Rare Blue Darwin's Frog Discovered in Chilean Patagonia, Raising Biological Questions
A rare blue Darwin's frog (Rhinoderma darwinii) has been observed in Chile's Aysen Region, specifically within the Melimoyu reserve. This unusual specimen, a male measuring 27.01 millimeters and weighing 1.83 grams, was discovered by photographer and environmental educator Jaime Beltrand during fieldwork. The striking blue coloration is particularly noteworthy as Darwin's frogs are typically green and brown. This is the first time such a pronounced blue hue has been recorded in the area despite over a decade of monitoring. The frog was also found carrying approximately four larvae in its vocal sac, a unique reproductive behavior where males nurture developing larvae internally. Researchers, including Andres Valenzuela, president of the Darwin's Frog NGO, suggest the unusual color may stem from changes in skin pigments, possibly a reduction in yellow pigmentation that reveals underlying blue tones. The specimen still exhibits some green areas, indicating a potentially incomplete loss of yellow pigment. 
