Effects of intrapopulation variability on von Bertalanffy growth parameter estimates from equal mark–recapture intervals

1997 ◽  
Vol 54 (9) ◽  
pp. 2025-2032
Author(s):  
E B Smith ◽  
F M Williams ◽  
C R Fisher
Keyword(s):  
Growth Parameters ◽  
Growth Parameter ◽  
Parameter Estimates ◽  
Growth Equation ◽  
Size Distributions ◽  
Von Bertalanffy ◽  
Initial Size ◽  
Estimation Errors ◽  
Mark Recapture ◽  
Intrapopulation Variability

The effects of intrapopulation variability on the parameter estimates of the von Bertalanffy growth equation have received discussion in the literature. Here we evaluated the effects of intrapopulation variability, using computer simulations, on four commonly used methods for estimating the von Bertalanffy growth parameters: the Ford-Walford plot, Ricker's method, Bayley's method, and Fabens' method. Intrapopulation variability in growth rates (k) and maximum sizes ( L infinity ) plus initial size distributions and measurement error, were tested for their effects on the accuracy of the parameter estimates using simulated mark-recapture data with equal recapture intervals. Fabens' method and a modified Ford-Walford plot provided the most accurate estimates in all cases, but when intrapopulation variability was large, they performed poorly. With moderate intrapopulation variability, the bias in estimates was small although between-sample variance was quite large. Biased initial size distributions without either small or large size classes cause a magnification of the estimation errors. Without knowledge of the degree of intrapopulation variability in a natural population, large errors of unknown magnitude in parameter estimation can result, and care should be taken when interpreting these estimates. However, if this variability can be quantified, then approximate parameter estimate errors can be obtained.

scholarly journals Two-step Procedure Based on the Least Squares and Instrumental Variable Methods for Simultaneous Estimation of von Bertalanffy Growth Parameters

2019 ◽  
Vol 10 (2) ◽  
pp. 49-81 ◽  
Author(s):  
Ivelina Yordanova Zlateva ◽  
Nikola Nikolov
Keyword(s):  
Least Squares ◽  
Instrumental Variable ◽  
Initial Conditions ◽  
Growth Parameters ◽  
Individual Growth ◽  
Simultaneous Estimation ◽  
Parameter Estimates ◽  
Growth Equation ◽  
Von Bertalanffy ◽  
Step Procedure

Advanced in the present article is a Two-step procedure designed on the methods of the least squares (LS) and instrumental variable (IV) techniques for simultaneous estimation of the three unknown parameters L∞, K and t0, which represent the individual growth of fish in the von Bertalanffy growth equation. For the purposes of the present analysis, specific MATLAB-based software has been developed through simulated data sets to test the operational workability of the proposed procedure and pinpoint areas of improvement. The resulting parameter estimates have been analyzed on the basis of consecutive comparison (the initial conditions being the same) between the results delivered by the two-step procedure for simultaneous estimation of L∞, K and t0 and the results obtained via the most commonly employed methods for estimating growth parameters; first, use has been made of the Gulland-and-Holt method for estimating the asymptotic length L∞and the curvature parameter K, followed by the von Bertalanffy method for estimation of t0.

scholarly journals Growth Parameters and Spawning Season Estimation of Four Important Flyingfishes in the Kuroshio Current Off Taiwan and Implications From Comparisons With Global Studies

2022 ◽  
Vol 8 ◽  
Author(s):  
Shui-Kai Chang ◽  
Tzu-Lun Yuan ◽  
Simon D. Hoyle ◽  
Jessica H. Farley ◽  
Jen-Chieh Shiao
Keyword(s):  
Growth Parameters ◽  
Growth Models ◽  
Growth Parameter ◽  
Optimal Growth ◽  
Kuroshio Current ◽  
Parameter Estimates ◽  
Special Importance ◽  
Von Bertalanffy ◽  
Multiple Model ◽  
The Kuroshio

Growth shapes the life history of fishes. Establishing appropriate aging procedures and selecting representative growth models are important steps in developing stock assessments. Flyingfishes (Exocoetidae) have ecological, economic, and cultural importance to many coastal countries including Taiwan. There are 29 species of flyingfishes found in the Kuroshio Current off Taiwan and adjacent waters, comprising 56% of the flyingfishes taxa recorded worldwide. Among the six dominant species in Taiwan, four are of special importance. This study reviews aging data of these four species, documents major points of the aging methods to address three aging issues identified in the literature, and applies multi-model inference to estimate sex-combined and sex-specific growth parameters for each species. The candidate growth models examined included von Bertalanffy, Gompertz, Logistic, and Richards models, and the resulting optimal model tended to be the von Bertalanffy model for sex-combined data and Gompertz and von Bertalanffy models for sex-specific cases. The study also estimates hatch dates from size data collected from 2008 to 2017; the results suggest that the four flyingfishes have two spawning seasons per year. Length-weight relationships are also estimated for each species. Finally, the study combines the optimal growth estimates from this study with estimates for all flyingfishes published globally, and statistically classifies the estimates into clusters by hierarchical clustering analysis of logged growth parameters. The results demonstrate that aging materials substantially affect growth parameter estimates. This is the first study to estimate growth parameters of flyingfishes with multiple model consideration. This study provides advice for aging flyingfishes based on the three aging issues and the classification analysis, including a recommendation of using the asterisci for aging flyingfishes to avoid complex otolith processing procedures, which could help researchers from coastal countries to obtain accurate growth parameters for many flyingfishes.

