Darwinian fishery science: lessons from the Atlantic silverside (Menidia menidia)

2005 ◽  
Vol 62 (4) ◽  
pp. 730-737 ◽  
Author(s):  
David O Conover ◽  
Stephen A Arnott ◽  
Matthew R Walsh ◽  
Stephan B Munch

The potential of fishing mortality to cause rapid evolutionary changes in life history has received relatively little attention. By focusing only on ecological responses, standard fisheries theory and practice implicitly assume either that genetic influences on life history in the wild are negligible or that natural selection and adaptation is a slow process that can be effectively ignored. Lack of contrary evidence has allowed these assumptions to persist. Drawing upon >25 years of research on the Atlantic silverside (Menidia menidia), we show that adaptive genetic variation in many traits is finely tuned to natural variation in climate. Much of this variation is caused by a gradient in size-selective winter mortality and involves two- to threefold changes in physiological traits that influence population productivity. Many other species are now known to display similar patterns. Harvest experiments show that these traits can evolve rapidly in response to size-selective fishing. Hence, the pool of genotypes that code for life history traits is a highly dynamic property of populations. We argue that the lessons from Menidia are applicable to many exploited species where similar observations would be difficult to obtain and advocate greater use of species models to address fundamental questions in fishery science.

2016 ◽  
Vol 74 (4) ◽  
pp. 1051-1061 ◽  
Author(s):  
Christopher S. Murray ◽  
Lee A. Fuiman ◽  
Hannes Baumann

Ocean acidification may impact the fitness of marine fish, however, studies reporting neutral to moderate effects have mostly performed short-term exposures to elevated CO2, whereas longer-term studies across life stages are still scarce. We performed a CO2 exposure experiment, in which a large number (n > 2200) of Atlantic silverside Menidia menidia offspring from wild spawners were reared for 135 days through their embryonic, larval, and juvenile stages under control (500 µatm) and high CO2 conditions (2300 µatm). Although survival was high across treatments, subtle but significant differences in length, weight, condition factor and fatty acid (FA) composition were observed. On average, fish from the acidified treatment were 4% shorter and weighed 6% less, but expressed a higher condition factor than control juveniles. In addition, the metrics of length and weight distributions differed significantly, with juveniles from the high CO2 treatment occupying more extreme size classes and the length distribution shifting to a positive kurtosis. Six of twenty-seven FAs differed significantly between treatments. Our results suggest that high CO2 conditions alter long-term growth in M. menidia, particularly in the absence of excess food. It remains to be shown whether and how these differences will impact fish populations in the wild facing size-selective predation and seasonally varying prey abundance.


1998 ◽  
Vol 55 (5) ◽  
pp. 1149-1157 ◽  
Author(s):  
Eric T Schultz ◽  
David O Conover ◽  
Amir Ehtisham

Genetic differences among populations of Atlantic silverside (Menidia menidia) are hypothesized to be evolutionary responses to intense, size-selective winter mortality at high latitudes. Three experiments were conducted to test features of winter mortality. In the first experiment, we varied size and whether food was provided or withheld; temperatures were permitted to follow ambient (New York) wintertime fluctuations. Mortality and depletion of energy reserves were more rapid in the units receiving no food. Small fish died before larger fish in these units, but not in the units receiving food. Energy depletion of fish in the no-food treatment resembled that of fish in the wild. In the second experiment, we varied size and population of origin, representing high-latitude (Nova Scotia), midlatitude (New York), and low-latitude (South Carolina) populations. These fish were provided food and showed minimal depletion of energy reserves, but mortality rates were high when water temperatures were low. Mortality did not vary with size in New York and South Carolina fish, but was highest in intermediate-size fish from Nova Scotia. There was a pronounced population difference in survival rate (Nova Scotia > New York > South Carolina). In the third experiment, food was withheld and extreme low temperatures were moderated. Energy depletion was rapid and small fish died before large fish. We conclude that populations in seasonal environments are likely to be subject to size-selective winter mortality when energy reserves are depleted and that juvenile growth rates have evolved in response to this selection pressure. In addition, high-latitude populations have evolved greater tolerance to other winter stresses associated with low temperatures.


