scholarly journals The sex lives of ctenophores: the influence of light, body size, and self-fertilization on the reproductive output of the sea walnut,Mnemiopsis leidyi

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1846 ◽  
Author(s):  
Daniel A. Sasson ◽  
Joseph F. Ryan
Keyword(s):  
Invasive Species ◽  
Body Size ◽  
Reproductive Output ◽  
Lower Percentage ◽  
Mnemiopsis Leidyi ◽  
Simultaneous Hermaphrodite ◽  
Egg Viability ◽  
Self Fertilization ◽  
The Cost ◽  
Insight Into

Ctenophores (comb jellies) are emerging as important animals for investigating fundamental questions across numerous branches of biology (e.g., evodevo, neuroscience and biogeography). A few ctenophore species including, most notably,Mnemiopsis leidyi, are considered as invasive species, adding to the significance of studying ctenophore ecology. Despite the growing interest in ctenophore biology, relatively little is known about their reproduction. Like most ctenophores,M. leidyiis a simultaneous hermaphrodite capable of self-fertilization. In this study, we assess the influence of light on spawning, the effect of body size on spawning likelihood and reproductive output, and the cost of self-fertilization on egg viability inM. leidyi. Our results suggest thatM. leidyispawning is more strongly influenced by circadian rhythms than specific light cues and that body size significantly impacts spawning and reproductive output.Mnemiopsis leidyiadults that spawned alone produced a lower percentage of viable embryos versus those that spawned in pairs, suggesting that self-fertilization may be costly in this species. These results provide insight into the reproductive ecology ofM. leidyiand provide a fundamental resource for researchers working with them in the laboratory.

scholarly journals The sex lives of ctenophores: the influence of light, body size, and self-fertilization on the reproductive output of the sea walnut, Mnemiopsis leidyi

2015 ◽  
Author(s):  
Daniel A Sasson ◽  
Joseph F Ryan
Keyword(s):  
Body Size ◽  
Reproductive Output ◽  
Lower Percentage ◽  
Mnemiopsis Leidyi ◽  
Simultaneous Hermaphrodite ◽  
Egg Viability ◽  
Self Fertilization ◽  
Critical Insight ◽  
The Cost ◽  
Insight Into

Ctenophores (comb jellies) are emerging as important animals for investigating fundamental questions across numerous branches of biology (e.g., evodevo, neuroscience. and biogeography). Several ctenophore species including, most notably, Mnemiopsis leidyi, are known as invasive species, adding to the importance of studying the ecology of these animals. Despite the growing interest, relatively little is known about ctenophore reproduction. Like most ctenophores, M. leidyi is a simultaneous hermaphrodite capable of self-fertilization. In this study, we assess the influence of light on spawning, the effect of body size on spawning likelihood and reproductive output, and the cost of self-fertilization on egg viability in M. leidyi. Our results suggest that M. leidyi spawning is more strongly influenced by circadian rhythms than specific light clues, and that body size significantly impacts spawning and reproductive output. We also find a lower percentage of viable embryos from M. leidyi that were spawned alone versus those that were spawned in pairs, suggesting that self-fertilization may be costly in these animals. These results provide critical insight into the reproductive ecology of these ctenophores and provide a fundamental resource for researchers working with M. leidyi in the laboratory.

scholarly journals The sex lives of ctenophores: the influence of light, body size, and self-fertilization on the reproductive output of the sea walnut, Mnemiopsis leidyi

2015 ◽  
Author(s):  
Daniel A Sasson ◽  
Joseph F Ryan
Keyword(s):  
Body Size ◽  
Reproductive Output ◽  
Lower Percentage ◽  
Mnemiopsis Leidyi ◽  
Simultaneous Hermaphrodite ◽  
Egg Viability ◽  
Self Fertilization ◽  
Critical Insight ◽  
The Cost ◽  
Insight Into

Ctenophores (comb jellies) are emerging as important animals for investigating fundamental questions across numerous branches of biology (e.g., evodevo, neuroscience. and biogeography). Several ctenophore species including, most notably, Mnemiopsis leidyi, are known as invasive species, adding to the importance of studying the ecology of these animals. Despite the growing interest, relatively little is known about ctenophore reproduction. Like most ctenophores, M. leidyi is a simultaneous hermaphrodite capable of self-fertilization. In this study, we assess the influence of light on spawning, the effect of body size on spawning likelihood and reproductive output, and the cost of self-fertilization on egg viability in M. leidyi. Our results suggest that M. leidyi spawning is more strongly influenced by circadian rhythms than specific light clues, and that body size significantly impacts spawning and reproductive output. We also find a lower percentage of viable embryos from M. leidyi that were spawned alone versus those that were spawned in pairs, suggesting that self-fertilization may be costly in these animals. These results provide critical insight into the reproductive ecology of these ctenophores and provide a fundamental resource for researchers working with M. leidyi in the laboratory.

scholarly journals Bigger Is Better, Sometimes: The Interaction between Body Size and Carcass Size Determines Fitness, Reproductive Strategies, and Senescence in Two Species of Burying Beetles

Diversity ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 662
Author(s):  
Mark C. Belk ◽  
Peter J. Meyers ◽  
J. Curtis Creighton
Keyword(s):  
Body Size ◽  
Reproductive Strategies ◽  
Reproductive Output ◽  
Cost Of Reproduction ◽  
Burying Beetles ◽  
Terminal Investment ◽  
Future Reproduction ◽  
The Cost ◽  
Investment Patterns ◽  
Nicrophorus Marginatus

