scholarly journals Life history characteristics of a cave isopod (Mesoniscus graniger Friv.)

ZooKeys ◽  
2018 ◽  
Vol 801 ◽  
pp. 359-370 ◽  
Author(s):  
Dávid Derbák ◽  
László Dányi ◽  
Elisabeth Hornung
Keyword(s):  
Life History ◽  
Sex Ratio ◽  
Size Distribution ◽  
Body Length ◽  
Reproductive Strategy ◽  
Population Characteristics ◽  
Female Dominance ◽  
Head Width ◽  
Data Set ◽  
Offspring Number

The special environmental conditions of caves provide habitat for several endemic and relict species, among them terrestrial isopods. The Baradla Cave system (north-eastern Hungary) hosts Mesoniscusgraniger (Frivaldszky, 1865) (Oniscidea, Microcheta, Mesoniscidae), a pygmy, blind, fragile troglophile woodlice species. Its stable environment can be characterised by the lack of light, high relative humidity (96%), low and constant temperature (about 10 °C). We explored the population characteristics (sex ratio, size distribution) and life history traits of the species (e.g. longevity, reproductive strategy, offspring number, and size). Sex ratio and size distribution of the individuals (head-width measurements) were estimated based on a yearly pooled pitfall-trap data set (N = 677). We studied the species’ reproductive strategy under natural conditions (Baradla Cave, Aggtelek National Park). Model populations were set up in the cave and checked monthly between March and October, 2016 (15 replicates, each with 12 randomly chosen adult individuals; ΣN = 180). Digital photos were taken of the live animals and their length was estimated based on the photos by using ImageJ software (average body length: 6.56 ± 0.79 mm). The results showed female dominance in the population [(male:female = 0.43:0.57); p < 0.001 (GLM)]. Female head width (0.87 ± 0.18 mm) was significantly greater than that of males [0.79 ± 0.08 mm; p < 0.001 (t-test)]. Based on our present data we assume that the offspring number per single female is low (3–5), and new-borns have a relatively large size (body length: 4.22 ± 0.53 mm) compared to the adults. The probability of reproduction was continuous by monthly intervals (binomial test) and longevity exceeds one year. Our results suggest that the species follows a stenodynamic life history.

The life history, nymphal growth rates, and feeding habits of Siphlonisca aerodromia Needham (Ephemeroptera: Siphlonuridae) in Maine

1986 ◽  
Vol 64 (2) ◽  
pp. 427-430 ◽  
Author(s):  
K. Elizabeth Gibbs ◽  
Terry M. Mingo
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Sex Ratio ◽  
Growth Rates ◽  
Feeding Habits ◽  
Main Channel ◽  
Head Width ◽  
Snow Melt ◽  
Animal Material ◽  
Nymphal Growth

Siphlonisca aerodromia Needham has a univoltine life history in Maine. Adults emerge in late May or early June. Each female contains about 394 large (0.46 mm long) eggs covered with coiled fibers that anchor the eggs to the substrate. Eggs are deposited in the main channel of the stream and small nymphs appear in January. Nymphal growth rate (GHW) was expressed as a percent per day increase in head width. Initially nymphs feed on detritus and grow slowly (GHW = 0.28–0.79) at water temperatures near 0 °C. Following snow melt, the nymphs move into the adjacent Carex floodplain. Here, water temperature increases, animal material, in the form of mayfly nymphs, becomes increasingly common in the diet, and growth rate increases (GHW = 2.13–2.89). The sex ratio of nymphs collected in May and June was 1:1.8 (male:female).

