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.

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.

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.

scholarly journals Reproductive Biology of Ovigerous Female Emerita emeritus (Crustacea, Decapoda) in Bengkulu Coastal Waters, Indonesia: Egg Production and Reproductive Output

2016 ◽  
Vol 74 (3) ◽  
pp. 103-109 ◽  
Author(s):  
Ouratul Edritanti ◽  
Achmad Farajallah ◽  
Yusli Wardiatno
Keyword(s):  
Embryonic Development ◽  
Surface Temperature ◽  
Reproductive Biology ◽  
Coastal Waters ◽  
Egg Production ◽  
Reproductive Output ◽  
Ovigerous Female ◽  
Abundant Species ◽  
Sea Surface ◽  
Egg Volume

Abstract Emerita emeritus is an abundant species in Bengkulu coastal waters, but the knowledge of its reproductive biology is poor. The present study was conducted to elucidate the reproductive aspects of ovigerous female E. emeritus, including fecundity, egg volume and reproductive output. This study was conducted between January 2015 and January 2016 in Bengkulu coastal waters, Indonesia. Samples were collected manually using shovels and hands. The results showed that ovigerous females occurred every month. Fecundity increased significantly in ovigerous females proportional to the size. No correlation was shown between sea surface temperature and egg production. Fecundity and reproductive output decreased throughout the embryonic development.

scholarly journals Spatiotemporal variation in the adult sex ratio, male aggregation, and movement of two tropical cloud forest dung beetles

2021 ◽  
Author(s):  
Julliana Barretto ◽  
Martha L Baena ◽  
Israel Huesca Domínguez ◽  
Federico Escobar
Keyword(s):  
Life History ◽  
Sex Ratio ◽  
Life History Traits ◽  
Cloud Forest ◽  
Habitat Preferences ◽  
Habitat Type ◽  
Dung Beetle ◽  
Adult Sex Ratio ◽  
The Face ◽  
Male Aggregation

Abstract While theory suggests that at conception the sex ratio should be balanced (1:1), this can be variable across space and time in wild populations. Currently, studies of the environmental factors that regulate adult sex ratio (ASR) in species with different life-history traits are scarce. Using capture-recapture over a year, we analyzed the influence of habitat type (forest and non-forest) and season (rainy and dry) on variation in ASR, male aggregation and the trajectory movement of two dung beetle species with different life-history traits: Deltochilum mexicanum (a hornless roller species) and Dichotomius satanas (a tunneler species with horns on its head and thorax). We found opposite tendencies. The D. mexicanum population tends to be female-biased, but the population of D. satanas tends to be predominantly male, and observed values were not related to habitat type or season. However, the 95% confidence intervals estimated were highly variable between seasons depending on habitat. On examining the monthly variation in ASR for both habitats, we found that it depends on the species. In addition, male aggregation differed between species depending on habitat type and season, and species movement patterns were closely related to their habitat preferences. Based on our results, we argue that comparative population studies of species with different life-history traits are necessary to understand the variation in demographic parameters as well as its ecological and evolutionary implications in the face of spatial and climatic environmental variation.

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.

Body size and segmentation patterns in free-living and parasitic polychaetes

2001 ◽  
Vol 79 (5) ◽  
pp. 741-745 ◽  
Author(s):  
Robert Poulin
Keyword(s):  
Life History ◽  
Body Length ◽  
Life History Traits ◽  
The Body ◽  
Free Living ◽  
Body Segments ◽  
The Family ◽  
Body Sizes ◽  
Number Of Segments ◽  
Over Time

Taxa that include both free-living and parasitic lineages present opportunities to examine if and how the life-history traits of parasitic organisms have diverged from those of their free-living relatives. In a comparative analysis the body sizes and numbers of body segments of parasitic polychaetes of the family Oenonidae were compared with those of free-living polychaetes from closely related families. There was no difference in body length between oenonids and free-living polychaetes. However, the parasitic oenonids attain, on average, a much higher number of body segments than their free-living counterparts. The number of segments per unit body length is also much higher in oenonids than in related free-living polychaetes. This suggests that new segments are produced at a higher rate or for longer periods in oenonids than in free-living polychaetes, in which the proliferation of new segments slows down over time to allow for the segments to grow in size. Given that each segment can produce gametes late in the life of the worm, the proliferation of segments in oenonids may be an adaptation to their parasitic life-style.

