scholarly journals Ecology of the Critically Endangered Singidia Tilapia (Teleostei: Cichlidae: Oreochromis esculentus) of lake Kayanja, Uganda and its conservation implications

2020 ◽  
Vol 12 (10) ◽  
pp. 16251-16256 ◽  
Author(s):  
Richard Olwa ◽  
Herbert Nakiyende ◽  
Elias Muhumuza ◽  
Samuel Bassa ◽  
Anthony Taabu-Munyaho ◽  
...  
Keyword(s):  
Fish Species ◽  
Nile Tilapia ◽  
Fish Farming ◽  
Critically Endangered ◽  
Nile Perch ◽  
Introduced Fish ◽  
Plant Materials ◽  
Blue Green Algae ◽  
Conservation Implications ◽  
In The Wild

Singidia Tilapia Oreochromis esculentus is a Critically Endangered native tilapia fish species endemic to lakes Victoria and Kyoga basins of East Africa, however, it disappeared from these main lakes due to overfishing, environmental degradation and predation by the introduced Nile Perch Lates niloticus.  Remnant populations of this fish species is now restricted to satellite lakes including Lake Kayanja of the Victoria basin.  This study provides updated information about the population abundance, critical habitat, threats and diet of Singidia Tilapia to inform conservation decisions to revive its populations in the wild.  Fish data collection and mapping of nursery and breeding habitats of Singidia Tilapia on Lake Kayanja was conducted between February 2016 and October 2017.  In all the areas mapped and sampled, Singidia Tilapia (with a size range of 11–27 cm TL) was the most abundant (43%) relative to exotic Nile Tilapia Oreochromis niloticus (21%) and Redbelly Tilapia Coptodon zillii (36%).  The emergence of introduced (exotic) tilapias like Nile Tilapia recorded in this study could be attributed to cage fish farming being carried out in this Lake.  The diet of Oreochromis esculentus consisted mainly of detritus (60.8 %), plant materials (27.7%) and blue-green algae (5.5%).  Destruction of critical habitats and presence of introduced fish species were noted as the major threats to this fish and its habitats.  The generated information could contribute to guiding stakeholders to undertake appropriate actions to conserve this threatened fish species and its habitats.

scholarly journals The impacts of introduced species on lake ecosystems: A case of Lakes Victoria and Naivasha, Kenya.

2019 ◽  
Author(s):  
Nicholas Outa ◽  
Dan Mungai ◽  
James Last A. Keyombe
Keyword(s):  
Introduced Species ◽  
Fish Species ◽  
Largemouth Bass ◽  
Water Hyacinth ◽  
Native Species ◽  
Nile Tilapia ◽  
Lake Victoria ◽  
Nile Perch ◽  
Lake Naivasha ◽  
Lake Ecosystems

Fish and other aquatic organisms have been introduced into new environments for various reasons. Provision of sports fishery, supplemental to stocks, to fill empty niches, control weeds, and disease vectors and even create a commercial fishery are some of the reasons why fish species are introduced into new ecosystems. Lake Victoria and Lake Naivasha in Kenya have seen several introductions as discussed in this paper. In Lake Victoria for example, some of the species introduced include Nile perch, Lates niloticus, Nile tilapia, Oreochromis niloticus, Tilapia zilii, and Oreochromis esclentus among others. The most successful introductions have been that of the Nile perch, Nile tilapia and water hyacinth. Lake Naivasha too has witnessed a number of introductions into its fisheries too. Some of the successful introductions into the lake are those of the Common carp, Cyprinus carpio, the largemouth bass, Micropterus salmoides, the Nile tilapia, O. niloticus and Louisiana red swamp crayfish, Procambarus clarkia. Aside from the fish species mentioned, some invasive plant species have also been introduced into these two lake ecosystems. Of notable success and impacts have been the water hyacinth, Eichhornia crassipes and Nile cabbage, Pistia stratiotes. These introductions have had both negative and positive impacts on the fisheries and the ecology of the two lakes. Some of the impacts have been predation on the native species by the introduced species like in the case of Nile perch and largemouth bass in Lake Victoria and Naivasha respectively. Competition for resources and hybridization with the native species has also been witnessed in the case of the tilapiines in the two lakes with undesirable results. Blockage of navigation routes caused by the invasive plants has been a major problem in the two lakes sometimes leading to massive postharvest losses by the fishermen. On the other hand, some introduced species have led to an increase in fish landings as well as utilization of the niches that were initially vacant within these ecosystems. It can therefore be concluded that introduced species often have more negative effects on the native species and therefore such introductions should be based on sound scientific research in order to minimize their effects within the new environments.

