The crab feeds on mollusks, annelid worms, other benthic invertebrates, and bits of fish. It feeds on insects, earthworms, other invertebrates and small vertebrates. Arthropods are invertebrates with segmented bodies and jointed limbs. They are opportunistic feeders and are mostly predators on benthic invertebrates. TLRs are present in vertebrates as well as invertebrates. Their classification as agnathans places hagfish as elementary vertebrates in between invertebrates and gnathostomes. It feeds primarily on insects and other small invertebrates. It also eats carrion, berries, seaweed, and insects and other small invertebrates. Many birds glean for insects, invertebrates, fruit, or seeds. The benthic zone consists of substrates below water where many invertebrates live. There are a variety of birds, bats, reptiles and invertebrates. They eat mainly fish and small marine invertebrates. Sexual cannibalism is present largely in spiders and other invertebrates, including gastropods. One example of asymmetric invertebrates includes all gastropod species. This stems from the similarity in structure of B-type lamins between invertebrates and vertebrates.