scholarly journals Polyandry is extremely rare in the firefly squid, Watasenia scintillans

2019 ◽  
Author(s):  
Noriyosi Sato ◽  
Sei-Ichiro Tsuda ◽  
Nur E Alam ◽  
Tomohiro Sasanami ◽  
Yoko Iwata ◽  
...  
Keyword(s):  
Life History ◽  
Empirical Evidence ◽  
Life History Traits ◽  
Spawning Season ◽  
Symmetric Distribution ◽  
Single Male ◽  
Common Life ◽  
Female Remating ◽  
Random Placement ◽  
The Mean

AbstractAlthough polygamy has versatile benefits for both sexes, many species favor monogamy for reasons with the clarity or unclarity. In cephalopods, all species are regarded to be polygamous, which could be attributed to their common life-history traits. Contrary to this prediction, we show empirical evidence for monogamy in the firefly squid, Watasenia scintillans. The peak spawning season comes after male disappearance owning to long-reserved spermatangia deposited by male at exact locations (bilateral pouches under neck collar) on female with a symmetric distribution. Such a non-random placement of spermatangia prompted us to hypothesize that females engage in lifetime monoandry. Hence we assigned genotypes of female-stored spermatangia and offspring. We found that in 94.7 % females, the spermatangia were delivered from a single male and all embryos in the same egg string sired by sperm from stored spermatangia. Throughout the season, relative testes mass was much smaller in W. scintillans than all other cephalopods previously examined. The mean number of male-stored spermatophores was approximately 30, the equivalent to 2.5 mates. Our demographic and morphometrical data agree with the prediction that monogyny is favored when potential mates are scarce such as absence of female remating. Together, these results suggest the likelihood of mutual monogamy.

scholarly journals Life History and Host Preference of Trichopria drosophilae from Southern China, One of the Effective Pupal Parasitoids on the Drosophila Species

Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 103 ◽  
Author(s):  
Chuandong Yi ◽  
Pumo Cai ◽  
Jia Lin ◽  
Xuxiang Liu ◽  
Guofu Ao ◽  
...  
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Southern China ◽  
Reproductive Potential ◽  
Drosophila Species ◽  
Choice Test ◽  
Parasitization Rate ◽  
Pupal Parasitoids ◽  
Lifetime Number ◽  
The Mean

This study aims to evaluate several life-history traits of a T. drosophilae population from southern China and its parasitic preference of three Drosophila species. For mated T. drosophilae females, the mean oviposition and parasitization period were 27.20 and 37.80 d, respectively. The daily mean parasitization rate was 59.24% per female and the lifetime number of emerged progeny was 134.30 per female. Trichopria drosophilae females survived 37.90 and 71.61 d under host-provided and host-deprived conditions, respectively. To assess the potential for unmated reproduction in T. drosophilae, the mean oviposition and parasitization period of unmated females was 22.90 and 47.70 d, respectively. They had a daily mean parasitization rate of 64.68%, produced a total of 114.80 offspring over their lifetime, and survived 52 d. Moreover, T. drosophilae showed a preference towards D. suzukii based on the total number of emerged offspring under a choice test. Our findings indicate that T. drosophilae from southern China appears to be suitable for the control of D. suzukii in invaded areas, due to its reproductive potential.

scholarly journals Life-history traits and description of the new gonochoric amphimictic Mesobiotus joenssoni (Eutardigrada: Macrobiotidae) from the island of Elba, Italy

2019 ◽  
Author(s):  
Roberto Guidetti ◽  
Elisa Gneuß ◽  
Michele Cesari ◽  
Tiziana Altiero ◽  
Ralph O Schill
Keyword(s):  
Life History ◽  
Life History Theory ◽  
Life History Traits ◽  
Life Cycles ◽  
Life History Strategies ◽  
Egg Hatching ◽  
Body Segments ◽  
Hatching Time ◽  
Laboratory Cultures ◽  
The Mean

Abstract Comparative analyses of life-history theory studies are based on the characteristics of the life cycles of different species. For tardigrades, life-history traits are available only from laboratory cultures, most of which have involved parthenogenetic species. The discovery of a new gonochoristic bisexual Mesobiotus species in a moss collected on the island of Elba (Italy) provides us with the opportunity to describe Mesobiotus joenssoni sp. nov. and to collect data on the life-history traits of cultured specimens to increase our knowledge of the life-history strategies present in tardigrades. This new species is differentiated from all other species of the genus by the presence of granules (~1 µm in diameter) on the dorsal cuticle of the last two body segments, two large bulges (gibbosities) on the hindlegs and long, conical egg processes. The species exhibits sexual dimorphism in body length, with females being longer than males of the same age. The mean lifespan of specimens was 86 days, with a maximum of 150 days. The mean age at first oviposition was 19.8 days and the mean egg hatching time 15.4 days. The life-cycle traits correspond to those collected for the only other two macrobiotid species with gonochoric amphimictic reproduction examined so far.

