Demographics of the endemic and threatened small cyprinid Pethia setnai from the Northern Western Ghats, India

2020 ◽  
Vol 71 (7) ◽  
pp. 810
Author(s):  
M. SriHari ◽  
Y. Gladston ◽  
S. M. Ajina ◽  
G. B. Sreekanth ◽  
Rajeev Raghavan ◽  
...  
Keyword(s):  
Western Ghats ◽  
Growth Parameters ◽  
Local Population ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
Fishing Mortality ◽  
Length Frequency ◽  
Growth Coefficient ◽  
First Time ◽  
The Western Ghats

The indigo barb Pethia setnai is a threatened small cyprinid endemic to the Western Ghats biodiversity hotspot of India. In this study, the length–weight relationship and length–frequency-based population dynamics of this species, which are important prerequisites for effective fisheries management, were investigated for the first time based on specimens collected from the Mhadei River in the northern part of the Western Ghats. Estimated von Bertalanffy growth parameters were as follows: theoretical maximum length, L∞, 70.88 mm; growth coefficient, k, 1.50 year–1; and theoretical age at length 0, t0, –0.016 years. Natural mortality of P. setnai was higher than fishing mortality, and the present exploitation level (0.37) was less than 60% of the predicted maximum exploitation, suggesting that the species is not exploited to a level that is detrimental to the local population.

scholarly journals POPULATION DYNAMICS OF MALAYAN LEAF FISH (Pristolepisgrooti Blkr.) IN RANAU LAKE, SOUTH SUMATRA

2018 ◽  
Vol 24 (2) ◽  
pp. 125
Author(s):  
Sevi Sawetri ◽  
Subagdja Subagdja ◽  
Dina Muthmainnah
Keyword(s):  
Mortality Rate ◽  
Growth Parameters ◽  
Total Mortality ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Frequency Data ◽  
Length Frequency ◽  
Lake Ecosystems ◽  
Exploitation Rate ◽  
Length Frequency Data

The Malayan leaf fish or locally named as kepor (Pristolepis grooti) is one of important biotic components in Ranau Lake ecosystems. This study aimed to estimate population dynamic and exploitation rate of kepor in Ranau Lake, South Sumatera. The population parameters are estimated based on length frequency data which were collected in March to October 2013. Growth parameters and fishing mortality rates were calculated using FiSAT software package. The results showed that kepor’s growth was negative allometric, which tended to gain length faster than weight. Kepor population was dominated (42%) by individual length of 10.0 to 11.0 cm. Predicted length infinity (L) was 17.28 cm with high value of growth rates (K) of 1.4 year-1. The natural mortality rate (M) is 2.57 year-1, the fishing mortality rate (F) is 5.36 year-1 and total mortality rate (Z) is 7.93 year-1. The exploitation rate of Malayan leaf fish in Ranau Lake (E = 0.68 year-1) has passed the optimum score.  

Age and stock structure of gemfish (Rexea solandri) in New Zealand waters

1999 ◽  
Vol 50 (2) ◽  
pp. 103 ◽  
Author(s):  
P. L. Horn ◽  
R. J. Hurst
Keyword(s):  
Growth Parameters ◽  
Age Determination ◽  
Natural Mortality ◽  
Stock Structure ◽  
Von Bertalanffy ◽  
Length Frequency ◽  
Frequency Distributions ◽  
The North ◽  
Spawning Areas

Age determination of gemfish by counting hyaline zones in otoliths was validated by following the progression of modes in length–frequency distributions and the progression of strong and weak year classes in age–frequency distributions. Length–frequency and otolith samples were examined from four areas (west Northland, east Northland and Bay of Plenty, Wairarapa coast, and the Stewart- Snares shelf). Age–frequency distributions and von Bertalanffy growth parameters were calculated and compared between areas. Two gemfish stocks are indicated on the basis of patterns of year class strengths, trends in commercial landings and likely spawning areas; one off the east and north of the North Island, and another off the west and south of the South Island. Estimates of natural mortality are presented for the two stocks.

