Zoology 10th Edition by Stephen Miller,John Harley

Exercise 9

Members of the phylum Gastrotricha are marine and fresh water. They inhabit interstitial spaces in bottom sediments. They have a complete digestive tract and are hermaphroditic. Members of the phylum Micrognathozoa inhabit interstitial spaces of cold-water springs of Greenland. They have a complex jaw system and cilia function in sensory perception, locomotion, and attachment. They reproduce through parthenogenesis. Members of the phylum Gnathostomulida occupy interstitial spaces in marine environments. They have an incomplete digestive tract and are monoecious. Members of the phylum Rotifera live in fresh water. They feed using a ciliated corona, have a complete digestive tract, and possess adhesive glands. They are dioecious, and many reproduce parthenogenetically. Members of the phylum Acanthocephala are endoparasites of vertebrates. They attach to their host intestinal wall with a spine-covered proboscis. Reproduction involves the development of larval stages within invertebrate intermediate hosts.
What is the value of parthenogenesis in unstable habitats like temperate lakes?