Regression of dark color in subterranean fishes involves multiple mechanisms: response to hormones and neurotransmitters

Autor(es)

Renato Grotta Grempel ^[1] ; Eleonora Trajano ^[2] ; Maria Aparecida Visconti ^[3]

Afiliação do(s) autor(es)

^[1] Universidade de São Paulo. Instituto de Biociências. Departamento de Fisiologia - Brasil

^[2] Universidade de São Paulo. Instituto de Biociências. Departamento de Zoologia - Brasil

^[3] Universidade de São Paulo. Instituto de Biociências. Departamento de Fisiologia - Brasil

• Tipo de documento: Artigo Científico
• Fonte: Neotropical Ichthyology; v. 18, n. 2 2020-06-26.

Resumo

ABSTRACT Organisms with source-populations restricted to the subterranean biotope (troglobites) are excellent models for comparative evolutionary studies, due to their specialization to permanent absence of light. Eye and dark pigment regression are characteristics of most troglobites. In spite of the advance in knowledge on the mechanisms behind eye regression in cave fishes, very little is known about pigmentation changes. Studies were focused on three species of the genus Pimelodella. Exemplars of the troglobitic P. spelaea and P. kronei were compared with the epigean (surface) P. transitoria, putative sister-species of the latter. Melanophore areas and densities are significantly lower in the troglobitic species. Evaluating the in vitro response of these cells to adrenaline, acetylcholine and MCH, we observed a reduced response in both troglobites to adrenaline. The same trend was observed with MCH, but not statistically significant. No response to acetilcholine was detected in all the three. Contrary to expectations, even though eye-regression in P. spelaea was much lower than in P. kronei, pigmentation regression was more advanced. Multiple mechanisms of loss showing a mosaic of traits in troglobitic fishes are discussed here. (AU)

• Processo FAPESP: 08/51593-3 - Transicao epigea/hipogea de pimelodella spp. (siluriformes: heptapteridae): fisiologia da pigmentacao
• Beneficiário: Renato Grotta Grempel
• Modalidade de apoio: Bolsas no Brasil - Mestrado