Life cycles of nemerteans that are symbiotic egg predators of decapod Crustacea: adaptations to host life histories

Hydrobiologia ◽  
1993 ◽  
Vol 266 (1-3) ◽  
pp. 1-14 ◽  
Author(s):  
Armand M. Kuris
Keyword(s):  
Life Histories ◽  
Life Cycles ◽  
Decapod Crustacea ◽  
Host Life

Coevolutionary interactions between host life histories and parasite life cycles

Parasitology ◽  
1998 ◽  
Vol 116 (S1) ◽  
pp. S47-S55 ◽  
Author(s):  
J. C. Koella ◽  
P. Agnew ◽  
Y. Michalakis
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Life Histories ◽  
Life History Traits ◽  
Evolutionary Ecology ◽  
Life Cycles ◽  
Microsporidian Parasite ◽  
History Of ◽  
Host Life ◽  
Host Parasite

SummarySeveral recent studies have discussed the interaction of host life-history traits and parasite life cycles. It has been observed that the life-history of a host often changes after infection by a parasite. In some cases, changes of host life-history traits reduce the costs of parasitism and can be interpreted as a form of resistance against the parasite. In other cases, changes of host life-history traits increase the parasite's transmission and can be interpreted as manipulation by the parasite. Alternatively, changes of host's life-history traits can also induce responses in the parasite's life cycle traits. After a brief review of recent studies, we treat in more detail the interaction between the microsporidian parasite Edhazardia aedis and its host, the mosquito Aedes aegypti. We consider the interactions between the host's life-history and parasite's life cycle that help shape the evolutionary ecology of their relationship. In particular, these interactions determine whether the parasite is benign and transmits vertically or is virulent and transmits horizontally.Key words: host-parasite interaction, life-history, life cycle, coevolution.

scholarly journals Robustness of life histories to environmental variability in complex versus simple life cycles

2021 ◽  
Author(s):  
Annie Jonsson
Keyword(s):  
Growth Rate ◽  
Life Histories ◽  
Environmental Variability ◽  
Life Cycles ◽  
Relative Advantage ◽  
Complex Life Cycle ◽  
Life Stages ◽  
Vital Rates ◽  
Habitat Separation ◽  
Simple Life

AbstractMost animal species have a complex life cycle (CLC) with metamorphosis. It is thus of interest to examine possible benefits of such life histories. The prevailing view is that CLC represents an adaptation for genetic decoupling of juvenile and adult traits, thereby allowing life stages to respond independently to different selective forces. Here I propose an additional potential advantage of CLCs that is, decreased variance in population growth rate due to habitat separation of life stages. Habitat separation of pre- and post-metamorphic stages means that the stages will experience different regimes of environmental variability. This is in contrast to species with simple life cycles (SLC) whose life stages often occupy one and the same habitat. The correlation in the fluctuations of the vital rates of life stages is therefore likely to be weaker in complex than in simple life cycles. By a theoretical framework using an analytical approach, I have (1) derived the relative advantage, in terms of long-run growth rate, of CLC over SLC phenotypes for a broad spectrum of life histories, and (2) explored which life histories that benefit most by a CLC, that is avoid correlation in vital rates between life stages. The direction and magnitude of gain depended on life history type and fluctuating vital rate. One implication of our study is that species with CLCs should, on average, be more robust to increased environmental variability caused by global warming than species with SLCs.

scholarly journals Community structure, life histories and secondary production of stoneflies in two small mountain streams with different degree of forest cover

2015 ◽  
Author(s):  
Pavel Beracko ◽  
Andrea Kušnírová ◽  
Michaela Partlová ◽  
Jana Ciceková
Keyword(s):  
Community Structure ◽  
Secondary Production ◽  
Life Histories ◽  
Forest Cover ◽  
Adult Emergence ◽  
Life Cycles ◽  
Mountain Streams ◽  
Annual Life Cycle ◽  
Forested Stream ◽  
The Difference

