Sperm Whale (Physeter macrocephalus) Adult fluke-up dive at sunset in Mid-riff region of the Gulf of California (Sea of Cortez), Mexico. (rr)

Sperm Whale (Physeter macrocephalus) Woman measures (98) the lower right mandible (jawbone) of an adult bull Sperm Whale, in the mid-riff region of the Gulf of California (Sea of Cortez), Mexico. Model released.

Sperm Whale (Physeter macrocephalus) Assorted teeth from lower jaws of beached Sperm Whales in the mid-riff region of the Gulf of California (Sea of Cortez), Mexico.

Sperm Whale (Physeter macrocephalus) surfacing (note blowhole detail, left side and forward on head. This is the species field diagnostic in the mid-riff region of the Gulf of California (Sea of Cortez), Mexico.

Sub-adult Sperm Whale, Physeter macrocephalus, spy-hopping in northern Gulf of California, Mexico