LIFE HISTORY AND BIOLOGY OF IPS LATIDENS (LECONTE) (COLEOPTERA: SCOLYTIDAE)

1985 ◽  
Vol 117 (7) ◽  
pp. 859-871 ◽  
Author(s):  
D.R. Miller ◽  
J.H. Borden
Keyword(s):  
Life History ◽  
Generation Time ◽  
Laboratory Data ◽  
Head Capsule ◽  
Single Male ◽  
South Central ◽  
Harem Size ◽  
The Mean ◽  
Ips Latidens ◽  
Rearing Methods

AbstractThe life history and biology of Ips latidens (LeConte) were investigated using bark-sandwich and whole-log rearing methods. In contrast with other Ips spp., some females initiated galleries under conditions of female-biased sex ratios, and sometimes 2 or more males were present in a gallery. In general, however, I. latidens exhibited typical ipine characteristics. A single male usually admitted 1–3 females into a gallery. Females oviposited at a rate of 2.25 eggs/day and achieved a mean fecundity of 64.4 eggs. The larval stage comprised 80% of the generation time (egg to teneral adult) and analysis of head-capsule widths disclosed 3 larval instars. The mean survivorship within broods was 56.0% after 70 days; the reproductive success of monogamous pairs of beetles was 36.1 teneral adults. Single females constructed 3–4 egg tunnels/gallery system; hence, harem size cannot always be inferred from the number of egg tunnels in each gallery. The mean generation time in the laboratory was 2.07 × greater than for I. pini. By comparing laboratory data on I. latidens with laboratory and field data on I. pini, the generation time of I. latidens is estimated at 64–124 days in the field. In south-central British Columbia, I. latidens probably has 1 generation, and possibly 2 broods, per year.

Putative Pleiotropic Effects of the Knock-Down Resistance (L1014F) Allele on the Life-History Traits in Anopheles Gambiae.

2020 ◽  
Author(s):  
Adandé A. Medjigbodo ◽  
Luc Salako Djogbénou ◽  
Oswald Y. Djihinto ◽  
Romaric B. Akoton ◽  
Emmanuella Abbey ◽  
...  
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Blood Feeding ◽  
Malaria Vectors ◽  
Resistance Allele ◽  
Knock Down ◽  
Fitness Effects ◽  
Larval Survivorship ◽  
The Mean ◽  
Hatching Rates

Abstract BackgroundExisting mechanisms of insecticide resistance have been known to help the survival of mosquitoes following contact with chemical compounds, even though they could negatively affect the life-history traits of resistant malaria vectors. In West Africa, the knock-down resistance mechanism, kdrR (L1014F) is the most common. However, little knowledge is available on its effects on mosquito life traits. We investigated the fitness effects associated with this knock-down resistance allele in Anopheles gambiae sensu stricto (s.s.).MethodsTwo laboratory reference strains of An. gambiae s.s., Kisumu (susceptible) and KisKdr (kdr resistant) were used. Female mosquitoes were fed and allowed to lay eggs. Fecundity and fertility were assessed by examining the number of eggs per mosquito and larval hatching rates. Larval survivorship and pupation rates were also measured. Female mosquitoes of both strains were fed through membrane feeding assays, then the blood feeding success, blood volume and adult survivorship were monitored. ResultsAn. gambiae carrying kdrR allele (KisKdr) showed a lower ability to lay eggs. The mean number of larvae in the susceptible strain Kisumu was overall threefold higher than that seen in KisKdr strain with significant difference in the hatching rates (81.89% in Kisumu versus 72.89% in KisKdr, p= 0.003). KisKdr larvae had a significant higher larval survivorship than Kisumu. The blood feeding success was significantly higher (p= 2.2.10-16) in the resistant mosquitoes (84%) than that in the susceptible ones (34.75%). However, the mean blood volume was 1.36 µL/mg, 1.45 µL/mg and 1.68 µL/mg in Kisumu, homozygote and heterozygote KisKdr respectively. After blood feeding, the heterozygote KisKdr displayed highest survivorship when compared to that of Kisumu.ConclusionsOur findings provide novel insights on fitness effects of the kdrR (L1014F) allele in An. gambiae. The presence of this resistance allele tends to have an impact on mosquito life-history traits such as fecundity, fertility, larval survivorship and blood feeding behaviour. These data could help to guide the implementation of more reliable strategies for the control of malaria vectors.