scholarly journals Socio-Economic Drivers of Fish Species Consumption Preferences in Kenya’s Urban Informal Food System

2021 ◽  
Vol 13 (9) ◽  
pp. 5278
Author(s):  
Oscar Ingasia Ayuya ◽  
Katrine Soma ◽  
Benson Obwanga
Keyword(s):  
Fish Species ◽  
Nile Tilapia ◽  
Food System ◽  
Lake Victoria ◽  
Informal Settlement ◽  
Clarias Gariepinus ◽  
Future Market ◽  
African Catfish ◽  
Nile Perch ◽  
Haplochromine Cichlids

In an effort to contribute to resilient food and nutritional security in urban slums, a food system approach was applied to understand the key socio-economic factors driving fish species consumption in Kibera, the largest informal settlement in Africa located in Nairobi, Kenya. Data were collected from 385 randomly selected households using a structured questionnaire. A multivariate probit model was applied to estimate the relationship between the variables in order to determine the socio-economic drivers of preferences for different fish species. The results indicated that Lake Victoria sardine (Rastrineobola argentea) had the highest preference (73%) among the respondents, followed by Nile tilapia (Oreochromis niloticus) (70%) and Nile perch (Lates niloticus) (23%), respectively, with other fish species at 12%, including African catfish, marbled lungfish, common carp, fulu and tuna (Clarias gariepinus, Protopterus aethiopicus, Cyprinus carpio, Haplochromine cichlids and Thunnus sp., respectively). Large household size showed an increase in preference for the Lake Victoria sardine, while higher income influenced preference for Nile tilapia and Nile perch positively, implying that when more income is available, Nile tilapia is the preferred fish over other fish species. Increased fish prices positively influenced preference for Nile tilapia, which is explained by the willingness to pay extra for quality and origin, for instance, to avoid the cheaply cultivated Chinese fish. In the case of the Lake Victoria sardine, lower prices positively affected the preferences. Religious and cultural practices and beliefs influenced preference for species and consumption of fish. Residents who migrated from western Kenya had a higher preference for the Lake Victoria sardine, while residents born and raised in Kibera had a higher preference for Nile tilapia. Neighbourhood effects reduced the preference for consuming Nile perch. These findings provide insights into future market opportunities for specific target groups. For instance, given that small-sized fish like the Lake Victoria sardine is highly demanded, in order to increase resiliency in food and nutrition security, small-sized cheap Nile tilapia will have a large potential in the future, with ever higher demand specifically from the residents born and raised in Kibera.

Jenis-Jenis Ikan Indonesia yang Kritis dan Terancam Punah

2021 ◽  
Vol 10 (1) ◽  
pp. 53-59
Author(s):  
Andri Iskandar ◽  
M Muslim ◽  
Andri Hendriana ◽  
W Wiyoto
Keyword(s):  
Foreign Language ◽  
Fish Species ◽  
Critically Endangered ◽  
Literature Study ◽  
Endangered Fish ◽  
The Public ◽  
Critically Endangered Species ◽  
The Status ◽  
In The Wild ◽  
Rule Out