<p>Our study examines community structure and nymphal biology (life cycles and secondary production) of stoneflies in two adjacent mountain streams with different degree of forest cover in the Prosiečanka River Basin (Chočské Vrchy Mts., West Carpathians). One of the streams has non-forested catchment, converted to meadows and pastures, while the other one has catchment with 60% covered by spruce forest. Differences in forest cover and in thermal regime of the streams were reflected by the difference of stonefly communities at their structural and functional level. Species <em>Nemoura cinerea and Leuctra aurita </em>created stonefly assemblage in non-forested stream, whereas <em>Nemoura cinerea</em> also occurred in naturally forested stream together with species <em>Leuctra armata, Leuctra nigra, Leuctra prima, Siphonoperla neglecta</em> and <em>Arcynopteryx dichroa</em>. All examined species had maximally annual life cycle and in eudominant species <em>Nemoura cinerea</em> one month shift was found in nymphal hatching and adult emergence between streams. Total secondary production of stoneflies in undisturbed stream (126.46 mg DW m<sup>-2</sup> y<sup>-1</sup>) was more than two times higher than the production in non-forested stream (47.39 mg DW m<sup>-2</sup> y<sup>-1</sup>). </p>

scholarly journals Diversity of echinostomes (Digenea: Echinostomatidae) in their snail hosts at high latitudes

Parasite ◽  
2021 ◽  
Vol 28 ◽  
pp. 59
Author(s):  
Camila Pantoja ◽  
Anna Faltýnková ◽  
Katie O’Dwyer ◽  
Damien Jouet ◽  
Karl Skírnisson ◽  
...  
Keyword(s):  
North America ◽  
Dna Sequences ◽  
Sequence Data ◽  
Molecular Data ◽  
Migratory Bird ◽  
Parasite Fauna ◽  
Life Cycles ◽  
Freshwater Ecosystems ◽  
Trematode Species ◽  
Host Life

The biodiversity of freshwater ecosystems globally still leaves much to be discovered, not least in the trematode parasite fauna they support. Echinostome trematode parasites have complex, multiple-host life-cycles, often involving migratory bird definitive hosts, thus leading to widespread distributions. Here, we examined the echinostome diversity in freshwater ecosystems at high latitude locations in Iceland, Finland, Ireland and Alaska (USA). We report 14 echinostome species identified morphologically and molecularly from analyses of nad1 and 28S rDNA sequence data. We found echinostomes parasitising snails of 11 species from the families Lymnaeidae, Planorbidae, Physidae and Valvatidae. The number of echinostome species in different hosts did not vary greatly and ranged from one to three species. Of these 14 trematode species, we discovered four species (Echinoparyphium sp. 1, Echinoparyphium sp. 2, Neopetasiger sp. 5, and Echinostomatidae gen. sp.) as novel in Europe; we provide descriptions for the newly recorded species and those not previously associated with DNA sequences. Two species from Iceland (Neopetasiger islandicus and Echinoparyphium sp. 2) were recorded in both Iceland and North America. All species found in Ireland are new records for this country. Via an integrative taxonomic approach taken, both morphological and molecular data are provided for comparison with future studies to elucidate many of the unknown parasite life cycles and transmission routes. Our reports of species distributions spanning Europe and North America highlight the need for parasite biodiversity assessments across large geographical areas.

Hybridization in leopard frogs (Rana pipiens complex): terrestrial performance of newly metamorphosed hybrid and parental genotypes in field enclosures

2001 ◽  
Vol 79 (9) ◽  
pp. 1552-1558 ◽  
Author(s):  
Matthew J Parris
Keyword(s):  
Growth Rates ◽  
Life Histories ◽  
Parental Species ◽  
Natural Populations ◽  
Life Cycles ◽  
Natural Hybridization ◽  
Evolutionary Potential ◽  
Leopard Frogs ◽  
Rana Blairi ◽  
Advanced Generation

Terrestrial ecology has been largely neglected in the study of amphibian life histories because it is difficult to manipulate most species during the terrestrial stage. I examined the terrestrial performance of Rana blairi, Rana sphenocephala, and four hybrid (two F1 and two advanced generation) genotypes in replicated experimental enclosures to test for differences in traits related to juvenile terrestrial fitness. I produced all genotypes by means of artificial fertilizations using frogs collected from natural populations in central Missouri, and juvenile frogs were obtained from larvae reared in experimental ponds. Following metamorphosis, froglets were raised in single-genotype groups in terrestrial enclosures through the first overwintering. The proportion surviving did not vary among genotypes, but the power to detect significant differences was low. F1 hybrid genotypes BS and SB demonstrated significantly higher growth rates than either parental species or advanced-generation hybrid genotypes. Observation of growth rates of advanced-generation hybrids equal to those of the parental species, and heterosis in F1 hybrids for growth rate, suggests that natural hybridization between R. blairi and R. sphenocephala can produce novel and relatively fit hybrid genotypes. Direct measurement of multiple fitness components for hybrid and parental genotypes is critical for assessing the evolutionary potential of natural hybridization in organisms with complex life cycles.

