of Bombay duck, and 87%, 75% and 65% in the case of Sea bass in primary, secondary and retail market, respectively. Poor transport facilities and a huge number of intermediaries in the marketing channels were the main problems of the marine fish marketing channel. Government intervention in the marketing channel of those marine species is necessary for sustainable and economic fish marketing systems.