Study of Fish Biodiversity of Nijhum Dwip, Noakhali, Bangladesh

Aims: The investigation was concerned to assess the diversity status of fish in Nijhum Dwip, Hatiya, Noakhali with its management actions. Place and Duration of Study: Nijhum dwip declared as marine protected area is blessed with unique ecosystem with holding numerous flora and fauna species diversity. Data and fish sample were collected from February, 2019 to July 2019 for a period of five month. Methodology: The current research was grounded on visiting fish landing center and fish market, on spot date collection, interview of the fishermen and the fish traders, sample collection and secondary data collection. Results: In investigation, 39 species in 22 families were witnessed. The maximum numbers of fish species (8) were observed from the family Cyprinidae. From the survey, 4 species were endangered (EN), 5 species were vulnerable (VU), 2 species were near threatened (NT), 22 species were least concern (LC) categories, 6 species were not threatened (NO) which is grounded on IUCN (2015) list of threatened fishes of Bangladesh. The marine fish and freshwater fish alignment in the research region were 33% and 67% in turn. Conclusions: The species scarcity or decline is demonstrated by the non-availability and less availability of some of the species in the adjacent area as well as in the country. The policy makers, researchers as well as local people would be able to aware with their existing biodiversity status and also significance of fish fauna of the study area by appropriate evaluation and proper documentation of fish fauna.

Study on the Present Status of Endangered Fishes and Productivity of Teesta River Closest to Barrage Region

This study was conducted to monitor the present condition of endangered fishes and productivity of Teesta river closest to Teesta barrage situated in the Lalmonirhat district of Bangladesh. Water and sediment samples were collected twice in a month during the study period from six different (3 upstream and 3 downstream) sites with three replications for each. Required information about threatened fishes was collected from the sampling region associated fishermen and fish markets. The study disclosed over 50 threatened fish species in Teesta river including several threatened fishes namely Bagarius bagarius, Sisor rabdophorus etc. The commonly available endangered fishes were Macrognathus aculiatus, Mastacembelus armatus, Barilius tileo, Raiamas bola, Botia dario, B. lohachata etc. which are rarely available in nationwide. Planktonic flora and fauna determination revealed that comparatively higher density of plankton (n >11500 per liter) as well as more number of planktonic flora (>21 nos.) and fauna (>9 nos.) were monitored in the early monsoon and monsoon season (April-September) and comparatively lower planktonic density (n<10000 per liter) and less number were found in premonsoon season (January-February). The investigation of benthic fauna showed that the riverine ecosystem near to barrage contained 16 species of macro-benthos from different groups. Lastly, it can be noticed that it is very essential to take all effective necessary actions to provide good productivity and conserve the ichthyo diversity of Teesta river that will help to conserve the commonly available endangered and critically endangered fishes of Teesta river. Res. Agric., Livest. Fish.7(3): 577-589, December 2020

Micralestes eburneensis Daget 1965 (Characiformes: Alestidae), a Near Threatened Fishes of the World

Micralestes eburneensis Daget 1965, an endemic characin fish of Ivory Coast / Liberia is assessed as Near Threatened due to its restricted range. In addition, there is strong fishing pressure, habitat loss and aquatic pollution from clandestine gold mining in the Cavally River bed.Moreover, given the development and intensification of mining activities in the study area, it is to be expected that the population of the endemic species will continue to decline. The strong anthropogenic pressure in this region on the Cavally hydrosystem and its environment must be taken into account for a future update of M. eburneensis conservation status.There is an immediate need for developing protection and management actions for this fish species.

Near Threatened Fishes of the World: Malapterurus teugelsi Norris, 2002 (Siluriformes: Malapteruridae)

Malapterurus teugelsi Norris, 2002, an endemic electric catfishes of the Kogon River Basin in Guinea, is assessed as Near Threatened due to its restricted distribution area, fishing pressure, mining activities, loss of habitats and aquatic pollution. This fish has a high cultural representation in the folklore of the local population. Moreover, in addition to its very limited distribution, very little information exists on its reproductive biology and its food ecology. Therefore, singular care must be paid to it for its conservation.

