Grasshopper Reproductive Strategies Measured in the Field: a Tradeoff Between Age at Maturity and Egg Production per Day

1997 ◽  
Vol 84 (4) ◽  
pp. 157-159 ◽  
Author(s):  
Helmut Kriegbaum
Keyword(s):  
Reproductive Strategies ◽  
Egg Production ◽  
Age At Maturity

scholarly journals Mating-Induced Trade-Offs upon Egg Production versus Fertilization and Offspring’s Survival in a Sawfly with Facultative Parthenogenesis

Insects ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 693
Author(s):  
Hong Yu ◽  
Min-Rui Shi ◽  
Jin Xu ◽  
Peng Chen ◽  
Jian-Hong Liu
Keyword(s):  
Reproductive Strategies ◽  
Egg Production ◽  
Limited Resources ◽  
Animal Kingdom ◽  
Trade Offs ◽  
Reproductive Response ◽  
Evolutionarily Conserved ◽  
Egg Protection ◽  
Facultative Parthenogenesis ◽  
Induced Changes

Investigation of mating-induced trade-offs between reproduction and survival is conducive to provide evolutionary insights into reproductive strategies and aging. Here, we used RNAseq and bioinformatics to reveal mating-induced changes of genes and pathways related to reproduction and survival in female Cephalcia chuxiongica, a pine defoliator with facultative parthenogenesis and long larval dormancy. Results showed that mating induced substantial downregulation on genes and pathways associated to immunity, stress response, and longevity. However, mating induced divergent reproductive response, with downregulation on genes and pathways related to egg production while upregulation on genes and pathways related to egg fertilization. Considering the nature of limited resources in adults, low fecundity, and egg protection behavior in C. chuxiongica, we suggest that mating triggers trade-offs between reproduction and survival in this insect and females of this species may have evolved specific strategies to adapt to the environmental and hosts’ conditions, e.g., restrict whole fecundity to ensure higher fertilization and offspring’s survival. Moreover, mating induced significant responses on genes and pathways that play important roles in vertebrate reproduction while their function in insects are unclear, such as the progesterone-mediated oocyte maturation pathway; the significant regulation after mating suggests that their function may be evolutionarily conserved in animal kingdom.

scholarly journals New insights in oocyte dynamics shed light on the complexities associated with fish reproductive strategies

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Alba Serrat ◽  
Fran Saborido-Rey ◽  
Cristina Garcia-Fernandez ◽  
Marta Muñoz ◽  
Josep Lloret ◽  
...  
Keyword(s):  
Reproductive Strategies ◽  
Egg Production ◽  
Binary Classification ◽  
Low Cost ◽  
Reproductive Potential ◽  
Major Change ◽  
Temporal Variations ◽  
Conceptual Approach ◽  
Potential Fecundity ◽  
Primary Oocyte

AbstractInformation on temporal variations in stock reproductive potential (SRP) is essential in fisheries management. Despite this relevance, fundamental understanding of egg production variability remains largely unclear due to difficulties in tracking the underlying complex fluctuations in early oocyte recruitment that determines fecundity. We applied advanced oocyte packing density theory to get in-depth, quantitative insights across oocyte stages and seasons, selecting the commercially valuable European hake (Merluccius merluccius) as a case study. Our work evidenced sophisticated seasonal oocyte recruitment dynamics and patterns, mostly driven by a low-cost predefinition of fecundity as a function of fish body size, likely influenced also by environmental cues. Fecundity seems to be defined at a much earlier stage of oocyte development than previously thought, implying a quasi-determinate – rather than indeterminate – fecundity type in hake. These results imply a major change in the conceptual approach to reproductive strategies in teleosts. These findings not only question the current binary classification of fecundity as either determinate or indeterminate, but also suggest that current practices regarding potential fecundity estimation in fishes should be complemented with studies on primary oocyte dynamics. Accordingly, the methodology and approach adopted in this study may be profitably applied for unravelling some of the complexities associated with oocyte recruitment and thereby SRP variability.

scholarly journals Energy acquisition and allocation to egg production in relation to fish reproductive strategies

2013 ◽  
Vol 16 (1) ◽  
pp. 23-57 ◽  
Author(s):  
Richard S McBride ◽  
Stylianos Somarakis ◽  
Gary R Fitzhugh ◽  
Anu Albert ◽  
Nathalia A Yaragina ◽  
...  
Keyword(s):  
Reproductive Strategies ◽  
Egg Production ◽  
Energy Acquisition

ANNUAL, INTRA-, AND INTER-SPECIFIC VARIATIONS IN BODY SIZE AND POTENTIAL FECUNDITY OF SOME TABANUS SPECIES (DIPTERA: TABANIDAE)

1986 ◽  
Vol 118 (12) ◽  
pp. 1265-1272
Author(s):  
D.J. Leprince ◽  
P. Jolicoeur
Keyword(s):  
Population Dynamics ◽  
Body Size ◽  
Reproductive Strategies ◽  
Egg Production ◽  
Wing Length ◽  
Potential Fecundity ◽  
Future Studies ◽  
The Third ◽  
Ovariole Number

AbstractBecause egg production in Tabanus atratus, T. catenatus, T. lineola, T. quinquevittatus, and T. similis is not known in southwestern Quebec, potential fecundity and body size were evaluated respectively from the analysis of ovariole number and wing length in field-collected females. Ovariole number appears to be proportional to the third power of wing length, and fecundity indices can be derived from that relationship. Significant differences in body size and potential fecundity of the species suggest that there are different reproductive strategies within the genus Tabanus. Body size and potential fecundity varied significantly in both sampling years in T. lineola but not in T. quinquevittatus or T. similis. These results may prove useful in future studies of population dynamics or phylogeny.

