scholarly journals ESTIMATION OF GROWTH, MORTALITY, AND EXPLOITATION STATUS OF NURSE TETRA (Brycinus nurse) AND TRUE BIG SCALE TETRA (Brycinus macrolepidotus) (FAMILY: ALESTIDAE) FROM THE NEW CALABAR RIVER, NIGERIA

2020 ◽  
Vol 25 (2) ◽  
pp. 113
Author(s):  
Olaniyi Alaba Olopade ◽  
Henry Eyina Dienye ◽  
Uzoma C Nworgu
Keyword(s):  
Growth Parameters ◽  
B Value ◽  
Fishing Effort ◽  
Growth Patterns ◽  
Allowable Limit ◽  
Growth Coefficient ◽  
Fish Samples ◽  
Landing Sites ◽  
Exploitation Rate ◽  
Exploitation Status

This study aimed to determine the growth patterns, mortality, and exploitation status of two species of Alestidae in the New Calabar River, Nigeria. For this purpose, fish samples were collected monthly from three landing sites from the local fishermen using gill nets (mesh sizes: 15-25mm), beach seine (mesh sizes: 2.3-10mm), and cast nets (mesh sizes: 15 -25mm). The length-weight relationship revealed exponent “b” value for Brycinus nurse was 3.54 and 3.21 for Brycinus macrolepidotus while the condition factors were 1.08 and 1.02 for Brycinus nurse and Brycinus macrolepidotus respectively. The growth parameters of Brycinus nurse asymptotic length (L) and growth coefficient (K) were 24.46 cm and 0.52 yr-1, respectively, while those for Brycinus macrolepidotus L was 28.88 cm and K was 0.22 yr-1. The reproductive load (L50/L) ratio was found to be 0.59 and 0.61 for B. nurse and B. macrolepidotus, respectively. Exploitation rate (E) for B. nurse was 0.26 and 0.11 for B. macrolepidotus while length-at-first capture (Lc) was 14.49 cm for B. nurse and 17.64 cm for B. macrolepidotus. The natural mortality was greater than the fishing mortality for both species and Logistic regression of the probability of capture routine values recorded for B. nurse were higher than that of B. macrolepidotus. Maximum exploitation rate (Emax) was less than 0.5 for both B. nurse (0.41) and B. macrolepidotus (0.42). These values were close to the maximum allowable limit; therefore, the species may be unsustainable when fishery intensifies in the future. To ensure sustainable exploitation of the two Alestid species in the area, fishing effort should be regulated.

scholarly journals First Assessment of the Thryssa vitrirostris (Engraulidae) Beach Seine Fishery in Northeastern Mozambique

J ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 116-132
Author(s):  
Bonifácio Manuessa ◽  
Eurico Morais ◽  
Teresa Cerveira Borges ◽  
Maria Teodósio ◽  
Francisco Leitão
Keyword(s):  
Standard Length ◽  
Growth Parameters ◽  
Mesh Size ◽  
Fishing Effort ◽  
Fishing Mortality ◽  
Beach Seine ◽  
Management Measures ◽  
Exploitation Rate ◽  
Exploitation Status ◽  
Sustainable Fishery

Monthly length-frequency data, from 2009 to 2014, was used to estimate the growth parameters, mortality, and spawning season, and to assess the exploitation status of Thryssa vitrirostris (Engraulidae) fisheries in Pebane. The von Bertalanffy asymptotic length (L∞) and growth rate (K) were 25.1 cm (standard length) and 0.41 per year (standard length), respectively. Two proxy recruitment peaks were found: the first peak of recruitment occurs from April to July, and the second recruitment peak from September to October. The total estimated mortality rates (Z), natural mortality (M), and fishing mortality (F) were Z = 1.31, M = 0.92, and F = 0.39. For the beach seine gear, the size at first catch of T. vitrirostris was Lc25 = 4.43 cm. The 50% retention size of the catch was Lc50 = 5.39 cm. The retention probability analyses revealed a large rate of juvenile fishing mortality (54.2%). The estimated exploitation rate (0.30) was below the maximum exploitation rate (0.48), and above the optimal sustainable exploitation rate (E50 = 0.28), evidencing a sustainable fishery. However, under such an exploitation regime, it is advised that a continuously monitoring-survey of T. vitrirostris is maintained. An increase in migration of fishermen has been recently recorded in Pebane, due to its rich fisheries, which can increase the fishing effort and the risk of overexploitation if management measures (such as mesh size increase) are not taken in advance.

