scholarly journals ­Reproductive strategies of two common sympatric Mediterranean sponges:Dysidea avara(Dictyoceratida) andPhorbas tenacior(Poecilosclerida)

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5458 ◽  
Author(s):  
Sonia de Caralt ◽  
Janina González ◽  
Xavier Turon ◽  
María J. Uriz
Keyword(s):  
Reproductive Effort ◽  
Reproductive Traits ◽  
Reproductive Period ◽  
Life Cycles ◽  
Life Strategy ◽  
Larval Size ◽  
Dysidea Avara ◽  
Species Specific ◽  
June July ◽  
Benthic Ecosystems

Despite their abundance in benthic ecosystems, life cycles and reproductive features of most sponge species remain unknown. We have studied the main reproductive features of two demosponges,Dysidea avaraandPhorbas tenacior,belonging to phylogenetically distant groups: Orders Dictyoceratida and Poecilosclerida, respectively. Both sponges are abundant and share habitat in the Mediterranean rocky sublittoral. They brood parenchymella larvae with different morphology and behaviour. Sampling was conducted monthly over a two-year period in a locality where both species coexist. The two species reproduced in spring-summer, and presented species-specific reproductive features despite being subject to the same environmental conditions.D. avarahas a shorter reproductive period thanP. tenacior, ending before the peak of temperature in summer, while the reproductive period ofP. tenaciorlasts until beginning of autumn. Brooding larvae were present in June-July inD. avara, and in August-October inP. tenacior. Larval size, reproductive effort and number of larvae produced (measured the month with the maximum production) were significantly higher inD. avarathan inP. tenacior. A higher reproductive effort and larval traits point to a more opportunistic life strategy inD. avarathan inP. tenacior.A lack of overlap in the timing of larval release, as well as different reproductive traits, may reduce competition and facilitate the coexistence of these two sympatric and abundant sponges.

Routine identification of four sympatric species of calanoid copepods Pseudocalanus spp. in the Atlantic Arctic using a species-specific polymerase chain reaction

2020 ◽  
Vol 48 (1) ◽  
pp. 62-72
Author(s):  
E. A. Ershova
Keyword(s):  
Polymerase Chain Reaction ◽  
Life Cycles ◽  
The Arctic ◽  
Relative Distribution ◽  
Chain Reaction ◽  
Specific Polymerase Chain Reaction ◽  
Routine Identification ◽  
Polymerase Chain ◽  
Species Specific ◽  
Plankton Communities

Сalanoid copepods of the genus Pseudocalanus play an important role in the plankton communities of the Arctic and boreal seas, often dominating in numbers and constituting a significant proportion of the biomass of zooplankton. Despite their high presence and significance in the shelf plankton communities, species-specific studies of the biology of these are significantly hampered by extremely small morphological differences between them, especially at the juvenile stages, at which they are virtually indistinguishable. In this paper, we describe a new, routine and low-cost molecular method for identifying all Pseudocalanus species found in the Atlantic sector of the Arctic: the Arctic P. acuspes, P. minutus and the boreal P. moultoni and P. elongatus, and apply it to describe the relative distribution of these species in four locations of the Arctic and sub-Arctic. With this method, species-specific polymerase chain reaction (ssPCR), mass identification of individuals of any developmental stage, including nauplii, is possible. This method can serve as an excellent tool for studying the species-specific biology of this group, describing their life cycles, as well as monitoring changes in Arctic marine ecosystems under the influence of changing climate.

scholarly journals Evolution of life cycles and reproductive traits: insights from the brown algae

2021 ◽  
Author(s):  
Svenja Heesch ◽  
Martha Serrano‐Serrano ◽  
Josué Barrera‐Redondo ◽  
Rémy Luthringer ◽  
Akira F. Peters ◽  
...  
Keyword(s):  
Brown Algae ◽  
Reproductive Traits ◽  
Life Cycles ◽  
Evolution Of Life

scholarly journals Longitudinal zonation of larval Hydropsyche (Trichoptera: Hydropsychidae): abiotic environmental factors and biotic interactions behind the downstream sequence of Central European species

Hydrobiologia ◽  
2021 ◽  
Author(s):  
Márk Ficsór ◽  
Zoltán Csabai
Keyword(s):  
Environmental Factors ◽  
Biotic Interactions ◽  
Life Cycles ◽  
Longitudinal Distribution ◽  
Central European ◽  
European Species ◽  
Longitudinal Gradients ◽  
Species Specific ◽  
Behavioural Aspects ◽  
Abiotic Environmental Factors

