scholarly journals Short Communication: Age and growth of elongated mudskipper, Pseudapocryptes elongatus (Cuvier, 1816) from Sundarbans, India

2018 ◽  
Vol 20 (1) ◽  
pp. 85-90 ◽  
Author(s):  
GOPALAN MAHADEVAN ◽  
PALANIVEL BHARATHIRAJAN ◽  
VELAYUTHAM RAVI ◽  
MOJTABA POULADI ◽  
MARYAM MIRZAEI VAND KHANGHAH

Mahadevan G, Bharathirajan P, Ravi V, Pouladi M, Mirzaei Vand Khanghah M. 2019. Short Communication: Age and growth of elongated mudskipper, Pseudapocryptes elongatus (Cuvier, 1816) from Sundarbans, India. Biodiversitas 20: 85-90. The estimation of age and mathematical expression of fish growth is complex and debated subject in fishery sciences. Growth parameters of elongated mudskipper, Pseudapocryptes elongatus were estimated based on the length frequency data using FiSAT II software (several tools such as Powell-Wetherall method, ELEFAN and von Bertalanffy growth estimates). Samples were collected from Sundarbans mangroves using gill and cast nets and by hand picking. The length-frequency (LFQ) of P.elongatus was recorded from January 2014 to December 2015 and the above tools estimated the growth parameters (L∞, K and t0) from the progression of LFQ modes through time. L∞ and K values of males were 220.50 mm and 1.3 yr-1, respectively and similarly, L∞ and K values of females were 221.05 mm and 1.21 yr-1, respectively. The t0 values estimated for males and females were-0.1915 years and-0.1661 years, respectively. The estimated growth performance index (Φ) values for males and females of P. elongatus were 4.394 and 4.503, respectively. The lifespan of both the sexes was found to be 4+ years.

1998 ◽  
Vol 49 (7) ◽  
pp. 705 ◽  
Author(s):  
Rosangela Lessa ◽  
Francisco Marcante Santana

Age and growth of C. porosus was estimated from seasonally formed marks in vertebrae of 504 specimens (30.0–101.0 cm total length), and from length–frequency data from 1128 individuals (29.4–120.5 cm). Estimated von Bertalanffy growth parameters were: from observed length-at-age, L∞ 125.1 cm, K 0.101 year-1 and t0 –2.89 year; from back-calculated lengths, L∞ 136.4 cm, K 0.077 year-1, t0 –3.27 year; and from length–frequency analysis, L∞ 131.0, K 0.080 and t0 –3.40. Growth did not differ significantly between sexes. Males and females were mature at 71.0 and 70.0 cm, respectively, corresponding to 6 years old. The largest shark aged from vertebrae was a 12-year-old female (101.0 cm). Growth rates calculated from mean observed lengths were 7.0 cm year-1 for the first four years and 4.0 cm year-1 after maturity. Lee’s phenomenon was not apparent. The annulus forms from September to January. Parameters derived from back-calculated lengths were considered to best describe growth. Like most carcharhinids, C. porosus follows the general pattern of K-selected species, exhibiting slow growth, late maturity and low fecundity. Resumo. A idade e o crescimento de C. porosus foram estimados a partir de marcas sazonais em vértebras de 504 indivíduos (30.0–101.0 cm comprimento total) e através de distribuição de freqÜências de comprimentos de 1128 indivíduos (29.4–120.5 cm). Os parâmetros de von Bertalanffy obtidos com comprimentos observados na captura foram: L∞ 125.1 cm, K 0.101 ano –1 e t0 –2.89 anos; com comprimentos retrocalculados: L∞ 136.4 cm, K 0.077 ano-1, t0 –3.27 anos, e da distribuição de freqÜências de comprimentos obteve-se: L∞ 131.0 cm, K 0.080 ano-1 e t0 –3.40. O crescimento não difere entre sexos. Machos e fêmeas são maduras com 71 e 70 cm, respectivamente, correspondendo a idade de 6 anos. O maior espécime cuja idade foi estimada das vértebras tinha 12 anos (101.0 cm). As taxas de crescimento calculadas dos comprimentos médios observados foram 7.0 cm ano-1 para os primeiros quatro anos e 4.0 cm ano-1 após a maturidade. O fenômeno de Lee não ocorreu. O anel se forma entre setembro e janeiro. Os parâmetros obtidos do retroclculo descreveram melhor o crescimento. Como muitos carcharhinideos, C. porosus segue o padrão das espécies da seleção K, exibindo crescimento lento, maturidade tardia e baixa fecundidade.


