Origin of relation between K and Linf and synthesis of relations among life history parameters

1997 ◽  
Vol 54 (5) ◽  
pp. 987-989 ◽  
Author(s):  
A L Jensen

Four patterns occur in growth and mortality parameters across species of fish. Three of these relations, Mxm = 1.65, M = 1.50K, and L(xm) = 0.66Linf where M is natural mortality, xm is age at maturity, L(xm) is length at maturity, and Linf is asymptotic length, were previously shown to result from optimization of the age at maturity. In this study the fourth relation, that between asymptotic size and the growth coefficient, Linf = CK-h, was obtained from a bioenergetic growth equation. A numerical value of h = 0.33 was predicted, and this agrees with the observed value. The relation between the growth coefficient K and size Linf results from the limited amount of assimilated food that must be used both for growth and body functions, and the body functions are a function of body size. The four Beverton and Holt invariants, together with the net reproductive rate, relate many life history parameters to a metabolic parameter and mortality.

1985 ◽  
Vol 42 (1) ◽  
pp. 164-168 ◽  
Author(s):  
A. L. Jensen

An equation is derived that relates net reproductive rate to six life history parameters; the equation is applied to determine changes in the net reproductive rate of lake whitefish (Coregonus clupeaformis) that result from variation in these life history parameters. Changes in age at maturity and survival of immature fish are the only parameters that have a large effect on the net reproductive rate. Age at maturity occurs near the inflection of the growth curve, and this implies a relationship between age at maturity, length at maturity, the growth coefficient, and asymptotic length.


PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248819
Author(s):  
Yujeong Park ◽  
Young-gyun Park ◽  
Joon-Ho Lee

Bemisia tabaci Mediterranean (Gennadius) (Hemiptera: Aleyrodidae) is an economically important insect pest worldwide. Previously, we have reported that most B. tabaci Mediterranean (MED) populations occurring in greenhouse tomatoes in Korea have been displaced from well-differentiated two genetic clusters (C1 and C2) to one (C2) during one-year period. To elucidate factors responsible for this phenomenon, we compared life history parameters of these two different genetic clusters through single and cross mating experiments on two different host plants, cucumber and tobacco, at 26°C. Intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (Ro) were significantly higher in the dominating cluster (C2) (0.247, 1.280, and 192.402, respectively on cucumber; 0.226, 1.253, and 133.792, respectively on tobacco) than in the other cluster (C1) (0.149, 1.161, and 50.539, respectively on cucumber; 0.145, 1.156, and 53.332, respectively on tobacco). Overall performances of cross mating groups, C2fC1m (C2 female × C1 male) and C1fC2m (C1 female × C2 male), were in-between those of C2 and C1, with C2fC1m performing better than C1fC2m. Thus, maternal inheritance appeared to be significantly associated with their life history parameters, with partial involvement of paternal inheritance. Our results demonstrated that the rapid displacement of genetic clusters of B. tabaci MED populations was clearly associated with differences in their life history parameters.


2019 ◽  
Vol 112 (5) ◽  
pp. 2116-2120
Author(s):  
M Amin Jalali ◽  
M Reza Mehrnejad ◽  
Peter C Ellsworth

Abstract Aspects of the nutritional ecology and life histories of five predatory coccinellids (Coleoptera: Coccinellidae)—two arboreal predator species, Oenopia conglobata contaminata (Menetries) and Adalia bipunctata (Linnaeus), and three herbaceous dwelling predator species, Coccinella undecimpunctata aegyptica (Reiche), Exochomus nigripennis (Erichson), and Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae)—were compared when fed either Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Aphalaridae), the key psylla pest of pistachio trees, or Aphis gossypii Glover (Hemiptera: Aphididae), a common aphid on herbaceous plants in pistachio orchards. The putative habitat preferences of four of the five coccinellids studied were consistent with their performance on the major herbivore present in those two habitats in terms of net reproductive rate. Oenopia conglobata contaminata and Ad. bipunctata showed higher net reproductive rates when fed on pistachio psylla prey, whereas C. undecimpunctata aegyptiaca and E. nigripennis had better reproductive output on aphid prey. Moreover, E. nigripennis was the most specialized of these generalist predators, eating more and reproducing better when fed aphids. Hippodamia variegata was relatively unaffected by the diet offered, suggesting greater ability to switch among herbivore prey and perhaps better potential as a biocontrol agent with abilities to exploit Ag. pistaciae without large life history tradeoffs.


