Can pregnant lizards adjust their offspring phenotypes to environmental conditions?

Shine, Richard; Downes, Sharon

doi:10.1007/s004420050754

Cited by 144 publications

(113 citation statements)

References 42 publications

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“…Only a small number of studies have previously observed an increase in individual offspring size in response to predator cues [7,19,21,42]. Wild-radish plants (Raphanus raphanistrum) increase seed mass when attacked by caterpillars (Pieris rapae); however, this response might not be adaptive for the offspring [7].…”

Section: Discussionmentioning

confidence: 99%

Juvenile exposure to predator cues induces a larger egg size in fish

Segers

Taborsky

2011

Proc. R. Soc. B.

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When females anticipate a hazardous environment for their offspring, they can increase offspring survival by producing larger young. Early environmental experience determines egg size in different animal taxa. We predicted that a higher perceived predation risk by juveniles would cause an increase in the sizes of eggs that they produce as adults. To test this, we exposed juveniles of the mouthbrooding cichlid Eretmodus cyanostictus in a split-brood experiment either to cues of a natural predator or to a control situation. After maturation, females that had been confronted with predators produced heavier eggs, whereas clutch size itself was not affected by the treatment. This effect cannot be explained by a differential female body size because the predator treatment did not influence growth trajectories. The observed increase of egg mass is likely to be adaptive, as heavier eggs gave rise to larger young and in fish, juvenile predation risk drops sharply with increasing body size. This study provides the first evidence that predator cues perceived by females early in life positively affect egg mass, suggesting that these cues allow her to predict the predation risk for her offspring.

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Section: Discussionmentioning

confidence: 99%

Juvenile exposure to predator cues induces a larger egg size in fish

Segers

Taborsky

2011

Proc. R. Soc. B.

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“…For example, offspring of Woodworthia 'Otago/ Southland' were proportionately shaped, in contrast with some lizard species in which cool-gestated offspring may have relatively short tails (Shine and Downes, 1999;Li et al, 2009) or relatively small or large mass (Shine and Harlow, 1993;While and Wapstra, 2009). In addition, at 2-3 months of age, geckos from different regimes were able to access a warm retreat as readily and to run by day as quickly.…”

Section: Effects Of Basking Regime and Delivery Mode On Offspring Phementioning

confidence: 93%

Maternal basking regime has complex implications for birthdate and offspring phenotype in a nocturnally foraging, viviparous gecko

Cree

Hare

2016

Journal of Experimental Biology

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Maternal basking regime can affect gestation length in viviparous squamates, but effects on offspring phenotype in species with extended pregnancies and ability to delay the birth season are unclear. We investigated the effects of three maternal basking regimes on maternal thermoregulation, gestation length, pregnancy outcome and offspring phenotype in the gecko Woodworthia 'Otago/ Southland'. This long-lived (30+ years), nocturnal forager has field pregnancies lasting up to 14 months, with fully developed offspring maintained in utero over winter. Within regimes, we also compared outcomes for spontaneous (early) deliveries with those from induced (late) deliveries to test the 'adaptive prolongation of pregnancy' hypothesis. Although a cool regime significantly extended gestation, the effect was reduced by increased maternal basking, and embryonic development under the cool regime was just as successful. Offspring from spontaneous births (but not induced births) were smaller and grew more slowly when from the cool regime. However, induced offspring did not differ in consistent ways from those delivered spontaneously and offspring from all groups had high viability, similar use of warm retreat sites and similar sprint speeds. Thus, consistent evidence for adaptive prolongation of pregnancy was lacking. Unusually for squamates, pregnant females can begin vitellogenesis before giving birth, and a profound drop in maternal body temperature near the end of pregnancy (∼6.3°C, confirmed under the warm regime) may assist survival of embryos in utero. Female lizards that maintain fully developed embryos in utero have the potential to make complex trade-offs among birthdate, offspring phenotype and future reproduction.

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“…In reptiles, maternal effects have been found to have a substantial influence on offspring phenotype (Shine and Downes 1999). Hence the interaction between offspring phenotype and survival will be the result of both the offspring's genotype and its maternal environment.…”

Section: Outbreeding Depression?mentioning

confidence: 99%

Mate Choice, Genetic Incompatibility, and Outbreeding in the Ornate Dragon Lizard, Ctenophorus Ornatus

LeBas

2002

Evolution

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Abstract. There has been recent interest in the role genetic incompatibility may play in mate or sperm choice. One source of incompatibility may be too similar or disparate genomes. An isolated population of the ornate dragon lizard, Ctenophorus ornatus, was followed over a breeding season and parentage assigned to the offspring using microsatellites. It was found that the adults in the population had an eight per cent chance of mating with a relative. I examined whether C. ornatus mate (or fertilize their eggs) with respect to genetic similarity. There was no difference in a female's relatedness to the male in whose territory she resided and her average relatedness to all other males. Neither was there a difference in the relatedness of the male that sired a female's offspring and the female's average relatedness to all other males. There was no evidence of a cost to mating with a more genetically similar mate, because offspring survival was not influenced by degree of inbreeding or outbreeding. However, females that were more outbred had fewer offspring survive. In this small population there are two possible explanations for the decreased fitness associated with outbreeding. First, the species may have an evolutionary history of inbreeding and thus may be susceptible to outbreeding depression. Second, as fitter individuals produce more offspring, these offspring have an increased probability of breeding with relatives, leading to an indirect relationship between fitness and outbreeding.

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Can pregnant lizards adjust their offspring phenotypes to environmental conditions?

Cited by 144 publications

References 42 publications

Juvenile exposure to predator cues induces a larger egg size in fish

Juvenile exposure to predator cues induces a larger egg size in fish

Maternal basking regime has complex implications for birthdate and offspring phenotype in a nocturnally foraging, viviparous gecko

Mate Choice, Genetic Incompatibility, and Outbreeding in the Ornate Dragon Lizard, Ctenophorus Ornatus

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