Toward a Theory of Human Multiple Birthing: Sociobiology and r/K Reproductive Strategies

1987 ◽  
Vol 36 (3) ◽  
pp. 289-296 ◽  
Author(s):  
J. Philippe Rushton
Keyword(s):  
Birth Weight ◽  
Menstrual Cycle ◽  
Mortality Rate ◽  
Population Biology ◽  
Reproductive Strategies ◽  
Egg Production ◽  
Large Numbers ◽  
Health Disorders ◽  
Age Of Menarche ◽  
The Continuum

AbstractUsing symbols from population biology, a continuum of reproductive strategies can be distinguished ranging from r, the production of large numbers of offspring provided with minimal care, to K, the production of few offspring nurtured intensively. While all humans are at the K end of the continuum, some are proposed to be more so than others. If multiple egg production is part of an r-reproductive strategy, certain facts may be ordered. Compared to mothers of singletons, for example, mothers of DZ twins nave a lower age of menarche, a shorter menstrual cycle, a higher number of marriages, a higher rate of coitus, more illegitimate children, a closer spacing of births, a greater fecundity, more wasted pregnancies, a larger family, an earlier menopause, and an earlier mortality. Further, all twins have a shorter gestation period, a lower birth weight, and a greater incidence of infant mortality, with DZ twins having a greater frequency of health disorders, a higher mortality rate, and a lower rate of enrollment in volunteer registries. Multiple birthing also occurs more frequently in families of lower than of higher social status, and in those of African than of European and especially than of Orientai descent.

scholarly journals Spermatophore consumption in a cephalopod

2013 ◽  
Vol 9 (4) ◽  
pp. 20130192 ◽  
Author(s):  
Benjamin J. Wegener ◽  
Devi Stuart-Fox ◽  
Mark D. Norman ◽  
Bob B. M. Wong
Keyword(s):  
Reproductive Strategies ◽  
Egg Production ◽  
Food Source ◽  
Buccal Cavity ◽  
Sperm Storage ◽  
Short Term ◽  
Strong Selection ◽  
Somatic Maintenance ◽  
Nourishing Food

An individual's gametes can represent a nourishing food source for a manipulative mate. Here, we provide evidence of ejaculate and sperm consumption in a cephalopod. Through labelling male spermatophores with 14 C radiolabel, we found that female squid, Sepiadarium austrinum , consumed the spermatophores of their partners and directed the nutrients received into both somatic maintenance and egg production. We further show that in this species—where fertilization occurs externally in the female's buccal cavity—sperm storage is short-term (less than 21 days). The combination of female spermatophore consumption and short-term external sperm storage has the potential to exert strong selection on male ejaculates and reproductive strategies.

scholarly journals Are there useful life history indicators of stock recovery rate in gadoids?

2014 ◽  
Vol 71 (6) ◽  
pp. 1393-1406 ◽  
Author(s):  
Peter J. Wright
Keyword(s):  
Life History ◽  
Population Growth ◽  
Egg Production ◽  
Reproductive Rate ◽  
Mortality Data ◽  
Age At Maturity ◽  
Instantaneous Rate ◽  
Recovery Potential ◽  
Early Survival ◽  
Stock Recovery

Age at maturity is one of the key variables determining the maximum rate of population growth and so may be a good indicator of stock recovery potential. Spawner age composition may also affect the probability of high recruitment and so could be relevant to stock recovery. This study examined the relation between early survival, age at maturity, and the demographic composition of spawners in many cod and haddock stocks. Reported measures of fecundity and maturity were used to estimate total egg production for comparison with numbers at age 1 and age at 50% maturity. The instantaneous rate of population growth (r) was estimated for cohorts from life history tables during periods when spawning biomass was depleted (e.g. <Bpa) using reproductive and mortality data for stocks. Age-specific survival was found to be far more important than reproductive rate in determining population growth rate. Stocks that experienced low and more variable survival matured early and had a high relative fecundity. Hence, while early maturing stocks have the potential for high population growth following favourable recruitment events, they would not be expected to recover any faster than late maturing stocks because of the generally low early survival rate that they experience. Measures of spawner age diversity and mean age were found to be positively correlated with offspring survivorship in a few cod stocks. However, in general, it appears difficult to infer recovery potential from life history characteristics, which may be expected, given that regional variation in reproductive success will ultimately be expected to shape local reproductive schedules.

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