scholarly journals Some biological properties of spiny eel (Mastacembelus mastacembelus, Banks & Solander, 1794) living in the Upper Euphrates River Basin, Turkey

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mehmet Zülfü Çoban ◽  
Mücahit Eroğlu ◽  
Mustafa Düşükcan
Keyword(s):  
River Basin ◽  
Growth Parameters ◽  
Age Groups ◽  
Mortality Rates ◽  
Biological Properties ◽  
Von Bertalanffy ◽  
Growth Type ◽  
Euphrates River ◽  
Fish Samples ◽  
Exploitation Rate

AbstractThis study was carried out to determine some bioecological characteristics of Mastacembelus mastacembelus, which is the only species of Mastacembelidae family living in Turkey. Fish samples were caught between 2014–2018 from Keban Dam Lake, one of the most important reservoirs of the upper Euphrates Basin. In totally, 348 Mastacembelus mastacembelus individuals were examined, including 178 males and 170 females. The age distributions were defined between the I–XV age groups. Total lengths ranged from 14.20 to 81.80 cm in males and from 15.60 to 77.30 cm in females. Total length–weight relationships were calculated as W = 0.0083 × TL2.6516 for males, W = 0.0043 × TL2.8310 for females and W = 0.0063 × TL2.7256 for all population, and the growth type was estimated as “negative allometric”. The von Bertalanffy growth parameters for all individuals were computed as L∞ = 90.99, k = 0.13, t0 = − 0.45. The total (Z), natural (M), fishing (F) mortality rates and exploitation rate (E) were estimated as Z = 0.313, M = 0.270, F = 0.043 and E = 0.137, respectively. The length at first capture (Lc) was found as 50.72. The optimum, maximum and economic yields were calculated as E0.5 = 0.361; Emax = 0.776; E0.1 = 0.664, respectively.

scholarly journals Population dynamics of eastern little tuna (Euthynnus affinis) in Ternate Waters

2021 ◽  
Vol 890 (1) ◽  
pp. 012053
Author(s):  
U Tangke ◽  
R Laisouw ◽  
A Talib ◽  
Azis Husen ◽  
R Kota ◽  
...  
Keyword(s):  
Sustainable Management ◽  
Growth Parameters ◽  
Total Mortality ◽  
Fishing Effort ◽  
Population Parameters ◽  
Management Information ◽  
Growth Coefficient ◽  
Stable Growth ◽  
Euthynnus Affinis ◽  
Data Collection Procedure

Abstract Eastern little tuna production still depends on stocks from nature, so it is feared that if production continues to increase it will threaten the sustainability of tuna resources, therefore for the sake of sustainable management information is needed on population parameters so that research is carried out from January to April 2021 with the aim of assessing the dynamics of the population of these resources. The data collection procedure was carried out by measuring the total length of the fish caught per fishing trip for 4 months using a meter with a unit (centimeter) cm and an accuracy of 1 mm. The results of the research showed that tuna in the southern waters of Ternate Island had stable growth parameters including maximum length (L∞) 68.25 cm with a growth coefficient (K) of 0.25 per month, t0 -0.20, with total mortality, natural and fishing values respectively. respectively are 0.64, 0.43, 0.21 and the level of exploitation is 0.33 where this value indicates that the rate of exploitation is smaller so it is necessary to increase fishing effort until the optimum value reaches 0.38.

scholarly journals Length-Weight Relationships and Condition Factors of the Naleh Fish, Barbonymus gonionotus (Pisces, Cyprinidae) Harvested from Nagan Raya Waters, Indonesia

2019 ◽  
Vol 53 (1) ◽  
pp. 75-82 ◽  
Author(s):  
A. S. Batubara ◽  
Z. A. Muchlisin ◽  
D. Efizon ◽  
R. Elvyra ◽  
M. Irham
Keyword(s):  
Growth Pattern ◽  
Condition Factor ◽  
Growth Parameters ◽  
Good Condition ◽  
Relative Weight ◽  
Stable Condition ◽  
B Value ◽  
Food Sources ◽  
Survey Method ◽  
Fish Samples

