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
Tapajós hermit little hermit, and the Tapajós hermit was believed to be most closely related to the black-throated hermit. In 1996 it was suggested that the Tapajós hermit was entirely invalid, and actually represented hybrids between the reddish and streak-throated hermits. In 2009 this hypothesis was shown to be incorrect, and the Tapajós hermit was instated as a valid species. Tapajós hermit The Tapajós hermit ("Phaethornis aethopygus") is a species of hummingbird in the family Trochilidae. It is found in the south-eastern Amazon in Brazil, and its common name refers to the Tapajós River, which forms the western border of its distribution.