scholarly journals ASPECTS OF THE BIOLOGY OF PORTUNUS SPINICARPUS STIMPSON 1971 (DECAPODA: PORTUNIDAE) IN THE GULF OF SALAMANCA, COLOMBIAN CARIBBEAN

2016 ◽  
Vol 35 ◽  
Author(s):  
Camilo B. García ◽  
Nardi Mendoza
Keyword(s):  
Condition Factor ◽  
Growth Parameters ◽  
Vital Statistics ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
Time Condition ◽  
Deep Waters ◽  
First Time

Some vital statistics of the population of Portunus spinicarpus inhabiting the Golfo de Salamanca, Colombian Caribbean, are presented for the first time. Condition factor was found stable the year round, Von Bertalanffy growth parameters were estimated as L∞=38.6 mm, K= 2.5 year-1, to= -0.0573 year. Natural mortality was estimated as 4.62 year-1. P. spinicarpus seem to prefer deep waters and sand-muddy bottoms.

scholarly journals Population dynamics of Chrysichthys nigrodigitatus (Lacépède, 1803) in Ikere-gorge, Oyo State, Nigeria

2021 ◽  
Vol 56 (1) ◽  
pp. 79-86
Author(s):  
S.O. Ajagbe ◽  
D.O. Odulate ◽  
R.O. Ajagbe ◽  
O.S. Ariwoola ◽  
F.I. Abdulazeez ◽  
...  
Keyword(s):  
Assessment Tool ◽  
Growth Parameters ◽  
Stock Assessment ◽  
Total Mortality ◽  
Fishing Mortality ◽  
Length Frequency ◽  
Optimum Length ◽  
Growth Coefficient ◽  
Exploitation Rate ◽  
Length Frequency Data

The growth and mortality parameters of Chrysichthys nigrodigitatus were estimated to assess the sustainability of its exploitation in Ikere-gorge, Oyo State, Nigeria. A total of 1210 of Chrys­ichthys nigrodigitatus were sampled from fishermen catches between January, 2017 and Decem­ber, 2018. C. nigrodigitatus were exploited with gillnet, cast net and traps (Malian trap net and bamboo). Total lengths were measured with fish measuring board. The FAO-ICLARM Stock Assessment Tool (FiSAT II) software was used to analyze length-frequency data of the fish. The estimated growth parameters are: asymptotic length is 60.9 cm, growth coefficient is 0.96, optimum length is 38.51 cm; length at maturity is 33.44 cm while length-at-first-capture is 12.62 cm. The estimated mortality parameters are: total mortality is 3.29 per year, natural mortality is 1.43 per year and fishing mortality is 1.86. It was observed that C. nigrodigitatus of Ikere-gorge were more vulnerable to exploitation at sizes less than their length at maturity. Likewise, the ex­ploitation rate (E = 0.57 yr-1) is greater than sustainable exploitation rate (Emax = 0.46 yr-1). This shows that exploitation of C. nigrodigitatus in Ikere-gorge is not sustainable. Therefore, there is need to reduce fishing pressure on C. nigrodigitatus to ensure its sustainability in Ikere-gorge.

scholarly journals Age, growth, mortality, and exploitation rate of blueline snapper, Lutjanus coeruleolineatus (Actinopterygii: Perciformes: Lutjanidae), from Dhofar Governorate, Sultanate of Oman

2021 ◽  
Vol 51 (2) ◽  
pp. 159-166
Author(s):  
Dawood Almamari ◽  
Said Rabia ◽  
Joo Myun Park ◽  
Laith A. Jawad
Keyword(s):  
Fishery Management ◽  
Growth Parameters ◽  
Total Mortality ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
Fishing Mortality ◽  
Sultanate Of Oman ◽  
Commercial Fish ◽  
Exploitation Rate ◽  
Reported Study