Abstract The objective of the present study was to examine the growth pattern and condition factors of the naleh fish, Barbonymus gonionotus Bleeker, 1849 in Nagan River, Nagan Raya District, Aceh Province, Indonesia. The sampling was conducted for 12 months from January 2016 to December 2016 using the explorative survey method. The sampling locations were determined based on the information given by local fishermen. A total of 761 fish samples were collected during the study. The Linear Allometric Model (LAM), Fulton’s and Relative Weight conditions factors were utilized to analyze the length-weight relationship and condition factor of the fish using growth parameters. The results showed that the highest coefficient of b was recorded in December, where the b value of males were 3.82 and 4.23 for the females with the average b value of males and females were 2.92 indicating an isometric growth pattern. The average Fulton’s condition factor (K) was 2.28 and the average Relative weight (Wr) condition factor was 100.59. It is concluded that fish had the isometric growth pattern and based on K and Wr value, the result implies that the waters are still in a good condition. Furthermore, the availability of food sources, low competitors, and low predators indicate that the aquatic environment is in a stable condition.

scholarly journals ASPEK BIOLOGI DAN PARAMETER POPULASI UDANG JINGA (Metapenaeus affinis H. Milne Edwards, 1837) DI PERAIRAN KOTABARU, KALIMANTAN SELATAN

2017 ◽  
Vol 9 (1) ◽  
pp. 11
Author(s):  
Tirtadanu Tirtadanu ◽  
Suprapto Suprapto ◽  
Ali Suman
Keyword(s):  
Growth Parameters ◽  
Growth Function ◽  
Fishing Effort ◽  
Population Parameters ◽  
Male And Female ◽  
Management Measures ◽  
Exploitation Rate ◽  
Mean Size ◽  
Biological Aspects ◽  
The Mean

Udang jinga (Metapenaeus affinis H. Milne Edwards, 1837) merupakan salah satu jenis udang ekonomis penting yang diusahakan di perairan Kotabaru dan saat ini produksinya cenderung mengalami penurunan. Salah satu data dan informasi yang diperlukan dalam mengkaji tingkat pemanfaatan dan dasar pengelolaannya adalah aspek biologi dan parameter populasi. Penelitian ini bertujuan mengkaji aspek biologi dan parameter populasi udang jinga sebagai bahan kebijakan pengelolaan perikanan udang di perairan Kotabaru, Kalimantan Selatan. Penelitian dilakukan pada bulan Januari – November 2016 di perairan Kotabaru. Parameter pertumbuhan diestimasi berdasarkan pergeseran modus struktur ukuran panjang dengan metode ELEFAN I. Hasil penelitian menunjukkan rata-rata ukuran udang jinga (M. affinis) betina yang tertangkap adalah 23,6 ± 3,45 mmCL dengan modus ukuran 24 mmCL dan rata-rata ukuran udang jantan adalah 20,7 ± 2,9 mm dengan modus ukuran 18 mmCL. Nisbah kelamin udang jinga jantan dan betina adalah 1 : 2,5. Musim pemijahan udang jinga diduga berlangsung sepanjang tahun dan puncak pada bulan Maret. Ukuran rata-rata pertama kali tertangkap (Lc) udang lebih kecil dari ukuran rata-rata pertama kali matang gonad (Lm) (21,7 < 28,5 mm CL) sehingga sebagian besar udang tertangkap berukuran kecil dan belum memijah. Persamaan pertumbuhan udang jinga jantan  CL(t)=35,95(1-e-2.02(t+0,31) dan udang jinga betina CL(t)= 38,3(1-e-1,92(t+0,29)). Tingkat pemanfaatan udang (E) menunjukkan lebih tangkap (overfishing) yakni 0,70/tahun pada jantan dan 0,73/tahun pada betina. Dengan demikian disarankan untuk melakukan pengurangan upaya penangkapan sebesar 40% dan penutupan musim penangkapan di bulan Maret.The jinga shrimp (Metapenaeus affinis H. Milne Edwards, 1837) was one of important commodity that was exploited in Kotabaru Waters, yet the production tend to be declined recently. The data and information on biological aspects and population parameters are needed to investigate the exploitation level and the basis of management measures. This research aims to investigate the biological aspects and population parameters of jinga shrimp Kotabaru waters, South of Kalimantan. This research was conducted on January – November 2016. The growth parameters were estimated as movement of length frequency mode by ELEFAN I method. The results showed that the mean size of female jinga shrimp (M. affinis) was 23,6 ± 3,45 mm CL and the mode was 24 mmCL. While, the mean size of male jinga shrimp was 20,7 ± 2.9 mm CL and the mode was 18 mmCL. The sex ratio of male and female shrimp was 1 : 2,5 . Spawning season of jinga shrimp was estimated throughout the year and the peak was in March. The length at first captured (Lc) was shorter than length at first matured (Lm) (21,7 < 28,5 mm CL). That means most of the catches was immature. The growth function of male and female jinga shrimp were and, CL(t)=35,95(1-e-2.02(t+0,31) respectively and CL(t)= 38,3(1-e-1,92(t+0,29)). The exploitation rate (E) of male and female shrimp fishing were  0,70/year 0,73/year, respectively. The reduction of fishing effort needed by 40% of the actual combined with the temporal fishing closure March.

