Estimation of Individual Growth Parameters of the Cortes GeoduckPanopea globosafrom the Central Gulf of California using a Multimodel Approach

2012 ◽  
Vol 31 (3) ◽  
pp. 725-732 ◽  
Author(s):  
Rolando Cruz-Vásquez ◽  
Guillermo Rodríguez-Domínguez ◽  
Edgar Alcántara-Razo ◽  
Eugenio Alberto Aragón-Noriega
Keyword(s):  
Gulf Of California ◽  
Growth Parameters ◽  
Individual Growth

scholarly journals Using Observed Residual Error Structure Yields the Best Estimates of Individual Growth Parameters

Fishes ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 35
Author(s):  
Marcelo V. Curiel-Bernal ◽  
E. Alberto Aragón-Noriega ◽  
Miguel Á. Cisneros-Mata ◽  
Laura Sánchez-Velasco ◽  
S. Patricia A. Jiménez-Rosenberg ◽  
...  
Keyword(s):  
Fish Species ◽  
Gulf Of California ◽  
Growth Parameters ◽  
Growth Models ◽  
Growth Parameter ◽  
Individual Growth ◽  
Von Bertalanffy ◽  
Error Structure ◽  
Endangered Fish ◽  
Constant Variance

Obtaining the best possible estimates of individual growth parameters is essential in studies of physiology, fisheries management, and conservation of natural resources since growth is a key component of population dynamics. In the present work, we use data of an endangered fish species to demonstrate the importance of selecting the right data error structure when fitting growth models in multimodel inference. The totoaba (Totoaba macdonaldi) is a fish species endemic to the Gulf of California increasingly studied in recent times due to a perceived threat of extinction. Previous works estimated individual growth using the von Bertalanffy model assuming a constant variance of length-at-age. Here, we reanalyze the same data under five different variance assumptions to fit the von Bertalanffy and Gompertz models. We found consistent significant differences between the constant and nonconstant error structure scenarios and provide an example of the consequences using the growth performance index ϕ′ to show how using the wrong error structure can produce growth parameter values that can lead to biased conclusions. Based on these results, for totoaba and other related species, we recommend using the observed error structure to obtain the individual growth parameters.

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 Sex-associated variations in coral skeletal oxygen and carbon isotopic composition of <i>Porites panamensis</i> in the southern Gulf of California

2015 ◽  
Vol 12 (22) ◽  
pp. 18795-18827 ◽  
Author(s):  
R. A. Cabral-Tena ◽  
A. Sánchez ◽  
H. Reyes-Bonilla ◽  
A. H. Ruvalcaba-Díaz ◽  
E. F. Balart
Keyword(s):  
Gulf Of California ◽  
Growth Parameters ◽  
Isotope Composition ◽  
Seasonal Pattern ◽  
Carbon Isotopic Composition ◽  
Coral Growth ◽  
Metabolic Effects ◽  
Published Data ◽  
Isotope Record ◽  
Δ18o And Δ13c

Abstract. Coral δ18O variations are used as a proxy for changes in near sea surface temperature and seawater isotope composition. Skeletal δ13C of coral is frequently used as a proxy for solar radiation because most of its variability is controlled by an interrelationship between three processes: photosynthesis, respiration, and feeding. Coral growth rate is known to influence the δ18O and δ13C isotope record to a lesser extent. Recent published data show differences in growth parameters between female and male coral; thus, skeletal δ18O and δ13C are hypothesized to be different in each sex. To assess this difference, this study describes changes in the skeletal δ18O and δ13C record of four female and six male Porites panamensis coral collected in Bahía de La Paz, whose growth bands spanned 12 years. The isotopic data were compared to SST, precipitation, PAR, chlorophyll a, and skeletal growth parameters. Porites panamensis is a known gonochoric brooder whose growth parameters are different in females and males. Splitting the data by sexes explained 81 and 93 % of the differences of δ18O, and of δ13C, respectively, in the isotope record between colonies. Both isotope records were different between sexes. δ18O was higher in female colonies than in male colonies, with a 0.31 ‰ difference; δ13C was lower in female colonies, with a 0.28 ‰ difference. A difference in the skeletal δ18O implies an error in SST estimates of &amp;approx; 1.0 °C to &amp;approx; 2.6 °C. The δ18O records showed a seasonal pattern that corresponded to SST, with low correlation coefficients (−0.45, −0.32), and gentle slopes (0.09 ‰ °C−1, 0.10 ‰ °C−1) of the δ18O–SST relation. Seasonal variation in coral δ18O represents only 52.37 and 35.66 % of the SST cycle; 29.72 and 38.53 % can be attributed to δ18O variability in seawater. δ13C data did not correlate with any of the environmental variables; therefore, variations in skeletal δ13C appear to be driven mainly by metabolic effects. Our results support the hypothesis of a sex-associated difference in skeletal δ18O and δ13C signal, and suggest that environmental conditions and coral growth parameters affect skeletal isotopic signal differently in each sex.

scholarly journals Alternative models for allozyme-associated heterosis in the marine bivalve Spisula ovalis.

