scholarly journals Age-based and reproductive biology of the Pacific Longnose Parrotfish Hipposcarus longiceps from Guam

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e4079 ◽  
Author(s):  
Brett M. Taylor ◽  
Eric Cruz
Keyword(s):  
Life History ◽  
Fishery Management ◽  
Stock Assessment ◽  
Fork Length ◽  
Growth Patterns ◽  
Life History Trait ◽  
Fishery Resource ◽  
Species Vulnerability ◽  
The Pacific ◽  
Improved Model

The Pacific longnose parrotfish Hipposcarus longiceps (Valenciennes 1840) represents a prime fishery resource throughout much of the tropical Pacific. In this study, we sampled the species from the Guam commercial fishery market across five consecutive years to characterize reproductive and age-based demographic information imperative for informed fishery management. Compared with other parrotfishes, this species was found to be large-bodied, but has only a moderate life span of 10 + years. Hipposcarus longiceps was confirmed as a diandric protogynous hermaphrodite with highly sex-specific growth patterns and an overall mean asymptotic length of 434 mm fork length (FL). Females were estimated to reach median maturity at 329 mm FL (2.4 years) and have a median length at female-to-male sex change of 401 mm FL. Life-history trait values derived here were used to update previous models relating life history and vulnerability to overexploitation. We found that enhancement of just one species’ trait values improved model fits considerably, which strengthens the conclusion that life-history traits are a strong determinant of species’ vulnerability in the parrotfishes. This information is an imperative complement to other data sources facilitating formal stock assessment of a key fishery target.

scholarly journals From the Adriatic to Northern Norway—geographic differences in moult increment and moult probability of the European lobster (Homarus gammarus), across the natural range

2020 ◽  
Author(s):  
Matthew T Coleman ◽  
Anne-Lisbeth Agnalt ◽  
Jack Emmerson ◽  
Martial Laurens ◽  
Joanne S Porter ◽  
...  
Keyword(s):  
Fishery Management ◽  
Stock Assessment ◽  
Generalized Additive Models ◽  
Growth Patterns ◽  
Additive Models ◽  
Geographical Differences ◽  
Homarus Gammarus ◽  
Northern Latitudes ◽  
Natural Range ◽  
Geographic Differences

Abstract This study collated existing data on lobster moult increment from studies across the range of Homarus gammarus, together with new tagging data from Orkney, United Kingdom. Generalized additive models were used to investigate geographical differences in absolute moult increment and moult probability. Absolute moult increment was seen to differ significantly between regions and between sexes and showed a non-linear relationship with pre-moult size. Smaller absolute moult increments were observed at southern and northern latitudes with larger increments observed in the centre of the species range. Temperature was identified as a significant factor explaining differences in absolute moult increment between regions, consistent with there being a thermal optimum for growth for in H. gammarus. Moult and double moult probabilities decline with pre-moult size, with greatest probability of moulting occurring around day 250. Probability of double moulting increased with mean annual sea surface temperature. Regionally variable growth patterns, and localized adaptation to abiotic variables such as temperature, should therefore be taken into account when defining lobster stock assessment and fishery management areas.

Juveniles recruitment and daily growth of the southern stock of Mugil liza (Actinopterygii; Fam. Mugilidae): new evidence for the current life-history model

2017 ◽  
Vol 99 (1) ◽  
pp. 215-221 ◽  
Author(s):  
Damián L. Castellini ◽  
Daniel Brown ◽  
Nicolás A. Lajud ◽  
Juan M. Díaz De Astarloa ◽  
Mariano González-Castro
Keyword(s):  
Life History ◽  
Fishery Management ◽  
Atlantic Coast ◽  
Age Determination ◽  
Calculated Data ◽  
Small Scale ◽  
Daily Growth ◽  
Western Atlantic ◽  
Fishery Resource ◽  
Growth Increments

Mugil liza is distributed along the western Atlantic coast. It is a commercially exploited species in Argentina, supporting a small-scale fishery conducted by an artisanal fleet. Age determination of fishes constitutes an important key issue for fishery management. The age, growth and recruitment of M. liza juveniles in Mar Chiquita coastal lagoon and Las Brusquitas creek (Buenos Aires, Argentina), were estimated by means of the analysis of the sagittal otoliths of fish collected during January to December of 2014. Ages were estimated by counting and measuring daily growth increments in otoliths under a light microscope. A total of 735 specimens ranging from 19 to 71.5 mm SL and from 67 to 212 days age was analysed. Lengths at previous ages were determined by back-calculation, a linear growth model was fitted to the back-calculated data: SL = 0.2468 + 2.0516; R2 = 0.9945. Two peaks of recruiters were observed from February to March, and from October to November in 2014. Mean ages in days of Querimana and juveniles at the recruitment time were 84.07 ± 14.43 days and 87.56 ± 19.51 days, respectively. The hatching dates of specimens showed two spawning seasons. One was from December 2013 to January 2014, and the second one from July to August 2014. The assessment carried on this work generated age determination values that support previous findings, contributing to make a more accurate description of the life-history model currently used. In addition, valuable information has been generated to give better advice for improving the management of the fishery resource.

