Stehouwer D J
Department of Psychology, University of Florida, Gainesville 32611.
Dev Psychobiol. 1988 May;21(4):383-95. doi: 10.1002/dev.420210409.
This study describes the development of different spontaneous and elicited behaviors of frogs and their relationship to morphological, physiological, and ecological changes of metamorphosis. Tadpoles were studied at all stages of development from Stage XVIII, the onset of metamorphosis, to Stage XXV, when metamorphosis of the froglets is complete. Behaviors examined included development of forelimb postural support, postural responses to vestibular stimulation, the hindlimb withdrawal reflex, the corneal reflex, ocular mobility, and habitat preference. Results showed that these behaviors differ markedly in their timing and rate of maturation. Forelimb postural support and postural responses to vestibular stimulation improved gradually between Stages XX and XXV. In contrast, the threshold of the hindlimb withdrawal reflex remained essentially unchanged until Stage XXV, when it increased suddenly and dramatically. The corneal reflex appeared suddenly at Stage XXI with a threshold similar to that of juvenile frogs. The ability to move the eyes in response to visual or vestibular stimulation was pronounced in tadpoles, but gradually declined between Stage XVIII and Stage XXV, so that froglets showed almost no ocular mobility. The preference of metamorphosing frogs for deep water, shallow water, shoreline, or land were examined in an aquarium during a 24-hr observation period using time-lapse videotape recordings. Results showed that tadpoles spent progressively less time in deep water and shallow water as metamorphosis proceeded. Preference for land emerged suddenly at Stage XXII and remained high thereafter. There were no stage-related differences in preferences for the shoreline.
本研究描述了青蛙不同自发行为和诱发行为的发展过程，以及它们与变态发育过程中的形态、生理和生态变化之间的关系。从变态发育开始的第十八阶段到幼蛙变态完成的第二十五阶段，研究了蝌蚪发育的各个阶段。所研究的行为包括前肢姿势支撑的发展、对前庭刺激的姿势反应、后肢退缩反射、角膜反射、眼球活动能力以及栖息地偏好。结果表明，这些行为在成熟时间和速率上有显著差异。前肢姿势支撑和对前庭刺激的姿势反应在第二十阶段到第二十五阶段之间逐渐改善。相比之下，后肢退缩反射的阈值在第二十五阶段之前基本保持不变，到该阶段时突然大幅增加。角膜反射在第二十一阶段突然出现，其阈值与幼蛙相似。蝌蚪对视觉或前庭刺激作出眼球活动的能力很明显，但在第十八阶段到第二十五阶段之间逐渐下降，以至于幼蛙几乎没有眼球活动能力。在一个水族箱中，通过延时录像记录，在24小时观察期内研究了变态发育中的青蛙对深水、浅水、海岸线或陆地的偏好。结果表明，随着变态发育的进行，蝌蚪在深水和浅水中停留的时间逐渐减少。对陆地的偏好在第二十二阶段突然出现，此后一直很高。对海岸线的偏好没有与阶段相关的差异。