AbstractThe aim of this review is to summarize the literature knowledge about how abiotic environmental factors and biotic interactions affect the sequentially overlapping longitudinal distribution of Central European species of the net-spinning freshwater caddisfly larvae of the genus Hydropsyche (Trichoptera: Hydropsychidae). In this relation, several physical and chemical parameters of water are discussed, as well as different species-specific traits, behavioural aspects and the interaction of coexisting species. Longitudinal gradients of river networks, especially annual temperature range, flow velocity and the particle size of suspended food material play a crucial role in forming the downstream succession of characteristic species, while increased levels of organic pollution, nutrients, salinity and heavy metals facilitates the presence of more tolerant ones. Several species-specific traits, such as respiration range, net-building frequency, head capsule size or optimal net-building velocity correlate with the position of a given species in the sequence. Coexistence of species with similar ecological demands in the overlapping zones of distribution is facilitated by differences in feeding and net-building habits, microhabitat preferences and staggering life cycles, but complicated at the same time by means of inter- and intraspecific territorial behaviour, such as fighting for the ownership of larval retreats or the practice of stridulation.

Altitudinal variation in reproductive strategy of the toad-headed lizard, Phrynocephalus vlangalii in North Tibet Plateau (Qinghai)

2007 ◽  
Vol 28 (4) ◽  
pp. 509-515 ◽  
Author(s):  
Yuan-Ting Jin ◽  
Nai-Fa Liu
Keyword(s):  
Litter Size ◽  
Altitudinal Gradient ◽  
Reproductive Effort ◽  
Reproductive Investment ◽  
Reproductive Traits ◽  
Tibet Plateau ◽  
Sand Lizard ◽  
Survival And Growth ◽  
The Common ◽  
Anatomical Constraints

Abstract Phrynocephalus vlangalii, a toad-headed viviparous sand lizard, is endemic in the Northern Tibet (Qinghai) Plateau in China. Lizards were collected from 14 localities along the large altitudinal gradient (2289-4565 m a.s.l) to analyze the variation of reproductive traits among localities. Both litter size and mean offspring (scaled embryo) mass were positively correlated with female snout-vent length (SVL). Females produced fewer and larger offspring with increasing elevation when the effect of body size (SVL) was removed. This strategy may possibly be correlated with early survival and growth of offspring. The decreased litter size cline along altitudinal gradient might be correlated with more anatomical constraints at higher altitudes. The lizard has lower coefficient of variation (CV) of litter size at higher environments. Moreover, females from higher elevations had less reproductive investment (relative litter mass, RLM). Study concluded that P. vlangalii fit into the common pattern of higher elevation animals that have smaller clutches of larger offspring and lower reproductive effort.

Freshwater Migration as a Determinant Factor in the Somatic Cost of Reproduction of Two Anadromous Coregonines of James Bay

1990 ◽  
Vol 47 (2) ◽  
pp. 318-334 ◽  
Author(s):  
Yvan Lambert ◽  
Julian J. Dodson
Keyword(s):  
Energy Cost ◽  
Reproductive Effort ◽  
Energy Content ◽  
Cost Of Reproduction ◽  
Energy Gain ◽  
Lake Whitefish ◽  
James Bay ◽  
Energy Increase ◽  
Species Specific ◽  
Somatic Energy

We tested the hypothesis that the species-specific costs of migration differentially affect reproductive effort and somatic cost of reproduction in sympatric anadromous populations of cisco (Coregonus artedii) and lake whitefish (C. clupeaformis) of James Bay. Reproductive effort, which includes the energy cost of migration, is higher for cisco. Female cisco allocate more energy to reproduction than its total energy gain. The energy invested by lake whitefish in reproduction is approximately equal to its seasonal energy gain. Reproduction results in large differences in the energy content of gonads, viscera, and carcass between reproductive and nonreproductive fish of the same length. Neither cisco nor lake whitefish are able to spawn two years in succession. The somatic energy increase of reproductive female cisco is 121% lower than the somatic energy increase of nonreproductive females; similar comparisons are 89% (female) and 103% (male) for lake whitefish. The energy cost of migration is largely responsible for the higher somatic cost of reproduction observed for cisco. These different somatic costs of migration are related to resource accumulation prior to migration and to differences in the aerobic cost of swimming between the two species in combination with the difficulty of the freshwater migration.

