Starfish or sea stars are echinoderms belonging to the class Asteroidea. (27 Pics)

Starfish or sea stars are echinoderms belonging to the class Asteroidea. 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.

from:http://en.wikipedia.org/wiki/Starfish

Expert in camouflage and in be Weird: The Common Potoo (Nyctibius griseus) (34 Pics)

The Common Potoo, Grey Potoo, Lesser Potoo or Poor-me-one (Nyctibius griseus), is a nocturnal bird which breeds in tropical Central and South America

This potoo is a large cypselomorph bird related to the nightjars and frogmouths, but like other potoos it lacks the bristles around the mouth found in the true nightjars. It is 33–38 cm long and pale greyish to brown, finely patterned with black and buff, camouflaged to look like a log; this is a safety measure to help protect it from predators, but its mode of perch is also a camouflage. It has large orange eyes.

The Common Potoo can be located at night by the reflection of light from its eyes as it sits on a post, or by its haunting melancholic song, a BO-OU, BO-ou, bo-ou, bo-ou, bo-ou, bo-ou, bo-ou, bo-ou dropping in both pitch and volume.It has special disruptive coloration so it camouflages into a branch, as shown on the picture.

The single egg is white with lilac spots. It is laid directly in a depression in a tree limb, usually some meters above ground. It is not clear whether there can be, on occasion, two eggs in a clutch

Source:http://en.wikipedia.org/wiki/Common_Potoo