Fig. 2
From: Comparing growth in surface and cave morphs of the species Astyanax mexicanus: insights from scales

Analyzing scales of Astyanax mexicanus. a–d Photographs of scales of surface fish from Rio Gallinas (left) and from cavefish from the Pachón cave (right). Examples are given for 3-year-old (top) and 5-year-old (bottom) individuals. Annual growth marks are indicated by the red ladder. Scale bar: 0.5 mm. e Correlation between age reads from scales and from otoliths for n = 33 surface fish individuals. f Boxplots showing the scale size/body length (TL) ratios of different A. mexicanus populations. The color code is indicated. *p < 0.05 and ***p < 0.0001, Mann–Whitney tests