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'
Spider fighting tournament, with the last two victorious spiders fighting each other in the finale. Spiders used in spider derbies in Singapore come from the species "Thiania bhamoensis" (also called "Fighting Spider"), a jumping spider. The practice has been the subject of a memoir entitled "Spider Boys," and a popular television series in Singapore called "Fighting Spiders." Capturing, admiring, nurturing, and staging fights among these spiders is a popular activity among many young people. The practice had a relatively large financial impact on those young people who participate in these practices both because of the sale value of a strong contender and