Population parameters, exploitation rate and diet of black-chinned Tilapia, Sarotherodon melanotheron Rüppell, 1852 (Pisces: Cichlidae), from Badagry Creek, Lagos, Nigeria

The study evaluated some population parameters of Sarotherodon melanotheron melanotheron within a lagoon complex in southern Benin: Lake Nokoué and Porto-Novo Lagoon. Data on the total length, total weight, and sex were recorded monthly between January and December 2015 for 1,745 specimens captured by local fishermen. The asymptotic length L∞ was estimated at 24.68 cm. The growth rate K was 0.86. The total, natural, and fishing mortalities were estimated at 2.46, 1.71, and 0.75 y−1, respectively. The size at first sexual maturity was 8.9 and 9.2 cm, respectively, for males andfemales. The size at first capture was estimated at 9.2 cm, which indicates that fish spawn at least once before capture. The current exploitation rate of 0.31 remains below the maximum exploitation rate Emax which was 0.604 but was equal to the exploitation rate retaining 50% of the biomass of the stock (E0.5 = 0.324). This suggests that the stock of S. m. melanotheron is not overexploited in the complex. However, it is recommended that the actual rate of exploitation be kept as it is to ensure a sustainable management of these fish populations.

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Population parameters of the pontic shad, Alosa immaculata Bennett, 1835 in the Fatsa coast of the south-eastern Black Sea

Ege Journal of Fisheries and Aquatic Sciences ◽

10.12714/egejfas.36.4.01 ◽

2019 ◽

Vol 36 (4) ◽

pp. 319-324

Author(s):

İsmet Balık

Keyword(s):

Black Sea ◽

Maximum Yield ◽

Total Mortality ◽

Reference Points ◽

Growth Equation ◽

Fishing Mortality ◽

Population Parameters ◽

The South ◽

South Eastern ◽

Exploitation Rate

The aim of this study is to estimate population parameters of pontic shad, Alosa immaculata Bennett, 1835 in the Fatsa coast of the south-eastern Black Sea. A total of 314 pontic shad specimens were collected from study area using artisanal fishing gears from March 2013 to February 2014. In the study, parameters of the von Bertalanffy growth equation were found as L∞=43.05 cm; k=0.430 per year and t0=-0.451 year. The growth performance index (Φ') was estimated as 2.90. The total mortality (Z), natural mortality (M), fishing mortality rates (F) were calculated as 1.33 year-1, 0.75 year-1 and 0.58 year-1, respectively. The annual instantaneous fishing mortality rate was greater than both the target (Fopt=0.375 year-1) and limit (Flimit=0.50 year-1) biological reference points. Similarly, the present level of exploitation rate (E=0.43) was higher than the exploitation ratio for maximum yield per recruit (Emax=0.375) suggesting that overexploitation occurred. These results showed that this species has been over-exploited in the Fatsa coast of the south-eastern Black Sea. Measures should be taken to reduce the current exploitation rate for sustainable fishing of pontic shad in the Fatsa coast of the south-eastern Black Sea.

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DISTRIBUSI UKURAN DAN PARAMETER POPULASI LOBSTER PASIR (Panulirus homarus) DI PERAIRAN ACEH BARAT

BAWAL Widya Riset Perikanan Tangkap ◽

10.15578/bawal.7.3.2015.121-128 ◽

2015 ◽

Vol 7 (3) ◽

pp. 121

Author(s):

Duranta D Kembaren ◽

Erfind Nurdin

Keyword(s):

