#mannerhead sharks

[bitch-dont-krill-my-vibe]

Weird Fact of the Day:  Bonnethead sharks are the only shark species which displays sexual dimorphism of the head (different appearance between sexes).

Males (right) have a prominent bulge along the front of the cephalofoil, whereas females (left) have a broadly rounded head.

NOTE:  Sexual dimorphism refers to different characteristics between sexes, and Cephalofoil refers to the outward extensions of the shark’s head that make up the “hammer”.

References: Kajiura, S.M., Tyminski, J.P., Forni, J.B. and Summers, A.P., 2005. The sexually dimorphic cephalofoil of bonnethead sharks, Sphyrna tiburo. The Biological Bulletin, 209(1), pp.1-5.

Photo from http://www.science.fau.edu/sharklab/pages/sexual_dimorphism_res.html