Genetics ◽  
1995 ◽  
Vol 139 (4) ◽  
pp. 1719-1726 ◽  
Author(s):  
P David ◽  
B Delay ◽  
P Berthou ◽  
P Jarne
Keyword(s):  
Genetic Basis ◽  
Linear Models ◽  
Growth Parameters ◽  
Shell Growth ◽  
Maximum Size ◽  
Age And Growth ◽  
Individual Growth ◽  
Marine Bivalve ◽  
Initial Growth ◽  
Genomic Effects

Abstract Correlations between allozyme heterozygosity and fitness-related traits, especially growth, have been documented in natural populations of marine bivalves. However, no consistent pattern has been exhibited, because heterotic effects on size vary with age and individual growth parameters are generally unknown. No consensus has emerged on the genetic basis of allozyme-associated heterosis. The species studied here, Spisula ovalis, displays annual shell growth lines, which allows us to compute individual age and growth dynamics over the whole life span. Our morphological study was coupled to a protein electrophoresis study at seven polymorphic loci. While the maximum size gained is not related to heterozygosity, the age at half maximum size, t1/2, is significantly negatively correlated with heterozygosity, indicating an heterotic effect on initial growth. The correlation between heterozygosity and size is expected to vanish when age increases, due to the form of the growth function. This decreasing correlation is consistent with previous studies. We compare the relative performances of five linear models to analyze the genetic basis of heterosis. Surprisingly, the largest part of variance in t1/2 is due to additive effects, the overdominant components being much weaker. Heterosis is therefore due to general genomic effects rather than to local overdominance restricted to allozymes or small neighboring chromosomal segments. A significant dependence of individual heterotic contributions of the enzyme loci upon expected heterozygosities, rather than metabolic function, further supports the hypothesis of enzymes acting as markers. General genomic effects can hold only if allozyme heterozygosity is positively correlated with heterozygosity at fitness-related genes scattered throughout the genome. This hypothesis is supported here by heterozygosity correlations between enzymatic loci.

Laser-Assisted on Demand Growth of Semiconducting Nanowires

2013 ◽  
Author(s):  
Sang-gil Ryu ◽  
David J. Hwang ◽  
Eunpa Kim ◽  
Jae-hyuck Yoo ◽  
Costas P. Grigoropoulos
Keyword(s):  
Growth Parameters ◽  
Direct Synthesis ◽  
Shape Selectivity ◽  
Individual Growth ◽  
Direct Integration ◽  
Uniform Size ◽  
Germanium Nanowires ◽  
On Demand ◽  
Illumination Direction ◽  
Single Substrate

We present laser-assisted direct synthesis of nanowires with site-, composition-, and shape-selectivity on a single substrate by employing a spatially confined laser heat source. Laser-assisted nanowire growth based on vapor-liquid-solid mechanism is conveniently studied with multiple growth parameters such as temperature, time, and illumination direction. On-demand direct integration of silicon and germanium nanowires are demonstrated in a hetero-array configuration by simply switching the reactant gases as the growth of nanowires is limited within the heat-affected zone induced by the laser. Since laser-induced local temperature field is able to drive the individual growth, each germanium nanowire is successfully synthesized with distinctively different geometric features from cylindrical to hexagonal pyramid shape. By regularly patterning gold catalysts prepared by electron beam lithography on Si(111), especially, we accomplished site- and shape-selective direct integration of germanium nanowires on a single substrate in vertical architecture. Considering that blanket furnace heating only produce nanowires with uniform size and shape, therefore, our work shows a route toward the facile fabrication of multifunctional nanowire based devices.

A maximum likelihood approach for estimating growth from tag–recapture data

1995 ◽  
Vol 52 (2) ◽  
pp. 252-259 ◽  
Author(s):  
You-Gan Wang ◽  
Mervyn R. Thomas ◽  
Ian F. Somers
Keyword(s):  
Maximum Likelihood ◽  
Growth Parameters ◽  
Profile Likelihood ◽  
Individual Variability ◽  
Maximum Length ◽  
Individual Growth ◽  
Von Bertalanffy ◽  
Maximum Likelihood Approach ◽  
Penaeus Semisulcatus ◽  
Likelihood Approach

The Fabens method is commonly used to estimate growth parameters k and l∞ in the von Bertalanffy model from tag–recapture data. However, the Fabens method of estimation has an inherent bias when individual growth is variable. This paper presents an asymptotically unbiassed method using a maximum likelihood approach that takes account of individual variability in both maximum length and age-at-tagging. It is assumed that each individual's growth follows a von Bertalanffy curve with its own maximum length and age-at-tagging. The parameter k is assumed to be a constant to ensure that the mean growth follows a von Bertalanffy curve and to avoid overparameterization. Our method also makes more efficient use of the measurements at tag and recapture and includes diagnostic techniques for checking distributional assumptions. The method is reasonably robust and performs better than the Fabens method when individual growth differs from the von Bertalanffy relationship. When measurement error is negligible, the estimation involves maximizing the profile likelihood of one parameter only. The method is applied to tag–recapture data for the grooved tiger prawn (Penaeus semisulcatus) from the Gulf of Carpentaria, Australia.

