scholarly journals Small-scale spatial variation in population- and individual-level reproductive parameters of the blue-legged hermit crabClibanarius tricolor

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3004 ◽  
Author(s):  
J. Antonio Baeza ◽  
Donald C. Behringer
Keyword(s):  
Life History ◽  
Body Size ◽  
Florida Keys ◽  
Population Level ◽  
Small Scale ◽  
Reproductive Parameters ◽  
Future Studies ◽  
Individual Level ◽  
Female Body Size ◽  
History Of

Management of the few regulated ornamental fisheries relies on inadequate information about the life history of the target species. Herein, we investigated the reproductive biology of the most heavily traded marine invertebrate in the western Atlantic; the blue-legged hermit crabClibanarius tricolor. We report on density, individual-level, and population-level reproductive parameters in 14 populations spanning the Florida Keys. In C. tricolor, abundance, population-level, and individual-level reproductive parameters exhibited substantial small-scale spatial variation in the Florida Keys. For instance, the proportion of brooding females varied between 10–94% across localities. In females, average (±SD) fecundity varied between 184 (±54) and 614 (±301) embryos crab-1 across populations. Fecundity usually increases with female body size in hermit crabs. However, we found no effect of female body size on fecundity in three of the populations. Altogether, our observations suggest that C. tricolor may fit a source-sink metapopulation dynamic in the Florida Keys with low reproductive intensity and absence of a parental body size—fecundity relationship resulting in net reproductive loses at some localities. We argue in favor of additional studies describing population dynamics and other aspects of the natural history of C. tricolor (e.g., development type, larval duration) to reveal ‘source’ populations, capable of exporting larvae to nearby populations. Our observations imply that future studies aimed at assessing standing stocks or describing other aspects of the life history of this hermit crab need to focus on multiple localities simultaneously. This and future studies on the reproductive biology of this species will form the baseline for models aimed at assessing the stock condition and sustainability of this heavily harvested crustacean.

scholarly journals Modelling the HIV-Associated TB Epidemic and the Impact of Interventions Aimed at Epidemic Control

2019 ◽  
pp. 25-55
Author(s):  
P. J. Dodd ◽  
C. Pretorius ◽  
B. G. Williams
Keyword(s):  
Natural History ◽  
Mathematical Models ◽  
Population Level ◽  
Explicit Representation ◽  
Epidemic Control ◽  
Future Directions ◽  
Individual Level ◽  
Tuberculosis Epidemiology ◽  
History Of ◽  
The Impact

Abstract In this chapter, we focus on mathematical models of tuberculosis epidemiology (TB) that include interactions with HIV and an explicit representation of transmission. We review the natural history of TB and illustrate how its features are simplified and incorporated in mathematical models. We then review the ways HIV influences the natural history of TB, the interventions that have been considered in models, and the way these individual-level effects are represented in models. We then go on to consider population-level effects, reviewing the TB/HIV modelling literature. We first review studies whose focus was on purely epidemiological modelling, and then studies whose focus was on modelling the impact of interventions. We conclude with a summary of the uses and achievements of TB/HIV modelling and some suggested future directions.

scholarly journals Smart Sanitation—Biosensors as a Public Health Tool in Sanitation Infrastructure

2020 ◽  
Vol 17 (14) ◽  
pp. 5146 ◽  
Author(s):  
Emma Rary ◽  
Sarah M. Anderson ◽  
Brandon D. Philbrick ◽  
Tanvi Suresh ◽  
Jasmine Burton
Keyword(s):  
Public Health ◽  
Health Monitoring ◽  
Disease Surveillance ◽  
Population Level ◽  
Cost Effective ◽  
Small Scale ◽  
Individual Level ◽  
Emergent Technologies ◽  
The Individual ◽  
Sanitation Infrastructure

The health of individuals and communities is more interconnected than ever, and emergent technologies have the potential to improve public health monitoring at both the community and individual level. A systematic literature review of peer-reviewed and gray literature from 2000-present was conducted on the use of biosensors in sanitation infrastructure (such as toilets, sewage pipes and septic tanks) to assess individual and population health. 21 relevant papers were identified using PubMed, Embase, Global Health, CDC Stacks and NexisUni databases and a reflexive thematic analysis was conducted. Biosensors are being developed for a range of uses including monitoring illicit drug usage in communities, screening for viruses and diagnosing conditions such as diabetes. Most studies were nonrandomized, small-scale pilot or lab studies. Of the sanitation-related biosensors found in the literature, 11 gathered population-level data, seven provided real-time continuous data and 14 were noted to be more cost-effective than traditional surveillance methods. The most commonly discussed strength of these technologies was their ability to conduct rapid, on-site analysis. The findings demonstrate the potential of this emerging technology and the concept of Smart Sanitation to enhance health monitoring at the individual level (for diagnostics) as well as at the community level (for disease surveillance).

