A whale-watching guide struck white gold last month when he encountered a rare, albino gray whale breaching off the west coast of Baja California, Mexico.

Footage of the whale, which tour guide and scuba instructor Manuel Gonzalez posted to Facebook in March, has drawn comparisons to Moby Dick, the white whale of literary legend described by Herman Melville in 1851. Unlike Moby, who was a gargantuan sperm whale with an appetite for New England mariner limbs, the gray whale recorded here was probably just chilling in the area for its annual mating season.

Likewise, the whiteness of this whale is not some overwrought metaphor — it's just genetics. [The 10 Weirdest Medical Cases in the Animal Kingdom]

Albinism is a genetic abnormality caused by an absence of the skin pigment melanin, which is responsible for dark coloration in hair, skin and fur. The condition is considered rare in most animals, though it has been observed in many different species, including zebras, snakes, gorillas and dolphins.

Years, before, in 2003, a different crew had seen a "pure-white whale calf" that may have been Milk Gallon as a baby; however, there is no photographic evidence to back this up, according to a 2017 report in the journal Aquatic Mammals.

Scientists haven't said yet whether this latest sighting is of Milk Gallon.

The Pink and White Album: Amazing Albino AnimalsWhale Album: Giants of the DeepImages: Sharks and Whales from AboveOriginally published on Live Science.