Stylophthalmine trait

The stylophthalmine trait is a trait used by the larvae of a few ray-finned fishes. The fish will develop elliptically shaped eyes found in long peduncles. This trait has been developed twice in the families Myctophidae (in species of Myctophum and Symbolophorus), Stomiidae (genus Idiacanthus), and Bathylagidae (Bathylagus).

Larva of a ribbon sawtail fish. It is demonstrating the stylophthalmine trait.

Three species with this trait were placed in the genus Stylophthalmus. Now, that genus is disputed.

References

1. King, D. (2014). "Looking through the deep - The Stylophthalmines and their amazing eyestalks". Life Nature Magazine. pp. 18-19.