The blueline snapper, Lutjanus coeruleolineatus (Rüppell, 1838), is a significant commercial fish species harvested from the traditional fishery in the Sultanate of Oman. Deficient data on this species, however, make the management strategies challenging, especially in fisheries ecology. A total of 978 specimens were obtained from Dhofar Governorate off the coast of the Arabian Sea during the period between February 2015 and March 2016. In total, 296 sectioned otoliths were analyzed and growth was estimated from non-seasonal growth by using von Bertalanffy method. The parameters of von Bertalanffy growth function, total mortality (Z), natural mortality (M), fishing mortality (F), and exploitation rate (E) were determined and compared with those for Lutjanidae fishes elsewhere. The age structure of male fishes was between 1 and 14 years for males while the age of females ranged from 1 to 18 years. Growth rate (K) was 0.21 y–1 and 0.16 y–1 for males and females, respectively. The hypothetical length of female (L∞ = 46 cm) was relatively higher than that of male (L∞ = 42 cm). The natural mortality (M) was 0.296, total mortality (Z) was 0.372, fishing mortality was 0.076, and exploitation rate (E) was estimated as 0.2. The presently reported study is conducted to examine this fish in relation to growth parameters by analyzing otolith structure. The results of the presently reported study will contribute towards planning the regional fishery management policies in Oman.

scholarly journals Temporal variation, growth and natural mortality of two species of mojarras (Perciformes: Gerreidae) from a tropical coastal lagoon: La Carbonera, Yucatan, Mexico

2013 ◽  
Vol 5 ◽  
pp. 57
Author(s):  
José Luis Bonilla-Gómez ◽  
Maribel Badillo-Alemán ◽  
Alfredo Gallardo-Torres ◽  
Xavier Chiappa-Carrara
Keyword(s):  
Seasonal Variation ◽  
Frequency Analysis ◽  
Coastal Lagoon ◽  
Growth Parameters ◽  
Model Parameters ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
Length Frequency ◽  
Tropical Coastal Lagoon ◽  
Length Frequency Analysis

This study reports seasonal variation, growth parameters and natural mortality for Eucinostomus gula and Eucinostomus argenteus inhabiting La Carbonera, a tropical coastal lagoon on the northwestern coast of theYucatan Peninsula, Mexico. Specimens were collected between April 2009 and March 2010. A total of 2700organisms of E. gula (> 80% in rainy season ) and 1577 organisms of E. argenteus (>50% in dry season)were collected during the study period. Length-weight relationship (LWR) obtained was W = 8.323E-03Lt2.92 in E. argenteus and W = 7.314E-03 Lt2.92 in E. gula. Growth parameters of von Bertalanffy growthfunction (VBGF) by length frequency analysis were in E. argenteus: L∞ = 13.65 cm, k = 0.54 year-1 and t0= - 0.37 years; and in E. gula: L∞ = 12.60 cm, k = 0.68 year-1 and t0 = - 0.28 years. Additionally, estimatednatural mortality in E. gula was 1.50 year-1 and in E. argenteus was 1.9 year-1. This study presents the firstestimation for both species of model parameters, growth performance index and mortality for the Yucatan Peninsula, which is relevant for the proper implementation of conservation measures for E. gula and E. argenteus in an important coastal zone of the Yucatan Peninsula.Se reportan la variación temporal, los parámetros de crecimiento y la mortalidad natural para Eucinostomus gula y Eucinostomus argenteus que habitan en la laguna costera tropical La Carbonera, al noroeste de la península de Yucatán, México. Los especímenes fueron recolectados entre abril de 2009 a marzo de 2010. Un total de 2 700 organismos de E. gula (> 80% en la estación lluviosa) y 1 577 organismos de E. argenteus (> 50% en la estación seca) fueron recolectados durante el período de estudio. Se determinó la relación peso-longitud (RPL) como: P = 8.323E-03 Lt 2.92 en E. argenteus y P = 7.314E-03  Lt2.92 en E. gula.  Para E. argenteus, los parámetros de crecimiento de la ecuación de crecimiento de von Bertalanffy (ECVB) fueron: L∞ = 13.65 cm,  k = 0.54 año-1 y t0 = - 0.37 años; mientras que para E. gula fueron: L∞ = 12.60 cm, k = 0.68 año-1 y t0 = - 0.28 años. La mortalidad natural en E. gula fue 1.50 año-1 y en E. argenteus fue 1.9 año-1. Este estudio presenta la primera estimación para ambas especies de los modelos de crecimiento, el índice del desempeño de crecimiento y la mortalidad natural para la península de Yucatán, lo que es relevante para la adecuada implementación de medidas de conservación de E. gula y E. argenteus en una valiosa zona costera de la península de Yucatán.

