This bomb-dropping worm, Swima bombiviridis, is among the top 10 species discovered in 2009, according to the International Institute for Species Exploration at Arizona State University. The annual roundup winnows down a list of about 20,000 species described each year to just a few mind-benders.
"It is a great way of getting the public involved in biodiversity," says Mary Liz Jameson, a biodiversity scientist at Wichita State University and chair of this year's selection committee. While the criteria for selection include scientific significance, Jameson admits that "the cool factor" also plays a part.
For example, the bomb-dropping worm found off the coast of California "has these green gills it can kind of throw off, and the predator will follow the gill instead of following the [worm], so it is tripping up the predator," Jameson said. "It's really cool."
Click ahead to see the other cool species on the top-10 list.
The cool factor of the giant pitcher plant from the Philippine island of Palawan is pretty obvious: Rodents and insects that fall into the football-sized "pitcher" can be trapped and slowly consumed by the plant's enzymes. Yup, it's a plant that eats rats.
What's more, the plant, dubbed Nepenthes attenboroughii, is named after Sir David Attenborough, a British TV naturalist who is a patron of Philippine conservation efforts. The plant is known only from a single locality and is "critically endangered," notes Jameson.
Weird Malagasy yam
An edible yam from Madagascar, Dioscorea orangeana, made the list for what researchers called its "weird" factor. Unlike other yams from the African island nation, it has several digital lobes instead of just one.
Conservation of the yam is a concern since it is known only from a 1.7-square-kilometer (0.7-square-mile) area that is unprotected, according to Britain's Kew Royal Botanical Gardens. where one of the discovery team members works.
A new type of sea slug discovered in Pak Phanang Bay in the Gulf of Thailand is unusual because it eats insects. Most other sea slugs, known as sacoglossans, eat algae. A few specialize in the eggs of snails and slugs.
The slug, Aiteng ater, was named after a popular puppet in the southern part of Thailand.
A frogfish with forward-facing eyes and a psychedelic skin pattern that could spark flashbacks to a trippy Grateful Dead show made the list, from Jameson's perspective, because it's "an absolutely gorgeous animal and here it is being described in 2009. You'd think that something that is that outstandingly beautiful would have been discovered before now."
The psychedelic frogfish, Histiophryne psychedelica, is found in Indonesian waters. Scientists said its colorful pattern may help it blend in with the venomous corals of its surroundings, offering it protection from predators.
Spider casts a wide web
A golden orb spider that likely casts some of the widest webs known high up in the forests of South Africa is the first new species to be described in its family since 1879.
Called Nephilia komaci, the spider has not actually been seen alive. Rather, scientists described it from museum specimens and more recently dead specimens found at the Tembe Elephant Park.
Nevertheless, scientists believe it is just a hair bigger than other Nephilia species, which are known for their largesse. The females of the new species have a body length of 1.5 inches and a leg span of 4 to 5 inches.
Males are a fraction of the size; their only role in life is to inseminate females — a task, in this case, where being big really doesn't matter.
The phallic mushroom
Herpetologist Robert Drewes at the California Academy of Sciences is reportedly thrilled to have a 2-inch-long, penis-shaped mushroom from the African island nation of Sao Tome and Principe named in his honor, Phallus drewesii.
"He wasn't offended by it," says Jameson. "I mean, wouldn't it be cool to have a new species named after you?"
Drewes initiated extensive biodiversity studies on Sao Tome and Principe and dedicated more than 30 years of his life to research in Africa. The shroom's discoverers said they named Phallus drewesii after Drewes because of that dedication.
A fanged fish
In this age of vampire hysteria, a minnow with toothlike fangs is a shoo-in for a top 10 list.
The translucent Dracula minnow, Danionella dracula, is a member of the Cyprininform group of fish, most of which lost their teeth about 50 million years ago. Males of the Dracula minnow species, however, re-evolved fanglike structures that protrude from the jaw bone.
The freshwater minnow was discovered in Myanmar. Scientists say the males use their fangs for sparring with each other. Females lack the vampiresque structures.
A model fish gets its own name
Scientists have used this electric fish species for several decades to study the physiology of electric organs and how fish use electricity to communicate, but referred to it in the scientific literature as Gymnotus carapo. But the fish are actually members of a separate species, incorrectly lumped together with G. carapo.
A team of neurophysiologists in Uruguay realized the mistake in 2009 and named the species Gymnotus omarorum, after pioneers in the study of electrogenesis, Omar Macadar and Omar Trujillo-Cenoz.
"This highlights how little we know about biodiversity when a 'model organism' can remain undescribed for 30 years," Jameson and her fellow committee members say.
The killer sponge
Most sea sponges are similar to their kitchen sink namesakes — happy to survive on bits of plant matter and bacteria that filter their way. In the dark depths of the sea, however, some sponges eat meat. A newly discovered carnivorous sponge, Chondrocladia (Meliiderma) turbiformis, rounds out the top 10.
This sponge from a seamount off New Zealand has a unique spicule that spurred its discoverers to coin the new term "trochirhabd." Similar structures are known only from Early Jurassic fossils, roughly 175 million to 200 million years ago. That suggests that carnivorous sponges have a deep history.