scholarly journals Habitat Shift for Plankton: The Living Side of Benthic-Pelagic Coupling in the Mar Piccolo of Taranto (Southern Italy, Ionian Sea)

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3619
Author(s):  
Fernando Rubino ◽  
Genuario Belmonte
Keyword(s):  
Life Histories ◽  
Single Species ◽  
Life Cycles ◽  
Point Of View ◽  
Resting Stages ◽  
Cyst Production ◽  
Marine Habitats ◽  
Mar Piccolo Of Taranto ◽  
Benthic Pelagic Coupling ◽  
Cyst Germination

Resting stages represent the answer for species to the variability of environmental conditions. In confined marine habitats, variability of conditions is high, and bottoms host plankton resting stages in the so-called “marine cyst banks”. The Mar Piccolo of Taranto was chosen as a pilot site in which to investigate how marine cyst banks and plankton affect each other in the living part of the benthic–pelagic coupling. The attempt was based on the use of multiple devices for integrated sampling of benthic and pelagic stages and allowed us to identify 207 taxa/categories in the whole system (127 as active forms, 91 as resting stages). The sediments added 80 taxa to the plankton list obtained only from the water column, thus confirming the importance of this kind of approach in perceiving the actual diversity of the studied site. The sediment cyst bank involved 0.15–1.00% of its content in daily benthic-pelagic exchanges, in terms of cyst germination and import, respectively. In addition, the cyst production, which was higher than the cyst germination, is responsible for the existence of a permanent biological reservoir in the sediments. The benthic-pelagic coupling, however, was completely depicted in the present investigation only for seven taxa. This result is due to the still scant knowledge of the life cycles and life histories of single species. Apart from the identification difficulties that still have to be clarified (which cysts belong to which species), the cycle presence/absence is also characterized by the diversification of strategies adopted by each species. The observation of plankton dynamics from the benthos point of view was useful and informative, unveiling a huge assemblage of resting forms in the sediments only minimally affected by cyst import/export, because it is more devoted to a storing role over long periods. Consequently, the continuation of life cycle studies appears necessary to understand the diversity of strategies adopted by the majority of plankton species.

scholarly journals Synchronized Tick Population Oscillations Driven by Host Mobility and Spatially Heterogeneous Developmental Delays Combined

2021 ◽  
Vol 83 (6) ◽  
Author(s):  
Xue Zhang ◽  
Jianhong Wu
Keyword(s):  
Delay Differential Equations ◽  
Developmental Delays ◽  
Coupled System ◽  
Single Species ◽  
Adult Tick ◽  
Life Cycles ◽  
Positive Equilibrium ◽  
Tick Population ◽  
Host Mobility ◽  
Delay Differential

AbstractWe consider a coupled system of delay differential equations for a single-species tick population dynamics, assuming feeding adult ticks are distributed by their hosts in a spatially heterogeneous environment consisting of two patches where egg ticks produced will complete their life cycles with different, normal and diapause, developmental delays. We show that the mobility of adult tick host and the diapause developmental delay combined drive a synchronized oscillation in the total tick populations around a uniquely defined positive equilibrium, and this synchronization makes the oscillatory patterns much simpler in comparison with multi-peak oscillations exhibited in the absence of host mobility.

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.

Neotypification of the Linnaean name Iris aphylla (Iridaceae)

Phytotaxa ◽  
2016 ◽  
Vol 273 (2) ◽  
pp. 141 ◽  
Author(s):  
EUGENY V. BOLTENKOV
Keyword(s):  
Chromosome Number ◽  
Western Europe ◽  
Genetic Data ◽  
Single Species ◽  
Point Of View ◽  
European Russia ◽  
European Countries ◽  
Forest Edges ◽  
Variable Species ◽  
Open Forests

Iris aphylla Linnaeus (1753: 38) (Iridaceae) is a highly variable species from the morphological point of view, especially in the height of stem, stem branching, size of leaves, and color of flowers. Moreover, it can be found in different habitats. In the Middle-Russian Upland, this plant is mostly associated with meadow steppes on slopes and, rarely, with edges of shrub thickets; also occurs along forest edges and in open forests, where blooming plants are rare (Kazakova et al. 2015). It is native to Central, Eastern, and some parts of Western Europe. The species is widespread in the Ukraine and mainly in the south of middle European Russia, while in the European countries its populations are sparser. Iris aphylla is of autotetraploid origin (Mitra 1956); plants with the chromosome number 2n = 48 are found more frequently in Europe (Wróblewska et al. 2010). Its numerous synonyms, including four subspecies, indicate the variability of this species. The genetic data confirm the conclusion that the subspecies of I. aphylla should be regarded as a single species (Wróblewska et al. 2010). According to my best knowledge (see also Jarvis 2007) the name I. aphylla is still lacking typification.

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>

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.

scholarly journals Creative Food Cycles: A Cultural Approach to the Food Life-Cycles in Cities

2020 ◽  
Vol 12 (16) ◽  
pp. 6487
Author(s):  
Manuel Navarro Gausa ◽  
Silvia Pericu ◽  
Nicola Canessa ◽  
Giorgia Tucci
Keyword(s):  
Sustainable Development ◽  
Food System ◽  
Life Cycles ◽  
Point Of View ◽  
Social Perceptions ◽  
Ongoing Research ◽  
The Sustainable Development ◽  
Open Platform ◽  
Design Culture ◽  
Eu Project

The new contemporary multi-city needs the landscape as a proactive eco-systemic infrastructure in order to rethink the whole food system, from the design of public spaces to domestic spaces. In this direction, Creative Food Cycles (CFC) is an EU project that, according to the Sustainable Development Goals (SDGs), addresses the topic of food as a cross-cutting factor and powerful accelerator toward the co-design of sustainability in cities. Design culture today has begun to question and innovate production, distribution, and recycling models of food cycles. In the post-consumption and disposal phase illustrated herein, making the most of food means conceiving waste as a resource for the creation of new sustainable materials or prototypes. The concept of food waste and food losses has been shown to be not only a topic at the center of the debate but also a powerful tool for raising awareness of sustainable development at the community level. The CFC actions shown here were developed with the objective of persuading consumers to change their behaviors, while at the same time exploring cultural and social perceptions. With the aim of making cities more sustainable, this paper describes tools to engage different stakeholders, such as architects, product designers, and citizens, from a cultural point of view. The ongoing research has turned in the end into an educational campaign and an open platform where prototypes, new materials, and products are developed as inspiration for change.

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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