Hermit crab on physical characteristics, genetic information, and combined data, support the longstanding hypothesis that the king crabs in the family Lithodidae are derived hermit crabs and should be classified as a family within Paguroidea. Other researchers have challenged this, asserting that the Lithodidae (king crabs) should be placed with the Hapalogastridae in a separate superfamily Lithodoidea. Six families are formally recognized in the superfamily Paguroidea, containing around 1100 species in total in 120 genera. The fossil record of "in situ" hermit crabs using gastropod shells stretches back to the Late Cretaceous. Before that time, at least some hermit crabs used ammonites'
Fiddler ray Fiddler rays are harmless and easily approached by divers. Southern fiddler rays are taken as bycatch by commercial trawlers and by recreational fishers; the flesh is of good quality and sold in small quantities. The Magpie fiddler ray (previously "Trygonorrhina melaleuca") is now considered a variant of "Trygonorrhina dumerilii". There are currently 2 recognized species in this genus: Fiddler ray Trygonorrhina, also known as the fiddler rays or banjo rays, is a genus of guitarfish, family Rhinobatidae. The two species are found along the eastern and southern coasts of Australia. They are benthic in nature, favoring shallow, sandy bays, rocky