Sperm Whale (Physeter macrocephalus) Sub-adult surfacing (note the peeling skin) Near Islam San Pedro Martir in the midriff region of the Gulf of California (Sea of Cortez), Mexico. (rr)

Sperm Whale (Physeter macrocephalus) Young spy-hopping (note the sloughing skin) Mid-riff region of the Gulf of California (Sea of Cortez), Mexico.

Sperm Whale (Physeter macrocephalus) Eight-inch tooth from lower right mandible (jawbone) of an adult bull 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.

Sperm Whale (Physeter macrocephalus) Woman with an eight-inch tooth from 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, calf, vertical underwater in northern Gulf of California, Mexico