Challenges for Diadromous Fishes in a Dynamic Global Environment

2009 ◽  
Keyword(s):  
Life Cycle ◽  
Life Histories ◽  
Life Cycles ◽  
Partial Migration ◽  
Environmental Stochasticity ◽  
Species Dynamics ◽  
Life Cycle Pattern ◽  
Aquatic Sciences ◽  
Diversity Of Life

<em>Abstract</em>.-In the study of species life histories and the structure of diadromous populations, an emerging trend is the prevalence of life cycle diversity-that is, individuals within populations that do not conform to a single life cycle pattern. A rapid rise in publications documenting within-population variability in life cycles has resulted in the use of numerous terms and phrases. We argue that myriad terms specific to taxa, ecosystem types, and applications are in fact describing the same phenomenon-life cycle diversity. This phenomenon has been obscured by the use of multiple terms across applications, but also by the overuse of typologies (i.e., anadromy, catadromy) that fail to convey the extent of life cycle variations that underlay population, metapopulation, and species dynamics. To illustrate this, we review migration and habitat-use terms that have been used to describe life cycles and life cycle variation. Using a citation index (Cambridge Scientific Abstracts © Aquatic Sciences and Fisheries Abstracts), terms were tallied across taxonomic family, ecosystem, type of application, analytical approach, and country of study. Studies on life cycle diversity have increased threefold during the past 15 years, with a total of 336 papers identified in this review. Most of the 40 terms we identified described either sedentary or migratory lifetime behaviors. The sedentary-migratory dichotomy fits well with the phenomenon of partial migration, which has been commonly reported for birds and Salmonidae and is postulated to be the result of early life thresholds (switch-points). On the other hand, the lexicon supports alternate modes of migration, beyond the simple sedentary-migratory dichotomy. Here more elaborate causal mechanisms such as the entrainment hypothesis may have application. Diversity of life cycles in fish populations, whether due to partial migration, entrainment, or other mechanisms, is increasingly recognized as having the effect of offsetting environmental stochasticity and contributing to long-term persistence.

Growth and life histories in Nematoda with particular reference to environmental factors

Nematology ◽  
2003 ◽  
Vol 5 (5) ◽  
pp. 653-664 ◽  
Author(s):  
Brian Boag ◽  
Gregor Yeates
Keyword(s):  
Life Histories ◽  
Developmental Stages ◽  
Relative Size ◽  
Nematode Species ◽  
Life Cycles ◽  
Growth Patterns ◽  
Female Size ◽  
Lower Growth ◽  
Physical Support ◽  
Unifying Principles

AbstractTo seek unifying principles underlying growth patterns in the phylum Nematoda, the volume of successive developmental stages was determined from published measurements. Within some groups occupying fairly uniform, non-living habitats ( e.g. , Longidoridae, Mononchida, non-parasitic Rhabditida) growth patterns are similar, as are the sizes of both sexes. In aquatic Chromadorida and Monhysterida, females are commonly larger than males. Plant-parasitic groups vary in the relative size of the sexes; within Criconematoidea there is some reduction of males in Hemicyliophora but extreme reduction in Tylenchulus. Despite freeliving and parasitic cycles of Strongyloides showing differing growth in stages 2 to 4, females are similar in both cycles. The strongylid parasites of vertebrates studied have a bacterial-feeding external stage and have lower growth rates and achieve smaller female size than Ascardia with direct life cycles. In taxa for which data are available, the increase in volume between stages 1 and 2 was 0.4-53-fold; that between stages 2 and 3, typically, 1.8-2.9-fold but up to 8191-fold; between stages 3 to 4, 1.7-3.8-fold but up to 100-fold; and between stage 4 to female, typically, 1.1-42-fold but up to 918-fold. Complete data are available for few nematode species and there is no apparent consistent pattern in which taxa contain 'outliers' at particular stages. Many more data are required to assess the impacts of habitat texture, physical support, food supply and experienced temperature on nematode growth and size.

Japanese Biographies: Life Histories, Life Cycles, Life Stages.

1994 ◽  
Vol 67 (1) ◽  
pp. 128
Author(s):  
Joshua S. Mostow ◽  
Susanne Formanek ◽  
Sepp Linhart
Keyword(s):  
Life Histories ◽  
Life Cycles ◽  
Life Stages
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