Aliya Spinner
Pronouns: she/him
Research Mentor(s): Roberto Marquez Pizano
Research Mentor School/College/Department: /
Program: RS
Session: Session 5 (2:40pm – 3:30pm)
Authors:
Abstract
Phylobates is a diverse genus of poison dart frog indigenous to the Amazon rainforest. Species and subspecies of this genus are so abundant that oftentimes, different species dominate adjacent square-mile patches of rainforest, or opposing sides of small rivers. Also interesting about Phylobates is that many members of the genus undergo a drastic change in pigmentation throughout their adult lives, from solid black froglets to the vibrant colors associated with poison dart frogs. The four species that we studied, in particular, either developed solid, full-body color, or a bright pair of dorsal lateral stripes on an otherwise black epidermis. In 1972, Taylor and Bagnara took revolutionary pictures through an electron microscope that laid the ground for their theory that this pigment change during maturation may be due to the rearrangement of different cell layers in the dermis of the frog’s skin. Especially, Taylor and Bagnara emphasized the importance of melanophores beneath and crystalline iridophore layers. Their images implied that these underlying melanophores grew “tentacles†that covered the color-creating crystal iridophores, disguising the frog as black. These tendrils were theorized to then withdraw with age, revealing the pigment layers underneath. However, little further research has been done since those original photographs were taken, and therefore we do not have much understanding of the mechanisms driving this change, nor any evidence that all species of Phylobates share the same mechanism for pigment changes during maturation. In this investigation, we used an electron microscope to photograph the dermis layers of four species of Phylobates frogs in various stages of development. This allowed us to properly visualize the mechanisms behind coloration for possibly the first time ever in the research of these animals.
