scholarly journals Population dynamics, spatial dispersion and somatic growth of the sand fiddler crab ilea pugilator

1984 ◽  
Vol 16 ◽  
pp. 269-279 ◽  
Author(s):  
DR Colby ◽  
MS Fonseca
Keyword(s):  
Population Dynamics ◽  
Spatial Dispersion ◽  
Fiddler Crab ◽  
Somatic Growth

Reproductive patterns and energy management strategies of females of the fiddler crab Leptuca uruguayensis with short reproductive seasons

2020 ◽  
Author(s):  
Agustina Marciano ◽  
Laura Susana López-Greco ◽  
Karine Delevati Colpo
Keyword(s):  
Reproductive Effort ◽  
Fiddler Crab ◽  
Management Strategies ◽  
Somatic Growth ◽  
Integrated Approach ◽  
Breeding Strategy ◽  
Reproductive Season ◽  
Female Size ◽  
Income Breeding ◽  
Size Number

Reproduction is a costly process that depends on the management of available resources. Here, we aimed to understand the energetic strategies of females of the fiddler crab Leptuca uruguayensis (Nobili 1901), in a population with short reproductive seasons. For this, we developed an integrated approach to recognize the brooding time, spawning pattern modulated by female size, number of spawns per female, and content of reserves in the ovary and hepatopancreas. Based on the condition of the ovary and hepatopancreas, the reproductive season was divided into three periods. In each of these periods, it was possible to record a spawning event, which was mainly represented by large females. Most of the females had one spawn during the breeding season, and only large females had two spawns, with an interval of approximately two months. We propose that L. uruguayensis presents a mixed capital-income breeding strategy associated with the female size and period of the reproductive season. We conclude that large females make the greatest reproductive effort for the population, because they can have two spawns, whereas medium and small females make a low contribution because they are still investing energy in somatic growth to increase fecundity in the next reproductive season.

Population Dynamics of Crenate Broomrape (Orobanche crenata) in Faba Bean (Vicia faba)

Weed Science ◽  
1993 ◽  
Vol 41 (4) ◽  
pp. 563-567 ◽  
Author(s):  
Francisca Lopez-Granados ◽  
Luis Garcia-Torres
Keyword(s):  
Growth Rate ◽  
Population Dynamics ◽  
Population Density ◽  
Population Growth ◽  
Faba Bean ◽  
Population Growth Rate ◽  
Spatial Dispersion ◽  
Climatic Conditions ◽  
Orobanche Crenata ◽  
Soil Temperatures

Progression of crenate broomrape population density (PD, number of emerged plants m-2) in faba bean was studied over 8 yr in Spain. Spatial dispersion and effect of climatic conditions on parasite population growth rate (PGR) also were studied. With repeated cropping of faba bean, infestations of crenate broomrape increased from an initial PD of 0.15 to an average of 26, with a maximum of about 40 to 45. The average population growth rate (PGR, ratio between the PD of any 2 consecutive years) was approximately 3. However, this figure varied widely among localities and years, from 0.8 to 7.7. A highly significant relationship (P = 0.01) was found between PGR and rainfall and soil temperatures during December to February, months of crop vegetative growth. Dispersion of crenate broomrape infestations mainly followed direction of crop rows, most likely due to the effect of tillage and harvesting operations, which were the same direction as sowing.

Spatial dispersion and density of the Paranemonia vouliagmeniensis population in Vouliagmeni Lagoon

2000 ◽  
Vol 80 (5) ◽  
pp. 941-942 ◽  
Author(s):  
Chariton-Charles Chintiroglou ◽  
Chrysanthi Antoniadou ◽  
Panagiotis Damianidis
Keyword(s):  
Population Dynamics ◽  
Spatial Dispersion ◽  
Abiotic Factors ◽  
Biological Parameters ◽  
Human Influence ◽  
Patterns Of Distribution

A number of biological parameters relevant to the population dynamics of Paranemonia vouliagmeniensis are discussed. The abiotic factors of the lagoon's waters are stable throughout the year. Paranemonia vouliagmeniensis populations follow different patterns of distribution (aggregated or random) in relation to human influence, and can thus become a reliable bioindicator for the lagoon.

scholarly journals Sexual dimorphism in the catfish Genidens genidens (Siluriformes: Ariidae) based on otolith morphometry and relative growth

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Thaís Rodrigues Maciel ◽  
André Martins Vaz-dos-Santos ◽  
José Ricardo de Souza Barradas ◽  
Marcelo Vianna
Keyword(s):  
Population Dynamics ◽  
Sexual Dimorphism ◽  
Parental Care ◽  
Reproductive Biology ◽  
Somatic Growth ◽  
Life Cycles ◽  
Growth Patterns ◽  
Population Declines ◽  
Otolith Growth ◽  
Relative Growth

ABSTRACT Genidens genidens is a species susceptible to population declines in view of their reproductive biology peculiarities. Morphometric differences between sexes are observed in the literature, and these differences should also be evident in otolith development. Growth patterns are one of the most important biological characteristics regarding population dynamics and management. In this context, the aim of the present study is to describe this species relative growth and identify differences between sex life cycles. Somatic growth-otolith growth relationships and somatic length-weight relationships were estimated based on two methodologies; the Huxley and the polyphasic allometric models. Both models demonstrated different growth patterns between sexes. The three axes of otolith growth were adequate descriptors of growth, and the results of the Huxley model demonstrated distinct growth patterns between sexes, with male otoliths larger in all three measured axes. In the polyphase model, male otoliths were thicker, while female otoliths were longer and higher. Both sexes presented similar length-weight relationships, which may indicate that oocyte production and parental care lead to similar costs for this species.

