HIGGINS, R.P.; NEUHAUS, B.*: Kinorhyncha

The Kinorhyncha are protostome, bilaterally symmetrical, exclusively free-living marine animals, less than 1 mm long, and ecologically part of the meiofauna, either endo- or mesobenthic, and euryhadyl. They occur throughout the world, generally in sedimients but sometimes associated with plants or other animals. Kinorhynchs are segmented as evidenced by their nervous system, the muscular system, a system of subcuticular glands, sequential rings of scalids on the head and variously divided cuticular rings on the neck and trunk, all together forming 13 segments. Significant information has been accumulated about post-embryonic development but nothing is known about kinorhynch embryology. Their body cavity is a sac filled with amoebocytes. the excretory system consists of a single pair of protonephridia lying dorsolateral to the gut in segments 10 and 11. About 150 species have been described and comprise 14 genera, 8 families and 2 orders. Their relationship to other phyla will be discussed.