Animal mesoderm forms by enterocoelic pouching, through invagination of the endoderm. The main deuterostome phyla are the Echinodermata and the Chordata. Echinoderms are exclusively marine and include starfish, sea urchins, and sea cucumbers. The chordates are dominated by the vertebrates (animals with backbones), which consist of fishes, amphibians, reptiles, birds, and mammals. The deuterostomes also include the Hemichordata (acorn worms). The Ecdysozoa are protostomes, named after their shared trait of ecdysis, growth by moulting. They include the largest animal phylum, the Arthropoda, which contains insects, spiders, crabs, and their kin. All of these have a body divided into repeating segments, typically
Pacific spiny lumpsucker Pacific spiny lumpsucker The Pacific spiny lumpsucker, scientific name Eumicrotremus orbis, is a species of bony fish in the Cyclopteridae family. The pacific spiny lumpsucker is a globular shaped fish that typically measures in length, with a maximum known length of around . The body of the fish is covered in cone-shaped plates, called tubercles. Females are dull green in color, while males are dull orange to reddish brown. The pacific spiny lumpsucker's anal fin has evolved into a large suction cup, allowing it to attach to surfaces. Pacific spiny lumpsuckers are most commonly found attached to solid objects and