Age-based demography of the glacier lanternfish (Benthosema glaciale) in the Flemish Cap

2015 ◽  
Vol 66 (1) ◽  
pp. 78 ◽  
Author(s):  
E. García-Seoane ◽  
M. Fabeiro ◽  
A. Silva ◽  
I. Meneses
Keyword(s):  
Population Dynamics ◽  
Somatic Growth ◽  
Growth Curves ◽  
Strong Relationship ◽  
Demographic Parameters ◽  
Fish Length ◽  
Natural Mortality ◽  
Von Bertalanffy ◽  
June July ◽  
Demographic Features

It is important to understand the population dynamics of myctophids for a better understanding of the functioning of the ecosystem. In this work, age-based demography parameters of glacier lanternfish (Benthosema glaciale (Reinhardt, 1837)) were calculated. This study was based on 1213 individuals collected in the Flemish Cap during June–July 2008 and 2010. Ages were estimated from counts of annuli in the whole otolith. A strong relationship was found between both diameters of the otolith and fish length, and between otolith weight and increment number. Males predominated in 2008 (37.6% were females) whereas no differences from the expected sex ratio of 1:1 were observed in 2010. The somatic growth of B. glaciale is quite fast for the first three years and decreasing thereafter. The von Bertalanffy growth curves revealed interannual differences and no sexual dimorphism in growth. The instantaneous natural mortality coefficient, M, was 0.65 year–1 for the overall population. The maximum age recorded was 7. Our results were compared with age-based demographic parameters from previous studies in the Flemish Cap and in other regions. Because myctophids are considered opportunistic strategists, changes in their demographic features may reflect shifts in the ecosystem.

scholarly journals Selectivity matters: rules of thumb for management of plate-sized, sex-changing fish in the live reef food fish trade

2017 ◽  
Author(s):  
Holly K. Kindsvater ◽  
John D. Reynolds ◽  
Yvonne Sadovy de Mitcheson ◽  
Marc Mangel
Keyword(s):  
Population Dynamics ◽  
Life History ◽  
Mating System ◽  
Egg Production ◽  
Somatic Growth ◽  
Fishing Effort ◽  
Relative Effect ◽  
Total Biomass ◽  
Food Fish ◽  
Fish Trade

AbstractEffective management of fisheries depends on the selectivity of different fishing methods, control of fishing effort, and the life history and mating system of the target species. For sex-changing species, it is unclear how the truncation of age structure or selection of specific size or age classes (by fishing for specific markets) affects population dynamics. We specifically address the consequences of plate-sized selectivity, whereby sub-mature, ‘plate-sized’ fish are preferred in the live reef food fish trade. We use an age-structured model to investigate the decline and recovery of populations fished with three different selectivity scenarios (asymptotic, dome-shaped, and plate-sized) applied to two sexual systems (female-first hermaphroditism and gonochorism). We parameterized our model with life-history data from Brown-marbled grouper (Epinephelus fuscoguttatus) and Napoleon fish (Cheilinus undulatus). ‘Plate-sized’ selectivity had the greatest negative effect on population trajectories, assuming accumulated fishing effort across ages was equal, while the relative effect of fishing on biomass was greatest with low natural mortality. Fishing such sex-changing species before maturation decreased egg production (and the spawning potential ratio) in two ways: average individual size decreased, and, assuming plasticity, females became males at a smaller size. Somatic growth rate affected biomass if selectivity was based on size-at-age because in slow growers, a smaller proportion of total biomass was vulnerable to fishing. We recommend fisheries avoid taking individuals near their maturation age, regardless of mating system, unless catch is tightly controlled. We also discuss the implications of fishing post-settlement individuals on population dynamics and offer practical management recommendations.

Life history characters and population dynamics of the boreal larvacean Oikopleura vanhoeffeni (Tunicata) in Conception Bay, Newfoundland

2010 ◽  
Vol 91 (8) ◽  
pp. 1587-1598 ◽  
Author(s):  
Nami Choe ◽  
Don Deibel
Keyword(s):  
Growth Rate ◽  
Population Dynamics ◽  
Life History ◽  
Body Size ◽  
Population Growth ◽  
Egg Production ◽  
Somatic Growth ◽  
Potential Fecundity ◽  
Population Growth Rates ◽  
Conception Bay

We examined the population dynamics and life history characters of the boreal larvacean Oikopleura vanhoeffeni in Conception Bay over two years and determined its role in secondary production. Based on the analysis of age structure inferred from statolith diameter, the generation time was approximately one year. Recruitment of new cohorts and maximum population growth rate occurred in the spring. Somatic growth rate was 0.017 d−1 from the year 2001 to 2002 and 0.043 d−1 from 2002 to 2003, with an acceleration in growth rate during April in response to the spring diatom bloom despite the coldest water temperatures. The annual production rate (i.e. somatic + house production) of 8.7 g C m−2 y−1 in 2001/2, and 3.8 g C m−2 y−1 in 2002/3, represented 2.9–6.7% of primary production and 37–87% of estimated mesozooplankton production, suggesting that O. vanhoeffeni is a major secondary producer in Conception Bay. Individuals matured at seasonally variable body size throughout the year and potential fecundity peaked as the individuals matured at their largest body size during the spring bloom, most likely resulting in maximum egg production and population growth rates at that time of year. Thus, a seasonal pulse of food is a major driving force that regulates the variation in life history characters and population dynamics of the boreal O. vanhoeffeni.

scholarly journals Controls on Somatic Growth and Population Dynamics of Rainbow Trout

2021 ◽  
Vol 102 (1) ◽  
Author(s):  
Josh Korman ◽  
Michael D. Yard ◽  
Maria C. Dzul ◽  
Charles B. Yackulic ◽  
Michael J. Dodrill ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Rainbow Trout ◽  
Somatic Growth
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