Comparison of 3.5-day-old embryos with mutations affecting the pectoral fins. (A,B) Frontal views, (C-I) dorsal views. Wild type (A) and leprechaun (B) mutant embryos showing the increase in pectoral fin size. (C) Wild-type pectoral fins. Both mutations in ikarus (D) and sonic you (E) lead to a variable reduction in the size of the pectoral fins; in D an ika mutant with a clear difference in size between left and right pectoral fin is shown. (F) In dackel mutants pectoral fins are almost invisible at this stage (arrow). (G) Boxer mutants have reduced pectoral fins. The distal parts of the pectoral fins seem to be more affected than the proximal part and show signs of degeneration. This is not observed in ika and syu mutants. (H) Mutant krom embryo showing variably bent pectoral fins. (I) stomp mutant embryo with a degenerating pectoral fin fold.