1982 ◽  
Vol 60 (11) ◽  
pp. 2841-2851 ◽  
Author(s):  
Carl M. Way ◽  
Thomas E. Wissing

The pisidiid clams, Pisidium variabile (Prime) and Pisidium compressum (Prime), from permanent ponds in southwestern Ohio are iteroparous, bivoltine, and have approximate longevities of 1 year. Intrapopulation differences in life history characteristics are discussed in relation to environmental heterogeneity. For the P. variabile population, only age at first reproduction (110 and 226 days for the spring and fall generations, respectively) is different for both annual generations. This is due to differences in environmental variables (temperature, dissolved oxygen levels, food availability) which set physiological limits on growth, reproduction, and maintenance functions. The spring and fall generations of P. compressum show differences in several life history characteristics: age at first reproductive (122 and 270 days, respectively), net reproductive rate (8.7 and 3.7, respectively), r (0.005 and 0.003, respectively), and the number of broods per year (2 and 1, respectively). The results of this study tend to question the validity of using current theories (e.g, r- and K-selection, bet-hedging) which attempt to predict the set of demographic characteristics that should be found in populations under varying environmental circumstances.


Author(s):  
Jayme Magalhães Santangelo ◽  
Bruno Nascimento Soares ◽  
Thecia Paes ◽  
Paulina Maia-Barbosa ◽  
Ralph Tollrian ◽  
...  

Cladocerans serve as prey for several aquatic predators like fish and Chaoborus larvae. However, because different predators consume different sized prey, cladocerans may display differing life-history responses depending on predator type. Although most studies use the genus Daphnia to evaluate phenotypic plasticity in cladocerans, other genera might also respond to predator infochemicals. In this study, we compared life-history responses of Daphnia similis and Moina macrocopa to infochemicals released by a vertebrate (fish) and an invertebrate (Chaoborus) predator. As expected, some life-history parameters were altered depending on the type of predator. Overall, fish infochemicals increased the size at primipara, clutch size, net reproductive rate and longevity in both cladocerans. We argue that increased body lengths in the presence of fish promote bigger clutch sizes. Conversely, responses to Chaoborus were weaker, affecting only the net reproductive rates and longevity. Non-daphniid cladocerans may display similar responses to Daphnia when exposed to predators. However, as Daphnia is usually underrepresented in tropical lakes, studying other genera might offer new insights into predator-prey relationships and food webs in lake ecosystems.


2018 ◽  
Vol 75 (3) ◽  
pp. 953-963 ◽  
Author(s):  
Sebastián A Pardo ◽  
Andrew B Cooper ◽  
John D Reynolds ◽  
Nicholas K Dulvy

Abstract Sensitivity to overfishing is often estimated using simple models that depend upon life history parameters, especially for species lacking detailed biological information. Yet, there has been little exploration of how uncertainty in life history parameters can influence demographic parameter estimates and therefore fisheries management options. We estimate the maximum intrinsic rate of population increase (rmax) for ten coastal carcharhiniform shark populations using an unstructured life history model that explicitly accounts for uncertainty in life history parameters. We evaluate how the two directly estimated parameters, age at maturity αmat and annual reproductive output b, most influenced rmax estimates. Uncertainty in age at maturity values was low, but resulted in moderate uncertainty in rmax estimates. The model was sensitive to uncertainty in annual reproductive output for the least fecund species with fewer than 5 female offspring per year, which is not unusual for large elasmobranchs, marine mammals, and seabirds. Managers and policy makers should be careful to restrict mortality on species with very low annual reproductive output <2 females per year. We recommend elasmobranch biologists to measure frequency distributions of litter sizes (rather than just a range) as well as improving estimates of natural mortality of data-poor elasmobranchs.