Estimates of growth and longevity of six species of freshwater shrimps (Macrobrachium spp.) (Decapoda: Caridea: Palaemonidae) from Costa Rica

2019 ◽  
Vol 40 (1) ◽  
pp. 45-57
Author(s):  
Mauricio A Ibarra ◽  
Ingo S Wehrtmann
Keyword(s):  
Costa Rica ◽  
Maximum Likelihood ◽  
Maximum Likelihood Method ◽  
Growth Models ◽  
Stock Assessment ◽  
Anthropogenic Impacts ◽  
Growth Patterns ◽  
Likelihood Method ◽  
Total Length ◽  
The Pacific

Abstract Information about growth is of particular relevance for stock assessment and management as well as for evaluating the aquaculture potential of any decapod species, but this information is lacking for the Central American species of MacrobrachiumSpence Bate, 1868. We collected specimens of six species of Macrobrachium monthly (February 2006 to August 2008) along the Pacific slope of Costa Rica. The collected individuals were sexed and weighted, and total length (TL) and carapace length (CL) were measured. The von Bertalanffy growth model was fitted to the data by applying the maximum likelihood method. The species analyzed reaching theoretically the largest sizes were M. americanum (Spence Bate, 1868), M. tenellum (Smith, 1871), and M. panamenseRathbun, 1912. With few exceptions, maximum sizes of all species were generally higher than those published in previous reports, suggesting that environmental conditions are favorable and anthropogenic impacts may be less severe in Costa Rica than in other countries. Only M. americanum exceeded the asymptotic total length estimates of other species, corroborating that this species is considered as one of the largest congeners worldwide. Estimated maximum age ranged from 3.9 (M. occidentaleHolthuis, 1950) to 11.5 yrs (M. tenellum). All six Macrobrachium species showed a positive allometric growth type. The model describing the length-weight relationship was statistically significant (P < 0.05) for all species. Although the maximum likelihood method has been applied so far mainly to compare different growth models, here we used this method to generate the first growth estimates for the six species from Costa Rica, and future studies might use this method to compare growth patterns among different species.

scholarly journals Multi-Model Approach on Growth Estimation and Association With Life History Trait for Elasmobranchs

2021 ◽  
Vol 8 ◽  
Author(s):  
Kwang-Ming Liu ◽  
Chiao-Bin Wu ◽  
Shoou-Jeng Joung ◽  
Wen-Pei Tsai ◽  
Kuan-Yu Su
Keyword(s):  
Life History ◽  
Growth Model ◽  
Growth Models ◽  
Stock Assessment ◽  
Information Criterion ◽  
Age And Growth ◽  
Life History Trait ◽  
Best Fit ◽  
Two Parameter ◽  
Model Approach

Age and growth information is essential for stock assessment of fish, and growth model selection may influence the accuracy of stock assessment and subsequent fishery management decision making. Previous descriptions of the age and growth of elasmobranchs relied mainly on the von Bertalanffy growth model (VBGM). However, it has been noted that sharks, skates and rays exhibit significant variety in size, shape, and life history traits. Given this variation, the VBGM may not necessarily provide the best fit for all elasmobranchs. This study attempts to improve the growth estimates by using multi-model approach to test four growth models—the VBGM, the two-parameter VBGM, the Robertson (Logistic) and the Gompertz models to fit observed or simulated length-at-age data for 38 species (44 cases) of elasmobranchs. The best-fit growth model was selected based on the bias corrected Akaike’s Information Criterion (AICc), the AICc difference, the AICc weight, the Bayesian Information Criterion (BIC), and the Leave-one-out cross-validation (LOOCV). The VBGM and two-parameter VBGM provide the best fit for species with slow growth and extended longevity (L∞ > 100 cm TL, 0.02 < k < 0.25 yr–1), such as pelagic sharks. For fast-growing small sharks (L∞ < 100 cm TL, kr or kg > 0.2 yr–1) in deep waters and for small-sized demersal skates/rays, the Robertson and the Gompertz models provide the best fit. The best-fit growth models for small sharks in shallow waters are the two-parameter VBGM and the Robertson model. Although it was found that the best-fit growth models for elasmobranchs were associated with their life history trait, exceptions were also noted. Therefore, a multi-model approach incorporating with the best-fit model selected for each group in this study was recommended in growth estimation for elasmobranchs.

