scholarly journals Life history traits and reproductive performance of the caridean shrimp Lysmata boggessi, a heavily traded invertebrate in the marine aquarium industry

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8231
Author(s):  
Michael D. Dickson ◽  
Donald C. Behringer ◽  
J. Antonio Baeza
Keyword(s):  
Population Dynamics ◽  
Life Histories ◽  
Sex Change ◽  
Reproductive Activity ◽  
Phase Ratio ◽  
Individual Level ◽  
Commercial Harvest ◽  
Peppermint Shrimp ◽  
Level Information ◽  
Data Gap

The most intense commercial harvest of marine aquarium species in North America occurs in the coastal waters surrounding Florida, yet very often little information exists on the life histories, population dynamics, or reproductive characteristics of these organisms. The peppermint shrimp Lysmata boggessi is one such species and is heavily targeted along the west coast of Florida. It is known primarily among aquarists for its ability to control pest anemones and in the scientific community for its unique sexual system, protandric simultaneous hermaphroditism. However, no study has addressed fishery interactions or long-term population dynamics for L. boggessi. We used monthly fisheries-dependent sampling, with a trained observer present, for a full year to assess seasonality in sex phase ratio (males to males + hermaphrodites), size at sex change, fecundity, embryo volume and reproductive output of an exploited L. boggessi population. L. boggessi exhibited distinct seasonality in size distribution, sex phase ratio, size at sex phase change and reproductive activity. The peak reproductive season was in spring, when the population was dominated by small but fecund hermaphrodites. Reproduction decreased during fall and winter and sex phase ratios favored male phase shrimp that exhibited delayed sex change. This population and individual level information is the first of its kind for L. boggessi and fills a much needed data gap for the informed management of this fishery.

scholarly journals Faster juvenile growth promotes earlier sex change in a protandrous hermaphrodite (barramundi Lates calcarifer)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Brien H. Roberts ◽  
John R. Morrongiello ◽  
David L. Morgan ◽  
Alison J. King ◽  
Thor M. Saunders ◽  
...  
Keyword(s):  
Growth Rate ◽  
Life Histories ◽  
Sex Change ◽  
Maximum Size ◽  
Growth Potential ◽  
Lates Calcarifer ◽  
Individual Level ◽  
Trade Offs ◽  
Animal Populations ◽  
Protandrous Hermaphrodite

AbstractThe relationship between growth and sexual maturation is central to understanding the dynamics of animal populations which exhibit indeterminate growth. In sequential hermaphrodites, which undergo post-maturation sex change, the size and age at which sex change occurs directly affects reproductive output and hence population productivity. However, these traits are often labile, and may be strongly influenced by heterogenous growth and mortality rates. We analysed otolith microstructure of a protandrous (i.e., male-to-female) fish (barramundi Lates calcarifer) to examine growth in relation to individual variation in the timing of sex change. Growth trajectories of individuals with contrasting life histories were examined to elucidate the direction and extent to which growth rate influences the size and age individuals change sex. Then, the relationships between growth rate, maturation schedules and asymptotic maximum size were explored to identify potential trade-offs between age at female maturity and growth potential. Rapid growth was strongly associated with decreased age at sex change, but this was not accompanied by a decrease in size at sex change. Individuals that were caught as large females grew faster than those caught as males, suggesting that fast-growing individuals ultimately obtain higher fitness and therefore make a disproportionate contribution to population fecundity. These results indicate that individual-level variation in maturation schedules is not reflective of trade-offs between growth and reproduction. Rather, we suggest that conditions experienced during the juvenile phase are likely to be a key determinant of post-maturation fitness. These findings highlight the vulnerability of sex-changing species to future environmental change and harvest.

scholarly journals Interpersonal Comparisons of the Good: Epistemic not Impossible

Utilitas ◽  
2015 ◽  
Vol 28 (3) ◽  
pp. 288-313 ◽  
Author(s):  
MATHEW COAKLEY
Keyword(s):  
Institutional Choice ◽  
Individual Level ◽  
Interpersonal Comparisons ◽  
Individual Good ◽  
Level Information ◽  
Action Policy ◽  
Social Mind ◽  
The Individual

To evaluate the overall good/welfare of any action, policy or institutional choice we need some way of comparing the benefits and losses to those affected: we need to make interpersonal comparisons of the good/welfare. Yet sceptics have worried either: (1) that such comparisons are impossible as they involve an impossible introspection across individuals, getting ‘into their minds’; (2) that they are indeterminate as individual-level information is compatible with a range of welfare numbers; or (3) that they are metaphysically mysterious as they assume the existence either of a social mind or of absolute levels of welfare when no such things exist. This article argues that such scepticism can potentially be addressed if we view the problem of interpersonal comparisons as fundamentally an epistemic problem – that is, as a problem of forming justified beliefs about the overall good based on evidence of the individual good.

