ABSTRACT

Chiasmocleis is the most species-rich New World microhylid genus. Among Atlantic Forest species in the genus, C. alagoana has the northernmost distribution. The species was described two decades ago; however, little is known about its natural history. Herein, we provide information on its reproductive biology, advertisement call, and external morphology based on specimens from the type locality and the type series. Reproduction occurs in the rainy season but only on days with torrential rains. The advertisement call consists of a series of pulsed notes common for most species of the genus. Structurally, each note consists of two groups of distinct pulses with amplitude modulations. This call structure is a candidate of synapomorphy for a subclade of the genus consisting of C. alagoana, C. cordeiroi, C. crucis, and C. schubarti. Morphologically, the species exhibit sexual dimorphism with females being larger and twice heavier than males. Both sexes have fringes on fingers and toes. Moreover, we report the presence of dermal spines over the body and webbing on feet in males and include these characters in an update diagnosis of the species.

摘要

Chiasmocleis 是物种最丰富的新大陆小水螅属。在该属的大西洋森林物种中，C. alagoana分布最北端。该物种是在二十年前描述的；然而，人们对其自然历史知之甚少。在此，我们根据来自模式产地和模式系列的标本，提供有关其生殖生物学、广告呼叫和外部形态的信息。繁殖发生在雨季，但仅限于暴雨的日子。广告呼叫由大多数该属物种常见的一系列脉冲音符组成。在结构上，每个音符由两组具有幅度调制的不同脉冲组成。这种调用结构是该属的一个亚进化枝的突触候选物，包括C. alagoana、C. cordeiroi、C. crucis和C. schubarti。在形态上，该物种表现出两性异形性，雌性比雄性大，重两倍。两性的手指和脚趾都有条纹。此外，我们报告了男性身体上存在真皮刺和足部织带，并将这些特征包括在对该物种的更新诊断中。