scholarly journals Age and individual growth of Mesodesma mactroides (Bivalvia) in the southernmost range of its distribution

2004 ◽  
Vol 61 (8) ◽  
pp. 1253-1259 ◽  
Author(s):  
Sandra M. Fiori ◽  
Enrique M. Morsán
Keyword(s):  
Growth Parameters ◽  
Atlantic Coast ◽  
Sandy Beaches ◽  
Growth Patterns ◽  
Individual Growth ◽  
Size Frequency Distribution ◽  
Frequency Distributions ◽  
Growth Increments ◽  
Size Frequency ◽  
External Shell

Abstract The yellow clam, Mesodesma mactroides, is an intertidal bivalve typical from sandy beaches of the South American Atlantic coast. Growth parameters of southernmost populations of M. mactroides were studied and compared with other populations. Thin shell sections were examined to describe internal shell layers and to contrast with external shell transparency. Periodicity of deposition of external growth increments was studied recording the degree of transparency of the shell border. Growth patterns were determined using modal progression analysis from size frequency distributions, analysis of external shell increments, and size-at-age data derived from inner shell layers. Growth parameters were described using the von Bertalanffy growth model. Both internal and external patterns were coincident and exhibited a succession of one translucent and one opaque region. The transparent region was deposited during summer. Growth differences found between populations may be related to unequal size of first ring in both beaches. This feature may originate from asynchrony in spawning and recruitment. The monthly analysis of shell length size frequency distribution shows that growth of M. mactroides is seasonal. Estimations of asymptotic size of studied populations and others located at the southern (coldest) half of the geographical range of distribution suggest a negative relation with latitude.

Age and growth of the banded guitarfish Zapteryx exasperata (Chondrichthyes: Trygonorrhinidae)

2018 ◽  
Vol 69 (1) ◽  
pp. 66 ◽  
Author(s):  
Fabián Cervantes-Gutiérrez ◽  
Javier Tovar-Ávila ◽  
Felipe Galván-Magaña
Keyword(s):  
Goodness Of Fit ◽  
Growth Parameters ◽  
Age And Growth ◽  
Biological Information ◽  
Individual Growth ◽  
Biometric Data ◽  
Growth Band ◽  
Growth Coefficient ◽  
Demographic Models ◽  
First Time

The banded guitarfish (Zapteryx exasperata) is the third most abundant ray species in the artisanal elasmobranch fishery of Baja California Sur, Mexico. However, there is no biological information about its age and growth parameters, limiting the application of some quantitative population assessment methods, such as demographic models. The aim of the present study was to estimate, for the first time, age and individual growth of Z. exasperata. Biometric data from 244 individuals and 236 vertebrae were analysed. The largest number of banded guitarfish in fishery landings was observed during April and August, with a female:male sex ratio of 1:1.8. The size range was 56.4–103-cm total length (TL) for females and 51.6–92cm TL for males, with females being significantly larger than males (P<0.05). The periodicity of the vertebral edge suggests that growth band pairs form annually. The estimated age structure was 5–22.6 years for females and 4–19.6 years for males, with significant differences between sexes (P<0.01). The goodness-of-fit of three models was evaluated. For the von Bertalanffy growth model, the parameters were as follows. For females: theoretical maximum length, L∞ = 100.71cm TL; growth coefficient, k = 0.144year–1; and theoretical age at length zero, t0 = –0.39years. For males: L∞ = 89.78cm TL; k = 0.174year–1; and t0 = –0.65years.

Well-Being Curves Across Transitions

2010 ◽  
Vol 69 (1) ◽  
pp. 15-29 ◽  
Author(s):  
Sonja Perren ◽  
Roger Keller ◽  
Marco Passardi ◽  
Urte Scholz
Keyword(s):  
Convergent Validity ◽  
Growth Parameters ◽  
Well Being ◽  
Situational Factors ◽  
Individual Growth ◽  
Personality Factors ◽  
Subjective Well Being ◽  
Retrospective Design ◽  
The Individual ◽  
Adaptation Processes

A newly developed instrument (retrospective well-being curves: WBC) was applied in two studies. In Study 1, a sample of 145 adults (M = 26.6 years) completed the WBC twice for different normative transitions. In Study 2, 151 university freshmen (M = 21.5 years) reported on their subjective well-being at 9 consecutive measurement points during their transition to university and completed the WBC at T10. In both studies, personality factors were assessed. Retest reliability of the individual growth parameters (intercept, linear, and quadratic change) was moderate to high (Study 1), whereas convergent validity of the growth parameters was moderate (Study 2). The results demonstrated distinct well-being trajectories for different transitions. Situational factors (e.g., timing) and personality factors (neuroticism and extraversion) were significantly associated with well-being. The results indicate that, although the use of the WBC may be limited by its retrospective design, the instrument provides a time-efficient way of measuring hedonic adaptation processes.

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