2024-03-28T16:03:39Z
https://soar-ir.repo.nii.ac.jp/oai
oai:soar-ir.repo.nii.ac.jp:00011840
2022-12-14T04:13:04Z
1169:1170
Fitness Consequences of Reciprocally Asymmetric Hybridization Between Simultaneous Hermaphrodites
Wiwegweaw, Amporn
Seki, Keiichi
Utsuno, Hiroki
Asami, Takahiro
Copyright © 2009 Zoological Society of Japan
PULMONATE BRADYBAENA-SIMILARIS
HELIX-ASPERSA MULLER
LAND-SNAIL
MATING-BEHAVIOR
REPRODUCTIVE COMPATIBILITY
PHYSA-ACUTA
DIVERGENCE
POPULATION
SPECIATION
GASTROPODA
Depending on fitness consequences, hybridization may rescue inbred populations; generate premating barriers, reproductive interference, or hybrid species; or extinguish a species. However, the fitness of hybrids is unpredictable without direct quantification of their performance in fitness components across multiple generations. The land snails Bradybaena pellucida and B. similaris, which are indigenous and non-indigenous in Japan, respectively, copulate with each other simultaneously and reciprocally. However, only B. pellucida produces hybrids, because it ends mating by removing the penis before transferring a spermatophore, while B. similaris inseminates B. pellucida. To evaluate the strength of an intrinsic postzygotic barrier against the hybrids produced by B. pellucida, we conducted breeding experiments in the laboratory and measured six life-history traits: (1) growth rate, (2) body weight at maturity, (3) number of days to first oviposition after being permitted to mate, (4) clutch size, (5) fecundity, and (6) hatchability. We also calculated the relative intrinsic fitness based on five of these trait values (excluding clutch size). F(1) hybrids exhibited heterosis in growth rate, body weight at maturity and relative intrinsic fitness. F(2) hybrids also showed heterosis in body weight at maturity. Nevertheless, the F(2) hybrids produced significantly fewer progeny than the mid-point value of the parental species. Thus, the F(2) hybrids exhibited weak out-breeding depression in reproduction, offsetting their vigor in body size. These results indicate that only a weak postzygotic barrier, contrasting with strong F(1) heterosis, has evolved during genetic divergence of the two sibling species in allopatry.
Article
ZOOLOGICAL SCIENCE. 26(3):191-196 (2009)
ZOOLOGICAL SOC JAPAN
2009-05
eng
journal article
VoR
http://hdl.handle.net/10091/15955
https://soar-ir.repo.nii.ac.jp/records/11840
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&DB=pubmed&term=19341339
19341339
https://doi.org/10.2108/zsj.26.191
10.2108/zsj.26.191
0289-0003
AA10545874
ZOOLOGICAL SCIENCE
26
3
191
196
https://soar-ir.repo.nii.ac.jp/record/11840/files/Fitness_Consequences_Reciprocally_Asymmetric_Hybridization.pdf
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2015-09-28