Chondrocranium and visceral skeleton of Atelopus tricolor and Atelophryniscus chrysophorus tadpoles (Anura, Bufonidae)

Abstract

Atelopus tricolor and Atelophryniscus chrysophorus have gastromyzophorous tadpoles. Aside from specific differences, the larval chondrocrania and visceral skeletons show several shared character states, including an almost quadrangular, open chondrocranium, cornua trabeculae with expanded tips, cartilago suprarostralis as a single element, a posteriorly projected arcus subocularis quadrati, a closed muscular tunnel, and a simplified branchial basket, with only three pairs of ceratobranchiales. They are compared with diverse character states of suctorial larvae considering them as causally related to the stream life adaptations.

Atelopus tricolor and Atelophryniscus chrysophorus have gastromyzophorous tadpoles. Aside from specific differences, the larval chondrocrania and visceral skeletons show several shared character states, including an almost quadrangular, open chondrocranium, cornua trabeculae with expanded tips, cartilago suprarostralis as a single element, a posteriorly projected arcus subocularis quadrati, a closed muscular tunnel, and a simplified branchial basket, with only three pairs of ceratobranchiales. They are compared with diverse character states of suctorial larvae considering them as causally related to the stream life adaptations. Atelopus tricolor y Atelophryniscus chrysophorus poseen larvas gastromizóforas. Dejando de lado las diferencias específicas, los condrocráneos y esqueletos hiobranquiales larvales comparten diversos estados de carácter, incluyendo el condrocráneo cuadrangular y abierto, los cuernos trabeculares con extremos expandidos, el cartílago suprarostral como elemento único, el arco subocular proyectado hacia atrás, el túnel muscular cerrado y la cestilla branquial simplificada, con sólo tres pares de ceratobranquiales. Algunos de estos estados de carácter son comparados con aquellos de larvas suctoras considerados como causalmente relacionados a los hábitats torrentícolas, para una mejor comprensión de de la vida en ambientes de corriente rápida.