The cost of reproduction hypothesis suggests that allocation to current reproduction constrains future reproduction. How organisms accrue reproductive costs and allocate energy across their lifetime may differ among species adapted to different resource types. We test this by comparing lifetime reproductive output, patterns of reproductive allocation, and senescence between two species of burying beetles, Nicrophorus marginatus and N. guttula, that differ in body size, across a range of carcass sizes. These two species of burying beetles maximized lifetime reproductive output on somewhat different–sized resources. The larger N. marginatus did better on large and medium carcasses while the smaller N. guttula did best on small and medium carcasses. For both species, reproduction is costly and reproduction on larger carcasses reduced lifespan more than reproduction on smaller carcasses. Carcass size also affected lifetime reproductive strategies. Each species’ parental investment patterns were consistent with terminal investment on carcasses on which they performed best (optimal carcass sizes). However, they exhibited reproductive restraint on carcass sizes on which they did not perform as well. Reproductive senescence occurred largely in response to carcass size. For both species, reproduction on larger carcasses resulted in more rapid senescence. These data suggest that whether organisms exhibit terminal investment or reproductive restraint may depend on type and amount of resources for reproduction.

Locking down behavioural compliance: The role of emotion and emotion regulation in breaches of COVID-19 mitigation measures in Aotearoa New Zealand

2021 ◽  
pp. 135910532110299
Author(s):  
Terise Broodryk ◽  
Kealagh Robinson
Keyword(s):  
Public Health ◽  
Young Adults ◽  
New Zealand ◽  
Health Behaviours ◽  
Mitigation Measures ◽  
Aotearoa New Zealand ◽  
High Knowledge ◽  
The Cost ◽  
Insight Into

Although anxiety and worry can motivate engagement with COVID-19 preventative behaviours, people may cognitively reframe these unpleasant emotions, restoring wellbeing at the cost of public health behaviours. New Zealand young adults ( n = 278) experiencing nationwide COVID-19 lockdown reported their worry, anxiety, reappraisal and lockdown compliance. Despite high knowledge of lockdown policies, 92.5% of participants reported one or more policy breaches ( M  = 2.74, SD = 1.86). Counter to predictions, no relationships were found between anxiety or worry with reappraisal or lockdown breaches. Findings highlight the importance of targeting young adults in promoting lockdown compliance and offer further insight into the role of emotion during a pandemic.

scholarly journals Complex community responses underpin biodiversity change following invasion

2021 ◽  
Author(s):  
Alessandra R. Kortz ◽  
Anne E. Magurran
Keyword(s):  
Invasive Species ◽  
Species Richness ◽  
Spatial Scales ◽  
Species Abundance ◽  
Ecological Systems ◽  
Multi Scale ◽  
Mechanistic Approach ◽  
Α Diversity ◽  
Biodiversity Change ◽  
Insight Into

AbstractHow do invasive species change native biodiversity? One reason why this long-standing question remains challenging to answer could be because the main focus of the invasion literature has been on shifts in species richness (a measure of α-diversity). As the underlying components of community structure—intraspecific aggregation, interspecific density and the species abundance distribution (SAD)—are potentially impacted in different ways during invasion, trends in species richness provide only limited insight into the mechanisms leading to biodiversity change. In addition, these impacts can be manifested in distinct ways at different spatial scales. Here we take advantage of the new Measurement of Biodiversity (MoB) framework to reanalyse data collected in an invasion front in the Brazilian Cerrado biodiversity hotspot. We show that, by using the MoB multi-scale approach, we are able to link reductions in species richness in invaded sites to restructuring in the SAD. This restructuring takes the form of lower evenness in sites invaded by pines relative to sites without pines. Shifts in aggregation also occur. There is a clear signature of spatial scale in biodiversity change linked to the presence of an invasive species. These results demonstrate how the MoB approach can play an important role in helping invasion ecologists, field biologists and conservation managers move towards a more mechanistic approach to detecting and interpreting changes in ecological systems following invasion.

Diplomacy Beyond History: Analytic-Violence, Producer-Centred Research, India

2021 ◽  
pp. 097492842098307
Author(s):  
Deep K. Datta-Ray
Keyword(s):  
New Method ◽  
The West ◽  
History Of ◽  
The Right ◽  
Nuclear Diplomacy ◽  
The Cost ◽  
Insight Into

The history of Indian diplomacy conceptualises diplomacy racially—as invented by the West—and restrictively—to offence. This is ‘analytic-violence’ and it explains the berating of Indians for mimicking diplomacy incorrectly or unthinkingly, and the deleting, dismissing, or denigrating, of diplomatic practices contradicting history’s conception. To relieve history from these offences, a new method is presented, ‘Producer-Centred Research’ (PCR). Initiating with abduction, an insight into a problem—in this case Indian diplomacy’s compromised historicisation—PCR solves it by converting history’s racist rationality into ‘rationalities’. The plurality renders rationality one of many, permitting PCR’s searching for rationalities not as a function of rationality but robust practices explicable in producer’s terms. Doing so is exegesis. It reveals India’s nuclear diplomacy as unique, for being organised by defence, not offence. Moreover, offence’s premise of security as exceeding opponent’s hostility renders it chimerical for such a security is, paradoxically, reliant on expanding arsenals. Additionally, doing so is a response to opponents. This fragments sovereignty and abdicates control for one is dependent on opponent’s choices. Defence, however, does not instigate opponents and so really delivers security by minimising arsenals since offence is eschewed. Doing so is not a response to opponents and so maintains sovereignty and retains control by denying others the right to offense. The cost of defence is courage, for instance, choosing to live in the shadow of nuclear annihilation. Exegesis discloses Balakot as a shift from defence to offence, so to relieve the Bharatiya Janata Party’s (BJP) leadership of having to be courageous. The intensity of the intention to discard courage is apparent in the price the BJP paid. This included equating India with Pakistan, permitting it to escalate the conflict, and so imperiling all humanity in a manner beyond history.

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