Connectivity, migration and recruitment in a catadromous fish

2018 ◽  
Vol 69 (11) ◽  
pp. 1733 ◽  
Author(s):  
Christopher M. Bice ◽  
Brenton P. Zampatti ◽  
John R. Morrongiello
Keyword(s):  
Fish Passage ◽  
Freshwater Flow ◽  
Species Management ◽  
River Hydrology ◽  
Potential Impact ◽  
Flow Closure ◽  
Navigation Lock ◽  
Species Specific ◽  
June July ◽  
Management And Conservation

Understanding the influence of river hydrology and connectivity on the migration and recruitment of diadromous fishes is fundamental for species management and conservation. We investigated the downstream catadromous spawning migration of adult female congolli (Pseudaphritis urvillii) using acoustic telemetry, and subsequent juvenile recruitment, in the lower reaches of the River Murray, Australia, in 2009–2011. The years 2009 and 2010 were characterised by diminished freshwater flow, closure of tidal barrages, and disconnection of freshwater and estuarine habitats; however, a navigation lock was operated to facilitate downstream fish passage in 2010. In both years, >70% of individuals tagged upstream undertook downstream migrations, in association with day-of-the-year (June–July) and moonphase (full), and accumulated upstream of the tidal barrages. In 2009, fish were unable to pass the barrages and remained upstream, but in 2010, an estimated >15000 individuals passed through the navigation lock, including 40% of individuals tagged upstream. These transitioned rapidly (<24h) through the estuary and into the ocean. In association, abundances of upstream migrant juveniles in spring–summer 2010–2011 were up to 180 times greater than in spring–summer 2009–2010. Our study illustrates the potential impact of tidal barriers on migrations and population dynamics of catadromous fish, and the importance of understanding species-specific migration ecology.

scholarly journals Molecular Diagnostics for the Sigatoka Disease Complex of Banana

2007 ◽  
Vol 97 (9) ◽  
pp. 1112-1118 ◽  
Author(s):  
Mahdi Arzanlou ◽  
Edwin C. A. Abeln ◽  
Gert H. J. Kema ◽  
Cees Waalwijk ◽  
Jean Carlier ◽  
...  
Keyword(s):  
Management Strategies ◽  
Leaf Tissue ◽  
Pcr Primers ◽  
Disease Diagnosis ◽  
Life Cycles ◽  
Diagnostic Tools ◽  
Disease Epidemiology ◽  
Disease Complex ◽  
Real Time Quantitative Pcr ◽  
Species Specific

The Sigatoka disease complex of banana involves three related ascomycetous fungi, Mycosphaerella fijiensis, M. musicola, and M. eumusae. The exact distribution of these three species and their disease epidemiology remain unclear, because their symptoms and life cycles are rather similar. Disease diagnosis in the Mycosphaerella complex of banana is based on the presence of host symptoms and fungal fruiting structures, which hamper preventive management strategies. In the present study, we have developed rapid and robust species-specific molecular-based diagnostic tools for detection and quantification of M. fijiensis, M. musicola, and M. eumusae. Conventional species-specific polymerase chain reaction (PCR) primers were developed based on the actin gene that detected DNA at as little as 100, 1, and 10 pg/μl from M. fijiensis, M. musicola, and M. eumusae, respectively. Furthermore, TaqMan real-time quantitative PCR assays were developed based on the β-tubulin gene and detected quantities of DNA as low as 1 pg/μl for each Mycosphaerella sp. from pure cultures and DNA at 1.6 pg/μl per milligram of dry leaf tissue for M. fijiensis that was validated using naturally infected banana leaves.

Energy budgets and reproductive ecologies of mayflies occupying disparate thermal environments

1989 ◽  
Vol 67 (11) ◽  
pp. 2782-2791 ◽  
Author(s):  
Michael J. Benton
Keyword(s):  
Body Size ◽  
Reproductive Effort ◽  
Energy Content ◽  
Aquatic Insect ◽  
Handling Time ◽  
Growth Efficiency ◽  
Life Cycles ◽  
Energy Budgets ◽  
Insect Larvae ◽  
Growth Ratio

Energy budgets were calculated for two populations of Ameletus occupying thermally disparate habitats. Growth, consumption, respiration, fecundity, and energy content of larvae and eggs were determined experimentally. Respiration rates increased and decreased with temperature throughout the life cycles of both species, although thermal effects became less pronounced with increased body size. Ameletus similior exhibited more uniform and consistently higher respiration values than Ameletus celer. Respiration costs were not constant over the life cycle of either species as has been reported for some other mayflies. Growth was influenced by both temperature (which affected instar duration) and body size (which affected growth ratio). Growth corresponded positively to temperature in both species, but was more uniform in A. celer. Net growth efficiency and assimilation were highest during cold periods in A. celer, but highest during warmer periods in A. similior. Consumption estimates were high even after adjustments for projected nonfeeding time, but unless food availability or handling time is limiting, the feeding rate of Ameletus relative to body mass may be higher than rates reported for other aquatic insect larvae. Several sources of error in consumption estimates existed, however. Assimilation efficiencies were low, but comparable to those for other herbivorous aquatic insects. Reproductive effort was higher in A. celer, but net reproductive effort was lower. The higher net reproductive effort by A. similior did not result in increased fecundity as expected, but in higher egg energy content. This and other factors suggest that A. similior displays more "K-selected" traits than A. celer, and indicates that greater fitness may not necessarily be synonymous with higher fecundity in all mayflies in all habitats.

