scholarly journals Population Aspects of Fishes in Geba and Sor Rivers, White Nile System in Ethiopia, East Africa

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Simagegnew Melaku ◽  
Abebe Getahun ◽  
Mulugeta Wakjira

This study was carried out to assess the diversity, condition factor, length-weight relationship, and sex ratio of fishes in Geba and Sor Rivers located in Baro-Akobo Basin, White Nile system within Ethiopia. Fish samples were collected in one wet and one dry season. The length-weight relationships were fitted using power equation for the most abundant species. A total of 348 fish specimens were collected using gillnets and hooks. These were identified into eight species and one Garra sp. representing seven genera and four families. Family Cyprinidae was the most dominant with six species (66.7%). Labeobarbus intermedius, Labeobarbus nedgia, and Labeo cylindricus were the most abundant fish species, respectively, with 60.72%, 16.83%, and 14.66% index of relative importance (IRI). The diversity index was higher for Geba River (H′ = 1.50) than for Sor River (H′ = 1.10). All the three most abundant species had negative allometric growth. Seasonal variations in the mean Fulton condition factor (FCF) were statistically significant for L. cylindricus (p<0.05). There was variation in the sex ratio with the females dominating in all the three most abundant species. Further investigation into the fish diversity, food, feeding, and reproductive behaviors of fish species especially in the tributaries of these rivers and their socioeconomic aspects is recommended.

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Gatriay Tut Deng

Because fishes live in less-accessible habitats, their remarkable diversity is rarely appreciated. The fishery sector is growing rapidly worldwide with the intention of improving the livelihood in developing nations. Therefore, conservation and management of aquatic resources become eminent. Morphometric measurements of fishes are important tools in fish biology and fisheries assessment and conservation. Ethiopia is one of the developing countries with rich water resources. Although there are plenty of water bodies in the country, they are less explored for their ichthyofaunal documentation. Therefore, this study aimed to explore the diversity and some biological aspects of fishes in Lake Maybahr. The fish sample was collected from selected sampling sites using gill nets with varying mesh sizes. Fish identification was done in the field using relevant taxonomic keys. After identification, the total length (TL) and total weight (TW) of the specimens were measured to the nearest 0.1 cm and 0.1 g, respectively. After measurement, the samples were labeled and preserved in a 10% formalin solution. Two fish species were documented in the study area. The length-weight relationships indicated that both species (C. carpio and O. niloticus) exhibited allometric growth during the wet season. But C. carpio demonstrated an isometric growth in the dry season. The diversity index (H’ = 0.69) revealed that fish diversity in the current study is far less than the result reported in the other studies. The evenness index (J’ = 0.99) showed that each species is fairly represented by a number of individuals. The correlation coefficient value of length and weight parameters is statistically significant at a 1% significance level (s, R2 = 0.85). The mean FCF revealed that both fish species are in good health. Further study on local people’s perception, initiating fishing activities, and organizing and providing training to youth is recommended.


2020 ◽  
Vol 13 (13) ◽  
pp. 69-74
Author(s):  
Jash Hang Limbu ◽  
Archana Prasad

The fish samples were collected from October 2017 to June 2018 in Nuwa River from four sampling stations by using cast net, bamboo fish trap and mosquito nets. Environmental parameters: water temperature, dissolved Oxygen (DO), CO2, pH, hardness and water velocity were analyzed during each field visit. Eight fish species were collected in present study. The most copious species were Schizothorax plagiostomus, and Schistura multifaciatus. Shannon-Weiner fish diversity index and species richness recorded were highest at station I and lowest at station III, similarly, evenness index was highest at station I and lowest at station III. The water volume, water depth, and the availability of substrates were found to be major influential factors for the weight and length of the fishes. The redundancy analysis (RDA) portrayed that environmental variables like dissolved oxygen, free- carbon dioxide, and pH were found to be pivotal variables to shape the fish assemblage structure of Nuwa River. The cluster analysis delineated that similarity between fish species subsided as the distance of sites turgid.


2020 ◽  
Vol 01 (01) ◽  
pp. 72
Author(s):  
James Last Keyombe ◽  
◽  
Kevin Obiero ◽  
Edna Waithaka ◽  
Nicholas Outa ◽  
...  

