SANTA BARBARA, Calif., July 4 (UPI) -- Tiny new species of octopi, each smaller than a quarter, have been discovered among previously overlooked jars in museum archives.
These itty-bitty critters, each weighing tenths of a gram, appear to live in tropical regions all over the world, from Mexico to the Philippines. They have scientists internationally reexamining everything they know about octopi.
"In the past, these animals were just assumed to be babies and often thrown in a jar and not looked at, if picked up at all," Eric Hochberg of the Santa Barbara Museum of Natural History told United Press International. "We're only beginning to discover that they're out there. There's a lot we still don't know, and we're trying to get a handle on what this all means."
Hochberg and his colleagues found the octopi by accident during a study of octopus diversity among his museum's collection. "I thought I knew the fauna fairly well until we tried to identify these very tiny animals. Typically you don't cut those animals if you think they're juveniles, but when we did we found they were fully mature," he explained.
The drab-colored animals probably are not venomous like their dangerous, brightly colored relative, the blue ring octopus, Hochberg said. Although scientists know little about the pygmy octopi's feeding habits, Hochberg said he believes they are predators that often live in crevices and feed on tiny crustaceans or snails. They probably are solitary, although some male and female pairs may share dens.
Hochberg and his colleagues in Paris and Australia are having difficulty classifying the octopi as parts of pre-existing octopus families, or genera, or new families of their own.
"An awful lot of those genera depend on color patterns, textures, traits that would be evident in live animals. And in many cases we haven't seen these animals live, we're seeing them in our collections, not in the sea or aquaria," Hochberg explained.
Classifying them by their internal features is also problematic because the animals are so tiny, making dissection difficult. "We're trying to get material available for DNA analysis," Hochberg said. He believes they are probably looking at least a dozen new species, however.
As soon as the researchers gather more information, they plan on presenting their findings at a symposium next year in Thailand that will focus cephalopods such as octopi and squid.
"This is all really extremely interesting," said marine zoologist Sigurd von Boletzky, with the National Center for Scientific Research in Banyuls sur Mer, France. Boletzky, who works extensively with pygmy squid, suggests the researchers should try to determine the octopi's life cycle, which in the 1.5 centimeter-long pygmy squid is extremely short.
"The typical lifespan of an average-sized octopus is a year to a year-and-a-half, Boletzky said. "As an educated guess, I would say these pygmy octopi live on the range of four to six months, but they may go as low as three months."
(Reported by Charles Choi, UPI Science News, in New York.)