The emperor shrimp (Periclimenes imperator) is a species of shrimp with a wide distribution across the Indo-Pacific. It lives commensally on a number of hosts, including the sea slugHexabranchus.A. J. Bruce first described it in 1967 based on eight specimens ranging from 4 millimetres (0.16 in) to 7.6 millimetres (0.30 in), and found Periclimenes rex to be its best resemblance.Emperor shrimp live in water up to 45 metres (148 ft) in depth, and can grow to a length of 1.9 centimetres (0.75 in).
The yellow boxfish (Ostracion cubicus) is a species of boxfish. It can be found in reefs throughout the Pacific Ocean and Indian Ocean as well as the south eastern Atlantic Ocean. It reaches a maximum length of 45 centimetres (18 in).
As the name suggests, it is box-shaped. When juvenile, it is bright yellow in color. As it ages, the brightness fades and very old specimens will have blue-grey coloration with faded yellow. It feeds mainly on algae, but will also feed on sponges, crustaceans and mollusks.
The fish's diet consists of marine algae, worms, crustaceans, mollusks, and small fish.
In 2006, Mercedes-Benz unveiled its Bionic concept car, which was inspired by the shape of the yellow boxfish.
Starfish or sea stars are echinoderms belonging to the classAsteroidea. The names "starfish" and "sea star" essentially refer to members of this class. However, common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as "brittle stars" or "basket stars". About 1,500 living species of starfish occur on the seabed in all the world's oceans, from the tropics to subzero polar waters. They are found from the intertidal zone down to abyssal depths, 6,000 m (20,000 ft) below the surface.
Starfish are among the most familiar of marine invertebrates. They typically have a central disc and five arms, though some species have more than this. The aboral or upper surface may be smooth, granular or spiny, and is covered with overlapping plates. Many species are brightly coloured in various shades of red or orange, while others are blue, grey or brown. Starfish have tube feet operated by a hydraulic system and a mouth at the centre of the oral or lower surface. They are opportunistic feeders and are mostly predators on benthic invertebrates. Several species having specialized feeding behaviours including eversion of their stomachs and suspension feeding. They have complex life cycles and can reproduce both sexually and asexually. Most can regenerate damaged parts or lost arms and they can shed arms as a means of defence. The Asteroidea occupy several significant ecological roles. Starfish, such as the ochre sea star (Pisaster ochraceus) and the reef sea star (Stichaster australis), have become widely known as examples of the keystone species concept in ecology. The tropical crown-of-thorns starfish (Acanthaster planci) is a voracious predator of coral throughout the Indo-Pacific region, and the northern Pacific sea star is considered to be one of the world's 100 worst invasive species.