Glassfrogs conceal blood in their liver to maintain transparency.

Journal Article (Journal Article)

Transparency in animals is a complex form of camouflage involving mechanisms that reduce light scattering and absorption throughout the organism. In vertebrates, attaining transparency is difficult because their circulatory system is full of red blood cells (RBCs) that strongly attenuate light. Here, we document how glassfrogs overcome this challenge by concealing these cells from view. Using photoacoustic imaging to track RBCs in vivo, we show that resting glassfrogs increase transparency two- to threefold by removing ~89% of their RBCs from circulation and packing them within their liver. Vertebrate transparency thus requires both see-through tissues and active mechanisms that "clear" respiratory pigments from these tissues. Furthermore, glassfrogs' ability to regulate the location, density, and packing of RBCs without clotting offers insight in metabolic, hemodynamic, and blood-clot research.

Full Text

Duke Authors

Cited Authors

  • Taboada, C; Delia, J; Chen, M; Ma, C; Peng, X; Zhu, X; Jiang, L; Vu, T; Zhou, Q; Yao, J; O'Connell, L; Johnsen, S

Published Date

  • December 2022

Published In

Volume / Issue

  • 378 / 6626

Start / End Page

  • 1315 - 1320

PubMed ID

  • 36548427

Pubmed Central ID

  • PMC9984244

Electronic International Standard Serial Number (EISSN)

  • 1095-9203

International Standard Serial Number (ISSN)

  • 0036-8075

Digital Object Identifier (DOI)

  • 10.1126/science.abl6620


  • eng