2005 ◽  
Vol 62 (4) ◽  
pp. 802-810 ◽  
Author(s):  
S B Munch ◽  
M R Walsh ◽  
D O Conover

Harvest selection may lead to detrimental evolutionary changes in exploited populations. Few studies have considered the indirect impacts that harvest selection may have arising through genetic correlations. Using data from a long-term fishing experiment on Atlantic silversides (Menidia menidia), we show that there are significant genetic correlations between adult length at harvest and several early life history characters known to influence recruitment success. Based on this analysis, we estimate the magnitude of the change in recruitment success that may arise indirectly from selection on adults. In contrast with studies of harvest selection on adult characteristics, we find the response of characters in the early life history to be relatively slow and that impacts on recruitment, if any, are likely to be driven by selective changes in fecundity.


2020 ◽  
Vol 650 ◽  
pp. 7-18 ◽  
Author(s):  
HW Fennie ◽  
S Sponaugle ◽  
EA Daly ◽  
RD Brodeur

Predation is a major source of mortality in the early life stages of fishes and a driving force in shaping fish populations. Theoretical, modeling, and laboratory studies have generated hypotheses that larval fish size, age, growth rate, and development rate affect their susceptibility to predation. Empirical data on predator selection in the wild are challenging to obtain, and most selective mortality studies must repeatedly sample populations of survivors to indirectly examine survivorship. While valuable on a population scale, these approaches can obscure selection by particular predators. In May 2018, along the coast of Washington, USA, we simultaneously collected juvenile quillback rockfish Sebastes maliger from both the environment and the stomachs of juvenile coho salmon Oncorhynchus kisutch. We used otolith microstructure analysis to examine whether juvenile coho salmon were age-, size-, and/or growth-selective predators of juvenile quillback rockfish. Our results indicate that juvenile rockfish consumed by salmon were significantly smaller, slower growing at capture, and younger than surviving (unconsumed) juvenile rockfish, providing direct evidence that juvenile coho salmon are selective predators on juvenile quillback rockfish. These differences in early life history traits between consumed and surviving rockfish are related to timing of parturition and the environmental conditions larval rockfish experienced, suggesting that maternal effects may substantially influence survival at this stage. Our results demonstrate that variability in timing of parturition and sea surface temperature leads to tradeoffs in early life history traits between growth in the larval stage and survival when encountering predators in the pelagic juvenile stage.


2013 ◽  
Vol 59 (4) ◽  
pp. 485-505 ◽  
Author(s):  
Jon E. Brommer

Abstract Individual-based studies allow quantification of phenotypic plasticity in behavioural, life-history and other labile traits. The study of phenotypic plasticity in the wild can shed new light on the ultimate objectives (1) whether plasticity itself can evolve or is constrained by its genetic architecture, and (2) whether plasticity is associated to other traits, including fitness (selection). I describe the main statistical approach for how repeated records of individuals and a description of the environment (E) allow quantification of variation in plasticity across individuals (IxE) and genotypes (GxE) in wild populations. Based on a literature review of life-history and behavioural studies on plasticity in the wild, I discuss the present state of the two objectives listed above. Few studies have quantified GxE of labile traits in wild populations, and it is likely that power to detect statistically significant GxE is lacking. Apart from the issue of whether it is heritable, plasticity tends to correlate with average trait expression (not fully supported by the few genetic estimates available) and may thus be evolutionary constrained in this way. Individual-specific estimates of plasticity tend to be related to other traits of the individual (including fitness), but these analyses may be anti-conservative because they predominantly concern stats-on-stats. Despite the increased interest in plasticity in wild populations, the putative lack of power to detect GxE in such populations hinders achieving general insights. I discuss possible steps to invigorate the field by moving away from simply testing for presence of GxE to analyses that ‘scale up’ to population level processes and by the development of new behavioural theory to identify quantitative genetic parameters which can be estimated.


