A new species of fish with a male organ on its head has been identified in the Mekong Delta in Vietnam, researchers said on Wednesday. Phallostethus cuulong is the newest member of the Phallostethidae family — small fish found in Southeast Asian waters that are distinguished primarily by the positioning of the male sexual organ. Male phallostethids have a copulatory organ, termed the priapium, under the throat for holding or clasping onto females and fertilising their eggs internally, according to conservationists. The fish was known to Vietnamese people in the Mekong Delta but had not been described scientifically before a team identified the species last year.