scholarly journals Cyanobacterial Akinete Distribution, Viability, and Cyanotoxin Records in Sediment Archives From the Northern Baltic Sea

2021 ◽  
Vol 12 ◽  
Author(s):  
Steffaney M. Wood ◽  
Anke Kremp ◽  
Henna Savela ◽  
Sultana Akter ◽  
Vesa-Pekka Vartti ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Sediment Core ◽  
Brackish Water ◽  
Life Cycles ◽  
Near Surface ◽  
Bloom Formation ◽  
The Baltic ◽  
Species Specific ◽  
Germination Experiments ◽  
Sediment Layers

Cyanobacteria of the order Nostocales, including Baltic Sea bloom-forming taxa Nodularia spumigena, Aphanizomenon flosaquae, and Dolichospermum spp., produce resting stages, known as akinetes, under unfavorable conditions. These akinetes can persist in the sediment and germinate if favorable conditions return, simultaneously representing past blooms and possibly contributing to future bloom formation. The present study characterized cyanobacterial akinete survival, germination, and potential cyanotoxin production in brackish water sediment archives from coastal and open Gulf of Finland in order to understand recent bloom expansion, akinete persistence, and cyanobacteria life cycles in the northern Baltic Sea. Results showed that cyanobacterial akinetes can persist in and germinate from Northern Baltic Sea sediment up to &gt;40 and &gt;400 years old, at coastal and open-sea locations, respectively. Akinete abundance and viability decreased with age and depth of vertical sediment layers. The detection of potential microcystin and nodularin production from akinetes was minimal and restricted to the surface sediment layers. Phylogenetic analysis of culturable cyanobacteria from the coastal sediment core indicated that most strains likely belonged to the benthic genus Anabaena. Potentially planktonic species of Dolichospermum could only be revived from the near-surface layers of the sediment, corresponding to an estimated age of 1–3 years. Results of germination experiments supported the notion that akinetes do not play an equally significant role in the life cycles of all bloom-forming cyanobacteria in the Baltic Sea. Overall, there was minimal congruence between akinete abundance, cyanotoxin concentration, and the presence of cyanotoxin biosynthetic genes in either sediment core. Further research is recommended to accurately detect and quantify akinetes and cyanotoxin genes from brackish water sediment samples in order to further describe species-specific benthic archives of cyanobacteria.

scholarly journals Long-term effects of snowmelt timing and climate warming on phenology, growth and reproductive effort of arctic tundra plant species

2021 ◽  
Author(s):  
Esther R. Frei ◽  
Greg H.R. Henry
Keyword(s):  
Plant Species ◽  
Reproductive Effort ◽  
High Arctic ◽  
Snow Accumulation ◽  
The Arctic ◽  
Plant Responses ◽  
Long Term Effects ◽  
Passive Warming ◽  
Species Specific

Arctic regions are particularly affected by rapidly rising temperatures and altered snow regimes. Snowmelt timing depends on spring temperatures and winter snow accumulation. Scenarios for the Arctic include both decreases and increases in snow accumulation. Predictions of future snowmelt timing are thus difficult and experimental evidence for ecological consequences is scarce. In 1995, a long-term factorial experiment was set up in a High Arctic evergreen shrub heath community on Ellesmere Island, Canada. We investigated how snow removal, snow addition and passive warming affected phenology, growth and reproductive effort of the four common tundra plant species <i>Cassiope tetragona</i>, <i>Dryas integrifolia</i>, <i>Luzula arctica</i> and <i>Papaver radicatum</i>. Timing of flowering and seed maturation as well as flower production were more strongly influenced by the combined effects of snowmelt timing and warming in the two shrub species than in the two herbaceous species. Warming effects persisted over the course of the growing season and resulted in increased shrub growth. Moreover, the long-term trend of increasing growth in two species suggests that ambient warming promotes tundra plant growth. Our results confirm the importance of complex interactions between temperature and snowmelt timing in driving species-specific plant responses to climate change in the Arctic.

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