The Role of Science in The Management of Biodiversity: a Case of Stingrays (Dasyatidae) Research to Provide Basic Data for Aquatic Fauna Conservation in South Sumatra

The study of fish diversity had been reported accross the South Sumatran waters, but the study focus on stingrays (family Dasyatidae) were very limited. In general, many stingrays species face high level of direct exploitation. A recent study to provide valid checklist of stingrays in South Sumatran waters found 14 species: Brevitrygon heterura, Fluvitrygon kittipongi, Fluvitrygon oxyrhyncha, Fluvitrygon signifier, Fluvitrygon sp ‘musi’ 1, Fluvitrygon sp ‘musi’ 2, Himantura undulata, Himantura uarnak, Maculabatis gerrardi, Pateobatis fai, Pateobatis uarnacoides, Pastinachus ater, Telatrygon biasa and Urogymnus polylepis. Following IUCN (The International Union for Conservation of Nature) Red List status 2018, ten species of stingrays are threatened, with four species as Endangered, five species as Vulnerable and one species as Data Deficient. These findings suggest the South Sumatran waters are important habitat for stingrays in Indonesia, and immediate conservation actions plan is needed. In this paper, we demonstrate the role of science in biodiversity management with stingrays (Dasyatidae, an iconic group of rare and threatened fishes) as study case.1.

Can fishways mitigate fragmentation effects on Great Plains fish communities?

Fishways are a common tool for mitigating the effects of habitat fragmentation on fish, but their utility in low-gradient, sand-bed rivers of the Great Plains is not well studied. The Lincoln Street Fishway on the Arkansas River became operational in 2015 and was built specifically to pass small-bodied threatened fishes. We compared current and historical surveys up- and downstream of the barrier to test the effect of the fishway on community structure and conducted tagging experiments to test the ability of fishes to move into and through the fishway. Differences in community structure and species richness between communities up- and downstream of the dam were reduced following construction of the fishway. Surveys within the fishway revealed that 74% of species from the sampled community were using the fishway. Fishes marked with visible implant elastomer downstream of the dam were recaptured in the fishway, qualitatively showing that small-bodied fishes could move into and upstream within the fishway. We further quantified upstream movement for three species of small-bodied minnow tagged with passive integrated transponder tags during manipulations of flows through the fishway. Our results illustrate the potential for fishways to mitigate the effects of habitat fragmentation on fishes in sand-bed rivers.

Threatened Fishes of the World: Orsinogobius Croaticus (Mrakovčić, Kerovec, Mišetić and Schneider, 1996) (Teleostei: Gobiidae)

Orsinogobius croaticus is a freshwater fish with a small and limited distribution range in the Adriatic basin in Croatia and Bosnia-Herzegovina, where it inhabits cold karstic rivers and springs. The main threats to its populations include habitat fragmentation, declining habitat quality and the introduction of alien species. Conservation recommendations are proposed to improve effective habitat preservation and to expand the knowledge about this species.

Threatened Fishes of the World: Telestes Croaticus (Steindachner, 1866) (Cypriniformes: Cyprinidae)

Telestes croaticus is a freshwater fish endemic in Croatia. It is a stygophile species, living above ground but occasionally retreating into subterranean waters. This species is found in the southwest region of Croatia, in the Lika-Jadova and Ričica drainages, in cold and clear waters in lowland habitats with little current, and in springs and associated wetlands. It is protected under Croatian law and was listed by the IUCN Red List as Endangered (EN). It has an extremely limited distribution which makes it vulnerable to different kind of traits such as habitat destruction, water extraction, dam construction, agricultural water pollution and especially the introduction of non-indigenous fish species. Suggested conservation actions for this species are: bans on watercourse regulation, reduction of pollution and eradication of alien fish species. Due to its fast decline in the last 10 years, it is our proposition that T. croaticus should be upgraded to a Critically Endangered species under criterion A2ace A4ace.

Threatened fishes of the world: Coptodon walteri (Thys van den Audenaerde 1968) (Perciformes: Cichlidae)

Coptodon walteri Thys van den Audenaerde 1968, an endemic cichlid of Ivory Coast and Liberia, is assessed as Near Threatened due to fishing pressure and loss of habitats, and aquatic pollution as a result of extensive clandestine gold mining in the bed of the Cavally River. There is an immediate need for developing conservation and management plans for this species.