Stochastic population dynamics in populations of western terrestrial garter snakes with divergent life histories

Ecology ◽  
2011 ◽  
Vol 92 (8) ◽  
pp. 1658-1671 ◽  
Author(s):  
David A. Miller ◽  
William R. Clark ◽  
Stevan J. Arnold ◽  
Anne M. Bronikowski
Keyword(s):  
Population Dynamics ◽  
Life Histories ◽  
Garter Snakes ◽  
Stochastic Population Dynamics

scholarly journals Reproductive phenology of the American Bullfrog in subtropical Brazil: photoperiod as a main determinant of seasonal activity

2016 ◽  
Vol 88 (3 suppl) ◽  
pp. 1909-1921 ◽  
Author(s):  
CAMILA I. MEDEIROS ◽  
CAMILA BOTH ◽  
IGOR L. KAEFER ◽  
SONIA Z. CECHIN
Keyword(s):  
Life Histories ◽  
Management Strategies ◽  
Reproductive Activity ◽  
Ex Situ ◽  
Reproductive Phenology ◽  
High Fertility ◽  
Seasonal Activity ◽  
Population Declines ◽  
American Bullfrog ◽  
The North

ABSTRACT The North American bullfrog Lithobates catesbeianus continues to invade ecosystems worldwide, potentially causing population declines and even extinctions. Within its native distribution, bullfrogs show prolonged reproductive seasons and high fertility. However, data on breeding biology of bullfrogs ex-situ in invaded localities mainly comes from anecdotal reports. Understanding how invasive species are adjusting their life histories to new colonized environments is important for conservation purposes. Here we describe temporal and spatial abundance, calling activity, spawning and tadpole distribution of bullfrogs in southern Brazil. Eighteen samplings occurred during one year. The abundance of individuals was positively related to longer photoperiods and higher temperatures. Reproductive activity was also positively associated with longer photoperiods. Calling sites, spawning and tadpoles were associated with microhabitats presenting hydrophytes, which may provide shelter and thermal stability to bullfrogs. The reproductive seasonal activity of bullfrogs can be highly variable across its growing geographical range, but in subtropical Brazil it is associated with photoperiod, a highly predictable abiotic determinant. In our study area, bullfrogs presented a breeding season twice as long as that observed in some native localities. We suggest that management strategies directed to bullfrog populations must consider the habitat structures and seasonal regimes determined by each invaded environment.

Population Dynamics and Life Histories of Foliaceous Corals

1985 ◽  
Vol 55 (2) ◽  
pp. 141-166 ◽  
Author(s):  
T. P. Hughes ◽  
J. B. C. Jackson
Keyword(s):  
Population Dynamics ◽  
Life Histories

Evolution of Sociality and Nonlinear Population Dynamics

2020 ◽  
pp. 100-113
Author(s):  
Daniel Oro
Keyword(s):  
Population Dynamics ◽  
Cultural Transmission ◽  
Life Histories ◽  
Minimum Size ◽  
Stable States ◽  
Individual Fitness ◽  
Social Species ◽  
Strong Source ◽  
Adaptive Behaviours ◽  
Threshold Setting

Sociality appears in many life histories during evolution. Some eusocial bees show evolutionary reversions to solitary behaviour, and populations of the same species can be solitary or social, likely depending on local environmental features. Social species need a minimum size to perform adaptive behaviours, such as the search for resources, which is crucial especially under perturbations. This minimum size may become a threshold, setting a phase transition for separating two stable states, from disorganized and maladaptive to organized and adaptive, which also shows hysteresis. The chapter also explores evolution via facilitation or cooperation (e.g. social information) under the theoretical framework of multilevel selection, by which there is likely an effect of the social group’s genes on individual fitness. Perturbations appear as a strong source of evolutionary processes. In humans, warfare acts as a very powerful selective pressure for competition between groups and thus for cooperation. Sociality has also many costs, such as a higher risk for the spread of infectious disease, the appearance of traps by social haunting philopatry, stronger aggression and competition, and a higher risk of being attacked by predators. Finally, the evolution of cultures is explored; optimization of social learning, social copying, and cultural transmission may have nonlinear consequences for population dynamics.

Heritability, polymorphism, and population dynamics: individual-based eco-evolutionary simulations

2021 ◽  
pp. 329-340
Author(s):  
Anna Kuparinen
Keyword(s):  
Population Dynamics ◽  
Life Histories ◽  
Evolutionary Dynamics ◽  
Atlantic Cod ◽  
Population Projections ◽  
Phenotypic Traits ◽  
Evolutionary Changes ◽  
Future Challenges ◽  
Evolutionary Simulations ◽  
Main Message

Contemporary evolution that occurs across ecologically relevant time scales, such as a few generations or decades, can not only change phenotypes but also feed back to demographic parameters and the dynamics of populations. This chapter presents a method to make phenotypic traits evolve in mechanistic individual-based simulations. The method is broadly applicable, as demonstrated through its applications to boreal forest adaptation to global warming, eco-evolutionary dynamics driven by fishing-induced selection in Atlantic cod, and the evolution of age at maturity in Atlantic salmon. The main message of this chapter is that there may be little reason to exclude phenotypic evolution in analyses of population dynamics, as these can be modified by evolutionary changes in life histories. Future challenges will be to integrate rapidly accumulating genomic knowledge and an ecosystem perspective to improve population projections and to better understand the drivers of population dynamics.

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