scholarly journals Growth and mortality estimates of Sardinella brasiliensis in the southeastern Brazilian Bight

1994 ◽  
Vol 42 (1-2) ◽  
pp. 113-127 ◽  
Author(s):  
Maria Cristina Cergole ◽  
Helio Valentini
Keyword(s):  
Growth Parameters ◽  
Total Mortality ◽  
Entire Period ◽  
Brazilian Coast ◽  
Growth Equation ◽  
Natural Mortality ◽  
Length Data ◽  
The Mean ◽  
The Difference ◽  
Von Bertalanffy Growth Equation

Length frequency analisys were applied for sardine data collected from commercial catches throughout the southeastern Brazilian coast in 1977-1987. Age/length keys were obtained by otolith ring countings and utilized to transform length into age composition. Growth parameters were estimated by the von Bertalanffy growth equation using age and length data for each year and for all the period of investigation. The mean growth parameters for the entire period were estimated as L∞ = 271 mm and K= 0.59 year-1. Instantaneous total mortality (Z) coefficients per year were estimated using catch curves and methods based on the mean length of the fish caught. Total mortality rate for the entire period was obtained through the average of the annual values. Natural mortality (M) was estimated using the Paul/s empirical equation (1980a), and fishing mortality (F) by the difference between total and natural mortality values.The results were Z = 3.6 year-1; M = 0.96 year-1; and F= 2.6 year-1.

Age, growth, and mortality of littlehead porgy, Calamus proridens, from southeast Florida coastal waters

2021 ◽  
Author(s):  
Michael L Burton ◽  
Jennifer C Potts ◽  
Ariel J Poholek ◽  
Jordan Page
Keyword(s):  
Coastal Waters ◽  
Southeastern United States ◽  
Fork Length ◽  
Total Mortality ◽  
Point Estimate ◽  
Growth Equation ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
Recreational Fisheries ◽  
Von Bertalanffy Growth Equation

Sectioned otoliths were used to age littlehead porgy Calamus proridens (n = 737) from southeastern Florida recreational fisheries. Otolith sections contained easily identifiable annuli and were reliable structures for aging littlehead porgy up to 11 yrs. Opaque zones were deposited from March to June (peaking in April). Littlehead porgy ranged from 1 to 11 yrs and 220 to 385 mm total length (TL). Body size relationships were TL = 1.09 FL + 16.06 (n = 3474, r2 = 0.95), FL = 0.87 TL – 1.15 (n = 3474, r2 = 0.95), W = 4.76 × 10 −5 TL2.80 (n = 6722, r2 = 0.86), and W = 1.2 × 10−4 FL2.71 (n = 3474, r2 = 0.90), where W is total weight (g) and FL is fork length (mm). Growth was not significantly different between two discrete geographic regions of Florida, and the von Bertalanffy growth equation was Lt = 335 (1 − e−0.41 (t + 2.13)) for all areas combined. The point estimate of natural mortality was M = 0.38, while age-specific estimates of M ranged from 0.60 to 0.41 yrs−1 for ages 1–11. Littlehead porgy were fully recruited to the headboat fishery by age-3 and catch curve analysis resulted in an estimate of total mortality Z = 1.08 for ages 3–7+. This study reports first estimates of life history parameters for littlehead porgy from Atlantic waters of the southeastern United States.

scholarly journals Growth parameters of Poecilia latipinna (Lesueur, 1821) (Actinopterygii, Poeciilidae) – an introduced species in brackish water of Wadi Al-Bahayes (Oman)

2021 ◽  
Vol 50 (3) ◽  
pp. 269-277
Author(s):  
Salim Serkan Güçlü ◽  
Saud M. Al Jufaili ◽  
Laith A. Jawad
Keyword(s):  
Growth Performance ◽  
Alien Species ◽  
Condition Factor ◽  
Growth Parameters ◽  
Growth Equation ◽  
Von Bertalanffy ◽  
Poecilia Latipinna ◽  
Weight Relationship ◽  
The Mean ◽  
Von Bertalanffy Growth Equation