Intraspecific variation in reproductive effort by female Parapediasia teterrella (Lepidoptera: Pyralidae) and its relation to body size

1990 ◽  
Vol 68 (1) ◽  
pp. 44-48 ◽  
Author(s):  
Larry D. Marshall
Keyword(s):  
Life History ◽  
Body Size ◽  
Egg Production ◽  
Egg Size ◽  
Reproductive Effort ◽  
Life History Evolution ◽  
Reproductive Parameters ◽  
Trade Offs ◽  
Egg Number ◽  
Lepidoptera Pyralidae

Daily egg production of the moth Parapediasia teterrella declined over the life-span of the female but egg size remained constant. The absence of water resulted in lower fecundity and early mortality. Egg size and lifetime fecundity showed considerable inter-individual variation and large females produced more and larger eggs than their smaller counterparts. Large females expended greater reproductive effort than small females. Hatching success was negatively related to egg size. In spite of this, large females laying large eggs had higher fitness than small females. I postulate that multiple reproductive strategies within a species, resulting from differences in reproductive effort expended, may explain why expected trade-offs in reproductive parameters (e.g., egg size versus egg number) were not found in this species. Furthermore, I argue that the prevalent interpretation of life-history evolution (that body size is the important determining parameter of life-history parameters) may reflect correlation of body size with reproductive effort, and reproductive effort may be more important in determining the nature of trade-offs between reproductive parameters.

Host species critical for offspring fitness and sex ratio for an oligophagous parasitoid: implications for host coexistence

2010 ◽  
Vol 100 (6) ◽  
pp. 735-740 ◽  
Author(s):  
J.A. Stenberg ◽  
P.A. Hambäck
Keyword(s):  
Body Size ◽  
Sex Ratio ◽  
Host Species ◽  
Resource Competition ◽  
Apparent Competition ◽  
Future Studies ◽  
Offspring Fitness ◽  
Female Body Size ◽  
Differential Outcomes ◽  
Strong Asymmetry

AbstractIn theory, inferior apparent competitors sharing a natural enemy with superior apparent competitors should be excluded in the absence of stabilising factors. Nevertheless, plentiful examples of coexisting apparent competitors exist. In this paper, we show that parasitoid resource competition within hosts affects both parasitoid sex ratio and female body size, with implication for population growth and apparent competition between the two closely related hosts experiencing a strong asymmetry in their interaction. While the superior competitor delivers parasitoids with higher fitness to the shared parasitoid pool, the inferior competitor delivers a higher proportion of female parasitoids. Hence, the inferior host experience an inflow of fit parasitoids from the superior competitor, which should increase the risk of exclusion, but also an outflow of parasitoid females, which should reduce the risk of exclusion and increase stability. We conclude that differential outcomes of parasitoid resource competition in different host species may have profound effects on shared parasitoid populations and should be included in future studies of apparent competition between hosts.

A multi-year and multi-site population study on the life history of Salamandrina perspicillata (Savi, 1821) (Amphibia, Urodela)

2008 ◽  
Vol 29 (2) ◽  
pp. 161-170 ◽  
Author(s):  
Carlo Utzeri ◽  
Claudio Angelini ◽  
Damiano Antonelli
Keyword(s):  
Life History ◽  
Body Size ◽  
Population Study ◽  
Climatic Conditions ◽  
Life History Variation ◽  
Differential Growth ◽  
History Of ◽  
Natural Pond ◽  
The Mean ◽  
Site Population

Abstract We studied nine populations of Salamandrina perspicillata for two to nine years and described the life history variation among these population. Despite experiencing similar climatic conditions, populations differed in mean body size: populations using still water bodies for oviposition were larger body-sized than those using brooks. One semi-natural pond was used by particularly small individuals and was probably recently colonised. The mean body size of ovipositing females varied from year to year. Measurements of individuals in successive years showed that the tail grew more than the trunk and this differential growth increased with age. Females did not oviposit every year and, within a given population, the number of ovipositing females varied widely from year to year.

scholarly journals Transitions between foot postures are associated with elevated rates of body size evolution in mammals

2019 ◽  
Vol 116 (7) ◽  
pp. 2618-2623 ◽  
Author(s):  
Tai Kubo ◽  
Manabu Sakamoto ◽  
Andrew Meade ◽  
Chris Venditti
Keyword(s):  
Body Size ◽  
Mammalian Species ◽  
Evolutionary Trajectory ◽  
Future Studies ◽  
Terrestrial Mammals ◽  
Size Evolution ◽  
Foot Posture ◽  
History Of ◽  
The Common ◽  
Body Size Evolution