Spiny Lobster ◽

Length Distribution ◽

Total Mortality ◽

Landing Site ◽

Point Of View ◽

Population Parameters ◽

Site Distribution ◽

Exploitation Rate ◽

Curve Method ◽

Lobster Fishery

Penelitian tentang distribusi ukuran dan parameter populasi lobster pasir di perairan Aceh Barat dilakukan pada bulanApril sampai November 2013. Penelitian ini bertujuan untukmengkaji status lobster di perairan Aceh Barat dilihat dari aspek distribusi ukuran dan parameter populasinya. Pengamatan dan pengukuran lobster dilakukan di tempat pengumpul lobster dengan sistem sampling acak. Sebaran frekuensi panjang karapas selanjutnya ditabulasikan dan dianalisa dengan metode kurva logistik. Struktur ukuran lobster yang tertangkap menunjukkan bahwa lobster jantan dominan tertangkap dibawah ukuran nilai tengah 72,5 mm dan sebaliknya diatas ukuran nilai tengah 72,5 mm yang didominasi jenis kelamin betina. Lobster terlebih dahulu tertangkap sebelum mencapai ukuran matang gonad (Lc = 65,8mm< Lm= 76,8 mm). Puncak musim pemijahan terjadi pada bulan Mei dan Agustus. Panjang asimtosis (CL∞ ) sebesar 119,5 mm dengan laju pertumbuhan (K) 0,39/tahun serta laju kematian total (Z) 1,44/tahun, laju kematian alamiah (M) 0,67/tahun dan laju keamatian akibat penangkapan (F) 0,77/tahun. Laju eksploitasi sudah mengarah kepada penangkapan yang berlebih (E=0,54), oleh karena itu perlu dilakukan tindakan pengelolaan perikanan lobster yang berkelanjutan. Salah satu upaya yang dapat di tempuh adalah dengan menerapkan sistem penutupan musim penangkapan lobster pada saat terjadinya puncak musim pemijahan.Research on the length distribution and population parameters of scalloped spiny lobster conducted in the Aceh Barat waters during April to November 2013. The aim of this study was to assess lobster fishery status in this waters from the point of view their length size and population parameters. Sampel collected randomly in the lobster landing site. Distribution of carapace length frequency was tabulated and analysed using logistic curve method. Length composition of male lobster was dominated under 72,5 mm midlenght, while female lobster was dominated above 72,5 mm midlength. This study found that the scalloped spiny lobster was caught before their reach the size of maturity (Lc = 65,8 mm < Lm = 76,8 mm). The peak season of spawning was indicated on May and August. Asimtotic length (CL∞) of scalloped spiny lobster was 119,5 mm with the growth rate (K) 0,39/year, total mortality (Z) 1,44/year, natural mortality (M) 0,67/year, and fishing mortality (F) 0,77/year. Exploitation rate was leading to the overfishing condition (E=0,54). Thus, it is needed to manage the lobster fishery in this area to gain the sustainability. We suggest that closing system season should be applied, especially in the peak spawning season.

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

BAWAL Widya Riset Perikanan Tangkap ◽

10.15578/bawal.9.1.2017.11-20 ◽

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.

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POPULATION PARAMETERS OF ENDEAVOUR SHRIMP (Metapenaeus ensis de Haan) IN BINUANGEUN AND ADJACENT WATERS, WEST JAVA

Indonesian Fisheries Research Journal ◽

10.15578/ifrj.25.1.2019.19-26 ◽

2019 ◽

Vol 25 (1) ◽

pp. 19

Author(s):

Ali Suman ◽

Prihatiningsih Prihatiningsih ◽

Pratiwi Lestari ◽

Andina Ramadhani Putri Pane

Keyword(s):

Carapace Length ◽

Total Mortality ◽

Growth Parameter ◽

Fishing Effort ◽

Population Parameters ◽

Chi Square ◽

Exploitation Rate ◽

Chi Square Test ◽

Males And Females ◽

First Maturity

Study on the population dynamic of endeavour shrimp (Metapenaus ensis) was conducted in Binuangeun waters based on data collected during period of survey, January to November 2016. The purpose of the study was to identify population parameters of the endeavour shrimp. Result showed that the endeavor shrimp growth pattern in Binuangeun waters was negative allometric and sex ratio of males and females was 1.0 : 2.7. The chi square test indicated that comparison of male and female of the endeavour shrimp was significantly different. It mean that there was imbalance in number between males and females. The length at first capture (Lc) of endeavour shrimp was 28.9 mm (carapace length),smaller than the length at first maturity (Lm) at 37.7 mm (carapace length). The growth parameter of endeavour shrimp was 1.33/year with maximum carapace length (Loo) of 51.45 mm. Instantenous total mortality (Z) and natural mortality (M) were 7.74/year and 1.88/year, respectively. While fishing mortality (F) and exploitation rate (E) respectively were 5.86/year and 0.76/year. The exploitation rate of endeavour shrimp in Binuangeun and adjacent waters was high. It was, therefore, recommended that fishing effort of the endeavour shrimp in that waters should be reduced about 52 % in the next year.

