Phylum Echinodermata Nada H. Lubbad Phylum Echinodermata

Phylum Echinodermata Defining Characteristics A complex series of fluid filled canals with numerous flexible feeding and locomotory appendages 5 pointed radial symmetry in adult(pentaradial symmetry) - Chinodermata means “spiny skin” - Echinoderms usually inhabit shallow coastal waters and ocean trenches Phylum Echinodermata

- Have small feet called tube feet that aid in movement, feeding, respiration, & excretion. - Do not have circulatory, respiratory of excretory systems. - Have a nervous system but no head or brain. - There are two sexes and they can produce sexually and asexually, fertilization is external. Phylum Echinodermata

- Change from a free-swimming bilaterally symmetrical larva to a bottom-dwelling adult with radial symmetry. Phylum Echinodermata

Echinoderms Skeleton Have an internal skeleton of calcium carbonate Ossicles vary in size and structure and are manufactured by specialized cells Feeding biology? eat mollusks, worms, and slow-moving animals Phylum Echinodermata

Water vascular system A separate coelom is used with interconnecting fluid filled tubes and canals A ring canal circles the mouth and gives off 5 radial canals The radial canal is exposed and runs along the ambulacral groove Phylum Echinodermata

Water Vascular System Phylum Echinodermata

Tube Feet The ampullae is a small ball that sits above the tube foot Contraction and expansion of the ampulla accomplishes movement Phylum Echinodermata

Taxonomic Summary Phylum Echinodermata Class Crinoidea Class Concentricycloidea Class Stelleroidea Subclass Asteroidea Subclass Ophiuroidea Class Echinoidea Class Holothuroidea Phylum Echinodermata

Subclass Asteroidea Phylum Echinodermata

Sea Stars The oral surface of each arm has a single ambulacral groove Have a large coelom where all the main organs occur Phylum Echinodermata

Phylum Echinodsermata Nutrition Mouth leads to a 2-part stomach: a large cardiac stomach and a smaller pyloric stomach. The pyloric stomach connects with digestive glands (=pyloric cecae) that runs into each arm. A short intestine extends from from the pyloric stomach to an anus on the aboral surface. Associated with the intestine are rectal cecae that pump the fecal wastes out of the anus. Phylum Echinodsermata

Phylum Echinodermata

Phylum Echinodermata

Phylum Echinodermata

Pedicellariae Specialized pinchers found on the aboral surface. Phylum Echinodermata

Reproduction Sexual Reproduction Can reproduce asexually by disk division Sexual Reproduction Dioecious with sperm or eggs produced in 2 or more gonads in each arm Larval stage = bipinnaria Phylum Echinodermata