Balanoglossus is an ocean-dwelling acorn worm (Enteropneusta) genus of great zoological interest because it is, like all Hemichordates, an "evolutionary link" between invertebrates and vertebrates. Balanoglossus is a deuterostome, and resembles the Ascidians or sea squirts, in that it possesses branchial openings, or "gill slits", but no notochord and no chorda. It does have a stomochord, however, which is gut chord within the collar. Their heads may be as small as 2.5 mm (1/10 in) or as large as 5 mm (1/5 in).
The anatomy, life habits, and later development of a new species of enteropneust, Harrimania planktophilus (hemichordata: Harrimaniidae) from barkley sound.
Apr 01, 2002; Introduction The deuterostome phylum Hemichordata is composed of three extant classes: the Enteropneusta are solitary worms, the...