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
Pacific spiny dogfish Bay, Gulf of Alaska, Between 2006 and 2014" (PDF). NOAA Technical Memorandum – via Science Direct. Pacific spiny dogfish The Pacific spiny dogfish ("Squalus suckleyi") is a common species of the Squalidae (dogfish) family of sharks and are among the most abundant species of sharks in the world. This species is closely related to "Squalus acanthias" and for many years they were treated as a single species. Recent research, using meristic, morphological and molecular data led to the resurrection of Pacific Spiny Dogfish as a separate species. The American Fisheries Society recommends the common name "Pacific Spiny Dogfish" for "Squalus