Brett Smith for redOrbit.com – Your Universe Online
According to a report in the Journal of Fish Biology,“¯American marine biologists discovered the first ever two-headed bull shark last year in the Gulf of Mexico. Different from conjoined twins whose bodies are connected in utero, the phenomenon known as dicephalia has previously been observed in other marine species such as blue or tope sharks.
“This is certainly one of those interesting and rarely detected phenomena,” said report co-author Michael Wagner, assistant professor of fisheries and wildlife at Michigan State University. “It´s good that we have this documented as part of the world´s natural history, but we´d certainly have to find many more before we could draw any conclusions about what caused this.”
Creatures with dicephalia often die quickly after birth, making their discovery extremely rare. The researchers were fortunate that a fisherman found the two-headed shark after opening the uterus of an adult shark he had caught.
“You´ll see many more cases of two-headed lizards and snakes,” Wagner said. “That´s because those organisms are often bred in captivity, and the breeders are more likely to observe the anomalies.”
According to Wagner, the two-headed shark would have never survived in the wild and it died very quickly after being discovered. He added that the shark´s body development suffered from the amount of energy that growing and maintaining two heads demands.
“It had very developed heads, but a very stunted body,” he told OurAmazingPlanet.
After transporting the shark to Wagner´s lab back at Michigan State, the marine biologist and his team were able to use magnetic resonance imaging (MRI) scanners to examine the anomalous shark in greater detail. The images revealed that the shark had two distinct heads, hearts and stomachs. The dual physiologies joined together in the back half of the animal and terminated in a single tail.
Wagner cautioned against hastily attributing the shark´s abnormal physiology to pollution in order to further a conservation agenda.
“Given the timing of the shark´s discovery with the Deepwater Horizon oil spill, I could see how some people may want to jump to conclusions,” Wagner said. “Making that leap is unwarranted. We simply have no evidence to support that cause or any other.”
Despite Wagner´s assertion, there have been many reports linking deformed creatures in the Gulf of Mexico to the Deep Water Horizon accident in 2010. Last year, Al Jazeera reported that the oil and chemical dispersants that were used to clean up the oil spill were causing mutations such as eyeless shrimp and clawless crabs.
“Disturbingly, not only do the shrimp lack eyes, they even lack eye sockets,” Louisiana commercial fisher Tracy Kuhn told the Arab news network.
“Some shrimpers are catching these out in the open Gulf [of Mexico],” she added, “They are also catching them in Alabama and Mississippi. We are also finding eyeless crabs, crabs with their shells soft instead of hard, full grown crabs that are one-fifth their normal size, clawless crabs, and crabs with shells that don’t have their usual spikes “¦ they look like they’ve been burned off by chemicals.”
Besides potentially causing widespread mutations, the fishing industry has also reported a significant drop in productivity since the spill.
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