Conjoined gray whale calves discovered off the coast of Mexico

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Lisa Winter

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227 Conjoined gray whale calves discovered off the coast of Mexico
Jesús Gómez/Guerrero Negro Verde

Mexican researchers have discovered conjoined gray whale twins in Laguna Ojo de Liebre, which is just off the Pacific Ocean, near Baja California Sur. Twinning is a rare occurrence in whales, and conjoined twins are even more exceptional. This is likely the first case of conjoined gray whales on record, though there have been limited descriptions of conjoined twins in other whale species. The announcement was first made on the Facebook page of Guerrero Negro Verde, a page dedicated to environmental affairs of the region. 

Sadly, the whale calves appear to be the product of a miscarriage and were delivered prematurely. Experts note that they were extremely underdeveloped and were only about 7 feet (2.1 meters) long, whereas healthy newborn gray whale calves are typically 13 feet (4 meters) long. No information is known about the mother, though many are wondering how she could have safely delivered out the miscarried calves, given their odd shape.


Gray whales are migratory. During the summer months, they are up in the Arctic waters of the Chukchi and Bering Seas in order to feed on crustaceans. They then migrate roughly 6,000 miles (9650 km) in order to mate in the warm waters near Mexico during the winter months. The next winter, the whales return to this area in order to give birth. Laguna Ojo de Liebre is an ideal place for newborn calves, as they are protected from predators like sharks and orcas.

The whales were conjoined at the midsection and had two heads and two tails. Because they were already deceased upon discovery, the calves were collected and will be studied. There is currently no indication that this was caused by radiation or pollution of any kind, and instead is just a sad biological anomaly. 



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  • gray whales,

  • whales,

  • twins,

  • conjoined twins