Westheide, Wilfried. (1982). Microphthalmus hamosus sp.n. (Polychaeta, Hesionidae)—an Example of Evolution Leading from the Interstitial Fauna to a Macrofaunal lnterspecific Relationship. Zoologica Scripta. 11(3): 189-193.
Microphthalmus hamosus sp.n. (Polychaeta, Hesionidae)—an Example of Evolution Leading from the Interstitial Fauna to a Macrofaunal lnterspecific Relationship
Microphthalmus hamosus sp.n. is described from Florida and North Carolina, USA. Striking characters as body shape, parapod construction, setation and shape of the anal plate can be referred to a close interspecific relationship with a macrofauna species: one specimen was found on Sipunculus nudus . The phylogenetic-systematic position of the new species within the genus is discussed. The speciation process leading to a niche outside the interstitial biotope included a secondary increase in body size and number of segments. Dollo's law is applicable on the setation: setae which have been lost in the previous adaptation to interstitial life do not reappear.