Circumstantial evidence of effect of trout farming on length-weight relations of native fish species: Barbus oligolepis (Battalgil, 1941) and Squalius cii (Richardson, 1857)

2020 ◽  
Vol 9 (3) ◽  
pp. 87-90
Author(s):  
elin Ertürk Gürkan
Keyword(s):  
Fish Species ◽  
Growth Parameters ◽  
B Value ◽  
Native Fish ◽  
Growth Type ◽  
Positive Allometry ◽  
Fish Samples ◽  
Extra Food ◽  
One Year ◽  
And Control

This study was carried out to reveal how the aquaculture activities, located near the stream bed, effect the length-weight relations of native freshwater fish. Fish samples were collected on monthly for one year on the Kocabaş Stream (Çanakkale), a trout farm constructed next to stream. Fish specimens were collected from up and down sections of the trout farm and control station selected from another branch of the stream by electrofishing between August 2015-July 2016. The growth type sign; b value in length-weight relationship indicates that both species are in positive allometry at the down station and isometric growth at the upper station. Fish farm might affect the growth type of both species positively due to contribution of extra food resources originated from the farm via discharge of waste water of trout farm at the down section. However, this hypothesis should be tested by proper growth parameters of the fish species.

scholarly journals Dinamika pertumbuhan sepat siam (Trichopodus pectoralis, Regan 1910) di Perairan Rawa Banjiran Patra Tani Sumatra Selatan

DEPIK ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 444-451
Author(s):  
Aroef Hukmanan Rais ◽  
Sevi Sawestri ◽  
Dina Muthmainnah
Keyword(s):  
Native Species ◽  
Condition Factor ◽  
Growth Parameters ◽  
Mesh Size ◽  
Flood Plain ◽  
The Other ◽  
Long Period ◽  
Fish Samples ◽  
Fishing Gears ◽  
Exploitation Rate