Abstract This work is one of the first studies on the growth of Poecilia latipinna outside its natural habitat. The objective of our study was to investigate the growth parameters of the population of P. latipinna, which is an alien species in Oman (Wadi Al-Bahayes). The population structure of P. latipinna in Wadi Al-Bahayes (Oman; 23°40′47″N; 58°11′36″E) was studied in June and August 2020, using 124 fish. In the course of this study, the number of individuals of each sex, age, weight and size composition were determined. In addition, the total length–weight relationship (LRW) was calculated, as well as the von Bertalanffy growth equation. The mean growth performance (phi prime) and the condition factor were calculated. Males accounted for 37.10% and females for 62.90% of the population. The length–weight relationship and the von Bertalanffy growth equation were W = 0.0214 × L 2.7889 R2 = 0.9212, Lt = 11.46 (1 − e −0.127 (t + 2.71)) for males and Lt = 14.51 (1 − e−0.072 (t + 3.98)) for females. The mean growth performance and the condition factor were calculated as 1.22 for males and 1.18 for females and 1.54 for all specimens. The study shows that the population of the species is characterized by a wide age range. Consequently, monitoring of this alien species is highly recommended.

scholarly journals Several Growth Characteristics of an Invasive Cyprinid Fish (Carassius gibelio Bloch, 1782)

2013 ◽  
Vol 5 (2) ◽  
pp. 133-138 ◽  
Author(s):  
Sait BULUT ◽  
Ramazan MERT ◽  
Beklan ALGAN ◽  
Musa ÖZBEK ◽  
Bülent ÜNAL ◽  
...  
Keyword(s):  
Condition Factor ◽  
Growth Parameters ◽  
Gibel Carp ◽  
Growth Equation ◽  
Von Bertalanffy ◽  
Age Composition ◽  
Carassius Gibelio ◽  
The Mean ◽  
Von Bertalanffy Growth Equation ◽  
Index Value

Age composition, length-weight relationships, growth, and condition factors of the gibel carp (Carassius gibelio Bloch, 1782) were determined using specimens collected from Seyitler Reservoir between July 2005 to June 2006. A total of 149 gibel carp were observed and examined. The age composition of the samples ranged between I and VII years of age. It has been determined than 82.55% of the obtained samples are comprised of females, 16.11% is comprised of males and 1.34% is comprised of immature. The population is dominated by females able to reproduce gynogenetically. The mean fork lengths and mean weights of the population were 14.8-32.5 cm and 43.1-807.3 g respectively. The length-weight relation were calculated as W = 0.0696 L2.132, r=0.838 for females, for males W = 0.2942 L2.6417 r=0.784 and W = 0.0274 L2.9382, r=0.813 for all samples. The mean Fulton Condition Factor was calculated as 2.342 for females, 2.064 for males and 2.276 for all samples. Age-length and age-weight relations were determined according to von Bertalanffy growth equation formula. Growth parameters of the population were Lt = 48.09 [1-e-0.093(t+0.29)], and Wt=2323.62 [1-e-0.093(t+0.29)]2.9382. The growth performance index value (Ø´) was computed as 5.37 for all specimens.

scholarly journals Yield-per-Recruit and Relative Mean Biomass Estimates, and their Management Consequences, to the Penaeus Indicus Fishery in the Gulf of Masirah

1996 ◽  
Vol 1 ◽  
pp. 51
Author(s):  
M. S. M. Siddeek ◽  
R. Mohan ◽  
D. W. Johnson
Keyword(s):  
Growth Parameters ◽  
Total Mortality ◽  
High Yield ◽  
Average Weight ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
Fishing Season ◽  
Penaeus Indicus ◽  
Length Data ◽  
Yield Per Recruit

The von Bertalanffy growth parameters estimated based on the 1990/91 carapace length data of Penaeus indicus  from the Gulf of Masirah, Oman were used to calculate total mortality, yield-per-recruit ( i.e. average weight of a shrimp from a cohort under a given fishing pattern) , and relative mean biomass ( i.e. exploited cohort biomass over un-exploited cohort biomass) for the population sampled. The instantaneous total mortality coefficient value indicated under exploitation in 1990/91. When different fishing seasons scenarios were considered with the current total mortality level but with a range of natural mortality values, high yield, per recruit and relative mean biomass values were shown for October-April and November-April fishing seasons. The fishing season is currently late August to end of April. Thus, a one to two-month delay in the fishing season appears to be beneficial to this fishery.