Coptodon zilli and Micropterus salmoides were introduced into Lake Naivasha in 1929 and 1959 respectively. The reasons for the introduction were to boost the fisheries and for recreational fishing respectively. However, the numbers of the two fish species in the lake have been declining over the years. It is therefore necessary to assess various aspects of their growth such as length-weight relationship, condition factor, sex ratio and length at first maturity to inform management and policy making for enhanced recovery and establishment of their populations. Length-weight relationship, condition factor, sex ratio and length at first maturity of the fish were studied from October 2016 to November 2018. A total of 303 fish samples; 193 C. zilli and 110 M. salmoides were studied. Results showed that C. zilli and M. salmoides had an allometry coefficient value of 2.9 and 3.1 and condition factor (K) value of 1.77 and 1.39 respectively. The sex ratios (male: female) of C. zilli and M. salmoides were 1.1:1 and 1.3: 1 respectively. The shortest total length for mature C. zilli and M. salmoides recorded were 12 cm and 26.5 cm while 21.8 cm and 51 cm were for the longest respectively. The fish growth pattern therefore failed to obey the cube law of b=3 thus exhibiting allometric growth. The two fish species were found to be in good condition with K factor above 1. It can therefore be concluded that the fish are generally in a good condition though the early maturity especially for C. zilli could be a sign of pressure either from environmental factors or human induced. Domination of the species by males, although a common feature in African lakes, is a case for concern since it presents uncertainty on the future of the fisheries. Restocking of Lake Naivasha with the two fish species should be considered and proper fishing practices enforced


2020 ◽  
Author(s):  
Cishahayo Laurent ◽  
Edwine Yongo ◽  
Edna Waithaka ◽  
Eunice Mutethya

Oreochromis leucostictus is one of the commercially important tilapiine in Lake Naivasha. Its stock in the lake has declined due to the effect of fishing and pollution. This study investigated on its length-weight relationship, condition factor, sex ratio and maturity. Fish samples (233) were caught using gillnets of mesh-sizes 2-5 inches. Each individual fish was measured (cm) and weighed (g) in the field. The specimens were preserved in ice and transported to the laboratory for analysis of maturity. The mean (±SE) total length and weight for all fish was 21.3±0.3 cm TL and 187.4±8.3 g, respectively. Males 22.3±0.4 cm were significantly larger than females 19.2±0.5 cm. The mean condition factor was 1.06, 0.99 and 1.04 for male, female and combined sexes, respectively. The overall population sex ratio was 2.19:1.0 (male: female) that deviated significantly from 1:1. The slope b of the length-weight relationship was 1.92, 3.07, 2.33 for males, females, and combined sexes, respectively. Length at 50% maturity was estimated at 21.0 cm for females and 26.0 cm for males. Ripe oocytes and testis were found in all fish sizes. Comparisons with earlier studies suggest that the parameters of its growth, condition and maturity vary greatly from the different habitats.


2018 ◽  
Vol 14 (2) ◽  
pp. 137
Author(s):  
Ragil Nur Cahyono ◽  
Agung Budiharjo ◽  
Sugiyarto Sugiyarto

The Cyprinidae fish family is a family of freshwater fish with the largest number of species and its presence is widespread almost all of the world. The main habitat of this family is the river's ecosystem, river damming changing the environmental conditions between the ecosystems before and after the dam's watergate. Such as Colo Dam that dammed Bengawan Solo River that allegedly affects the diversity of species of Cyprinidae fish. So this study was conducted in order to determine the diversity and kinship of the Cyprinidae fish family in the ecosystem before and after the Colo Dam watergate. Sampling was conducted September-October 2017 at Sukoharjo Colo Dam by Purposive sampling method. Identify fish species used Kottelat identification books. The diversity of fish species was calculated by Shannon Wiener's diversity index. The correlation between abiotic factor and fish diversity was analyzed by a regression test. The kinship of the fish was analyzed by the Ntsys cluster method (2.02i). The results showed that the Cyprinidae fish species that live in the Colo Dam ecosystem contain 10 species, the diversity of Cyprinidae fish in the fast-water ecosystem of station I is higher (0,96) then the slow-water ecosystem of station II, III, and IV (0,47; 0,73, and 0,58). Abiotic factors of current velocity affect the level of fish diversity reaches 91%. The Cyprinidae fish kinship rate has a coefficient of resemblance between 60% - 85%, fish with the same genus and many similarities in morphological characters and their behavior is categorized as having a close kinship.


