Fiddler crab Fiddler crab A fiddler crab, sometimes known as a "calling crab", may be any of approximately 100 species of semi-terrestrial marine crabs which make up the genus Uca. As members of the family Ocypodidae, fiddler crabs are most closely related to the ghost crabs of the genus "Ocypode". This entire group is composed of small crabs – the largest being slightly over two inches across. Fiddler crabs are found along sea beaches and brackish inter-tidal mud flats, lagoons and swamps. Fiddler crabs are most well known for their sexually dimorphic claws; the males’ major claw is much larger than the
Coastal peacock spider this display. Coastal peacock spider Maratus speciosus, sometimes called the coastal peacock spider, is an Australian species of jumping spider (family Salticidae). They are only known to inhabit the vegetation of the coastal sand dunes of southwestern Western Australia. Like other "Maratus" spiders, the males of the species engage in a courtship display during which they raise their third pair of legs and their abdomen, presenting their colorful opisthosomal plate to potential female partners. Unlike other "Maratus", however, the males of this species have a set of bright orange hairs (setae) along both edges of the opisthosoma which only become