Life Histories of Charophytes from Permanent and Temporary Wetlands in Eastern Australia

1999 ◽  
Vol 47 (3) ◽  
pp. 383 ◽  
Author(s):  
Michelle T. Casanova ◽  
Margaret A. Brock
Keyword(s):  
Life History ◽  
Sexual Reproduction ◽  
Vegetative Growth ◽  
Life Histories ◽  
Distribution Patterns ◽  
Reproductive Organs ◽  
Annual Species ◽  
Large Numbers ◽  
Eastern Australia ◽  
Life History Patterns

The results of an experiment on the demography of charophytes in permanent and temporary sites in two wetlands are outlined and the charophytes that germinated and established are described in relation to their life histories. Three life-history patterns are represented. First, Monoecious annual species germinate easily and rapidly after inundation, they grow quickly and initiate sexual reproduction at the expense of vegetative expansion, produce relatively few, large oospores and die in winter. Second, Dioecious annual species are slower to germinate than Monoecious annuals, they grow more slowly, but also initiate sexual reproduction early in life. They usually produce large numbers of small oospores and die in unfavourable seasons. Both winter-growing and summer-growing Dioecious annuals were represented in experiments. Third, Dioecious perennials germinate after a lag time and establishment; vegetative growth and expansion takes place early in spring. Reproduction in Dioecious perennials is stimulated by increasing water temperatures and other environmental cues. Vegetative reproductive organs are produced in autumn and individual shoots can be very long-lived. Life-history parameters such as germination requirements, establishment requirements and timing of vegetative growth and reproduction can be important in determining the distribution patterns in charophytes.

scholarly journals Metabolism and Development during Conidial Germination in Response to a Carbon-Nitrogen-Rich Synthetic or a Natural Source of Nutrition inNeurospora crassa

mBio ◽  
2019 ◽  
Vol 10 (2) ◽  
Author(s):  
Zheng Wang ◽  
Cristina Miguel-Rojas ◽  
Francesc Lopez-Giraldez ◽  
Oded Yarden ◽  
Frances Trail ◽  
...  
Keyword(s):  
Life History ◽  
Sexual Reproduction ◽  
Nitrogen Metabolism ◽  
Asexual Reproduction ◽  
Sexual Development ◽  
Vegetative Growth ◽  
Synthetic Medium ◽  
Conidial Germination ◽  
Content Type ◽  
Genes Expression

ABSTRACTFungal spores germinate and undergo vegetative growth, leading to either asexual or sexual reproductive dispersal. Previous research has indicated that among developmental regulatory genes, expression is conserved across nutritional environments, whereas pathways for carbon and nitrogen metabolism appear highly responsive—perhaps to accommodate differential nutritive processing. To comprehensively investigate conidial germination and the adaptive life history decision-making underlying these two modes of reproduction, we profiled transcription ofNeurospora crassagerminating on two media: synthetic Bird medium, designed to promote asexual reproduction; and a natural maple sap medium, on which both asexual reproduction and sexual reproduction manifest. A later start to germination but faster development was observed on synthetic medium. Metabolic genes exhibited altered expression in response to nutrients—at least 34% of the genes in the genome were significantly downregulated during the first two stages of conidial germination on synthetic medium. Knockouts of genes exhibiting differential expression across development altered germination and growth rates, as well as in one case causing abnormal germination. A consensus Bayesian network of these genes indicated especially tight integration of environmental sensing, asexual and sexual development, and nitrogen metabolism on a natural medium, suggesting that in natural environments, a more dynamic and tentative balance of asexual and sexual development may be typical ofN. crassacolonies.IMPORTANCEOne of the most remarkable successes of life is its ability to flourish in response to temporally and spatially varying environments. Fungi occupy diverse ecosystems, and their sensitivity to these environmental changes often drives major fungal life history decisions, including the major switch from vegetative growth to asexual or sexual reproduction. Spore germination comprises the first and simplest stage of vegetative growth. We examined the dependence of this early life history on the nutritional environment using genome-wide transcriptomics. We demonstrated that for developmental regulatory genes, expression was generally conserved across nutritional environments, whereas metabolic gene expression was highly labile. The level of activation of developmental genes did depend on current nutrient conditions, as did the modularity of metabolic and developmental response network interactions. This knowledge is critical to the development of future technologies that could manipulate fungal growth for medical, agricultural, or industrial purposes.

scholarly journals The Intertwined Life Histories and Transmission Ecologies of Plant, Arthropod, and Vertebrate Viruses

2021 ◽  
Author(s):  
Jan Slingenbergh
Keyword(s):  
Life History ◽  
Life Histories ◽  
Virus Transmission ◽  
Circulatory System ◽  
Reproductive Organs ◽  
Life History Strategies ◽  
Mechanical Transmission ◽  
Host Tropism ◽  
Host Body ◽  
Virus Retention

