http://localhost:8080/xmlui/handle/123456789/40 2026-04-14T18:44:11Z 2026-04-14T18:44:11Z Sumon, Md. Afsar Ahmed http://localhost:8080/xmlui/handle/123456789/464 2025-05-28T05:12:11Z 2015-12-01T00:00:00Z

EFFECTS OF HORMONE ON GONADAL DEVELOPMENT OF Sperata aor Sumon, Md. Afsar Ahmed Two experiments were conducted to develop suitable artificial breeding tanks and breeding techniques of a threatened catfish, Sperata aor for a period of seven (7) months from May to November, 2015. The first experiment was conducted in cemented tanks with 3 different treatments viz. cemented floor only, cemented floor with 6-inch muddy bottom and cemented floor with 6-inch sandy bottom to determine their survivality in artificial condition. Each treatment was done in two tanks with same condition. The higher survival rate was observed 93.75% in cemented tank with sandy bottom followed by 25% in cement tank with muddy bottom and 6.25% in cemented tank only. Then cemented tank with sandy bottom condition was selected as breeding tank. In second experiment, two inducing agents viz. Flash hormone ((Synthetic gonadotropin releasing hormone analog (0.002%), Domoperidin (0.998%) and Prepelin glycol (99%)) and PG (Pituitary Gland) extracts were trialed for three different treatments with three replications for artificial breeding. To observe the effective dose for induced breeding, the females were first injected with Flash at the rate of 0.5 (T1), 1.0 (T2), and 1.5 (T3) ml/kg body wt. while the second doses were performed with Flash at the rate of 1.0 (T1),1.5 (T2), and 2.0 (T3), ml/kg body wt. after 6 h from the first dose. On the other hand, the males were administered a single dose of 1 ml Flash /kg body wt. at the time of second dose of the female. Consequently, the females were first injected at the rate of 1.0 (T1), 1.5 (T2), and 2.0 (T3) mg PG/kg body wt. while the second doses were performed with PG at the rate of 1.5 (T1),2.0 (T2), and 2.5 (T3), mg/kg body wt. after 6 hrs. from the first dose. Instead, the males were administered a single dose of 2 mg PG /kg body wt. at the time of second dose of the female. None of the trialed fishes released any eggs nor do any sperm by 72 hrs. after injection with different doses. Then the injected brood fishes were sacrificed to know the effectiveness of two different hormones. Histological study of gonad of S. aor indicated the presence of fully maturation stages of both male and female treated with Flash at T2 treatment. It was full development stages in both ovaries and testis found in Flash hormone at T2. These findings indicated that Flash hormone seems to be highly effective in gonadal maturation. Even though treated S. aor with Flash hormone did not response to release eggs and sperms but it is obvious that this hormone might be used in effectively to maximize the ovulation of S. aor in hatchery.

2015-12-01T00:00:00Z DAS, SUBRATA KUMAR http://localhost:8080/xmlui/handle/123456789/463 2025-05-25T05:35:04Z 2015-12-01T00:00:00Z

DIVERSITY AND HABITAT ECOLOGY OF INDIGENOUS FISH SPECIES IN RATARGUL SWAMP FOREST SYLHET BANGLADESH DAS, SUBRATA KUMAR Ratargul swamp forest is only the freshwater swamp forest of Bangladesh which supports diverse fisheries communities compared to others. The present study was conducted from April to October 2015 to assess the status of indigenous fish species of Ratargul swamp forest along with relevant hydrological and ecological aspects. A total 62 fish species comprising 28 threatened species were recorded from the study area. Cypriniformes (37.46%) was the most dominant order followed by Siluriformes (35.123%), Perciformes (19.456%), Synbranchiformes (3.298%), Clupeiformes (2.282%), Beloniformes (1.161%), Osteoglossiformes (0.725%), Tetraodontiformes (0.462%) and Anguiliformes (0.026%). Among the identified fish species 19.98% was recorded as threatened according to IUCN (International Union for Conservation of Nature). The Mean Shannon-Wiener diversity index, Margalef richness index, Pielou’s evenness index and Simpson dominance index were found to be 3.690±0.191, 9.497± 1.314, 0.971±0.003 and 0.982±0.003, respectively. In case of SIMPER (Similarity Percentages) analysis the highest number of similar species was found during July to August and the lowest during April to October. At the similarity of 76.9%, four groups were attained where June, July, August and September showed in a cluster while April, October and May showed separate clusters. Non-metric Multidimensional scaling shows 60% similarity for all months. On the other hand, 70% similarity observed among all the months except April. Environmental parameters such as photoperiod, rainfall, relative humidity, temperature, transparency, dissolved oxygen, p , ammonia and nitrite were determined and found in acceptable limit for fisheries communities. Diversity of plankton assemblage were assessed and a total of 34 planktons belonging to Chlorophyceae (10 taxa), Bacillariophyceae (4 taxa), Cyanophyaceae (6 taxa), Euglenophyceae (2 taxa), Rotifer (4 taxa), Cladocera (5 taxa), Copepods (2 taxa) and Protozoans (2 taxa). A total of 8 major groups of benthos were identified including Oligichaetes, Polychaetes, Gastropods, Bivalvia, Copepods, Isopods, Crab and Prawn larvae. A total of 20 different species were identified which belongs to Emergent (15 taxa), Floating (3 taxa) and Submerged (2 taxa). It may be concluded that Ratargul swamp forest is enriched with fish biodiversity having 28 threatened fish species of Bangladesh. H

