Hermit crab wood and stone are used by some species). The tip of the hermit crab's abdomen is adapted to clasp strongly onto the columella of the snail shell. Most hermit crabs are nocturnal. Hermit crabs can be divided into two groups: As hermit crabs grow, they require larger shells. Since suitable intact gastropod shells are sometimes a limited resource, vigorous competition often occurs among hermit crabs for shells. The availability of empty shells at any given place depends on the relative abundance of gastropods and hermit crabs, matched for size. An equally important issue is the population of organisms that prey
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