A new deep-sea swell shark is one of the hundreds of potentially new species discovered on a recent expedition to the Philippines.

The shark, so named because it can suck in water to swell up and frighten predators, is likely new to science. Other known species of swell shark live elsewhere in the Pacific and Indian Oceans, according to expedition scientists at the California Academy of Sciences.

(Related: "Megamouth Shark Picture: Ultra-Rare Shark Found, Eaten.")

Biologists spent 42 days on and around Luzon Island (see map), the largest island in the Philippine archipelago, surveying creatures of the land and sea.

"We found new species during nearly every dive and hike as we surveyed the country's reefs, rain forests, and the ocean floor," Terry Gosliner, leader of the 2011 Philippines Biodiversity Expedition, said in a statement.

While many of the species still need to be confirmed as new using microscopes or DNA sequencing, the team is confident that three hundred or so are new to science.

—Rachel Kaufman

Pictures: "Pancake" Sea Slug Among New Philippines Species

An "inflatable" shark and colorful sea slugs join hundreds of new species hauled up during a recent expedition to the Philippines.