Figure 6.

Galr2 receptor inhibition reduced Meckel's cartilage length in both specialists and increased chondrocyte density in scale-eaters. (a) Galr2 and Galr1 + 2 inhibition protocol during pupfish development. C. desquamator embryos are depicted. (b) Alcian blue cartilage staining at Stage 32–33. IOD: interocular distance, MC: Meckel's cartilage. The MC length and IOD are shown in red. (c) Chondrocytes at the symphysis. (d) Changes in the log-transformed Meckel's length and the log-transformed interocular distance at stage 32–33 across species and treatments. (e) Chondrocyte numbers at the symphysis across species and treatments. *p < 0.05, **p < 0.01, ***p < 0.001 Tukey's HSD test. f. Representative control and treated larvae of each species at stage 32–33. Arrows point to abnormal lower jaws. M: molluscivores, G: generalist, S: scale-eaters. Scale-bars = 0.4 mm. Galr1 and Galr2 cartoons were modified from [85].