The exploitation of Sepat siam (Trichopodus pectoralis, Regan 1910) that include native species of floodplain has been done on many years. One of the main fishing areas of this commodity is Patratani floodplain, Muara Enim Regency, South Sumatra. This commodity has been exploited over a long period and is expected to have a high pressure of fishing. The aim of this paper is to compare the utilization of sepat siam resources based on growth, mortality, and exploitation parameters between 2010 and 2017. Fish samples were collected monthly started from March to December in 2010, and April to December in 2017. The sample got from local fishers who fished around Patratani flood-plain waters. Sepat siam samples were measured on length (cm) and weight (gram) every month. The analysis has concluded based on the condition factor in both years. The growth parameters were analyzed by FiSATII software. The result of FiSAT II analysis drawn the growth factor was 0.86 in 2010, and have been growing slow to be 0.55 in 2017. The length infinitive in 2010 was around 21.5 cm and decreased to 18.3 in 2017. The other results showed that the exploitation level decreased from 0.61 in 2010 to 0.53 in 2017. The exploitation rate proved that the utilization of sepat siam was decreased but sill on overfishing conditions. The length size of sepat siam related to the optimum mesh size fishing gears was decreasing in 2017 compared to 2010. The age analysis shows for 21.5 cm of the infinitive length is achieved for 7 months in 2010, while 18.3 cm of that is reached for 10,5 months in 2017.Keywords:Exploitation levelFloodplainSepat siamABSTRAKKegiatan penangkapan Sepat siam (Trichopodus pectoralis, Regan 1910) yang merupakan spesies asli ikan rawa banjiran sudah dilakukan bertahun-tahun. Salah satu lokasi penangkapan komoditas ini adalah di rawa banjiran Patratani, Kabupaten Muara Enim, Provinsi Sumatra Selatan.Komoditas ini telah mengalami eksploitasi dalam jangka waktu yang lama dan diperkirakan mengalami tekanan penangkapan yang besar.Tulisan ini bertujuan untuk menampilkan eksploitasi atau pemanfaatan ikan sepat siam berdasarkan parameter pertumbuhan, mortalitas, dan eksploitasi pada tahun 2010 dan 2017. Sampel ikan dikumpulkan setiap bulan yaitu dimulai Maret hingga Desember 2010.Kegiatan pengumpulan sampel dilanjutkan pada April hingga Desember 2017.Sampel ikan diperoleh dari tangkapan nelayan lokal yang memancing di sekitar perairan rawa banjiran Patratani.Sampel ikan diukur panjang (cm) dan berat (gram).Parameter pertumbuhan dianalisis menggunakan perangkat lunak FiSAT II. Hasil analisis FiSAT II menggambarkan faktor pertumbuhan sepat siam pada 2010 sebesar 0,86, dan tumbuh melambat menjadi 0,55 pada 2017. Panjang infinitif sepat siam pada 2010 sekitar 21,5 cm dan turun menjadi 18,3 pada 2017. Analisis tingkat eksploitasi menunjukkan hasil menurun dari 0,61 pada 2010 dan 0,53 pada 2017, namun masih dalam kondisi penangkapan ikan menunjukkan tangkapan berlebih. Hubungan antara ukuran panjang sepat siam dengan ukuran optimal alat tangkap menunjukkan hasil menurun pada 2017. Analisis usia menunjukkan bahwa panjang infinitif 21,5 cm dicapai selama 7 bulan pada 2010, sementara perlu waktu 10,5 bulan pada 2017 untuk mencapai panjang infinitif 18,3 cm.Katakunci:Tingkat eksploitasiRawa BanjiranSepat siam

Estimating some population parameters and stock assessment of Dark Sleeper Odontobutis potamophila in the Gaosha River, Wuyuan County, Jiangxi Province, China

2017 ◽  
Author(s):  
Wu Bin Wang Haihua ◽  
Fu Huiyun Zhang Yanping
Keyword(s):  
Growth Parameters ◽  
Stock Assessment ◽  
Total Mortality ◽  
Landing Site ◽  
Jiangxi Province ◽  
Recruitment Pattern ◽  
Growth Coefficient ◽  
West Part ◽  
Exploitation Rate ◽  
Odontobutis Potamophila

A study was conducted to investigate the growth parameters, mortality and recruitment pattern of Odontobutis potamophila collected in the Gaosha river fish landing site, west part of Wuyuan County (Latitude: 29° 14' 29" N, Longitude: 117° 45' 49" E). O.potamophila were collected from November, 2013 to October, 2014. Growth parameters, asymptotic length (L) = 192mm and growth coefficient (k) = 0.22 year-1. Growth performance index(Ø’) =3.91, total mortality (Z) = 0.72 year-1, natural mortality (M) = 0.32 year-1, fishing mortality (F) = 0.40 year-1 and exploitation rate (E) = 0.55year-1.The estimated exploitation rate (E) has slightly exceeded the optimum value of E indicating this species was sustainable exploitation in the study area. The exploitation ratios were computed as Emax= 0.61, E10= 0.52, E50= 0.34. The length at first capture at 50%, (Lc) was 77 mm. The recruitment pattern of the species was found continuous all-round the year with one peak. The observation of the annual recruitment of O.potamophila found to occur from May to July. Steady biomass also increased with length class until 121-125 mm, and the total steady state biomass was found to be 2240 kg.

scholarly journals DINAMIKA POPULASI DAN STATUS PEMANFAATAN UDANG TIGER (Penaeus monodon Fabricius 1798) DI PERAIRAN TARAKAN, KALIMANTAN UTARA

2020 ◽  
Vol 12 (1) ◽  
pp. 11
Author(s):  
Umi Chodrijah ◽  
Ria Faizah ◽  
Tirta Danu
Keyword(s):  
Growth Parameters ◽  
Penaeus Monodon ◽  
Total Mortality ◽  
Optimal Level ◽  
Survey Method ◽  
Von Bertalanffy ◽  
Population Parameters ◽  
Exploitation Rate ◽  
Tiger Prawn ◽  
Exploitation Status

