|Palaemonid shrimps live in a wide range of environments, from freshwater to the deep ocean. They have a long rostrum with teeth above and below. Their first two legs are chelate (clawed), the second legs being larger and longer than the first. The carpus (segment next to claw) is undivided, and the second abdominal segment overlaps the 1st and 3rd segment. Most are small, rarely reaching longer than 5 cm (2 in), but some get large enough to be of some commercial value. This family includes many transparent or nearly transparent species. Many are commensal (living on or in another organism without causing harm to the host organism), attracted to hosts such as sponges, corals and anemones. The more colorful ones are able to alter their color to match their background or hosts.