Intrapopulation variation in life history traits of Boa constrictor occidentalis in Argentina

2003 ◽  
Vol 24 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Mariano Sironi ◽  
Margarita Chiaraviglio ◽  
Sergio Lucino ◽  
Miguel Bertona
Keyword(s):  
Life History ◽  
Litter Size ◽  
Air Temperature ◽  
Life History Traits ◽  
Intrapopulation Variation ◽  
Boa Constrictor ◽  
Management Plans ◽  
Dry Seasons ◽  
The Mean

AbstractWe provide data on intrapopulation variation of life history traits of Boa constrictor occidentalis in the District of Pocho, Córdoba, Argentina. A total of 153 individuals were captured. The distribution of individuals among four size classes differed significantly among the five years of study. The proportion of mature individuals did not differ between sexes but it showed variation among years. Females were longer and heavier than males. The mean litter size of the species was 24 and there was a linear relationship between litter size and maternal snout-vent length. Most boas were captured during the dry season. There were no significant sex differences in the time of capture and air temperature in either the wet or the dry seasons. However, we found significant differences in the time of capture and air temperature between the seasons. The long-term monitoring of wild populations should be a priority for the development of conservation and management plans for this boid.

scholarly journals Azadirachtin-induced effects on various life history traits and cellular immune reactions of Galleria mellonella (Lepidoptera: Pyralidae)

2017 ◽  
Vol 69 (2) ◽  
pp. 335-344 ◽  
Author(s):  
Aylin Er ◽  
Deniz Taşkıran ◽  
Olga Sak
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Galleria Mellonella ◽  
Adult Emergence ◽  
Immune Parameters ◽  
Lepidoptera Pyralidae ◽  
The Mean ◽  
Integrated Pest Control ◽  
Cellular Immune ◽  
Sublethal Concentrations

The effects of the botanical insecticide azadirachtin were examined on the life history traits, fecundity and immune parameters of Galleria mellonella L. (Lepidoptera: Pyralidae). We determined that for the topical application of azadirachtin, the LC50 was 16.564 ppm; at 100 ppm the adult emergence time was prolonged, however the longevity of adults remained unchanged above sublethal concentrations. The mean number of healthy eggs and the fecundity of adults decreased, whereas the number of defective eggs increased with azadirachtin treatment. At concentrations >50 ppm female G. mellonella adults laid no eggs. Azadirachtin reduced total hemocyte counts at 24 and 48 h posttreatment, however the alterations in differential hemocyte counts were only significant at 100 ppm. Laminarin-induced nodulation response and the spreading ability of hemocytes were also suppressed with azadirachtin treatment. Our results suggest that azadirachtin, as a good candidate for integrated pest control, has the capability to affect the biological parameters and cellular immunity of the model insect G. mellonella.

scholarly journals Age structure and body size of the endangered species Darevskia bendimahiensis (Schmidtler, Eiselt & Darevsky, 1994) from eastern Turkey (Squamata, Sauria, Lacertidae)

Herpetozoa ◽  
2019 ◽  
Vol 32 ◽  
pp. 159-163
Author(s):  
Elif Yıldırım ◽  
Yusuf Kumlutaş ◽  
Kamil Candan ◽  
Çetin Ilgaz
Keyword(s):  
Life History ◽  
Body Size ◽  
Endangered Species ◽  
Age Structure ◽  
Sexual Maturity ◽  
Life History Traits ◽  
Eastern Turkey ◽  
The Future ◽  
The Mean ◽  
Spearman’S Correlation

The life-history traits of the parthenogenetic lizard Darevskiabendimahiensis were studied by skeletochronology in a population inhabiting highlands in Çaldıran, Van, Turkey. Endosteal resorption was observed in 18 specimens (55%). The mean age was 4.91 ± 0.19 SD years. The mean snout-vent length (SVL) was 51.11 ± 1.15 SD mm. The age at sexual maturity was estimated as 3 years. Longevity was 7 years. Snout-vent length and age were positively correlated (Spearman’s correlation; r = 0.797, P = 0.000). The aim of this study is to contribute to the future conservation activities for this endangered species.

scholarly journals Density-Dependent Phenotypic Plasticity in the South American Locust, Schistocerca cancellata (Orthoptera: Acrididae)

2019 ◽  
Vol 112 (5) ◽  
pp. 458-472 ◽  
Author(s):  
Martina E Pocco ◽  
M Marta Cigliano ◽  
Bert Foquet ◽  
Carlos E Lange ◽  
Eliana L Nieves ◽  
...  
Keyword(s):  
Life History ◽  
Phenotypic Plasticity ◽  
Life History Traits ◽  
South American ◽  
The South ◽  
Density Dependent ◽  
Strong Resemblance ◽  
Males And Females ◽  
The Mean ◽  
Phase Polyphenism

