Aquatic Life History Trajectories Are Shaped by Selection, Not Oxygen Limitation

2019 ◽  
Vol 34 (3) ◽  
pp. 182-184 ◽  
Author(s):  
Dustin J. Marshall ◽  
Craig R. White
Keyword(s):  
Life History ◽  
Oxygen Limitation ◽  
Aquatic Life

An assessment of the introduced mosquitofish (Gambusia affinis holbrooki) as a predator of eggs, hatchlings and tadpoles of native and non-native anurans

2000 ◽  
Vol 27 (2) ◽  
pp. 185 ◽  
Author(s):  
Spogmai Komak ◽  
Michael R. Crossland
Keyword(s):  
Life History ◽  
Quantitative Data ◽  
Laboratory Experiments ◽  
Gambusia Affinis ◽  
Pest Species ◽  
Aquatic Life ◽  
Life History Stages ◽  
Aquatic Fauna ◽  
Native Fishes ◽  
Natural Water Bodies

The introduced mosquitofish (Gambusia affinis holbrooki) is a pest species in Australia and has been implicated in the decline of populations of native fishes and anurans. However, few quantitative data exist regarding interactions between Gambusia and native aquatic fauna. We used replicated laboratory experiments to investigate predation by G. a. holbrooki on eggs, hatchlings and tadpoles of native (Limnodynastes ornatus) and non-native (Bufo marinus) anurans. Our aims were to determine (1) whether the susceptibility of anurans to predation by G. a. holbrooki changes during larval development, and (2) the potential for G. a. holbrooki as a predator of the introduced toad B. marinus. Gambusia were significant predators of all aquatic life-history stages of L. ornatus, but were significant predators of B. marinus only at the hatchling stage. When offered both species simultaneously, Gambusia consumed tadpoles of L. ornatus but avoided those of B. marinus. The differences between the responses of Gambusia to L. ornatus and B. marinus are probably due to differences in palatability and toxicity of eggs, hatchlings and tadpoles of these species. The results indicate that G. a. holbrooki is unlikely to significantly affect larval populations of B. marinus via predation. However, Gambusia has the potential to significantly affect larval populations of L. ornatus in natural water bodies where these species co-occur.

Influence of Benthos Life History upon the Estimation of Secondary Production

1979 ◽  
Vol 36 (12) ◽  
pp. 1425-1430 ◽  
Author(s):  
T. F. Waters
Keyword(s):  
Life History ◽  
Trophic Level ◽  
Secondary Production ◽  
Standing Stock ◽  
Sampling Errors ◽  
Aquatic Life ◽  
Preferred Habitat ◽  
Benthic Secondary Production ◽  
Probable Effect ◽  
And Behavior

Synchrony of cohorts is one of the life history features having most important effects upon the estimation of benthic secondary production, because most methods depend heavily upon recognition of discrete cohorts. The Hynes method, intended to circumvent the necessity of cohort distinction, still depends upon determination of trophic level, voltinism, minimum and maximum sizes, and length of aquatic life. Knowledge of preferred habitat, distribution, and behavior are essential for accurate production estimates. Use of the production:mean standing stock (P/B) ratio (fairly constant at about 5 for cohort P/B of benthic invertebrates) to approximate production from standing stock data, also must account for trophic level, voltinism, and length of aquatic life. Various life history features are compared as to their probable effect on production estimation; in addition, they are compared to the effect of sampling errors. Key words: benthos, life history, production, secondary production, productivity

scholarly journals Observations on metamorphosing tadpoles of Hyalinobatrachium orientale (Anura: Centrolenidae)

2020 ◽  
Vol 19 (2) ◽  
pp. 217-223
Author(s):  
Isabel Byrne ◽  
Robyn Thomson ◽  
Rory Thomson ◽  
Duncan Murray-Uren ◽  
J. Roger Downie
Keyword(s):  
Life History ◽  
Body Size ◽  
Relative Humidity ◽  
Forest Understory ◽  
Internal Organs ◽  
Aquatic Life ◽  
Anuran Amphibians ◽  
Understory Plants ◽  
Terrestrial Life