2015-12-01T00:00:00Z SINHA, MANISH http://localhost:8080/xmlui/handle/123456789/462 2025-05-25T05:24:44Z 2015-12-01T00:00:00Z

POSSIBILITIES OF NATURAL SPAWNING GROUND OF CARP SPECIES AT SURMA AND KUSHIARA RIVER IN SYLHET SINHA, MANISH The study was conducted to assess the possibilities of natural spawning ground of carp fishes in Surma and Kushiara river for a period of four months during April to July 2015. Four locations were selected for this study to explore the existence of spawning ground and availability of carp spawn in the Sylhet haor basin. The sampling points were Hetimganj point (Surma river), Bhadeswar point (Kushiara river), Monumukh point (Kushiara river) and Atgram point (Surma river). The research was carried out by setting up two Savar nets at each sampling points of river site for the collection of fish seed sample. The sampling net was observed four times in a day at six hours interval and fish seed samples were collected. The collected samples were transferred and stocked immediately in a small pond (1 decimal) at the Fish Seed Multiplication Farm (FSMF), Golapganj. The collected samples were reared for a period of 15 days for species identification. Water quality parameters were observed monthly during the study period. A good catch of carp fish seeds were observed in Hetimganj point compared to other three points. About 3105 gm of carp fish seed was collected from this point. Spawn fishing intensity was 186.56 gm/day/net in new moon and 20 gm/day/net in full moon at Hetimganj point. The water quality parameters of the four selected sampling sites were found in the suitable range and no significant difference of the parameters among the sampling sites. It is revealed that the availability of carp fish seed at Hetimganj point manifested the natural spawning ground in Surma River. The results indicate the possibilities of spawning ground of carp species in the river of greater Sylhet region. Therefore, a further large scale study is necessary to confirm the existence of natural spawning ground of Indian Major Carp in this region.

2015-12-01T00:00:00Z KARIM, MD. RASHIDUL http://localhost:8080/xmlui/handle/123456789/310 2025-02-11T09:31:18Z 2014-12-01T00:00:00Z

CARP BIODIVERSITY STATUS ON HALDA RIVER KARIM, MD. RASHIDUL The Halda River of Bangladesh has immense importance as it is the only natural spawning ground of Indian major carp species. The study was conducted for a period of 12 months from July 2013 to June 2014 in Halda river at Garduara point in Chittagong districts of Bangladesh. Garduara point at the mouth of Boalia and Chengkhali tributary of Halda river was selected by taking into consideration that the site will give shelter a large number of fishes because it is the conjoined area where the Halda river meets with Boalia and Cheng khali tributary. Sampling was done during full and new moon for two successive days in each month. A total of 53 fish species belonging to 18 families were identified. But the concerning fact was carp species of the Halda river at Garduara point and 15 species were identified. Among them 5 were Not Threatened (NT), 2 Vulnerable (VU), 5 Endangered (EN) and 3 Exotic (EX). The Shannon-Weaver diversity index (H') ranged from 1.72 (in July) to 2.13 (in January), tiniest Margalef richness index was witnessed in November/December (1.05), while utmost value observed in July (1.22), peak mean evenness value (0.79) was encountered in January and bottommost (0.63) in July and the uppermost mean dominance value (0.85) was observed in January and lowest (0.7) in July. The Shannon-Weaver and Pielou’s index was found to be significant among the seasons at 0.05% significance level. But the Margalef and Simpson index was not significant among the seasons. The carp species of Halda river at Garduara point found to be not evenly distributed. Among the Indian major carps encountered in the study area, Catla catla found to be comprised 4.78% of the total biomass followed by Cirrhinus cirrhosus 5.74%, Labeo rohita 4.95% and Labeo calbasu 0.66%. The Halda river is used as breeding, nursing and feeding ground by many fishes. So the proper management of this river is suggested.

2014-12-01T00:00:00Z