Zoology: Worm Crossword

the concentration of sense organs, nervous control, etc., at the anterior end of the body, forming a head and brain, both during evolution and in the course of an embryo's development.
a light-sensitive pigmented spot on the bodies of invertebrates such as flatworms, starfishes, and microscopic crustaceans, and also in some unicellular organisms.
the action or process of regenerating or being regenerated, in particular the formation of new animal or plant tissue.
each segment in the strobila of a tapeworm, containing a complete sexually mature reproductive system.
A ganglion is a nerve cell cluster or a group of nerve cell bodies located in the autonomic nervous system and sensory system, mostly outside the central nervous system except certain nuclei.
a specialized excretory cell found in the simplest freshwater invertebrates, including flatworms, rotifers and nemerteans; these are the simplest animals to have a dedicated excretory system.
the anterior end of a tapeworm, bearing suckers and hooks for attachment.
a raised band encircling the body of oligochaete worms and some leeches, made up of reproductive segments.
A primary host or definitive host is a host in which the parasite reaches maturity and, if possible, reproduces sexually.
an organism that supports the immature or nonreproductive forms of a parasite.