Crab
Videos
Crabs are decapod crustaceans, either the Brachyura or various groups within the closely related Anomura, characterised by having a heavily armoured shell, their tail segments concealed under the body
Adult pea crab, one of the smallest species, a few millimetres across
Coconut crab, the largest terrestrial arthropod, weighing up to 4.1 kg (9 lb)
Japanese spider crab, with a leg span of as much as 4 m (13 ft)
The mottled lightfoot crab is herbivorous.
Gill
Videos
A gill is a specialized respiratory organ that many aquatic animals use for aquatic gas exchange, i.e. to extract dissolved oxygen from water and to excrete carbon dioxide. Branchia is the zoologists'
The red gills of this common carp are visibly exposed as a result of a gill flap birth defect.
Freshwater fish gills magnified 400 times
The red gills inside a detached tuna head (viewed from behind)
An alpine newt larva showing the external gills, which flare just behind the head