It remains poorly understood how the life history strategies and transmission ecologies of viruses of plants, arthropods, and vertebrates are interrelated. The present analysis hinges on the virus transmission success. Virus transmission reflects where in the host-body viruses are retained or replicating. Plants, arthropods, and vertebrates share a protective outer-layer, a circulatory system, and reproductive organs. The latter enables vertical virus transmission and associates with virus-host mutualism. Two broadly opposing virus life history strategies are considered. Acute viruses tend to be replicative and are swiftly transmitted to the next host. Instead, persistent viruses keep virus replicating costs and host damage to a minimum. The intertwined life histories and transmission ecologies are accordingly pieced together, based on the virus mono- or instead dual-host tropism, the location of virus retention or replication on or in the host-body, the presence of cyclical or mechanical transmission by arthropods, and of horizontal and vertical host-to-host transmission modes. It is shown that in the arthropod and in the vertebrate animal host, virus circulation in the hemocoel or blood circulation goes hand-in-hand with vertical transmission. Instead, plant phloem viruses do not transmit via seed. The latter is the rule for the plant-only viruses. The risk management implications are discussed in brief.

On the Nematode Parasite of the frit-fly, Oscinella frit, L

1930 ◽  
Vol 8 (3) ◽  
pp. 123-132 ◽  
Author(s):  
T. Goodey
Keyword(s):  
Life History ◽  
Royal Society ◽  
Reproductive Organs ◽  
Body Cavity ◽  
The Body ◽  
Nematode Parasite ◽  
Plant Tissues ◽  
Present Communication ◽  
Large Numbers ◽  
Fly Larvae

In a paper recently published in the Philosophical Transactions of the Royal Society of London, the writer describes the discovery of certain small Tylenchoid nematodes in the swollen stems of the seedling oats suffering from frit-fly attack at Winches Farm, St. Albans. Adults of both sexes and larvæ undergoing the last two moults were found in the destroyed plant tissues surrounding the fly larvæ. The spermatized female worms were next discovered within the body-cavity of the frit-fly larvæ. In due course, they were obtained from pupæ of the fly, having increased in size, and finally were found within adult flies of both sexes lying coiled within the abdomen as comparatively large sausage-shaped worms. As a result of the presence of the worm, the flies are sterilised, being unable to develop their reproductive organs. The worms become viviparous and shed large numbers of larvæ into the body-cavity of the fly and these, after undergoing a certain amount of growth, make their way into the gut of the host and pass to the exterior via the anus. In the present communication a brief account is given of the principal observations on the new parasite, its life-history and the effects on the host, described in detail in the original paper.

Comparison of life histories of two deep-water sharks from eastern Australia: the piked spurdog and the Philippine spurdog

2016 ◽  
Vol 67 (10) ◽  
pp. 1546 ◽  
Author(s):  
Cassandra L. Rigby ◽  
Ross K. Daley ◽  
Colin A. Simpfendorfer
Keyword(s):  
Life History ◽  
Deep Water ◽  
Life Histories ◽  
Growth Models ◽  
New South ◽  
South Wales ◽  
Eastern Australia ◽  
History Of ◽  
Males And Females ◽  
Species Specific

Deep-water sharks have low biological productivity and are vulnerable to exploitation with species-specific regional life history required to enable effective management. The present study describes the life history of two squalids collected from Australia: (1) the piked spurdog (Squalus megalops) from the tropical Great Barrier Reef; and (2) the Philippine spurdog (S. montalbani) from New South Wales. Maximum observed ages for males and females were 18 and 25 years for S. megalops and 28 and 27 years for S. montalbani. Multiple growth models were all well supported and indicated very slow growth rates for both species. The tropical S. megalops population was smaller and older at maturity than previously reported temperate populations. Males were mature at 352-mm stretched total length (LST) and 12.6 years, whereas females were mature at 422mm LST and 19.1 years. Squalus montalbani males were mature at 700mm LST and 21.8 years, whereas females were mature at 800mm LST and 26 years. Fecundity was lower for S. megalops than S. montalbani with two to three compared with nine to 16 embryos. Both species have a conservative life history, although in the event of overfishing the longer-lived, later-maturing and deeper-dwelling S. montalbani is likely to take longer to recover than S. megalops.

Life history adaptations of the fingernail clams Sphaerium occidentale and Musculium securis to ephemeral habitats

1981 ◽  
Vol 59 (12) ◽  
pp. 2219-2229 ◽  
Author(s):  
P. M. McKee ◽  
G. L. Mackie
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Life Histories ◽  
Stochastic Theory ◽  
Environmental Stresses ◽  
Temporary Pond ◽  
Continue Development ◽  
Large Numbers ◽  
Fingernail Clams ◽  
Ephemeral Habitats