Effect of temporal changes in size composition on estimates of von Bertalanffy growth parameters for Gemfish, Rexa solandri (Cuvier), Gempylidae

1992 ◽  
Vol 43 (5) ◽  
pp. 1229 ◽  
Author(s):  
K.R. Rowling ◽  
DD Reid
Keyword(s):  
Likelihood Ratio ◽  
Growth Parameters ◽  
Growth Parameter ◽  
Size Composition ◽  
Likelihood Ratio Tests ◽  
Standard Errors ◽  
Parameter Estimates ◽  
Von Bertalanffy ◽  
Different Populations ◽  
Best Estimates

Estimates of von Bertalanffy growth parameters were made for mature (>3-year-old) gemfish (Rexea solandri), using otoliths sampled biennially from commercial catches between 1980 and 1986. During this period, there was a significant decline in the mean length of mature gemfish in the catch. Large variations in growth-parameter estimates were found over the period sampled (e.g. L∞ ranged between 87.3 and 130.3 cm for males and between 113.1 and 134.7 cm for females). Likelihood-ratio tests showed many of the growth-parameter estimates to be significantly different between the years sampled. Inclusion in the analyses of data for juvenile (1- to 3-year-old) fish considerably reduced both the standard errors of the parameter estimates and the significance of the variations between them. Comparison of parameters estimated by following the growth of individual cohorts spawned in 1975 and 1981 suggested that the variations in the parameters for the 1980-86 data were caused by differences in the length composition of the samples rather than by changes in the growth rate of the fish. The results suggest the need for care when comparing growth parameters estimated for different populations, especially when there are large differences in length composition. The best estimates of growth parameters for gemfish were considered to be those derived from the aggregate data for the whole of the period sampled, including the data for juveniles. For male gemfish these best estimates (with asymptotic standard errors in parentheses) were L∞ =97.5 (0.8) cm, K=0.212 (0.005) year-1 and to = - 0.54 (0.05) years, and for females the estimates were L∞ = 109.4 (0.6) cm, K= 0.180 (0.003) year-1 and to= -0.63 (0.04) years. Likelihood-ratio tests showed these estimates of L∞ and K to be significantly different between the sexes.

scholarly journals Pertumbuhan dan Struktur Umur Kerang Kepah (Meretrix meretrix) di Kampung Nipah Desa Sei Nagalawan Kecamatan Perbaungan Kabupaten Serdang Bedagai

2017 ◽  
Vol 4 (2) ◽  
pp. 316
Author(s):  
Nafi Sakila ◽  
Dinda Ayu Ramadhani ◽  
Ani Suryanti
Keyword(s):  
Natural Resources ◽  
Random Sampling ◽  
Growth Parameters ◽  
Growth Parameter ◽  
Sampling Technique ◽  
Simple Random Sampling ◽  
Sampling Time ◽  
Size Group ◽  
Age Group ◽  
Von Bertalanffy

Sei Nipah has enormous potential for natural resources. Natural resources that serve as the main livelihood in fulfilling daily needs in Kampung Nipah is shellfish. Shellfish (M. meretrix) is one of the shells that many interested by the surrounding community. The purpose of this research is to know growth parameter and age group of shellfish (M. meretrix) in Kampung Nipah. The sampling technique was done randomly (simple random sampling). Sampling time is done at low tide. Sampling was conducted in March - May 2017. The results showed differences in the length of different shells each month. The size group of shellfish (M. meretrix) found only one size group during the three months of the study. Analysis of shellfish growth parameters based on data of long frequency distribution showed length of infiniti (L?) 33,10 mm and growth growth (K) that was 1,21 per month. Von Bertalanffy Growth Parameters Lt = 33.1 (1-e [-1.21 (t + 0.12)]) Long infiniti size is seen the growth of shellfish shells can no longer be worked Shells reach maximum length at the age of 13 months with a shell length of 33.10 mm.The youthful shells have rapid growth and as age increases, when it reaches old age the rate of growth will slow even.