2013 ◽  
Vol 103 (4) ◽  
pp. 406-413 ◽  
Author(s):  
Chia-Yu Chen ◽  
Ming-Chih Chiu ◽  
Mei-Hwa Kuo

AbstractTo estimate the net effect of climate change on natural populations, we must take into account the positive and negative effects of temperature oscillations and climate variability. Warming because of climate change will likely exceed the physiological optima of tropical insects, which currently live very close to their thermal optima. Tropical insects will be negatively affected if their optima are exceeded otherwise warming may affect them positively. We evaluate the demographic responses of the cowpea aphid,Aphis craccivora, to summer warming in subtropical and tropical Taiwan, and examine the effects of diel temperature oscillation on these responses. Aphids were reared at four temperatures (current summer mean, +1.4, +3.9 and +6.4 °C), the latter three simulating different levels of warming. At each average temperature, aphids experienced constant or oscillating (from −2.9 to +3.6 °C of each mean temperature) regimes. As the simulated summer temperatures increased, so did the negative effects on life-history traits and demographic parameters. Compared with aphids reared in constant temperatures, aphids reared in oscillating temperatures developed more slowly and had a longer mean generation time, but their net reproductive rate was higher. These findings demonstrate that climate warming will affect demographic parameters and life-history traits differentially. Studies that use constant temperatures are unlikely to accurately predict biotic responses to climate change.


Insects ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 292
Author(s):  
Fatemeh Ganjisaffar ◽  
Thomas M. Perring

Ooencyrtus lucidus Triapitsyn & Ganjisaffar (Hymenoptera: Encyrtidae) was recently recovered from fresh sentinel eggs of Bagrada hilaris (Burmeister) (Hemiptera: Pentatomidae) in California. In the present study, life history traits of O. lucidus were studied at 26 ± 0 . 5 ∘ C, 40 ± 10 % RH, and a photoperiod of 14 L: 10 D hours. Results showed that 95.2% of the parasitized eggs yielded successful emergence of adults. The total immature developmental time was 14.27 and 13.95 days for females and males, respectively. The sex ratio of O. lucidus was 0.5 (females/offspring). Mated females laid on average 6.0 eggs per day and 222.7 eggs during their mean ovipositional period of 37.3 days. There was no significant difference in reproduction parameters between mated and non-mated females. The net reproductive rate ( R 0 ) was 103.8 females/female/generation, the intrinsic rate of increase ( r m ) was 0.171 females/female/day, the finite rate of increase ( λ ) was 1.187 population multiplication/day, the mean generation time (T) was 27.1 days, and the doubling time (DT) was 4.0 days. The highest longevity was observed in mated and non-mated females fed with honey, and they lived for 70.8 and 70.1 days, respectively. Providing females with host eggs in addition to honey, reduced their longevity by 24% in mated and 28% in non-mated individuals. Non-mated females and males deprived of honey only lived for 3.5 and 2.5 days after emergence, respectively. Our results indicate that O. lucidus has sufficient life history traits to make it a promising egg parasitoid for the biological control of B. hilaris.


2019 ◽  
Vol 19 (5) ◽  
Author(s):  
Feng Hong ◽  
Hong-Liang Han ◽  
Po Pu ◽  
Dong Wei ◽  
Jia Wang ◽  
...  

Abstract The green peach aphid, Myzus persicae Sulzer (Hemiptera: Aphididae), is an important agricultural pest with a wide range of host plants. To study effects of host species on the life history traits of M. persicae, aphids were individually reared on five host plants: Brassica campestris L. (Brassicales: Brassicaceae), Capsicum annuum L. (Tubiflorae: Solanaceae), Nicotiana tabacum L. (Tubiflorae: Solanaceae), Raphanus sativus L. (Brassicales: Brassicaceae), and Vicia faba L. (Rosales: Leguminosae). TWOSEX-MSchart software was used for the statistical analysis according to the age-stage, two-sex life table theory. The results showed that the shortest preadult stage and adult/total prereproductive period of M. persicae were 6.48, 0.19, and 6.67 d on V. faba, respectively. While the adult and total longevity of M. persicae on R. sativus (25.00 and 31.62 d) and N. tabacum (24.40 and 30.56 d) were significantly longer than that on the other three hosts, as was the reproductive period. The fecundity of M. persicae on R. sativus (80.83 nymphs per female), N. tabacum (71.72 nymphs per female), and V. faba (70.39 nymphs per female) was also greater than that on B. campestris and C. annuum. It was demonstrated that V. faba, R. sativus, and N. tabacum were more suitable plants for the growth of M. persicae exhibiting a shorter preadult stage, longer longevity, and greater fecundity than the remaining two species, as confirmed by the higher intrinsic rate of increase and net reproductive rate.


2014 ◽  
Vol 71 (6) ◽  
pp. 1393-1406 ◽  
Author(s):  
Peter J. Wright

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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