Quantifying the effect of SVOC condensation on cloud droplet number in different airmass types

2020 ◽  
Author(s):  
Liine Heikkinen ◽  
Samuel Lowe ◽  
Cheng Wu ◽  
Diego Aliaga ◽  
Wei Huang ◽  
...  
Keyword(s):  
Water Vapor ◽  
Size Distribution ◽  
Cloud Droplet ◽  
Ambient Air ◽  
Population Characteristics ◽  
Basis Set ◽  
Activation Process ◽  
Multiple Model ◽  
Aerosol Composition ◽  
Data Set

<p>Clouds are made of droplets that arise from the activation of suitable aerosol particles (termed cloud condensation nuclei, CCN). In the activation process, water vapor saturation ratio exceeds a critial ratio enabling CCN runaway-growth to cloud droplet sizes. The number concentration of cloud droplets (CDNC) is highly dependent on the aerosol population properties (size distribution and composition), relative humidity, and the vertical wind component. While the activation of CCN consisting of non-volatile particulate matter is fairly well understood, the same process involving semi-volatile organic vapors (SVOCs) has received less attention despite their significant presence in ambient air. A recent cloud parcel modeling study shows substanial CDNC enhancement due to SVOC condensation (Topping <em>et al</em>., 2013). Surprisingly, the topic has not been widely investigated nor the results replicated with other cloud parcel models (CPM). Thus, in the current study we seek to quantify the CDNC enhancement by SVOC condensation using a recently developed CPM framework (Lowe <em>et al.</em>, 2020, <em>in prep</em>.). Moreover, the CPM initialization is performed, for the first time, with state-of-the art measurement data including measured SVOC data for multiple airmass types.</p><p>Here, the CPM, which uses spectral microphysics for the simulation of CCN activation and hydrometeor growth, also includes a SVOC condensation equation analogous to those of water vapor. Equilibrium initialization of the SVOC volatility basis set (VBS) partitioning coefficients is performed iteratively, and constrained by the organic to inorganic ratio in the particle phase determined by ambient measurements performed at the Chacaltaya Global Atmospheric Watch (GAW) Station located at 5240 m a.s.l. in the Bolivian Andes, in spring 2018. The uniquely comprehensive data set recorded, which tracks all of the relevant aerosol population characteristics in near real-time, reveals a high degree of variability in aerosol composition, size distribution and loading depending on the air mass origin. Lagrangian backward simulations during the measurement period at Chacaltaya GAW reveal at least 18 significantly different airmass origins (Aliaga <em>et al.</em>, 2020, <em>in prep.</em>). Such variability served multiple model initialization scenarios for individual case studies. We will show a suite of CDNC enhancements by SVOC condensation under different initialization scenarios actualized in data recorded at Chacaltaya GAW Station, including airmasses originating from the Amazon (biomass burning and biogenic VOCs), Andean plateau (volcanic activity), and La Paz/El Alto metropolitan areas (anthropogenic emissions).</p><p><strong>References:</strong></p><div>Topping, D., Connolly, P. and McFiggans, G., 2013. Cloud droplet number enhanced by co-condensation of organic vapours. <em>Nature Geoscience</em>, <em>6</em>(6), p.443.</div>

The smallest known Palaeozoic mantis shrimp specimen, and possibilities for where to find more

2020 ◽  
Vol 295 (2) ◽  
pp. 149-157
Author(s):  
Carolin Haug ◽  
Joachim T. Haug
Keyword(s):  
Life History ◽  
Body Length ◽  
Important Data ◽  
Data Set ◽  
Mantis Shrimp ◽  
Total Length ◽  
Data Point ◽  
Bear Gulch

Mantis shrimps are fierce predatory crustaceans in modern day oceans. Fossils of mantis shrimps are still a rarity. They occurred back in the Carboniferous, 300 million years ago, but already with quite a diversity of different forms. Interestingly, all these fossils are comparably large, usually several centimetres body length. From the Mesozoic, numerous mantis shrimp fossils have also been reported, the largest specimens being far in the centimetre range as well, but the smallest specimens being only about 4–5 mm. With this data set, we can reconstruct aspects of the life history for (at least some) Mesozoic mantis shrimps, but not for Palaeozoic forms. We report here a new fossil mantis shrimp specimen from the Carboniferous Bear Gulch limestones, USA. The specimen is quite small, in its rolled-up position about 10 mm across the laterally preserved body, but 25 mm in estimated total length. This is considerably shorter than any mantis shrimp so far known from the Palaeozoic. Hence, the specimen provides an important data point. Furthermore, it provides some indications where we could possibly find more specimens of comparable or even smaller size: The specimen resembles certain co-occurring fossils, representatives of Cyclida, in some aspects, suggesting that among the material of Cyclida we might find more small-sized mantis shrimps.