ABSTRACTIndonesia has a high diversity of fish species. Some fish species are critical and endangered. Information on Indonesian native and endemic fish species needs to be disseminated to the public. Such information is available in various sources and is generally in a foreign language. Therefore, the purpose of this research is to inventory and distribute information about several species of fish native to Indonesian public waters that need special attention because they are endangered and critically endangered. Species of fish, especially species that have been critically endangered, do not rule out turning into extinct in the wild (extinct in the wild). The decline in the status of the above from vulnerable (vulnerable) to endangered (endangered) and critical (critically endangered) or even become extinct in the wild (extinct in the wild) caused by various factors, including the existence of fisheries activities that tend to exploit natural resources without offset by conservation activities and increasing pollution of water conditions. With this information, it is expected to anticipate the extinction of these species. The study was conducted using the literature study method. Based on the search results, there were 22 endangered fish species and 15 critically endangered fish species. The Indonesian government has designated 20 protected fish species. Domestication of endangered and critical species is urgent to do, to prevent the extinction of these species. ABSTRAKIndonesia memiliki keanekaragaman spesies ikan yang tinggi. Beberapa spesies ikan sudah kritis dan terancam punah. Informasi jenis-jenis ikan asli dan endemik Indonesia perlu diserbarluaskan ke masyarakat. Informasi tersebut terdapat diberbagai sumber dan umumnya berbahasa asing. Oleh karena itu, tujuan penelitian ini adalah untuk menginventarisasi dan mendistribusikan informasi tentang beberapa spesies ikan asli penghuni perairan umum Indonesia yang perlu mendapat perhatian khusus karena berstatus terancam punah (endangered) dan kritis (critically endangered). Spesies-spesies ikan tersebut terutama spesies yang sudah berstatus kritis terancam punah, tidak menutup kemungkinan berubah menjadi punah di alam liar (extinct in the wild). Terjadinya penurunan status diatas dari rentan (vulnerable) ke terancam punah (endangered) dan kritis (critically endangered) atau bahkan menjadi punah di alam liar (extinctin the wild) disebabkan oleh berbagai macam faktor, diantaranya adanya kegiatan perikanan yang cenderung mengeksploitasi sumber daya alam tanpa diimbangi dengan kegiatan konservasi serta meningkatnya pencemaran terhadap kondisi perairan. Dengan adanya informasi ini diharapkan dapat melakukan antisipasi pencegahan kepunahan spesies tersebut. Penelitian dilakukan dengan metode studi literatur. Berdasarkan hasil penelusuran, diperoleh 22 spesies ikan yang terancam punah (endangered) dan 15 spesies ikan yang sudah kritis (critically endangered). Pemerintah Indonesia telah menetapkan 20 spesies ikan yang dilindungi. Domestikasi spesies-spesies yang terancam punah dan kritis sudah mendesak untuk dilakukan, untuk mencegah kepunahan spesies tersebut. 

Detection of critically endangered marine species with dwindling populations in the wild using eDNA gives hope for sawfishes

2021 ◽  
Vol 168 (5) ◽  
Author(s):  
Ramón Bonfil ◽  
Paola Palacios-Barreto ◽  
Oscar Uriel Mendoza Vargas ◽  
Melina Ricaño-Soriano ◽  
Píndaro Díaz-Jaimes
Keyword(s):  
Marine Species ◽  
Critically Endangered ◽  
In The Wild

scholarly journals Microsatellite analysis reveals low genetic diversity in managed populations of the critically endangered gharial (Gavialis gangeticus) in India

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Surya Prasad Sharma ◽  
Mirza Ghazanfarullah Ghazi ◽  
Suyash Katdare ◽  
Niladri Dasgupta ◽  
Samrat Mondol ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Indian Subcontinent ◽  
Population Decline ◽  
Mitochondrial Control Region ◽  
Critically Endangered ◽  
Term Survival ◽  
Low Level ◽  
Genetic Status ◽  
In The Wild ◽  
Gavialis Gangeticus

AbstractThe gharial (Gavialis gangeticus) is a critically endangered crocodylian, endemic to the Indian subcontinent. The species has experienced severe population decline during the twentieth century owing to habitat loss, poaching, and mortalities in passive fishing. Its extant populations have largely recovered through translocation programmes initiated in 1975. Understanding the genetic status of these populations is crucial for evaluating the effectiveness of the ongoing conservation efforts. This study assessed the genetic diversity, population structure, and evidence of genetic bottlenecks of the two managed populations inhabiting the Chambal and Girwa Rivers, which hold nearly 80% of the global gharial populations. We used seven polymorphic nuclear microsatellite loci and a 520 bp partial fragment of the mitochondrial control region (CR). The overall mean allelic richness (Ar) was 2.80 ± 0.40, and the observed (Ho) and expected (He) heterozygosities were 0.40 ± 0.05 and 0.39 ± 0.05, respectively. We observed low levels of genetic differentiation between populations (FST = 0.039, P < 0.05; G’ST = 0.058, P < 0.05 Jost’s D = 0.016, P < 0.05). The bottleneck analysis using the M ratio (Chambal = 0.31 ± 0.06; Girwa = 0.41 ± 0.12) suggested the presence of a genetic bottleneck in both populations. The mitochondrial CR also showed a low level of variation, with two haplotypes observed in the Girwa population. This study highlights the low level of genetic diversity in the two largest managed gharial populations in the wild. Hence, it is recommended to assess the genetic status of extant wild and captive gharial populations for planning future translocation programmes to ensure long-term survival in the wild.