Udang tiger (Penaeus monodon Fabricius 1798) di Tarakan merupakan salah satu komoditas ekspor dan sudah dimanfaatkan cukup lama serta memiliki permintaan dan nilai ekonomis yang tinggi. Penelitian dinamika populasi dan status pemanfaatan udang tiger di perairan Tarakan dan sekitarnya dilakukan untuk mengevaluasi status stok sumberdaya udang agar pengelolaannya dapat berkelanjutan. Penelitian ini dilakukan pada bulan Januari-November 2016 dengan metode survey. Status pemanfaatan diduga berdasarkan laju eksploitasi dan estimasi rasio pemijahan berbasis data panjang (LB-SPR). Hasil pengamatan menunjukkan udang tiger memiliki panjang karapas asimptotik (CL∞) sebesar 65,45 mm, laju pertumbuhan (K) sebesar 1,55 /tahun dan nilai t0 sebesar -0,20/tahun sehingga diperoleh persamaan pertumbuhan Von Bertalanffy CLt = 65,45(1 – e-1,55(t+-0,20)). Laju mortalitas total (Z) sebesar 6,56/ tahun, mortalitas alami (M) sebesar 1,95/tahun, mortalitas penangkapan (F) sebesar 4,62/tahun dan tingkat pemanfaatan (E) sebesar 0,70 /tahun. Tingkat pemanfaatan udang tiger di perairan Tarakan lebih besar dari tingkat pemanfaatan optimal sehingga disarankan untuk menurunkan upaya sebesar 40% dari upaya saat ini.Tiger prawn (Penaeus monodon Fabricius 1798) was one of the export commodity and had been exploited for longtime ago so it was necessary to study about its population parameters and exploitation status for its sustainable management. This research aimed to study about the population parameters and exploitation status of tiger prawn. The research were carried out from January to November 2016 using survey method and the enumeration programme. The growth parameters were based on the Modal Progression Analysis. Exploitation status was estimated based on length based spawning potential ratio (LB-SPR). The results showed that the asymptotic length (CL∞) was 65.45 mm, the growth rate (K) was 1.55 /year and = t0 was -0,20/year so Von Bertalanffy Growth Model was CLt = 65.45(1 - e -1.55(t+-0.20)). Total mortality (Z) was 6.56/years, natural mortality was 1.95/years and fishing mortality was 4.62/years and the highest recruitment of tiger prawns occured in May. The exploitation rate (E) was 0,70/years. The exploitation rate now is higher then the optimal level so it is recommended to reduce 40% of the current efforts.

scholarly journals Population dynamics of Mormyrus rume (Valenciennes, 1847; Osteoglossiformes; Mormyridae) Of Ikere-Gorge, Iseyin, Oyo State, Nigeria

2020 ◽  
Vol 19 (1) ◽  
pp. 51-57
Author(s):  
Stephen O. Ajagbe ◽  
Folashade. F. Ojo-fakuade
Keyword(s):  
Growth Parameters ◽  
Management Strategies ◽  
Total Mortality ◽  
Mesh Size ◽  
Fish Population ◽  
Population Parameters ◽  
Growth Coefficient ◽  
Exploitation Rate ◽  
Length Frequency Data ◽  
Mormyrus Rume

The structure of a fish population is determined by the equilibrium between growth, recruitment and total mortality. But, there is paucity of information on the growth and mortality of Mormyrus rume in Nigeria. Therefore this study is needful to determine its population parameters, with a view of evolving management strategies for its sustainable exploitation. Estimates of population parameters of Mormyrus rume were obtained from length-frequency data of 836 individuals collected monthly for a period of 24 months from January 2017 to December 2018. The estimated growth parameters were: asymptotic length (L∞) was 100.8cm; growth coefficient (K) was 0.62/year; growth performance (Ɵ) was 3.8; length at maturity (Lm) was 52.57cm; reproductive load (Lm/L∞) was 0.52 and optimum length (Lopt) was 65.10cm. Likewise, natural, fishing and total mortalities were 0.93, 1.46 and 2.39 respectively. The values of exploitation rate (0.61) and ratio of total mortality and growth coefficient (3.85) showed that Mormyrus rume is most exploited in Ikere-gorge. Therefore, appropriate fishing regulations should be enforced to regulate fishing gears and mesh size that will fish Mormyrus rume at sustainable level. Keywords: Recruitment, mortality, growth, exploitation, length

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