Reproductive biology of Orchestia gammarellus (Crustacea: Amphipoda) living in a sewage treatment works

1993 ◽  
Vol 73 (2) ◽  
pp. 405-416 ◽  
Author(s):  
M. B. Jones ◽  
G. D. Wigham
Keyword(s):  
Life History ◽  
Sex Ratio ◽  
Embryonic Development ◽  
Body Length ◽  
Life History Traits ◽  
Ovigerous Female ◽  
Seasonal Pattern ◽  
Sewage Treatment ◽  
Female Size ◽  
Egg Volume

A population of the supralittoral Orchestia gammarellus (Pallas) (Amphipoda: Talitridae), living in a percolating filter of a sewage treatment works has been studied over 12 months. The population showed a seasonal pattern of occurrence, few animals being collected during the winter. The sex ratio was biased significantly to females except during the breeding season when it did not deviate significantly from 1:1. Ovigerous females, never collected in high numbers (1–14 per month), were found from April to August, with peak occurrence in May/June. Juveniles were present throughout the year, but peak recruitment occurred in summer, following the period of reproduction by females. The smallest ovigerous female had a body length of 12.6 mm and the largest measured 20.0 mm. Egg numbers (5–31 per brood) increased with increasing female size and egg volume more than doubled during embryonic development. These findings are discussed in relation to the possible methods of colonization of this unique habitat and the influence of sewage on crustacean life-history traits.

scholarly journals Life history traits of Characidium pterostictum (Characiformes, Crenuchidae) along the longitudinal gradient of a Neotropical river in southern Brazil

2017 ◽  
Vol 107 (0) ◽  
Author(s):  
Raquel C. Fitz ◽  
◽  
Cesar A. Rodenbusch ◽  
Renato B. Dala-Corte ◽  
Marco A. Azevedo ◽  
...  
Keyword(s):  
Life History ◽  
Body Size ◽  
Sex Ratio ◽  
Standard Length ◽  
Reproductive Strategy ◽  
Life History Traits ◽  
Southern Brazil ◽  
Longitudinal Gradient ◽  
Female Total ◽  
Size Standard

ABSTRACT Life history traits of Characidium pterostictum Gomes, 1947 (Characiformes, Crenuchidae) from three different reaches of the upper Sinos river, southern Brazil, were described and comparatively analyzed according to the longitudinal gradient. For all reaches, results indicated a seasonal reproductive strategy with a higher intensity during warmer months of higher photoperiod (November to February). Only females were found in the upstream reach and they were more numerous than males in all the sampled reaches. Mean absolute fecundity ranged from 5189 (±2131 SD) to 7394 (±3807 SD), whereas mean relative fecundity (oocytes per mg of female total weight) ranged from 1.08 (±0.40 SD) to 1.12 (±0.29 SD). Oocyte development was characterized as synchronic in two groups, typical of total spawning. Longitudinal gradient comparison suggests that body size (standard length) of C. pterostictum individuals and sex ratio were the only characteristics that differed between sampled reaches. Larger individuals and thus females tended to be more frequently found in upstream reaches of the Sinos river, with a decrease in body size and in the proportional number of females towards downstream.

scholarly journals The impact of sex ratio and economic status on local birth rates

2013 ◽  
Vol 9 (2) ◽  
pp. 20130027 ◽  
Author(s):  
A. Chipman ◽  
E. Morrison
Keyword(s):  
Life History ◽  
Sex Ratio ◽  
Economic Status ◽  
Life History Strategy ◽  
Reproductive Behaviour ◽  
Female Competition ◽  
Birth Rates ◽  
Economically Deprived ◽  
Human Mating ◽  
The Impact

