Bristles of chitin known as setae help them anchor during locomotion or in their burrows, and parts of their bodies are divided by septa.
There are approximately 12,000 species in this phylum, which consists of only protostome coelomates. Members of it have well developed cerebral ganglia, closed circulatory systems, and complete one-way digestive tracts. Bristles of chitin known as setae help them anchor during locomotion or in their burrows, and parts of their bodies are divided by septa. For 10 points, name this phylum containing polychaetes and earthworms, generally known as the segmented worms.
There are approximately 12,000 species in this phylum, which consists of only protostome coelomates.
{annelida} [or {annelids}]