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.  

scholarly journals Stock dynamics of the brushtooth lizardfish Saurida undosquamis (Richardson, 1848) from a tropical multispecies fishery in the southeastern Arabian Sea

2019 ◽  
Vol 32 ◽  
pp. 9
Author(s):  
Theparambil Mohamed Najmudeen ◽  
Pallangattu Kochukandan Seetha ◽  
Payiyappanal Ulahannan Zacharia
Keyword(s):  
Arabian Sea ◽  
Growth Parameters ◽  
Total Mortality ◽  
Fishing Effort ◽  
Reference Points ◽  
Trophic Levels ◽  
Southeastern Arabian Sea ◽  
Eastern Arabian Sea ◽  
The Mean ◽  
First Maturity

The brushtooth lizardfish Saurida undosquamis (Richardson, 1848) is a high trophic level benthic predator and is one among the most exploited demersal finfish species from eastern Arabian Sea by Indian trawlers. However, in recent years, the landings of many top predator fishes including S. undosquamis showed a declining trend resulting in a steady decline in the mean trophic levels of the fishes caught commercially in the region. We investigated the growth, mortality and stock dynamics of S. undosquamis harvested by mechanised trawls in the southeastern Arabian Sea, using length-based methods for the data collected during 2012–2016. Besides, Bayesian state-space implementation of the Schaefer model (BSM) and catch-based MSY (CMSY) estimation were also made using the data for the period 1985–2016. Total length of the fish ranged from 5.5 to 34.5 cm with average annual mean length of 22.0 cm during 2012–2016. The growth parameters L∞ and K were 37.3 cm and 0.41 year−1, respectively. The natural, fishing and total mortality coefficients were 0.92, 2.58 and 3.5, respectively and exploitation ratio was 0.82. The length at first maturity was estimated at 21.4 cm for females. The mean size in the catch is lower than the optimum length for exploitation. Fisheries reference points (MSY, Fmsy, Bmsy) as well as relative stock size (B/Bmsy) and exploitation (F/Fmsy) estimated from catch data and broad priors for resilience (r), implies an exploitation of 30% below Bmsy level. Results from the length-based Thompson and Bell prediction model indicates that reducing the present level of fishing effort by 40% would lead to a harvest of the species at a sustainable level. As “fishing down food web” is reported in recent years from eastern Arabian Sea, the exploitation of top predators need to be maintained at sustainable levels to prevent ecosystem changes along the region.

scholarly journals Relationship between newborn leptin levels and selected growth parameters

2019 ◽  
Vol 47 (6) ◽  
pp. 2591-2597 ◽  
Author(s):  
Amer Mahmoud Sindiani ◽  
Rawan Obeidat ◽  
Omar Jbarah ◽  
Ethar Hazaimeh
Keyword(s):  
Gestational Age ◽  
Head Circumference ◽  
Growth Parameters ◽  
Cross Sectional ◽  
Intrauterine Growth ◽  
The North ◽  
Term Newborns ◽  
The Mean ◽  
The Difference ◽  
Umbilical Cord Vein

Objectives This study aimed to determine leptin levels in term newborns who were born in the north of Jordan. We also aimed to investigate the relationships of leptin levels with fetal growth parameters, and to assess the difference in leptin levels according to sex and gestational age. Methods A cross-sectional descriptive study that involved 170 term newborns was conducted. A working sheet for data collection was created for each newborn and included sex, weight, length, head circumference, gestational age, and Apgar score. Blood samples were obtained from the umbilical cord vein of newborns after delivery to measure serum leptin levels. Data are shown as frequency, percentages, means, and standard deviations. Results We found that the mean leptin level was 1.17 ± 0.48 ng/mL. The independent t-test showed that the mean leptin level in boys (0.93 ± 0. 34 ng/mL) was significantly lower than that in girls (1.38 ± 0.47 ng/mL). Pearson’s correlations showed that leptin levels of newborns were positively and significantly correlated with weight, length, and head circumference. Conclusion In Jordanian healthy term newborns, leptin levels correlate with sex and intrauterine growth parameters.