Observations on metamorphosing tadpoles of Hyalinobatrachium orientale (Anura: Centrolenidae). Metamorphosis, when anuran amphibians resorb their tails and remodel their mouthparts and internal organs, is a vulnerable stage in the frog’s life history. As larvae metamorphose from tadpoles to adult frogs, they are neither suited to aquatic life nor ready for active terrestrial life. Previous studies have examined the duration of metamorphosis in a range of species, with respect to tadpole size, habitat, and other factors; however, the duration of metamorphosis relative to where it takes place has not been reported in centrolenids. In Hyalinobatrachium orientale, metamorphosis takes place on the upper surfaces of the leaves of low understory plants and lasts 3.5–4.0 days, a little longer than expected for the tadpole of this body size. Metamorphs seem to shift their perches from leaf to leaf randomly. There are no significant differences in the temperature or relative humidity of the upper and lower surfaces of leaves in the forest understory; thus, the presence of the metamorphs on the upper surfaces of leaves may provide moisture from the upper story vegetation after rain and protect them from terrestrial predators.

scholarly journals Aquatic and terrestrial organisms display contrasting life history strategies as a result of environmental adaptations

2019 ◽  
Author(s):  
Pol Capdevila ◽  
Maria Beger ◽  
Simone P. Blomberg ◽  
Bernat Hereu ◽  
Cristina Linares ◽  
...  
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Life History Strategies ◽  
Minor Role ◽  
Aquatic Animal ◽  
Aquatic Life ◽  
Terrestrial Species ◽  
Trade Offs ◽  
Population Turnover ◽  
Terrestrial Environments

AbstractAimsAquatic and terrestrial realms display stark differences in key environmental factors and phylogenetic composition. Despite such differences, their consequences for the evolution of species’ life history strategies remain poorly understood. Here, we examine whether and how life history strategies vary between terrestrial and aquatic species.LocationGlobal.Time periodVariable, the earliest year being in 1906 and the most recent in 2015.Major taxa studiesMacroscopic animals and plants species.MethodsWe use demographic information for 638 terrestrial and 117 aquatic animal and plant species, to derive key life history traits capturing their population turnover, and investments in survival, development, and reproduction. We use phylogenetically corrected least squares regression to explore the differences in the trade-offs between life history traits in both realms. We then quantify the life history strategies of aquatic and terrestrial species using a phylogenetically corrected principal component analysis.ResultsWe find that the same trade-offs structure terrestrial and aquatic life histories, resulting in two dominant axes of variation describing species’ pace- of-life and reproductive spread through time. Life history strategies differ between aquatic and terrestrial environments, with phylogenetic relationships playing a minor role. We show that adaptations of plants and animals to terrestrial environments have resulted in different life history strategies, particularly with their reproductive mode and longevity. Terrestrial plants display a great diversity of life history strategies, including the species with the longest lifespans. Aquatic animals, on the contrary, exhibit higher reproductive frequency than terrestrial animals, likely due to reproductive adaptations (i.e. internal fecundation) of the later to land.Main conclusionsOur findings show that aquatic and terrestrial species are ruled by the same life history principles, but have evolved different strategies due to distinct selection pressures. Such contrasting life history strategies have important consequences for the conservation and management of aquatic and terrestrial species.

Observations on the life history of the caecilian Typhlonectes compressicaudus (Dumeril and Bibron) in the Amazon basin

1978 ◽  
Vol 56 (4) ◽  
pp. 1005-1008 ◽  
Author(s):  
G. E. E. Moodie
Keyword(s):  
Life History ◽  
Life Style ◽  
Amazon Basin ◽  
Aquatic Invertebrates ◽  
Dry Season ◽  
Predatory Fish ◽  
Aquatic Life ◽  
Poison Glands ◽  
History Of

Ecological observations on the poorly known aquatic caecilian Typhlonectes compressicaudus are described. This species appears to be wholly adapted to an aquatic life style. The diet probably consists of aquatic invertebrates. The animal gives birth at the end of the dry season. The secretions of the poison glands are lethal to at least one species of predatory fish with which it coexists.

scholarly journals Interannual flow variability in a large subtropical–temperate floodplain: a challenge for fish reproduction

2019 ◽  
Vol 76 (3) ◽  
pp. 390-400 ◽  
Author(s):  
E. Abrial ◽  
L.A. Espínola ◽  
A.P. Rabuffetti ◽  
M.L. Amsler ◽  
K.M. Wantzen
Keyword(s):  
Life History ◽  
Reproductive Traits ◽  
Paraná River ◽  
Water Levels ◽  
Fish Reproduction ◽  
Aquatic Life ◽  
River Floodplain ◽  
Parana River ◽  
Floodplain Ecosystems ◽  
Middle Paraná