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PARAMETER POPULASI DAN BIOLOGI REPRODUKSI IKAN BENTONG (Selar crumenophthalmus) DI PERAIRAN KWANDANG,GORONTALO UTARA

BAWAL Widya Riset Perikanan Tangkap ◽

10.15578/bawal.6.2.2014.111-117 ◽

2015 ◽

Vol 6 (2) ◽

pp. 111 ◽

Cited By ~ 1

Author(s):

Ria Faizah ◽

Lilis Sadiyah ◽

Tuti Hariati

Keyword(s):

Total Mortality ◽

Maturity Stage ◽

Natural Mortality ◽

Fishing Mortality ◽

Frequency Data ◽

Population Parameters ◽

Length Frequency ◽

Exploitation Rate ◽

Length Frequency Data ◽

Pelagic Fisheries

Perairan Kwandang merupakan salah satu basis utama perikanan pelagis kecil di perairan laut Sulawesi. Salah satu jenis yang banyak dimanfaatkan adalah ikan bentong (Selar crumenophthalmus). Penelitian ini bertujuan untukmenduga parameter populasi, tingkat pemanfaatan (E), dan biologi reproduksi dari ikan bentong. Data panjang cagak dikumpulkan dari PP Kwandang dari bulan Januari hingga November 2012. Pendugaan parameter populasi dilakukan dengan menggunakan metode Bhattacharya dengan bantuan software FISAT II Hasil analisis menunjukkan bahwa laju pertumbuhan (K) sebesar 0,76 per tahun dengan L”=24,7 cm. Laju kematian total (Z) sebesar 2,63 per tahun, dengan laju kematian alamiah (M) sebesar 1,28 per tahun, laju kematian akibat penangkapan (F) sebesar 1,3 per tahun dan laju pemanfaatan 0,51. Tingkat pemanfaatan ikan bentong sudah relatif optimum. Rasio jenis kelamin ikan bentong jantan dan betina adalah 1: 1,02. TKGI paling banyak ditemukan. Musim pemijahan ikan bentong diduga terjadi pada bulan November dan Desember.The Kwandang waters is one of the main base for small pelagic fisheries in Sulawesi sea. Bigeye scad (Selar crumenophthalmus) is one of species from small pelagic is exploited. The objectives of the research was to estimate the population parameters, exploitation rate and reproductive biology of bigeye scad. Length frequency data were collected from PP Kwandang, from January November 2012. Estimation of population parameters of bigeye scad used FISAT II method. The results showed that growth rate as follows (K) = 0,76 year-1 , L”=24,7 cm. Total mortality rate (Z) = 2,63 year-1, with natural mortality (M) = 1, year-1 and fishing mortality (F) = 1,3 year-1 and exploitation rate (E)=0,51. The exploitation rate are already optimum. Sex ratio of male and female are 1:1,02. The most commonly founded is Gonado Maturity Stage of I. The spawning season of bigeye scad estimated was November and December

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The population dynamics of the bony tongue, Heterotis niloticus (Cuvier, 1829) in the Cross River, Nigeria

Tropical Freshwater Biology ◽

10.4314/tfb.v29i1.1 ◽

2020 ◽

Vol 29 (1) ◽

pp. 1-21

Author(s):

G.A. Otogo ◽

U.I. Enin

Keyword(s):

Population Dynamics ◽

Assessment Tools ◽

Series Data ◽

Fishing Mortality ◽

Population Parameters ◽

Length Frequency ◽

K Value ◽

Cross River ◽

Exploitation Rate ◽

The Cross

The population dynamics of Heterotis niloticus of the Cross River, Nigeria was investigated for 15 months (October 2010 – December 2011) with the aim to determine the population parameters including growth and mortality rates. Time series data on the length - frequency distribution was collected from the artisanal landings using cast nets and gill nets at Ayadehe and Oku Ibuko beaches in Itu L.G.A. of Akwa Ibom State. The length - frequency data were analysed using FiSAT (FAO - ICLARM Stock Assessment tools). Maximum length of H. niloticus obtained from the field was 92.0 cm with a corresponding weight of 6.0 kg. Population parameters from length – frequency analysis were estimated as follows: Asymptotic length (L∞) = 103.87cm total length, growth coefficient (K) = 0.32 per year, amplitude of oscillation (C = 0.5) and winter point (WP) = 0.6. The K value of 0.32 showed that the fish is a slow growing species. The WP of 0.6 suggests that H. niloticus experiences slowest growth rate in the months of June – July possibly associated with spawning activity and low ambient temperature recorded during this period. The longevity was estimated at 9 years 4 months and growth performance index (o’) was 3.54. The fish instantaneous total mortality (Z) was estimated at 1.51 per year; natural mortality (M) was 0.608; fishing mortality (F) was 0.902 and exploitation rate (E) of 0.60. This exploitation rate indicates that fishing mortality is becoming excessive and is therefore being overfished. Possible interventions and recommendations are that the effort be reduced or stabilized. The close of fishery in July - August, the peak of reproduction is recommended and should be implemented. In addition, mesh size be increased to reduce growth overfishing on juveniles and sub adults. Key words: Heterotis niloticus, population dynamics, Cross River, Nigeria

