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
Eastern spiny mouse species is nocturnal, avoiding the heat of the day and foraging at night for seeds, and sometimes insects and grasses. It is a sociable animal and lives in small groups. Females become mature at about two months of age and can produce litters of up to five young after a gestation period of about 42 days. Another female in the family group may help with care of the young, which are weaned after about a fortnight. Its spiny hair may help to prevent predation, perhaps making the animal harder to swallow, and this mouse is also capable of shedding its