The Adaptive Significance Of The Maternal Care In Plestiodon Chinensis

Parental care is defined as any behavioral investment by the parent to increase the fitness of assisted offspring. To explore the pattern and evolutionary causes of parental care is crucial for a better understanding of the core theories of behavior and life history evolution including sexual selection, mother-offspring conflict and reproductive costs. Though being a hot topic in current evolutionary and behavioral ecology and having received considerable scientific attention, the evolutionary cause and adaptive significance of parental care are still far from well known, primarily due to the paucity of comparable data. Some species of lizards display diverse forms of parental care, and are considered as the ideal objects to study the evolution of parental care. We used Plestiodon chinensis for the study object, observeing the behavior of parent caring and analyzing the cost for offsprings and itself. Through controling experiment for Plestiodon chinensis parent, we divided into four grops: No reproduction individuals, normal breeding(complete nest eggs after breeding), and remove eggs after spawning and remove the parent after spawning. Then analyze the impact of the parent care for hatchability, hatchling athletic ability, offspring survival rate and growth. Analyze the maternal investment by the time of parent out of the nest and through the maternal body mass and physical condition to analyze the changes in the cost of their breeding. The main results are as following:1. The clutch size is positively correlated with the materal snout-vent length, the correlation of hatchling wet mass and materal snout-vent length is not significant. Also there is no significant difference for the hatchling phenotype;2. The maternal care increases the hatchability and the survival rate of the hatchlings, but there is no significant effect on exercise capacity and the growth of the hatchlings;3. The parent does not go out of the nest after breeding. There is no significant difference between the individuals which do not breed. Meanwhile, there is no difference of the time between the parents who have been removed eggs and the ones before breeding or the ones do not breed.4. Maternal care does not have a significant impact on maternal body mass and physical condition.