A perspective on steepness, reference points, and stock assessment

2013 ◽  
Vol 70 (6) ◽  
pp. 930-940 ◽  
Author(s):  
Marc Mangel ◽  
Alec D. MacCall ◽  
Jon Brodziak ◽  
E.J. Dick ◽  
Robyn E. Forrest ◽  
...  
Keyword(s):  
Life History ◽  
Fishery Management ◽  
Stock Assessment ◽  
Reference Points ◽  
Production Model ◽  
Published Data ◽  
Difficult Situation ◽  
Life History Parameters ◽  
Stock Recruitment ◽  
Age Structured

We provide a perspective on steepness, reference points for fishery management, and stock assessment. We first review published data and give new results showing that key reference points are fixed when steepness and other life history parameters are fixed in stock assessments using a Beverton–Holt stock–recruitment relationship. We use both production and age-structured models to explore these patterns. For the production model, we derive explicit relationships for steepness and life history parameters and then for steepness and major reference points. For the age-structured model, we are required to generally use numerical computation, and so we provide an example that complements the analytical results of the production model. We discuss what it means to set steepness equal to 1 and how to construct a prior for steepness. Ways out of the difficult situation raised by fixing steepness and life history parameters include not fixing them, using a more complicated stock–recruitment relationship, and being more explicit about the information content of the data and what that means for policy makers. We discuss the strengths and limitations of each approach.

Review of the life history, fisheries, and stock assessment for small tunas in the Atlantic Ocean

2021 ◽  
Author(s):  
Flávia Lucena-Frédou ◽  
Bruno Mourato ◽  
Thierry Frédou ◽  
Pedro G. Lino ◽  
Rubén Muñoz-Lechuga ◽  
...  
Keyword(s):  
Life History ◽  
Atlantic Ocean ◽  
Stock Assessment

scholarly journals Mapping the adaptive landscape of a major agricultural pathogen reveals evolutionary constraints across heterogeneous environments

2021 ◽  
Author(s):  
Anik Dutta ◽  
Fanny E. Hartmann ◽  
Carolina Sardinha Francisco ◽  
Bruce A. McDonald ◽  
Daniel Croll
Keyword(s):  
Life History ◽  
Large Scale ◽  
Life History Traits ◽  
Genetic Correlations ◽  
Stress Factors ◽  
Life History Trait ◽  
Adaptive Landscape ◽  
Heterogeneous Environments ◽  
Growth Responses ◽  
Trade Offs

AbstractThe adaptive potential of pathogens in novel or heterogeneous environments underpins the risk of disease epidemics. Antagonistic pleiotropy or differential resource allocation among life-history traits can constrain pathogen adaptation. However, we lack understanding of how the genetic architecture of individual traits can generate trade-offs. Here, we report a large-scale study based on 145 global strains of the fungal wheat pathogen Zymoseptoria tritici from four continents. We measured 50 life-history traits, including virulence and reproduction on 12 different wheat hosts and growth responses to several abiotic stressors. To elucidate the genetic basis of adaptation, we used genome-wide association mapping coupled with genetic correlation analyses. We show that most traits are governed by polygenic architectures and are highly heritable suggesting that adaptation proceeds mainly through allele frequency shifts at many loci. We identified negative genetic correlations among traits related to host colonization and survival in stressful environments. Such genetic constraints indicate that pleiotropic effects could limit the pathogen’s ability to cause host damage. In contrast, adaptation to abiotic stress factors was likely facilitated by synergistic pleiotropy. Our study illustrates how comprehensive mapping of life-history trait architectures across diverse environments allows to predict evolutionary trajectories of pathogens confronted with environmental perturbations.

scholarly journals Natural variation in fecundity is correlated with species-wide levels of divergence in Caenorhabditis elegans

2021 ◽  
Author(s):  
Gaotian Zhang ◽  
Jake D Mostad ◽  
Erik C Andersen
Keyword(s):  
Life History ◽  
Caenorhabditis Elegans ◽  
Life History Traits ◽  
Life History Trait ◽  
Selective Sweeps ◽  
C Elegans ◽  
Genome Wide ◽  
Genetic Complexity ◽  
Genomic Regions ◽  
Global Population

Abstract Life history traits underlie the fitness of organisms and are under strong natural selection. A new mutation that positively impacts a life history trait will likely increase in frequency and become fixed in a population (e.g. a selective sweep). The identification of the beneficial alleles that underlie selective sweeps provides insights into the mechanisms that occurred during the evolution of a species. In the global population of Caenorhabditis elegans, we previously identified selective sweeps that have drastically reduced chromosomal-scale genetic diversity in the species. Here, we measured the fecundity of 121 wild C. elegans strains, including many recently isolated divergent strains from the Hawaiian islands and found that strains with larger swept genomic regions have significantly higher fecundity than strains without evidence of the recent selective sweeps. We used genome-wide association (GWA) mapping to identify three quantitative trait loci (QTL) underlying the fecundity variation. Additionally, we mapped previous fecundity data from wild C. elegans strains and C. elegans recombinant inbred advanced intercross lines that were grown in various conditions and detected eight QTL using GWA and linkage mappings. These QTL show the genetic complexity of fecundity across this species. Moreover, the haplotype structure in each GWA QTL region revealed correlations with recent selective sweeps in the C. elegans population. North American and European strains had significantly higher fecundity than most strains from Hawaii, a hypothesized origin of the C. elegans species, suggesting that beneficial alleles that caused increased fecundity could underlie the selective sweeps during the worldwide expansion of C. elegans.

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