An octopus (octopus vulgaris) lifts one of its tentacles in his bassin at the zoo in Basel, Switzerland
What is killing the octopus of Vila Nova de Gaia? That question has obsessed the Portuguese city, located just across the Douro river from Porto, since Jan. 2, when 1,100 lbs. (500 kg) of dead octopus were found on a 1.8-mile (3 km) stretch of local beach.
- The following day, another 110 lbs (50 kg) appeared; today there was just one expired creature. "It's very strange that so many should be killed, and in such a confined area," says Nuno Oliveira, director of the Gaia Biological Park, a nature refuge on the outskirts of Vila Nova de Gaia. "There's nothing in the scientific literature for this kind of mass mortality among octopus."
- Twelve hundred pounds is a lot of dead cephalopod, especially when no one seems to know for sure what killed them. Local biologists have ruled out pollution or contamination because no other species were affected.
- And although some suggest that perhaps a boat, illegally fishing the multilegged creatures, threw them overboard in a panicked attempt to avoid detection, that possibility also seems unlikely. "The sea has been very rough," says Oliveira. "No one has been out fishing for days."
Gulf of California
Number remaining: 200 to 300
One of the rarest cetaceans in the world, the Vaquita is endangered by both its limited range and the ease with which it gets caught in fishing nets.
Sumatra, in Indonesia
Number remaining: fewer than 600
This small tiger has lived only in Sumatra for a million years, making it hard to escape human expansion. Most survivors dwell in reserves, but about 100 live beyond the borders of the protected areas.
Cross River Gorilla
Nigeria and Cameroon
Number remaining: fewer than 300
Thought to be extinct in the 1980s, the species is holding on, for now. Hunted for bush meat and crowded out by development, it may not last long.
Indonesia and Vietnam
Number remaining: fewer than 60
Perhaps the planet's rarest large mammal. Its horn is prized by poachers, and its forests are prized by developers. Both could spell doom for the species.
The circumpolar Arctic
Number remaining: fewer than 25,000
Human development and poaching have long threatened the polar bear, but climate change and the loss of sea ice are now pushing it onto the critical list.
Mekong Giant Catfish
Mekong region of Southeast Asia
Number remaining: hundreds
Prized for its enormous size (the largest ever caught was 646 lb., or 293 kg), it is now protected in Thailand, Laos and Cambodia, but fishing goes on.
Number remaining: fewer than 70
All but wiped out, this primate was placed under protection in 2000. It is still in grave danger, but in 2003 its numbers rose for the first time in decades.
China, Burma, Vietnam
Number remaining: fewer than 2,000
Loss and fragmentation of habitat are to blame for the panda's perilous state. Captive breeding and species protection are helping the panda hang on—barely.
Borneo Pygmy Elephant
Number remaining: about 1,500
Shorter than the Asian elephant by about 20 in. (50 cm), the Borneo pygmy elephant is also more docile. Palm plantations have reduced its range, leaving it crowded for space
North American Great Plains
Number remaining: about 1,000
The continent's only native ferret is one of its most endangered mammals. In 1986, there were only 18 individuals left, but the species is clawing back.