Diversity ◽  
2018 ◽  
Vol 10 (3) ◽  
pp. 69 ◽  
Author(s):  
Christopher Murray ◽  
Hannes Baumann

Concurrent ocean warming and acidification demand experimental approaches that assess biological sensitivities to combined effects of these potential stressors. Here, we summarize five CO2 × temperature experiments on wild Atlantic silverside, Menidia menidia, offspring that were reared under factorial combinations of CO2 (nominal: 400, 2200, 4000, and 6000 µatm) and temperature (17, 20, 24, and 28 °C) to quantify the temperature-dependence of CO2 effects in early life growth and survival. Across experiments and temperature treatments, we found few significant CO2 effects on response traits. Survival effects were limited to a single experiment, where elevated CO2 exposure reduced embryo survival at 17 and 24 °C. Hatch length displayed CO2 × temperature interactions due largely to reduced hatch size at 24 °C in one experiment but increased length at 28 °C in another. We found no overall influence of CO2 on larval growth or survival to 9, 10, 15 and 13–22 days post-hatch, at 28, 24, 20, and 17 °C, respectively. Importantly, exposure to cooler (17 °C) and warmer (28 °C) than optimal rearing temperatures (24 °C) in this species did not appear to increase CO2 sensitivity. Repeated experimentation documented substantial inter- and intra-experiment variability, highlighting the need for experimental replication to more robustly constrain inherently variable responses. Taken together, these results demonstrate that the early life stages of this ecologically important forage fish appear largely tolerate to even extreme levels of CO2 across a broad thermal regime.


Koedoe ◽  
2004 ◽  
Vol 47 (1) ◽  
Author(s):  
R.F. Terblanche ◽  
H. Van Hamburg

Due to their intricate life histories and the unique wing patterns and colouring the butterflies of the genus Chrysoritis are of significant conservation and aesthetic value. Thisoverview probes into practical examples of butterfly life history research applicable to environmental management of this relatively well-known invertebrate group in South Africa. Despite the pioneer work on life histories of Chrysoritis in the past, more should be done to understand the life history of the butterflies in the wild, especially their natural host plants and the behaviour of adults and larvae. A system of voucher specimens of host plants should be introduced in South Africa. Although various host plant species in nature are used by the members of Chrysoritis, including the Chrysoritis chrysaor group, the choice of these in nature by each species is significant for conservation management and in the case of Chrysoritis aureus perhaps even as a specific characteristic.A revision of the ant genus Crematogaster will benefit the conservation management of Chrysoritis species since some of these ant species may consist of a number of specieswith much more restricted distributions than previously thought. Rigorous quantified tudies of population dynamics of Chrysoritis butterflies are absent and the introductionof such studies will benefit conservation management of these localised butterflies extensively.


1983 ◽  
Vol 10 (4) ◽  
pp. 283-292 ◽  
Author(s):  
Raymond P. Coppinger ◽  
Charles Kay Smith

A coming ‘Age of Interdependent Forms’ seems destined to mark the success of what could be called ‘despecialized/interspecific fitness’ among neotenic strains (perpetuating juvenile traits) of species such as humans and domestic animals. Humans as well as the first domesticants underwent a neotenic evolution in the wild during the repeated interglacial periods which, acting on a number of mammalian forms, selected against adult species-specific ancestral adaptations to a stable environment. Neotenic species continue to look and behave more like ancestral youths than adults—even after sexual maturity and throughout their life-history. As they retain lifelong youthful dependency motivations, they can easily, under suitable conditions, become interdependent forms. By the time of melting of the last Pleistocene glacier, all the domestic partners had already become more dependency-prone than formerly, and were behaviourally despecialized enough to form the alliance that is now changing the order of Nature.


2018 ◽  
pp. 403-424
Author(s):  
Matthew R. Walsh ◽  
Michelle Packer ◽  
Shannon Beston ◽  
Collin Funkhouser ◽  
Michael Gillis ◽  
...  

Much research has shown that variation in ecological processes can drive rapid evolutionary changes over periods of years to decades. Such contemporary adaptation sets the stage for evolution to have reciprocal impacts on the properties of populations, communities, and ecosystems, with ongoing interactions between ecological and evolutionary forces. The importance and generality of these eco-evolutionary dynamics are largely unknown. In this chapter, we promote the use of water fleas (Daphnia sp.) as a model organism in the exploration of eco-evolutionary interactions in nature. The many characteristics of Daphnia that make them suitable for laboratory study in conjunction with their well-known ecological importance in lakes, position Daphnia to contribute new and important insights into eco-evolutionary dynamics. We first review the influence of key environmental stressors in Daphnia evolution. We then highlight recent work documenting the pathway from life history evolution to ecology using Daphnia as a model. This review demonstrates that much is known about the influence of ecology on Daphnia life history evolution, while research exploring the genomic basis of adaptation as well as the influence of Daphnia life history traits on ecological processes is beginning to accumulate.


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