Reproductive biology of the great capricorn beetle,Cerambyx cerdo(Coleoptera: Cerambycidae): a protected but occasionally harmful species

2017 ◽  
Vol 107 (6) ◽  
pp. 799-811 ◽  
Author(s):  
L.M. Torres-Vila
Keyword(s):  
Reproductive Biology ◽  
Body Length ◽  
Relative Size ◽  
Reproductive Traits ◽  
Oviposition Period ◽  
Female Size ◽  
Egg Volume ◽  
Ecological Features ◽  
Management Measures ◽  
Cerambyx Cerdo

AbstractCerambyx cerdo(Cc) is a protected saproxylic beetle in Europe, although it is increasingly reported as an oak ‘pest’. Cc ecological features are relatively well known, but, its reproductive biology is still poorly understood. Hence, we investigated the reproductive traits of Cc under laboratory conditions. In females, body length was 44.1 ± 0.9 mm, 28–53 (mean ± SE, range); fecundity 143 ± 11 eggs, 33–347; fertility 78 ± 1%, 65–93; oviposition period 44 ± 3 days, 13–128 and longevity 59 ± 5 days, 16–157. Fecundity was positively correlated with female size, longevity and oviposition period. Daily fecundity was 3.5 ± 0.2 eggs/day, 0.9–6.5 showing a fluctuating synovigenic pattern with a slight decreasing trend over time. Egg length was 3.74 ± 0.01 mm, 2.3–6.0 and egg volume 5.45 ± 0.04 mm3, 2.4–9.6. Egg size was correlated with female size, but, the relative size of eggs was larger in smaller females. Incubation time was 13.5 ± 0.1 days, 7–28. Hatching was superior in larger eggs and neonate size was positively correlated to egg volume. Females were polyandrous (up to 19 matings), but, multiple mating did not enhance fecundity or fertility. In males, body length was 41.8 ± 0.8 mm, 29–53 and longevity 49 ± 3 days, 9–124. Male longevity was unrelated to body size. Males were polygynous (up to 16 matings) and mating number did not affect male longevity. Overall, females were larger and lived longer than males. Cc reproductive traits are compared with those other Cerambycidae, especially with the congeneric pestCerambyx welensii. Our data may be valuable to improve the protection/management measures of Cc in dehesa woodlands and other oak forests.

Life history characteristics and strategies of the American eel, Anguilla rostrata

1999 ◽  
Vol 56 (5) ◽  
pp. 795-802 ◽  
Author(s):  
Kenneth Oliveira
Keyword(s):  
Life History ◽  
Rhode Island ◽  
Life History Traits ◽  
Life History Strategies ◽  
Anguilla Rostrata ◽  
Female Size ◽  
Silver Eel ◽  
Male Size ◽  
American Eel ◽  
Female Age

Several life history hypotheses for the American eel, Anguilla rostrata, were examined using seaward-migrating silver-phase eels collected in the Annaquatucket River, Rhode Island, U.S.A. Female eels were significantly larger and older than males. Female eels also had a significantly higher mean growth rate. The addition of life history data from Annaquatucket River eels to published silver eel data from locations throughout the eels' range shows that female size at migration is positively correlated with latitude (r = 0.56, p = 0.05) but male size is not (r = 0.54, p = 0.17). Female age was not related to latitude (r = 0.57, p = 0.27) but male age showed a positive relationship (r = 0.87, p = 0.05). Growth rates for females and males were inversely related to latitude (r = -0.98, p = 0.02 and r = -0.95, p = 0.05, respectively). Differences between the latitudinal relationships and life history traits of the sexes may be due to differences in life history strategies.

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