2019 ◽  
Vol 18 (2) ◽  
pp. 87 ◽  
Author(s):  
. Jusmaldi ◽  
Nova Hariani

Biology of the spotted barb Barbodes binotatus (Valenciennes, 1842) in Barambai River, east Kalimantan is unknown. This study aimed to analyses sizes of fish, sex ratio, length-weight relationship and condition factor of the spotted barb. A total of 347 fish samples were collected by several gears in Barambai River from August to October 2017. The results of this research showed that the total length of the fish ranged from 45.67 to 146.01 mm and weight ranged from 1.27-43.34 g. The sex ratio of male and female were 1:1.12. The length-weight equations for males was W = 1x10-5 L3.063, W = 8x10-6L3.108 for females, and W = 9 x 10-6 L3.091 for both sexes. The condition factor (K) for the spotted barb was ranged between 0.826 – 2.214 with mean value of 1.163.  AbstrakBiologi ikan wader bintik dua Barbodes binotatus (Valenciennes, 1842) di Sungai Barambai, Kalimantan Timur belum diketahui. Penelitian ini bertujuan menganalisis ukuran ikan, nisbah kelamin, hubungan panjang bobot, dan faktor kon-disi. Total 347 sampel ikan dikumpulkan dengan menggunakan berbagai alat tangkap di Sungai Barambai dari bulan Agustus sampai Oktober 2017. Hasil penelitian menunjukkan bahwa panjang total ikan berkisar dari 45,67 sampai 146,01 mm dan bobot tubuh berkisar 1,27- 43,34 gram. Nisbah kelamin jantan dan betina 1: 1,12. Model hubungan panjang bobot ikan jantan W = 1x10-5 L3,063, ikan betina W = 8x10-6L3,108,dan keseluruhan jenis ikan W =  9 x 10-6  L3,091. Faktor kondisi (K) ikanwader bintik dua berkisar antara 0,826 - 2,214 dan rata-rata 1,163. 


2019 ◽  
Vol 11 (2) ◽  
pp. 205-209
Author(s):  
Oluwadamilare E. OBAYEMI ◽  
Olusola O. KOMOLAFE ◽  
Oluwakemi V. OKUNOLA ◽  
Sakirat T. ASAFA ◽  
Mary A. AYOADE

This study investigated the length-weight relationships and condition factors of three fish species in an abandoned gold mine reservoir. The fishes were caught on monthly basis between August 2015 and July 2016 using gill nets and traps. The results showed that Coptodon zillii, Oreochromis niloticus and Sarotherodon galilaeus had a mean total length and mean weight of 15.52±4.64 cm and 95.80±66.27 g; 15.27±4.18 cm and 89.54±63.20 g; 15.57±4.80 cm and 102.0±85.81 g respectively. Also, the mean condition factor obtained for the fish species are 2.24±0.52 in C. zillii; 2.26±0.62 in O. niloticus and 2.27±0.46 in S. galilaeus. Similarly, the slope (b) values and correlation coefficient for the three fish species are 2.018 and 0.969 for C. zillii; 1.977 and 0.926 for O. niloticus and 2.436 and 0.965 for S. galilaeus. Furthermore, the total length, weight and condition factor between C. zillii, O. niloticus and S. galilaeus differ significantly (p>0.05). The study concluded that despite being an abandoned gold mine reservoir, the environment is well suitable for the fishes.


2017 ◽  
Vol 22 (1) ◽  
pp. 120-126
Author(s):  
Dipendra Joshi ◽  
Bijaya K. C.

