Invertebrate paleontology deals with fossils such as molluscs, arthropods, annelid worms and echinoderms. The crab feeds on mollusks, annelid worms, other benthic invertebrates, and bits of fish. The blood of most annelid worms and some marine polychaetes use chlorocruorin to transport oxygen. The earthworm is a limbless annelid worm with a hydrostatic skeleton that moves by peristalsis. Examples include mollusks, annelid worms, and the entoprocta. It is a voracious carnivore and feeds primarily on fishes, insects, annelid worms, and crustaceans. Omnivorous, its diet includes both plants and small crustaceans, insects, and annelid worms. Amongst the Kinabalu earthworm's natural predators is another large annelid, the Kinabalu giant red leech. The other members of the Lophotrochozoa are the annelid worms and seven marine phyla. "Kuphus polythalamia", which despite the name "worm" is a bivalve mollusc, rather than an annelid. Many have a two-host lifecycle, involving a fish and an annelid worm or a bryozoan. The genus Enchytraeus includes about 40 species of annelid worms. The Orthonectids may be degenerate annelid worms. The bristle worm, a marine annelid, has been modified. The coelom of annelid is schizocoelic while that of Balanoglossus is enterocoelic.