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TRUKTUR UKURAN DAN BEBERAPA PARAMETER POPULASI IKAN CAKALANG (Katsuwonus pelamis Linnaeus, 1758) DI SAMUDERA PASIFIK UTARA PAPUA

BAWAL Widya Riset Perikanan Tangkap ◽

10.15578/bawal.9.2.2017.113-121 ◽

2017 ◽

Vol 9 (2) ◽

pp. 113

Author(s):

Thomas Hidayat ◽

Tegoeh Noegroho ◽

Karsono Wagiyo

Keyword(s):

Growth Rate ◽

Mortality Rate ◽

Size Structure ◽

Fork Length ◽

Total Mortality ◽

Status Quo ◽

Skipjack Tuna ◽

Population Parameters ◽

Katsuwonus Pelamis ◽

Exploitation Rate

Ikan cakalang (Katsuwonus pelamis Linnaeus, 1758) merupakan salah satu sumberdaya ikan pelagis besar yang mempunyai nilai ekonomis penting. Informasi mengenai struktur ukuran dan beberapa parameter populasinya masih sangat terbatas khususnya di perairan Indonesia timur. Penelitian ini dilakukan di Morotai, Biak dan Jayapura dari Januari sampai Desember 2013. Tujuan penelitian ini adalah untuk menganalisis ukuran ikan yang tertangkap dan menganalisis parameter populasi meliputi laju pertumbuhan, mortalitas dan tingkat eksploitasi. Estimasi parameter pertumbuhan, mortalitas dan laju eksploitasi dihitung menggunakan program FiSAT (FAO-ICLARM Stock Assessement Tools). Ukuran ikan cakalang hasil tangkapan pancing tonda dan pancing ulur berkisar antara 15 – 94 cmFL (Fork Length), dengan modus antara 40-45 cmFL. Ukuran pertama kali tertangkap sebesar 40,1 cmFL dan kebanyakan adalah ukuran ikan yang sedang memijah. Hasil analisis menggunakan FiSAT II diperoleh laju pertumbuhan (K) sebesar 0,41/tahun, panjang asimptotik (L) 101,85 cmFL. Laju kematian alami (M) 0,6 / tahun, laju kematian karena penangkapan (F) 0,62 /tahun dan laju mortalitas total (Z) 1,22 /tahun. Tingkat eksploitasi ikan cakalang hampir fully exploited (E= 0,46). Disarankan tidak perlu ada penambahan upaya penangkapan atau status quo untuk menjaga agar sumberdaya ikan cakalang tetap terjaga kelestariannya. Skipjack tuna (Katsuwonus pelamis Linnaeus, 1758) is one of the large pelagic fish resources which have high economic value. Information on the size structure and population parameters is still limited especially in the waters of eastern Indonesia. The Research was conducted from January to December 2013 at Morotai, Biak and Jayapura. The aim of this study was to analyze the size of the fish caught and some of population parameters such as the growth rate, mortality rates, and exploitation rate. Estimated of growth parameters, mortality and exploitation rate using the program FiSAT (FAO-ICLARM Stock Assessement Tools). The size of skipjack tuna caught by troll line and handline in between 15-94 cmFL, with a mode of 40-45 cmFL. The Length at first capture was 40.1 cmFL, most of them had condition of spawning. By using program FiSAT II analysis resulted that growth rate (K) of skipjack tuna was 0.41/year, with length asimptotik (L) reaches 101.85 cmFL. The natural mortality rate (M) was 0.6 / year. The fishing mortality rate (F) was 0.62 / year and total mortality rate (Z) was 1.22 / year. The exploitation rate of skipjack tuna was nearly fully exploited (E = 0.46). It was recommended the exploitation rate of this fish should be no additional effort (status quo) to keep sustainability of the skipjack tuna resource.

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

BAWAL Widya Riset Perikanan Tangkap ◽

10.15578/bawal.12.1.2020.11-17 ◽

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.

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

Global Journal of Agricultural Sciences ◽

10.4314/gjass.v19i1.7 ◽

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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