Ghodaghodi Lake is an ox-bow perennial lake of Ghodaghodi Lake Complex, situated in Kailali district. The present study was conducted to understand the fish diversity, community structure and distribution pattern in Ghodaghodi Lake. A total of 13 fish species were recorded from the different section of Ghodaghodi Lake, belonging to five order, eight family and eleven genera. According to fish catch the dominant order and family of Ghodaghodi Lake were found to be Cypriniformes (40%) and Cyprinidae (40%) respectively. The dominant fish species of Ghodaghodi Lake was Labeo gonius followed by Mystus tengara, Nandus nandus and Channa striatus. The highest diversity index (2.46), species richness (6.14) and evenness (0.96) of fish were recorded from station III during the month of January. Lowest diversity index (1.75) and evenness (0.90) was found in station II and during the month of October (2.25 and 0.88). Similarly, lowest species richness was found in station I (3.91) and during the month of July (5.82). Fish diversity and number in Ghodaghodi Lake were found to have decreased. This could be due to pollution, illegal fishing and excessive proliferation of aquatic weeds.Journal of Institute of Science and TechnologyVolume 22, Issue 1, July 2017, page: 120-126


2020 ◽  
Vol 44.1 ◽  
pp. 7540-7552
Author(s):  
Hélène Dembe Louvinguila Tenda ◽  
Armel Ibala Zamba ◽  
Joseph Goma-Tchimbakala ◽  
Lérège Batiabo Mikembi ◽  
Honest Freedom Poaty Ngot ◽  
...  

Objectifs : La présente étude a été initiée pour établir les relations poids-longueur et les facteurs de condition de Ethmalosa fimbriata, Sardinella maderensis, Coptodon guinensis, Oreochromis schwebischi, Neochelon falcipinnis, Mugil cephalus, Parachelon grandisquamis, Eucinostomus melanopterus, Hemichromis elongatus, Pomadasys jubelini, Eleotris daganensis, Bathygobius soporator, Trachinotus teraia, Lutjanus goreensis, Mugil banannensis, et Sarotherodon melanotheron, 16 espèces les plus abondantes de la lagune Mvassa en République du Congo. Méthodologie et résultats : Les échantillonnages des poissons ont été réalisés sur 9 stations à l’aide des filets maillants de 8, 10, 20 et 30 mm de côté de la maille. Les relations poidslongueur ont été réalisées en utilisant l’équation P = aLSb et leurs coefficients de condition en utilisant l’équation K = 100*(P ⁄ LSb ). Au total, 1566 spécimens, réparties en 5 ordres, 8 familles, 16 espèces dont 10 ont été capturées en saison sèche, 14 en saison des pluies et 8 espèces communes pour les deux saisons ont été utilisés dans le cadre de cette étude. Le coefficient de détermination r 2 était significatif pour les deux saisons et variait de 0,91 pour Neochelon falcipinnis et 0,99 pour Pomadasys jubelini avec une moyenne de 0,97 ± 0,02. En saison sèche, le coefficient d’allométrie b de la relation poids-longueur variait de 2,04 pour Mugil cephalus à 3,48 Sardinella maderensis avec une moyenne de 2,79 ± 0,03. Le facteur de condition variait en moyenne de 0,66 ± 0,06 pour Sardinella maderensis à 12,22± 0,28 pour Mugil cephalus. En saison des pluies, le coefficient d’allométrie b variait de 2,41 pour Eucinostomus melanopterus à 3,94 pour Sardinella maderensis, avec une moyenne de 3,01 ± 0,05. Le facteur de condition variait de 0,02± 0,002 pour Parachelon grandisquamis à 6,73 ± 0,41 pour Eucinostomus malanopterus. Pour les huit espèces communes, le coefficient d’allométrie b était plus élevé en saison de pluie qu’en saison sèche pour la plupart des espèces (63 %). Conclusion et application des résultats : Ces résultats rapportent des informations relatives à la biologie des poissons rencontrés dans la lagune Mvassa, mais aussi sur l’influence de la saison sur les relations poids-longueur et les coefficients de condition. Dembe Louvinguila et al., 2020 Journal of Animal & Plant Sciences (J.Anim.Plant Sci. ISSN 2071-7024) Vol.44 (1) : 7540-7552 https://doi.org/10.35759/JAnmPlSci.v44-1.1 7541 Seasonal effects on weight-length relationships and condition factors for 16 fish species from the Mvassa Lagoon, Lower Guinea, Republic of the Congo ABSTRACT Objectives: This study was initiated to establish weight-length relationships and condition factors of Ethmalosa fimbriata, Sardinella maderensis, Coptodon guinensis, Oreochromis schwebischi, Neochelon falcipinnis, Mugil cephalus, Parachelon grandisquamis, Eucinostomus melanopterus, Hemichromis elongatus, Pomadasys jubelini, Eleotris daganensis, Bathygobius soporator, Trachinotus teraia, Lutjanus goreensis, Mugil banannensis, et Sarotherodon melanotheron, 16 most abundant species of the Mvassa lagoon in the Republic of Congo. Methodology and results: Fish samples were taken at 9 stations utilizing 8, 10, 20 and 30 mm mesh gillnets. The weight-length relationships were performed using equation P = aLSb and their condition coefficients using equation K = 100*(P/LSb ). A total of 1566 specimens, divided into 5 orders, 8 families, 16 species of which 10 were caught in the dry season, 14 in the rainy season and 8 common species for both seasons were used in this study. The correlation coefficient r 2 was significant for both seasons and ranged from 0.91 for Neochelon falcipinnis and 0.99 for Pomadasys jubelini with an average of 0.97 ± 0.02. In the dry season, the allometry coefficient b of the weight-length relationship ranged from 2.04 for Mugil cephalus to 3.48 Sardinella maderensis with an average of 2.79 ± 0.03. The condition factor ranged on average from 0.66 ± 0.06 for Sardinella maderensis to 12.22 ± 0.28 for Mugil cephalus. In the rainy season, the allometry coefficient b ranged from 2.41 for Eucinostomus melanopterus to 3.940 for Sardinella maderensis, with an average of 3.014 ± 0.05. The condition factor ranged from 0.02 ± 0.002 for Parachelon grandisquamis to 6.73 ± 0.41 for Eucinostomus malanopterus. For the eight common species, the allometry coefficient b was higher in the rainy season than in the dry season for most species (63%). Conclusion and application of the results: These results report information on the biology of the fish encountered in the Mvassa lagoon, but also on the influence of the season on weight- length relationships and condition coefficients


