Images of Hemichordate Species found around the World.

A) Ptychodera flava (the Hawaiian acorn worm), has been found in many different marine ecoregions of the world. It was the first described hemichordate species [2]. B) Saccoglossus bromophenolosus has been found in the waters of Maine and Washington state. This species was apparently introduced from Maine to Washington due to the oyster industry in the early 1900s [45]. C) Zooid of the pterobranch Cephalodiscus gracilis, a species found in Bermuda. D) Rhabdopleura normani zooids living within a coenecium. Images: A) and B) photo credit Billie J. Swalla, C) and D) photo credit Kenneth M. Halanych.