2015 ◽  
Vol 96 (7) ◽  
pp. 1379-1386 ◽  
Author(s):  
C. Viswanathan ◽  
M. Pravinkumar ◽  
T.V. Suresh ◽  
V. Elumalai ◽  
S.M. Raffi

The present study provides novel information on carapace width-weight (CWR) relationship and growth parameters of the mud crab Scylla olivacea (Herbst, 1796) inhabiting the Pichavaram mangroves, east coast of India based on length frequency data sets during June 2010 to May 2012. CWR revealed linear regression between carapace width and weight in both sexes, and overall CWR exponent (b) values acquired for males and females are 3.035 (r2 = 0.962) and 2.925 (r2 = 0.933) respectively. The growth parameters, CW∞, K and to derived for males and females were 148.05, 0.762 year−1 and −0.637 and 138.80 mm, 0.856 year−1 and −0.681 respectively. The growth of S. olivacea was assessed through various methods in such a way that the outcome of one method functions as a rider, check and control over the other.


2000 ◽  
Vol 51 (1) ◽  
pp. 35 ◽  
Author(s):  
Malcolm P. Francis ◽  
Caoimhghin Ó Maolagáin

Rig (Mustelus lenticulatus) specimens were aged by counting growth bands in whole vertebrae that were illuminated laterally with fibre-optic lights. Bands were counted by two readers who used information on the diameter of the vertebrae of new-born young and 1-year-old juveniles to identify the inner bands. The greatest estimated age was 12.1 years for a female of 137 cm total length, but few rig were more than 8 years old. For west coast South Island (WCSI) rig, there was no significant difference in growth rates of males and females. After pooling both sexes, there was no significant difference in growth rates between WCSI and east coast South Island (ECSI) rig. The combined WCSI and ECSI von Bertalanffy growth curve was Lt = 147.2 (1 – e −0.119[t + 2.35]). This curve agreed well with growth curves derived from length–frequency data, but validation of the ageing technique is still required. WCSI males mature at ~85 cm and 5–6 years, and females at ~100 cm and 7–8 years. ECSI rig probably mature at similar lengths and ages. Tagged rig have been recaptured after nearly 14 years at liberty. Longevity probably exceeds 15 years, and may exceed 20 years.


1985 ◽  
Vol 42 (5) ◽  
pp. 963-975 ◽  
Author(s):  
J. G. Casey ◽  
H. L. Pratt Jr. ◽  
C. E. Stillwell

Age and growth of the sandbar shark (Carcharhinus plumbeus) was determined from rings in the vertebrae of 475 individuals, tagging data from 220 sharks at liberty for up to 17 yr, and length–frequency data from 2594 individuals. The oldest male sandbar aged in this study was 15 yr old and 154 cm fork length (FL); the oldest female was 21 yr old and 204 cm FL. The sexes grew at similar rates, 5.2–7.3 cm/yr. Females reached a larger adult size. Age to maturity was estimated at 13 yr in males and 12 yr in females. Tag returns indicated that sandbar sharks may live for over 30 yr. von Bertalanffy parameters for males are L∞ = 257, K = 0.0501, t0 = −4.5 and for females are L∞ = 299, K = 0.040, t0 = −4.9.


2018 ◽  
Vol 24 (2) ◽  
pp. 125
Author(s):  
Sevi Sawetri ◽  
Subagdja Subagdja ◽  
Dina Muthmainnah

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.  


2019 ◽  
Vol 77 (2) ◽  
pp. 613-623
Author(s):  
Shijie Zhou ◽  
Sarah Martin ◽  
Dan Fu ◽  
Rishi Sharma

Abstract Estimating fish growth from length frequency data is challenging. There is often a lack of clearly separated modes and modal progression in the length samples due to a combination of factors, including gear selectivity, slowing growth with increasing age, and spatial segregation of different year classes. In this study, we present an innovative Bayesian hierarchical model (BHM) that enables growth to be estimated where there are few distinguishable length modes in the samples. We analyse and identify the modes in multiple length frequency strata using a multinormal mixture model and then integrate the modes and associated variances into the BHM to estimate von Bertalanffy growth parameters. The hierarchical approach allows the parameters to be estimated at regional levels, where they are assumed to represent subpopulations, as well as at species level for the whole stock. We carry out simulations to validate the method and then demonstrate its application to Indian Ocean longtail tuna (Thunnus tonggol). The results show that the estimates are generally consistent with the range of estimates reported in the literature, but with less uncertainty. The BHM can be useful for deriving growth parameters for other species even if the length data contain few age classes and do not exhibit modal progression.


