Starfish to starfish by the French zoologist de Blainville in 1830. It is derived from the Greek "aster", ἀστήρ (a star) and the Greek "eidos", εἶδος (form, likeness, appearance). The class Asteroidea belongs to the phylum Echinodermata. As well as the starfish, the echinoderms include sea urchins, sand dollars, brittle and basket stars, sea cucumbers and crinoids. The larvae of echinoderms have bilateral symmetry, but during metamorphosis this is replaced with radial symmetry, typically pentameric. Adult echinoderms are characterized by having a water vascular system with external tube feet and a calcareous endoskeleton consisting of ossicles connected by a mesh of
Spiny mouse organism to study menstruation and reproductive disorders, as Mus musculus, the common laboratory mouse, does not menstruate. At least two species of African spiny mice, "Acomys kempi" and "Acomys percivali", are capable of autotomic release of skin upon being captured by a predator. They are the only mammals known to do so. They can completely regenerate the autotomically released or otherwise damaged skin tissue - regrowing hair follicles, skin, sweat glands, fur and cartilage with little or no scarring. It is believed that the corresponding regeneration genes could also function in humans. In a research article published on May 16,