It was in early January 2014 that scientists found a monster of the deep in the shallow waters of Laguna Ojo de Liebre. This lagoon is on Mexico’s Pacific coast, in the northwest of the Mexican province of Baja California Sur. Laguna Ojo de Liebre – “eye of the hare lagoon” – is part of the Vizcaíno Biosphere Reserve, a UNESCO World Heritage Site.
The area, once called Scammon’s Lagoon, and the surrounding waters provide excellent habitats for a wide variety of marine species and waterfowl. For example, harbor seals, blue whales, gray whales and four species of marine turtles are all to be found here. What’s more, many of the animals use these waters as their breeding grounds.
However, this particular creature was entirely unfamiliar. Once experts lifted it out of the water and were able to examine it closely, they realized what it was. Moreover, the animal was so astonishingly rare that there were no known previous scientific records of it.
The experts realized that what they were looking at was a set of gray whale twins that were conjoined. That is to say, as they’d developed in their mother’s womb, the fetuses had fused together, in this case at the stomach. Whether they had been still-born, or had died soon after birth, remains a mystery. It is also unknown if the mother survived the birth.
Although conjoined twins are not unknown in whales, the database of the Natural History Museum of Los Angeles County didn’t turn up any other cases of conjoined gray whale young. However, such twins have been recorded in sei, minke and humpback whales. Jim Dines, the collections manager at the museum, told National Geographic that, “because of their reproductive biology, whales and dolphins almost always have a single baby.”
However, Dines added, “In the case of twins, the mother has to provide nourishment for two growing fetuses. And that may result in two slightly smaller fetuses rather than one normal-sized one. These were pretty sizeable. There’s a fair chance the mother was trying to deliver them and couldn’t.” Given the extreme rarity of conjoined whales, it’s unsurprising that scientists are unable to come to firm conclusions.
Dines went on to say that a normal gray whale pregnancy lasts for about 13.5 months. He estimated that these conjoined babies were probably between 8.5 and 10.5 months old. Moreover, even if these twins had gone to a full-length gestation, he felt that it would have been extremely unlikely that they’d have survived in the wild.
Dines explained that because the twins were joined at the stomach, this would have made it virtually impossible for them to breathe. Like all whales, these animals would have to come to the surface for air. However, being joined at the stomach would mean that their blowholes were pointing to the side instead of upwards. Consequently, they’d be unable to take in the air they needed to survive.
Gray whales are sometimes known as Californian or Pacific gray whales and their scientific name is Eschrichtius robustus. They are a type of baleen whale, which means that they feed by swimming through the sea and filtering out their prey, such as various crustaceans, from the water. The baleen is the filter-like adaptation in the gray whale’s mouth through which it sucks in water.
These magnificent, dark gray creatures can weigh up to 40 tons and grow up to 49 feet in length, with a typical lifespan of between 55 and 70 years. The gray whale lacks a dorsal fin, instead having a back that’s humped and ridged. They generally feed in shallow waters near the shore.
The whales do most of their feeding during the summer months, when they are in chilly northern seas. This enables them to lay down fat reserves for their long journey south. Once the calves are born, they can drink up to a staggering 300 gallons of the mother whale’s milk each day. The milk is a hefty 53 percent fat; human milk, on the other hand, is just 3 to 5 percent fat.
One of the most astonishing things about these gargantuan animals is the huge distances that their annual migrations take them. The eastern Pacific gray whales travel all the way south from the cold waters of the far northern Pacific to the warmer climes off the Californian and Mexican coast. After the winter, they subsequently swim back to the Arctic region. This can mean they’ve made a round trip of around 12,000 miles.
However, it is known that at least one gray whale exceeded the usual 12,000 migration journey. Moreover, in the process they created a record for the world’s longest mammal migration on record. The whale, known as Varvara, was tracked with satellite-monitored tags by Russian and American scientists for six months in 2011 and 2012 as she swam across the Pacific. After her return journey to Russia’s Sakhalin Island from Baja, Mexico, Varvara had covered some 13,760 miles.
The whale that gave birth to the conjoined twins would have travelled south from the feeding grounds it frequents during the summer months in the Bering Sea and Chukchi Sea, which lie between Russia and Alaska. The female whale would have found a partner and bred once it reached the Pacific Sea off California and Mexico. Later, it would calve in the same waters.
One of the best places to see gray whales is the San Ignacio Lagoon in the Gulf of California. There, the animals will actually swim to boats carrying whale watchers. In fact, on occasion they will even allow themselves to be touched. This has earned the whales the local nickname of the “friendly ones.”
The eastern gray whales, the ones that travel each year to the Pacific off California and Mexico, are thriving. Currently, their population is estimated at between 20,000 and 22,000. In contrast, the western gray whales, which scientists believe migrate between the Sea of Okhotsk off the coast of Russia and waters in southern Korea, is considered to be critically endangered. Indeed, the population of this group may be as low as 130.
Furthermore, we have already lost one population of gray whales to extinction. They once inhabited the North Atlantic, but died out there sometime in the 18th century. The reasons for their extinction are unclear, but overfishing could have been the cause. There is even some fossil evidence to indicate that these whales may also have bred and calved in the Mediterranean.
When the conjoined whale twins were discovered in January 2014, it was just three years after the catastrophic tsunami that engulfed the Fukushima nuclear plant in Japan. This led some people to speculate that the underlying reason for this rare conjoined whale phenomenon might be radiation that leaked from the stricken plant.
However, Jim Dines offered words of reassurance. “In the past year or so, when we have marine mammals that strand here in California and we’ve had the tissues tested for radiation, there’s nothing there,” he said. “Just because an animal like a whale has twins, [that] doesn’t mean it’s been subjected to radiation. Humans have twins all the time.”