Author(s):  
Mohammad Reza Mirzaei ◽  
Zulfigar Yasin ◽  
Aileen Tan Shau Hwai

Length-weight relationship, growth parameters and mortality rates ofAnadara granosain the intertidal zone of Balik Pulau, Penang Island, West Coast of Malaysia were investigated based on monthly length-frequency data (December 2011 to November 2012). A total of 548 individuals ranging from 11.25 to 33.13 mm size were subjected to analysis. Logarithmic relationship between the length and weight was LogW = 2.328LogL − 2.537 (R2 = 0.922) for combined sexes. From this equation it was clear that the exponent ‘b’ value forA. granosashowed a negative allometric growth (b < 3). A von Bertalanffy growth function with an asymptotic length (L∞) of 35.40 mm and a growth constant (K) of 1.1 year−1was established from length frequency distributions. Thet0(−0.140) was estimated by substituting theL∞andKin the Pauly's equation. The sizes attained byA. granosawere 10.13, 14.36, 17.89, 20.82, 23.56 and 25.29 mm at the end of 2, 4, 6, 8, 10 and 12 months, respectively. The estimated growth performance index (Ø) was 3.13 while the estimated lifespan of the cockles was about 2.72 years at the study area. The estimated value of total mortality based on length-converted catch curve wasZ = 3.02 year−1. The natural mortality (M) and fishing mortality (F) rates were 1.84 and 0.48 year−1, respectively. The exploitation level (E) ofA. granosawas 0.20, which indicated slight fishing pressure on the stock.


2005 ◽  
Vol 62 (7) ◽  
pp. 1626-1639 ◽  
Author(s):  
Michael R O'Farrell ◽  
Louis W Botsford

The percentage of unfished lifetime egg production (LEP) has been used to represent persistence in precautionary fisheries management, but estimation of this reference point requires substantial data and it is sensitive to errors in natural mortality rate. We present an estimation method that quantifies the change in LEP by a fishery when only length frequency samples, one early in the fishery and one recent, are available for assessment. Using simulated length frequency data with known parameter values, estimates of LEP had undetectable bias when challenged with random sampling variability and sample sizes as low as 100. Simulation of artificial data with (i) growth parameters that differed from the estimation model, (ii) transient size structures, and (iii) recruitment variability led to predictably biased estimates. In a direct comparison with the spawning potential ratio reference point, fractional LEP was much less sensitive to errors in natural mortality rate. Application of this method to length frequency data for blue rockfish (Sebastes mystinus) for years between 1980 and 2003 suggests that during this interval, LEP has been reduced to levels of concern.


2021 ◽  
Vol 2 (1) ◽  
pp. 16-23
Author(s):  
Joseph Aggrey-Fynn ◽  
Divine Worlanyo Hotor

Sphyraena sphyraena (Linnaeus, 1758) and Apsilus fuscus (Valenciennes, 1830) are commercially important fish species in Ghana. The stocks are exploited mainly by the artisanal and semi-industrial fisheries. Growth and mortality rates, and exploitation levels of the two stocks in inshore waters of Ghana were assessed as a contribution to fill the knowledge gap on the species. Samples were obtained from three landing sites along the coast of Ghana from February to July, 2017. Length-frequency data were used to estimate growth, mortality and exploitation ratios. The modal class for S. sphyraena was 37.0–39.9 cm total length (TL) and 34.0–35.9 cm TL for A. fuscus. The length and weight relationships established that growth in S. sphyraena was negative allometric, whereas that of A. fuscus was isometric. The estimated growth parameters from the length frequency data fitted with the von Bertalanffy growth function were asymptotic length (L∞) of 69.9 cm TL for S. sphyraena and 53.5 cm TL for A. fuscus. The growth constant (K) was calculated as 1.64 yr-1 for S. sphyraena and 0.50 yr-1 for A. fuscus. The mean length-at-first capture (Lc) was found to be lower than the mean length at sexual maturity (Lm) for both species. The sex ratio showed a dominance of females over males in S. sphyraena, and 1:1 for A. fuscus. The total mortality rate (Z) for S. sphyraena was more than for A. fuscus. The estimated natural mortality (M) was 1.88 yr-1 for S. sphyraena and 0.74 yr-1 for A. fuscus whilst fishing mortality (F) rate was 3.04 yr-1 for S. sphyraena and 0.93 yr-1 for A. fuscus. The exploitation ratio showed that both fish stocks were exploited over the optimum levels. The estimated population parameters of the species obtained from the study, therefore, might be useful for the sustainable management of the stocks.


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