Abstract Historically, the South American locust, Schistocerca cancellata (Serville, 1838), has been considered the most serious agricultural pest in Argentina. An outbreak of a magnitude not recorded since 1954 started in 2015 through 2017 in northern Argentina and neighboring Paraguay and Bolivia. Schistocerca cancellata is widely considered as a true locust, with pronounced locust phase polyphenism, although the expression of its phenotypic plasticity has never been quantitatively tested under different density conditions. In this study, we explicitly quantified density-dependent reaction norms in behavior, coloration, and morphology in last instar nymphs of S. cancellata under isolated and crowded conditions. We also quantified density-dependent plasticity in adults (size) and in some life history traits. Our results showed that crowded nymphs were significantly more active and more attracted to congeners than isolated nymphs, and developed a much higher percentage of black pattern color. We also found that density had strong effects on body size and there was a sex-dependent pattern in both nymphs and adults, revealing that differences in size between males and females were less pronounced in crowded locusts. We have recorded for the isolated nymphs the presence of about 50% more hairs in the hind femora than in crowded nymphs. Finally, the mean duration of each nymphal instar and adult stage was significantly longer in isolated individuals. We have found strong resemblance with the desert locust, S. gregaria (Forskål, 1775) in several traits, and we conclude that S. cancellata exhibits an extreme form of density-dependent phenotypic plasticity in behavior, coloration, morphology, and life history traits.

Properties of Ethylmethane Sulfonate-Induced Mutations Affecting Life-History Traits in Caenorhabditis elegans and Inferences About Bivariate Distributions of Mutation Effects

Genetics ◽  
2000 ◽  
Vol 156 (1) ◽  
pp. 143-154 ◽  
Author(s):  
Peter D Keightley ◽  
Esther K Davies ◽  
Andrew D Peters ◽  
Ruth G Shaw
Keyword(s):  
Life History ◽  
Caenorhabditis Elegans ◽  
Reproductive Output ◽  
Life History Traits ◽  
Genetic Correlations ◽  
Induced Mutations ◽  
Bivariate Distributions ◽  
Ethylmethane Sulfonate ◽  
The Mean ◽  
Positive Correlations

Abstract The homozygous effects of ethylmethane sulfonate (EMS)-induced mutations in Caenorhabditis elegans are compared across life-history traits. Mutagenesis has a greater effect on early than late reproductive output, since EMS-induced mutations tend to cause delayed reproduction. Mutagenesis changes the mean and variance of longevity much less than reproductive output traits. Mutations that increase total or early productivity are not detected, but the net effect of mutations is to increase and decrease late productivity to approximately equal extents. Although most mutations decrease longevity, a mutant line with increased longevity was found. A flattening of mortality curves with age is noted, particularly in EMS lines. We infer that less than one-tenth of mutations that have fitness effects in natural conditions are detected in the laboratory, and such mutations have moderately large effects (~20% of the mean). Mutational correlations for life-history traits are strong and positive. Correlations between early or late productivity and longevity are of similar magnitude. We develop a maximum-likelihood procedure to infer bivariate distributions of mutation effects. We show that strong mutation-induced genetic correlations do not necessarily imply strong directional correlations between mutational effects, since correlation is also generated by lines carrying different numbers of mutations.

Age Structure and Life Expectancy in a Stellagama stellio (Linnaeus, 1758) Population from Kütahya, Turkey

2021 ◽  
Vol 28 (6) ◽  
pp. 327-332
Author(s):  
Muge Gidis ◽  
Eyup Baskale
Keyword(s):  
Life History ◽  
Standard Deviation ◽  
Sexual Dimorphism ◽  
Life Expectancy ◽  
Age Structure ◽  
Life History Traits ◽  
Age At Maturity ◽  
Males And Females ◽  
The Mean ◽  
The Difference

The life history traits of the rough-tailed agama, Stellagama stellio (Linnaeus, 1758) in a population from Kütahya, Turkey were described by the skeletochronological method. From a total of 54 individuals, the mean ages ± standard deviation (SD) of males and females were calculated as 5.03 ± 2.076 years and 4.79 ± 1.584 years, respectively, and age distributions were not significantly different between sexes. The age at maturity was 2 years for both sexes. The longevity of females was 8 years, whereas for males it was 9 years. Mean snout-vent length (SVL) ± SD was 101.7 ± 9.6 mm in females and 104.9 ± 14.4 mm in males and did not significantly differ between the two sexes. We examined the sexual dimorphism of S. stellio in relation to the difference in population age structure between the sexes using the skeletochronological method. Male individuals were slightly larger than female individuals at the same age, but this difference was not statistically significant. We also estimated the maximum ages for S. stellio, which agree with other populations in Turkey.

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