Fig. 1.

Cavefish are adapted to nutrient-poor environments. (A) Percentage of weight loss after a 2-mo fast. Eleven to 13 fish per population were used. Each cave population was significantly different from the surface population. ***P < 0.0001 (Tukey HSD test). (B) Total triglyceride content/protein in adult (>1-y-old) fish. Each population was significantly different from one another. *P < 0.05 (Tukey HSD test). (C) Pictomicrograph of livers. (Scale bars: 2 mm.) (D) Oil red O staining of liver sections. (Scale bars: 250 μm.) Red symbols (Pachón, Tinaja, and Molino) represent cavefish, and blue symbols represent surface fish. M, Molino; P, Pachón; S, surface; T, Tinaja.