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 eel 43 species known from two genera: Aethiomastacembelus, with 19 known species, and Afromastacembelus, with 24 known species. Spiny Eels from Sri Lanka, China, Southeast Asia and India are also from two genera: Macrognathus and Mastacembelus. The most commonly found Spiny eels in the Aquarium trade are the Macrognathus and Mastacembelus from Sri Lanka, China, Southeast Asia and India. These include such eels as the Peacock and Striped Peacock, the Tire Track and or White spotted eel, the Zig Zag, Fire, Siamese, and Zebra eels. Spiny eel The name spiny eel is used to describe members of two different families of