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Lee Nyanti ◽  
Chen-Lin Soo ◽  
Afina-Yian Chundi ◽  
Elsa-Cordelia-Durie Lambat ◽  
Alvinna Tram ◽  
...  

Construction of cascade dams has been shown to have impacts on fish assemblages and biodiversity. Yet, there is no literature on fish assemblages in the Murum River that connects the cascading Bakun and Murum dams in Sarawak, Malaysia. Hence, study on this modified ecosystem is necessitated to better understand the effects of the cascade dam construction on fish fauna. For this, fish samples were caught at five stations located along the river during both dry and wet seasons. Environmental parameters were taken concurrently with fish sampling. Length-weight relationship, condition factors, and diet composition of selected fish species in the river were also determined. The present study demonstrated that there are indications of the impact of cascading dams on the formation of a complex ecosystem in the Murum River, that is, changing from the shallow downstream of the Murum Dam to the deep transitional and inundated zone of the Bakun reservoir. The transitional zone in the Murum River exhibited the lowest fish species diversity, richness, and evenness during the dry season due to low pH and DO coupled with high turbidity. The biological indices improved when the water quality improved during the wet season. On the contrary, the diversity and evenness indices at the inundated tributary station decreased remarkably during the wet season, likely due to the migration of fish during the onset of the rainy season. This study showed that Barbonymus schwanenfeldii has a wider feeding habit which contributes to its higher distribution and abundance in the Murum River. The growth patterns of B. schwanenfeldii, Cyclocheilichthys apogon, Hampala macrolepidota, Lobocheilos ovalis, and Osteochilus enneaporos were better during wet than dry season. Overall, the condition factor of all native fish species in the Murum River was in poor to fair condition, whereas the exotic species, Oreochromis mossambicus, exhibited excellent condition (K value > 2) for both seasons. The increase in the number of O. mossambicus coupled with its high condition factor indicates biological intrusion and a potential threat to the native fish species in the Murum River. Continuous monitoring is essential to detect in-time risk issues associated with environmental degradation and biological invasion in this regulated and inundated river ecosystem.


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