An improved method for estimating individual growth variability in fish, and the correlation between von Bertalanffy growth parameters

2002 ◽  
Vol 59 (3) ◽  
pp. 424-432 ◽  
Author(s):  
Graham M Pilling ◽  
Geoffrey P Kirkwood ◽  
Stephen G Walker
Keyword(s):  
Random Effects ◽  
Standard Method ◽  
Growth Parameters ◽  
Growth Parameter ◽  
Individual Growth ◽  
Reliable Estimate ◽  
Random Effects Model ◽  
Von Bertalanffy ◽  
Data Set ◽  
Growth Variability

A new method for estimating individual variability in the von Bertalanffy growth parameters of fish species is presented. The method uses a nonlinear random effects model, which explicitly assumes that an individual's growth parameters represent samples from a multivariate population of growth parameters characteristic of a species or population. The method was applied to backcalculated length-at-age data from the tropical emperor, Lethrinus mahsena. Individual growth parameter variability estimates were compared with those derived using the current "standard" method, which characterizes the joint distribution of growth parameter estimates obtained by independently fitting a growth curve to each individual data set. Estimates of mean von Bertalanffy growth parameters from the two methods were similar. However, estimated growth parameter variances were much higher using the standard method. Using the random effects model, the estimated correlation between population mean values of L[Formula: see text] and K was –0.52 or –0.42, depending on the marginal distribution assumed for K. The latter estimate had a 95% posterior credibility interval of –0.62 to –0.17. These represent the first reliable estimate of this correlation and confirm the view that these parameters are negatively correlated in fish populations; however, the absolute correlation value is somewhat lower than has been assumed.

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 690Growth in childhood and age at menarche: Insights from individual trajectory modelling

2021 ◽  
Vol 50 (Supplement_1) ◽  
Author(s):  
Lynne Giles ◽  
Melissa Whitrow ◽  
Alice Rumbold ◽  
Michael Davies ◽  
Vivienne Moore
Keyword(s):  
Random Effects ◽  
Growth Parameters ◽  
Growth Parameter ◽  
Hazard Ratio ◽  
Age At Menarche ◽  
Parameter Estimates ◽  
Early Puberty ◽  
Random Effects Models ◽  
Childhood Growth ◽  
Menstrual History

Abstract Background The relationship between patterns of weight gain across childhood and the onset of puberty remains unclear. We aimed to derive growth parameters (size, tempo, and velocity) from models of weight across childhood and to estimate their effects on age at menarche. Methods Serial height and weight measurements from birth to age 9.5 years for 557 children who took part in the Generation 1 cohort study were used, along with girls’ menstrual history at age 12-13 years. Shape invariant random effects models were fit to log(weight+1) for all available participants’ data (282 girls, 260 boys), and AIC used to identify the best-fitting model. In time-to-event models subsequently fit to the girls’ data to estimate effects of the growth parameters on menarcheal age, a censoring age of 12 years was used to define early puberty. Results A model with 4df and fixed and random effects for size and tempo and a fixed effect for velocity was preferred. Some 19% of girls began menstruating before age 12 years. Size and tempo were each associated with an increased hazard of earlier menarche; a 0.1 unit gain in size was associated with a hazard ratio of 1.75 (95%CI 1.32–2.33), and a 0.1 unit gain in tempo with a hazard ratio of 7.84 (95%CI 3.41–18.05). Conclusions Using all participants’ data gave more precise growth parameter estimates. Key messages Understanding mechanisms that drive increased size and tempo of childhood growth may help to elucidate the links between obesity and girls’ risk of early puberty.

Muskellunge Management: Fifty Years of Cooperation Among Anglers, Scientists, and Fisheries Biologists

2017 ◽  
Keyword(s):  
Growth Model ◽  
Mortality Rates ◽  
Fish Mortality ◽  
Minimum Length ◽  
Parameter Estimates ◽  
Von Bertalanffy ◽  
Mark Recapture ◽  
Passive Integrated Transponder ◽  
Reliable Parameter ◽  
Spring Lake

<em>Abstract</em>.—Accurate estimates of growth and mortality are important for management of recreational fisheries. Accurate age estimates often require the sacrifice of fish; thus, assessments of growth and mortality rates of trophy fishes such as Muskellunge <em>Esox masquinongy </em>often lack sufficient data. Mark–recapture history can be used as a nonlethal alternative to estimate growth and mortality in fishes. To determine the utility of this approach, we used data from a 17-year Muskellunge mark–recapture program conducted on two Illinois reservoirs (Kinkaid Lake and North Spring Lake). Von Bertalanffy parameter estimates by sex, lake, and tag type (passive integrated transponder and T-bar anchor tags) were obtained using a novel modification of the Fabens growth model and compared to von Bertalanffy growth estimates using known- or scale-aged fish. Mortality was calculated using both age- and length-based methods. Fabens growth model estimates of asymptotic length (<em>L</em><sub>∞</sub>) and growth coefficient (<EM>K</EM>) were within 6% (≤62 mm) and 23% (≤0.11) of corresponding von Bertalanffy growth model parameter estimates from known- or scale-aged fish by lake and sex. Provided that all sizes of fish are sampled, 4 years of mark–recapture data with more than 100 recaptures were found to be sufficient to produce reliable parameter estimates. Growth parameters differed between male fish tagged with passive integrated transponder or T-bar anchor tags but did not differ by tag type for females. Differences in Muskellunge growth and mortality rates between the two study lakes suggest that changing from a regionally applied minimum length limit to lake-specific minimum length limits may be warranted. Our results highlight the feasibility of mark–recapture data as a nonlethal technique to estimate population-specific growth and mortality rates for Muskellunge and the potential value of this approach in facilitating lake-specific Muskellunge management.

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