scholarly journals Population dynamics of Bombay duck Harpodon nehereus (Hamilton, 1822) of the Bay of Bengal along Bangladesh coast

2018 ◽  
Vol 45 (2) ◽  
pp. 101-110
Author(s):  
MN Sarker ◽  
Md Humayun ◽  
Md Atiar Rahman ◽  
Md Sharif Uddin
Keyword(s):  
Growth Parameters ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Frequency Data ◽  
Length Frequency ◽  
Recruitment Pattern ◽  
Exploitation Rate ◽  
Bombay Duck ◽  
Two Peaks ◽  
Length Frequency Data

Population parameters of Harpadon nehereus were estimated using FiSAT-II. length-frequency data collected from different landing centers along the coast of Bangladesh. The Von Bertalanffy growth parameters L∞and K for the species were 45.05 cm and 1.30/year, respectively. The annual rate of natural mortality (M) and fishing mortality (F) were found to be 1.86 and 2.58, respectively. The estimated value of the exploitation rate (E) using the lengthconverted catch curve was 0.58 and E max was found to be 0.582. The recruitment pattern of this species was continuous and two peaks per year. The present investigation clearly showed the over fishing (E > 0.50) condition for H. nehereus in Bangladesh. The estimated length-weight relationship for the combined sex was found to be W = 0.003199 L3.Bangladesh J. Zool. 45(2): 101-110, 2017

scholarly journals Temporal variation, growth and natural mortality of two species of mojarras (Perciformes: Gerreidae) from a tropical coastal lagoon: La Carbonera, Yucatan, Mexico

2013 ◽  
Vol 5 ◽  
pp. 57
Author(s):  
José Luis Bonilla-Gómez ◽  
Maribel Badillo-Alemán ◽  
Alfredo Gallardo-Torres ◽  
Xavier Chiappa-Carrara
Keyword(s):  
Seasonal Variation ◽  
Frequency Analysis ◽  
Coastal Lagoon ◽  
Growth Parameters ◽  
Model Parameters ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
Length Frequency ◽  
Tropical Coastal Lagoon ◽  
Length Frequency Analysis

This study reports seasonal variation, growth parameters and natural mortality for Eucinostomus gula and Eucinostomus argenteus inhabiting La Carbonera, a tropical coastal lagoon on the northwestern coast of theYucatan Peninsula, Mexico. Specimens were collected between April 2009 and March 2010. A total of 2700organisms of E. gula (> 80% in rainy season ) and 1577 organisms of E. argenteus (>50% in dry season)were collected during the study period. Length-weight relationship (LWR) obtained was W = 8.323E-03Lt2.92 in E. argenteus and W = 7.314E-03 Lt2.92 in E. gula. Growth parameters of von Bertalanffy growthfunction (VBGF) by length frequency analysis were in E. argenteus: L∞ = 13.65 cm, k = 0.54 year-1 and t0= - 0.37 years; and in E. gula: L∞ = 12.60 cm, k = 0.68 year-1 and t0 = - 0.28 years. Additionally, estimatednatural mortality in E. gula was 1.50 year-1 and in E. argenteus was 1.9 year-1. This study presents the firstestimation for both species of model parameters, growth performance index and mortality for the Yucatan Peninsula, which is relevant for the proper implementation of conservation measures for E. gula and E. argenteus in an important coastal zone of the Yucatan Peninsula.Se reportan la variación temporal, los parámetros de crecimiento y la mortalidad natural para Eucinostomus gula y Eucinostomus argenteus que habitan en la laguna costera tropical La Carbonera, al noroeste de la península de Yucatán, México. Los especímenes fueron recolectados entre abril de 2009 a marzo de 2010. Un total de 2 700 organismos de E. gula (> 80% en la estación lluviosa) y 1 577 organismos de E. argenteus (> 50% en la estación seca) fueron recolectados durante el período de estudio. Se determinó la relación peso-longitud (RPL) como: P = 8.323E-03 Lt 2.92 en E. argenteus y P = 7.314E-03  Lt2.92 en E. gula.  Para E. argenteus, los parámetros de crecimiento de la ecuación de crecimiento de von Bertalanffy (ECVB) fueron: L∞ = 13.65 cm,  k = 0.54 año-1 y t0 = - 0.37 años; mientras que para E. gula fueron: L∞ = 12.60 cm, k = 0.68 año-1 y t0 = - 0.28 años. La mortalidad natural en E. gula fue 1.50 año-1 y en E. argenteus fue 1.9 año-1. Este estudio presenta la primera estimación para ambas especies de los modelos de crecimiento, el índice del desempeño de crecimiento y la mortalidad natural para la península de Yucatán, lo que es relevante para la adecuada implementación de medidas de conservación de E. gula y E. argenteus en una valiosa zona costera de la península de Yucatán.

