Starfish Starfish Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea. 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 species of starfish occur on the seabed in all the world's oceans, from the tropics to frigid polar waters. They are found from the intertidal zone down to abyssal depths, below the surface. Starfish are marine invertebrates. They typically have a central disc and five arms, though some species have a larger number of arms. The aboral or upper surface may be smooth,
Cairo spiny mouse Red List of Threatened Species, lists it as being of "Least Concern". A recent study, still under peer review at the time of writing, indicates that this species could become a candidate animal model for the human menstrual cycle. It exhibits a 9-day cycle, and is the first rodent found to have such a cycle. Gene sequencing is currently underway to investigate this, and other unique physiological traits displayed by this species. Cairo spiny mouse The Cairo spiny mouse ("Acomys cahirinus"), also known as the common spiny mouse, Egyptian spiny mouse, or Arabian spiny mouse, is a nocturnal species of