Age, growth and reproductive biology of the saddled seabream (Oblada melanura) in the North Aegean Sea, Eastern Mediterranean

2020 ◽  
Vol 49 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Ismail Burak Daban ◽  
Ali Ismen ◽  
Mukadder Arslan Ihsanoglu ◽  
Koray Cabbar
Keyword(s):  
Growth Parameters ◽  
Eastern Mediterranean ◽  
Length Distribution ◽  
Total Mortality ◽  
Aegean Sea ◽  
Growth Equation ◽  
Weight Relationship ◽  
The North ◽  
North Aegean Sea ◽  
First Maturity

AbstractThis study determines the length distribution, length– weight relationship, age, growth parameters, mortality rate, sex ratios, length at first maturity and reproduction of saddled seabream (Oblada melanura) collected monthly by fishermen around the Northern Aegean Sea between November 2017 and October 2018. The length–weight relationship was calculated as W=0.0091×L3.11 (R2=0.95) and positive allometric growth was found. The condition factor and GSI varied between 0.81–1.58 and 0.01–9.61, respectively. The spawning season extended from May to July and peaked in June. Total lengths at 50% maturity were 18.97 cm for males and 18.83 cm for females. Parameters of the von Bertalanffy growth equation were: L∞ =29.91 cm, K =0.27 per year, t0 =−0.82 year and age varied between 1 and 8. The instantaneous rates of total mortality (Z) and natural mortality (M) were 1.36 and 0.58 per year, respectively. Rates for fishing mortality F and exploitation E were 0.78 and 0.57 per year, respectively. The mean absolute fecundity (F) was 117 075±23 243 oocytes, ranging from 19130 to 470 132.

scholarly journals Properties of age compositions and mortality estimates derived from cohort slicing of length data

2014 ◽  
Vol 72 (1) ◽  
pp. 44-53 ◽  
Author(s):  
Lisa E. Ailloud ◽  
Matthew W. Smith ◽  
Amy Y. Then ◽  
Kristen L. Omori ◽  
Gina M. Ralph ◽  
...  
Keyword(s):  
Growth Parameters ◽  
Age Groups ◽  
Total Mortality ◽  
Frequency Distributions ◽  
Accuracy And Precision ◽  
High K ◽  
Length Data ◽  
High Age ◽  
Low K ◽  
Mortality Estimates

Abstract Cohort slicing can be used to obtain catch-at-age data from length frequency distributions when directly measured age data are unavailable. The procedure systematically underestimates the relative abundance of the youngest age groups and overestimates abundance at older ages. Cohort-sliced catch-at-age data can be used to estimate total mortality rate (Z) using a regression estimator or the Chapman–Robson estimator for right truncated data. However, the effect of cohort slicing on accuracy and precision of resulting Z estimates remains to be determined. We used Monte Carlo simulation to estimate the per cent bias and per cent root mean square error of the unweighted regression, weighted regression, and Chapman–Robson mortality estimators applied to cohort-sliced data. Incompletely recruited age groups were truncated from the cohort-sliced catch-at-age data using previously established recommendations and a variety of plus groups was used to combine older age groups. The sensitivity of the results to a range of plausible biological combinations of Z, growth parameters, recruitment variability, and length-at-age error was tested. Our simulation shows that cohort slicing can work well in some cases and poorly in others. Overall, plus group selection was more important in high K scenarios than it was in low K scenarios. Surprisingly, defining the plus group to start at a high age worked well in some cases, although length and age are poorly correlated for old ages. No one estimator was uniformly superior; we therefore provide recommendations concerning the appropriate estimator and plus group to use, depending on the parameters characterizing the stock. We further recommend that simulations be performed to determine exactly which plus group would be most appropriate given the scenario at hand.

scholarly journals Growth, Mortality and Exploitation Levels of Sphyraena sphyraena (Pisces: Sphyraenidae) and Apsilus fuscus (Pisces: Lutjanidae) in Ghanaian Waters

2021 ◽  
Vol 2 (1) ◽  
pp. 16-23
Author(s):  
Joseph Aggrey-Fynn ◽  
Divine Worlanyo Hotor
Keyword(s):  
Growth Parameters ◽  
Total Mortality ◽  
Growth Function ◽  
Frequency Data ◽  
Length Frequency ◽  
Fish Stocks ◽  
Von Bertalanffy Growth Function ◽  
Inshore Waters ◽  
The Mean ◽  
Length Frequency Data

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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