scholarly journals Population Dynamics and Stock Assessment of Gudusia chapra (Hamilton-Buchanan) in the Rajdhala Reservoir, Netrakona, Bangladesh

2007 ◽  
Vol 19 (3) ◽  
Author(s):  
M. A. RAHMAN ◽  
M. M. HAQUE
Keyword(s):  
Population Dynamics ◽  
Growth Parameters ◽  
Stock Assessment ◽  
Total Mortality ◽  
Maximum Sustainable Yield ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Length Frequency ◽  
Recruitment Pattern ◽  
Pattern Maximum

Population dynamics and stock assessment of chapila (Gudusia chapra, Hamilton-Buchanan) in the Rajdhala reservoir, Netrakona, Bangladesh was studied from January 2003 to December 2004 using length-frequency based analysis of FiSAT software to evaluate the growth parameters, mortality rates, exploitation rates, recruitment pattern, maximum sustainable yield (MSY) and the corresponding fishing mortality at this level. The annual rates of natural mortality, fishing mortality and total mortality were 1.34, 1.37 and 2.71 yr-1 in 2003 and 1.37, 1.58 and 2.95 yr-1 in 2004 respectively. The study revealed that the fishes were recruited in the fishery twice a year and the fishes were harvested at a higher level than the optimum fishing pressure. Twenty four percent of the present exploitation pressure on chapila is suggested to be reduced to get the MSY of this fish from the reservoir.

scholarly journals Breeding, growth and exploitation of Brachyplatystoma rousseauxii Castelnau, 1855 in the Caqueta River, Colombia

2013 ◽  
Vol 11 (3) ◽  
pp. 637-647 ◽  
Author(s):  
Edwin Agudelo Córdoba ◽  
Ángela Viviana Joven León ◽  
César Augusto Bonilla-Castillo ◽  
Miguel Petrere Junior ◽  
Marlón Peláez ◽  
...  
Keyword(s):  
Life History Traits ◽  
First Year ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Peruvian Amazon ◽  
Length Frequency ◽  
Males And Females ◽  
The Difference ◽  
First Time ◽  
Mortality Estimates

The main life history traits of the large Amazonian migratory catfish Brachyplatystoma rousseauxii were determined in the Caqueta River, Colombia. The breeding season occurred during the rising and falling water periods. The size at first sexual maturity was significantly larger for females (88.5 cm Ls) than males (81.7 cm). Both males and females reproduce for the first time between their third and fourth year. The growth characteristics were estimated using length frequency analyses. Females grew systematically larger than males, the difference being about 9% after the first year and increasing to 12% for ten years old individuals. Mortality estimates, calculated from different models, some taking into account the effect of body size, ranged from 0.32 to 0.42 year-1 for natural mortality and from 0.72 to 0.82 year-1 for fishing mortality, indicating high fishing pressure in the Caqueta River, higher than in the Peruvian Amazon. Resulting exploitation rates (0.63 to 0.72) pointed towards overexploitation of the species in the Caqueta. The situation calls for a concerted management between the countries sharing this resource (Brazil, Colombia, and Peru) and potential solutions are proposed.

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