Experimental Examination of the Potential for Three Introduced Fish Species to Prey on Tadpoles of the Endangered Booroolong Frog, Litoria booroolongensis

2011 ◽  
Vol 45 (2) ◽  
pp. 181-185 ◽  
Author(s):  
David A. Hunter ◽  
Michael J. Smith ◽  
Michael P. Scroggie ◽  
Dean Gilligan
Keyword(s):  
Fish Species ◽  
Introduced Fish ◽  
Experimental Examination

scholarly journals Monitoring invasive mammalian predator populations sharing habitat with the Critically Endangered Puerto Rican parrot Amazona vittata

Oryx ◽  
2005 ◽  
Vol 40 (1) ◽  
pp. 95-102 ◽  
Author(s):  
Richard Engeman ◽  
Desley Whisson ◽  
Jessica Quinn ◽  
Felipe Cano ◽  
Pedro Quiñones ◽  
...  
Keyword(s):  
Puerto Rican ◽  
Habitat Type ◽  
Critically Endangered ◽  
Mammal Species ◽  
Forest Sites ◽  
The World ◽  
Mammalian Predators ◽  
In The Wild ◽  
Amazona Vittata ◽  
Black Rats

Critically Endangered Puerto Rican parrots Amazona vittata are one of the rarest birds in the world. Several exotic mammal species capable of preying on Puerto Rican parrots cohabit the Caribbean National Forest with the only wild population of these parrots. We used tracking plates, monitoring blocks and trapping to index black rats, small Indian mongooses and feral cats in parrot habitat and in public-use areas in the same habitat type. We had high trap success for black rats at all sites (42% of all sites combined), among the highest reported in the world. Rat response to monitoring (nontoxic bait) blocks was universally high, regardless of ground or tree placement. Mongooses were present at all sites, with a greater proportion of plates tracked within the forest than at public-use sites. Cats were present at all forest sites and one of the public-use sites. Presence of the three species did not appear to be linked to human disturbance. Because only 30–40 Puerto Rican parrots survive in the wild, with as few as three pairs nesting in 2002, we concluded that the abundance and pervasiveness of exotic mammalian predators poses a greater threat to the parrots than has been generally acknowledged. This is evidenced by mammalian predation during recent parrot breeding seasons, including six fledglings taken by mongooses and one nest failure from rats during 2000–2003.

scholarly journals The first unified inventory of non-native fishes of the South Caucasian countries, Armenia, Azerbaijan, and Georgia

2021 ◽  
pp. 32
Author(s):  
Tatia Kuljanishvili ◽  
Levan Mumladze ◽  
Bella Japoshvili ◽  
Namig Mustafayev ◽  
Shaig Ibrahimov ◽  
...  
Keyword(s):  
Black Sea ◽  
Fish Species ◽  
Caspian Sea ◽  
Native Species ◽  
Biological Diversity ◽  
Native Fish ◽  
The Black Sea ◽  
The South ◽  
In The Wild ◽  
Native Fishes

The South Caucasus (SC) region is recognized for its high biological diversity and various endemic animal taxa. The area has experienced many fish introductions over the years, but the overall information about non-native fishes in the three SC countries, Armenia, Azerbaijan, and Georgia did not exist. Although these three countries belong to the Kura River drainage, Caspian Sea basin (only the western half of Georgia drains into the Black Sea), the legislative framework for each country regarding introduction of non-native fish species and their treatment is different and poorly developed. The goal of the present study was to make an initial inventory of non-native fish species in the three SC countries, and summarize the existing knowledge as a basis for future risk assessment models and formulation of regional management policies. Here, we present a unified list of 27 non-native species recorded in the wild in Armenia, Azerbaijan, and Georgia. Among these 27 species, eight were translocated from the Black Sea basin to the Caspian Sea basin. Out of these 27 non-native fishes, 15 species have become established (three of them being considered invasive) and six fish species could not survive in the wild.

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