Terrestrial mammals have evolved various foot postures: flat-footed (plantigrady), tiptoed (digitigrady), and hooved (unguligrady) postures. Although the importance of foot posture on ecology and body size of mammalian species has been widely recognized, its evolutionary trajectory and influence on body size evolution across mammalian phylogeny remain untested. Taking a Bayesian phylogenetic approach combined with a comprehensive dataset of foot postures in 880 extant mammalian species, we investigated the evolutionary history of foot postures and rates of body size evolution, within the same posture and at transitions between postures. Our results show that the common ancestor of mammals was plantigrade, and transitions predominantly occurred only between plantigrady and digitigrady and between digitigrady and unguligrady. At the transitions between plantigrady and digitigrady and between digitigrady and unguligrady, rates of body size evolution are significantly elevated leading to the larger body masses of digitigrade species (∼1 kg) and unguligrade species (∼78 kg) compared with their respective ancestral postures [plantigrady (∼0.75 kg) and digitigrady]. Our results demonstrate the importance of foot postures on mammalian body size evolution and have implications for mammalian body size increase through time. In addition, we highlight a way forward for future studies that seek to integrate morphofunctional and macroevolutionary approaches.

scholarly journals Reproductive biology of Atlantoraja cyclophora (Regan 1903) (Elasmobranchii: Rajidae) off southern Brazil

2005 ◽  
Vol 62 (6) ◽  
pp. 1095-1103 ◽  
Author(s):  
María Cristina Oddone ◽  
Carolus Maria Vooren
Keyword(s):  
Temporal Variation ◽  
Rio Grande ◽  
Population Level ◽  
Reproductive Parameters ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Individual Level ◽  
Adult Females ◽  
Egg Deposition ◽  
Resting Period

Abstract A total of 459 (245 females, 214 males) Atlantoraja cyclophora was captured by bottom trawl off the coast of Rio Grande do Sul between 30°40′S and 34°30′S during surveys conducted in winter 2001 and summer/autumn 2002 at depths of 100–300 m. Total length at maturity was 52.8 cm for females and 48.5 cm for males. Symmetry and functional parity of the gonads were observed in both sexes, but there was no significant temporal variation in either sex for any of the reproductive parameters studied. Ovulation and egg-deposition were similarly intensive in both seasons. In adult females, there was an ovarian resting period at an individual level, though it was not synchronized at a population level. Distribution of egg-bearing females was not related to depth or species' range.

Example Four: Facultative Anadromy in Salmonid Fishes

2020 ◽  
pp. 86-92
Keyword(s):  
Life History ◽  
Life Histories ◽  
Population Level ◽  
Dynamic State ◽  
Salmonid Fishes ◽  
Individual Level ◽  
State Variable ◽  
Level Model ◽  
Fitness Benefits ◽  
The Individual

This chapter offers a fourth example model, with the objective of (1) illustrating the application of state- and prediction-based theory (SPT) to a new kind of decision—a life history decision—in a case where dynamic state variable modeling (DSVM) has been applied successfully; and (2) describing the unique ability of models utilizing SPT to address population-level questions of particular interest to conservationists and managers. In this case, SPT produced individual-level decisions similar to those of DSVM, but including them in a population-level model led to quite different conclusions than those implied by the individual-level DSVM analysis. Salmonid fishes exhibit amazing life history diversity. One fundamental distinction among salmonid life histories is whether or not individuals migrate to the ocean. In general, facultative anadromy can be seen as an adaptive behavior that trades off the fitness benefits of going to the ocean versus those of remaining resident. The anadromy versus residency decision is important to fish conservation and resource management.

scholarly journals Clutch size in the small-sized lizard Eurolophosaurus nanuzae (Tropiduridae): does it vary along the geographic distribution of the species?

2011 ◽  
Vol 101 (1-2) ◽  
pp. 61-64 ◽  
Author(s):  
Conrado A. B Galdino ◽  
Monique Van Sluys
Keyword(s):  
Life History ◽  
Body Size ◽  
Clutch Size ◽  
Endemic Species ◽  
Life History Traits ◽  
Geographic Range ◽  
Southeastern Brazil ◽  
Rock Outcrop ◽  
Female Body Size ◽  
Clutch Mass

We studied life history traits of females of the lizard Eurolophosaurus nanuzae (Rodrigues, 1981), an endemic species of rock outcrop habitats in southeastern Brazil. During October 2002 and 2003 we sampled three populations in sites that encompass the meridional portion of the geographic range of the species. Clutch size varied from one to three eggs, with most females carrying two eggs. Clutch size did not vary among populations, but was correlated to female body size. Only larger females produced clutches of three eggs. Females of the small-sized E. nanuzae produce eggs as large as those of medium-sized tropidurids, thus investing a considerable amount of energy to produce clutches resulting in high values of relative clutch mass.

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