Life histories of the fingernail clams Sphaerium occidentale and Musculium securis from a temporary pond are examined to show adaptations to ephemeral habitats. Musculium securis ceases growth upon birth and only newborn occur in the dry pond, whereas all length classes of S. occidentale are omnipresent. Aestivation is not obligatory in the life cycle of either species. Both grow and reproduce regardless of aestivation experience.Life history strategies of both clams counteract environmentally imposed, density-independent mortality pressures. Sphaerium occidentale has slower growth and greater longevity than M. securis which must complete its life cycle before the pond dries. During aestivation, broods continue development in S. occidentale but not in M. securis. If water is present in fall, both opportunistically use this period for development. Both produce large numbers of small newborn and exhibit multivoltine and iteroparous strategies, although M. securis releases consecutive broods only during a single spring birth period and only if the aquatic season is extended, whereas S. occidentale releases consecutive broods during a spring birth period, in autumn if water is present, and during a 2nd year. A mixed tactic, according to the stochastic theory, has been adopted by both for survival under highly variable environmental stresses.

scholarly journals Evaluating estuarine nursery use and life history patterns of Pomatomus saltatrix in eastern Australia

2018 ◽  
Vol 598 ◽  
pp. 187-199 ◽  
Author(s):  
HT Schilling ◽  
P Reis-Santos ◽  
JM Hughes ◽  
JA Smith ◽  
JD Everett ◽  
...  
Keyword(s):  
Life History ◽  
Pomatomus Saltatrix ◽  
Eastern Australia ◽  
Life History Patterns

scholarly journals The Haemogregarines of Mammals and Reptiles

Parasitology ◽  
1908 ◽  
Vol 1 (4) ◽  
pp. 318-321 ◽  
Author(s):  
W. S. Patton
Keyword(s):  
Life History ◽  
New Species ◽  
Sexual Reproduction ◽  
Life Histories ◽  
Sexual Cycle ◽  
Blood Sucking ◽  
Intracellular Parasites ◽  
Asexual Multiplication ◽  
History Of ◽  
Vegetative Cycle

In two recent papersm Sambon and Seligmann (1907, 1908) have recorded some observations on the intracellular parasites of snakes, and have described no less than ten new species. The authors, in discussing the life histories of these parasites, have made the startling discovery that, “the life history of the haemogregarines like that of the haemoprotozoa is divided into two cycles: a schizogonic or ‘vegetative’ cycle spent in the blood of vertebrates and characterised by asexual multiplication, and a sporogonic or sexual cycle spent in the digestive organs of blood-sucking invertebrates and characterised by sexual reproduction.” The authors then go on to speak quite familiarly of young merozoites, adult schizonts, adult sporonts, and so on.

Life history patterns and trophic ecology of Trichoptera in two Alaskan (U.S.A.) subarctic streams

1988 ◽  
Vol 66 (6) ◽  
pp. 1258-1265 ◽  
Author(s):  
John G. Irons III
Keyword(s):  
Life History ◽  
Boreal Forest ◽  
Life Histories ◽  
Trophic Ecology ◽  
Similar Species ◽  
Allochthonous Input ◽  
Interior Alaska ◽  
West Fork ◽  
Life History Patterns ◽  
Periphyton Biomass

Monument Creek and West Fork, two interior Alaskan streams that are tributaries of the Chena River, are characterized by low water temperatures, low allochthonous input and periphyton biomass, and lengthy ice cover. Nine species of Trichoptera were found: Rhyacophila vofixa (Rhyacophilidae), Glossosoma verdona, Glossosoma alascense (Glossosomatidae), Brachycentrus americanus (Brachycentridae), Hydatophylax variabilis, Ecclisomyia conspersa, Onocosmoecus unicolor, Chyranda centralis, and Apatania crymophila (Limnephilidae). There were four shredders, three scrapers, one omnivore, and one predator. Within the shredder and scraper guilds, species had partially overlapping univoltine life histories, perhaps allowing functionally similar species to use the same food resources. The trichopteran fauna of interior Alaska seems to be composed of species typical of boreal forest, with arctic, western montane, and Siberian influences.

Hormones and Behavior

2019 ◽  
pp. 11-26
Author(s):  
Maren N. Vitousek ◽  
Laura A. Schoenle
Keyword(s):  
Life History ◽  
Life Histories ◽  
Life History Traits ◽  
Developmental Plasticity ◽  
Endocrine System ◽  
Phenotypic Traits ◽  
Social Environments ◽  
Trade Offs ◽  
And Behavior

Hormones mediate the expression of life history traits—phenotypic traits that contribute to lifetime fitness (i.e., reproductive timing, growth rate, number and size of offspring). The endocrine system shapes phenotype by organizing tissues during developmental periods and by activating changes in behavior, physiology, and morphology in response to varying physical and social environments. Because hormones can simultaneously regulate many traits (hormonal pleiotropy), they are important mediators of life history trade-offs among growth, reproduction, and survival. This chapter reviews the role of hormones in shaping life histories with an emphasis on developmental plasticity and reversible flexibility in endocrine and life history traits. It also discusses the advantages of studying hormone–behavior interactions from an evolutionary perspective. Recent research in evolutionary endocrinology has provided insight into the heritability of endocrine traits, how selection on hormone systems may influence the evolution of life histories, and the role of hormonal pleiotropy in driving or constraining evolution.

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