Cranial anatomy of the amazing bromeliad tadpoles of Phyllodytes gyrinaethes (Hylidae: Lophyohylini), with comments about other gastromyzophorous larvae

ALTIG, R; HAAS, A; VERA CANDIOTI, MF; PEIXOTO, O

ZOOMORPHOLOGY (BERLIN. PRINT)

SPRINGER

Lugar: Berlin; Año: 2017

0720-213X

The ecomorphological guild ??gastromyzophorous??joins tadpoles that inhabit flowing water andhave an abdominal sucker which is employed to adhere tosubstrates. Historically, gastromyzophorous larvae wereknown in the Bufonidae and Ranidae, but a new suckerbearinghylid tadpole was recently described from phytotelmonsin Brazilian forests. We describe the larvalinternal anatomy of Phyllodytes gyrinaethes and ask whetherits exceptional external morphology is accompanied byderived anatomical internal features that can be related to thespecial habitat. We also compare it to the anatomy of suckerbearingtadpoles from other families with a focus on charactersexclusive of each lineage and the shared, convergentfeatures. The skeleton of P. gyrinaethes is highly modifiedrelative to that of pond-type hylines and shows a profoundrestructuring of the oral region, palatoquadrates, and thebranchial baskets. Among the muscles, besides the overallreduction in the branchial musculature, the most unusualfeature in this species are the enormous, anteriorly orientedmm. levatores mandibulae externus profundus that likelyproduce the abduction of the two halves of the snout. Thepresence of the abdominal sucker is coupled with changes insome muscle trajectories and hypertrophy of the subhyoidligaments, and the sucker connectivity differs in someaspects compared with those of bufonids and ranids (e.g., thepresence of massive mm. diaphragmatopraecordialis parallelto the sucker plane). P. gyrinaethes tadpoles, with theircombination of both rare and unique morphological featuresplus their confined microhabitat with exceptional functionaland ecological requirements, represent an extreme morphotypewithin Hylidae and anuran tadpoles in general.