Fluctuations of temperature and water levels are the two main drivers of aquatic life in river floodplain ecosystems. The large Middle Paraná River floodplain exhibits marked seasons and important interannual hydrological changes. Using a three-factor-based approach (fish reproductive traits, hydroclimatic conditions, and floodplain recruitment patterns), we analyzed how fish life history evolves within this fluctuating environment. We observed that hydroclimatic conditions can be considered through three main interannual variations that prompt the most abundant Paraná species to adopt four different main reproductive strategies: (i) typical periodic strategists are dependent on large spring–summer floods and juveniles strongly predominate in the floodplain when such a condition occurs, (ii) periodic–opportunistic strategists are associated with floods, regardless of their timing, (iii) periodic–equilibrium strategists take advantage of spring–summer floods whatever the intensity and duration, and (iv) equilibrium strategists have low flood dependence and higher stability in temporal fish recruitment. This work brings forth a first synthesis of fish life history in the Middle Paraná River and evidences how important both hydrological and temperature fluctuations are to interpret its complexity.

scholarly journals Developmental Stage Affects the Consequences of Transient Salinity Exposure in Toad Tadpoles

2019 ◽  
Vol 59 (4) ◽  
pp. 1114-1127 ◽  
Author(s):  
Allison M Welch ◽  
Jordan P Bralley ◽  
Ashlyn Q Reining ◽  
Allison M Infante
Keyword(s):  
Life History ◽  
Larval Development ◽  
Salinity Stress ◽  
Critical Role ◽  
Developmental State ◽  
Freshwater Ecosystems ◽  
Aquatic Life ◽  
Elevated Salinity ◽  
Size At Metamorphosis ◽  
Timing Of Exposure

AbstractDevelopment can play a critical role in how organisms respond to changes in the environment. Tolerance to environmental challenges can vary during ontogeny, with individual- and population-level impacts that are associated with the timing of exposure relative to the timing of vulnerability. In addition, the life history consequences of different stressors can vary with the timing of exposure to stress. Salinization of freshwater ecosystems is an emerging environmental concern, and habitat salinity can change rapidly due, for example, to storm surge, runoff of road deicing salts, and rainfall. Elevated salinity can increase the demands of osmoregulation in freshwater organisms, and amphibians are particularly at risk due to their permeable skin and, in many species, semi-aquatic life cycle. In three experiments, we manipulated timing and duration of exposure to elevated salinity during larval development of southern toad (Anaxyrus terrestris) tadpoles and examined effects on survival, larval growth, and timing of and size at metamorphosis. Survival was reduced only for tadpoles exposed to elevated salinity early in development, suggesting an increase in tolerance as development proceeds; however, we found no evidence of acclimation to elevated salinity. Two forms of developmental plasticity may help to ameliorate costs of transient salinity exposure. With early salinity exposure, the return to freshwater was accompanied by a period of rapid compensatory growth, and metamorphosis ultimately occurred at a similar age and size as freshwater controls. By contrast, salinity exposure later in development led to earlier metamorphosis at reduced size, indicating an acceleration of metamorphosis as a mechanism to escape salinity stress. Thus, the consequences of transient salinity exposure were complex and were mediated by developmental state. Salinity stress experienced early in development resulted in acute costs but little long-lasting effect on survivors, while exposures later in development resulted in sublethal effects that could influence success in subsequent life stages. Overall, our results suggest that elevated salinity is more likely to affect southern toad larvae when experienced early during larval development, but even brief sublethal exposure later in development can alter life history in ways that may impact fitness.

Interrelationships of factors of social development are more complex than Life History Theory predicts

2019 ◽  
Vol 42 ◽  
Author(s):  
Boris Kotchoubey
Keyword(s):  
Life History ◽  
Social Development ◽  
Life History Theory ◽  
Strong Correlations ◽  
Behavioral Features

Abstract Life History Theory (LHT) predicts a monotonous relationship between affluence and the rate of innovations and strong correlations within a cluster of behavioral features. Although both predictions can be true in specific cases, they are incorrect in general. Therefore, the author's explanations may be right, but they do not prove LHT and cannot be generalized to other apparently similar processes.

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