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) 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) 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.

Sub-adult Humpback Whale, Megaptera novaeangliae, breaching in northern Gulf of California, Mexico

Sub-adult Humpback Whale, Megaptera novaeangliae, surface lunge-feeding on krill in northern Gulf of California, Mexico

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.

Sperm Whale, Physeter macrocephalus, sub-adult and curious in the northern Gulf of California, Mexico