Human mating and reproductive behaviour can vary depending on various mechanisms, including the local sex ratio. Previous research shows that as sex ratios become female-biased, women from economically deprived areas are less likely to delay reproductive opportunities to wait for a high-investing mate but instead begin their reproductive careers sooner. Here, we show that the local sex ratio also has an impact on female fertility schedules. At young ages, a female-biased ratio is associated with higher birth rates in the poorest areas, whereas the opposite is true for the richest areas. At older ages, a female-biased ratio is associated with higher birth rates in the richest, but not the poorest areas. These patterns suggest that female–female competition encourages poorer women to adopt a fast life-history strategy and give birth early, and richer women to adopt a slow life-history strategy and delay reproduction.

Demographic life history traits of reproductive natterjack toads (Bufo calamita) vary between northern and southern latitudes

2006 ◽  
Vol 27 (3) ◽  
pp. 365-375 ◽  
Author(s):  
Delfi Sanuy ◽  
Christoph Leskovar ◽  
Neus Oromi ◽  
Ulrich Sinsch
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Large Female ◽  
Breeding Period ◽  
Female Size ◽  
Data Set ◽  
Bufo Calamita ◽  
Trade Offs ◽  
Age Variation ◽  
The Cost

AbstractDemographic life history traits were investigated in three Bufo calamita populations in Germany (Rhineland-Palatinate: Urmitz, 50°N; 1998-2000) and Spain (Catalonia: Balaguer, Mas de Melons, 41°N; 2004). We used skeletochronology to estimate the age as number of lines of arrested growth in breeding adults collected during the spring breeding period (all localities) and during the summer breeding period (only Urmitz). A data set including the variables sex, age and size of 185 males and of 87 females was analyzed with respect to seven life history traits (age and size at maturity of the youngest first breeders, age variation in first breeders, longevity, potential reproductive lifespan, median lifespan, age-size relationship). Spring and summer cohorts at the German locality differed with respect to longevity and potential reproductive lifespan by one year in favour of the early breeders. The potential consequences on fitness and stability of cohorts are discussed. Latitudinal variation of life history traits was mainly limited to female natterjacks in which along a south-north gradient longevity and potential reproductive lifespan increased while size decreased. These results and a review of published information on natterjack demography suggest that lifetime number of offspring seem to be optimized by locally different trade-offs: large female size at the cost of longevity in southern populations and increased longevity at the cost of size in northern ones.

Population dynamics of Stenothoe valida Dana, 1852 (Amphipoda, Stenothoidae) at Cheongsapo beach of Busan, Republic of Korea

Crustaceana ◽  
2021 ◽  
Vol 94 (4) ◽  
pp. 413-429
Author(s):  
Ye Ji Lee ◽  
Won Gyu Park
Keyword(s):  
Population Dynamics ◽  
Life History ◽  
Sex Ratio ◽  
Brood Size ◽  
Ovigerous Female ◽  
Seasonal Pattern ◽  
Recruitment Rate ◽  
Republic Of Korea ◽  
Female Size ◽  
History Of

Abstract The population dynamics of Stenothoe valida Dana, 1852 were studied at Cheongsapo beach of Busan, Republic of Korea, from March 2019 to March 2020. Sampling was conducted once a month at low tide during spring tides. Specimens were grouped by the cephalic length at 0.025 mm intervals, and classified into four categories: females, ovigerous females, males and juveniles. The sex ratio, defined as females : total males + females, exceeded 0.5 during most of the study period. Brood size was significantly coupled with ovigerous female size. Two to four cohorts appeared at each study period. New cohorts occurred at almost every sampling except in the samples Jun-2, and Nov-2. Life span was estimated at 1-2 months. The juvenile ratio, the ratio of ovigerous females, and the recruitment rate estimated by FiSAT were commonly high in summer and winter. The life history of S. valida was not coupled with water temperature, but had a strong seasonal pattern.

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