Echinoderms Chapter 10 Section 5

Characteristics of Echinoderms Phyla: Echinodermata Characteristics Invertebrates Internal skeleton Water vascular system System of fluid-filled tubes Live in salt water Radially symmetrical

Body Structure Have endoskeleton internal skeleton, made of hardened plates Body parts in multiples of 5 Arranged like spokes on a wheel

Movement Water vascular system Tube Feet Internal system of fluid-filled tubes in echinoderms Portions of the tubes in the system contract, or squeeze together Tube Feet Extensions of the water vascular system The function is for movement and obtaining food Sticky, act like sticky suction cups

Parts of a Sea Star

Reproduction and Life Cycle Either male or female Eggs fertilized in water, sperm is released Fertilized eggs develop into tiny, swimming larvae Go through metamorphosis

Diversity of Echinoderms Four major groups Sea Stars Brittle Stars Sea Urchins Sea Cucumbers

SEA STARS Eat mollusks, crabs, and even other echinoderms Move using their tube feet Also use tube feet to obtain food Sea stars force their stomach out through its mouth https://www.youtube.com/watch?v=l6dnmLDu6Eg

Brittle Star Arms are long and slender, flexible joints Slither along the ocean floor, snakelike motion Use tube feet for catching food, no suction cups

Sea Urchins No arms Movable spines cover and protect their bodies Tube feet that extend out from spines, aid in movement Scrape and cut food with five teethlike structures

Sea Cucumbers Look like cucumbers Red, brown, green, blue… Rows of tube feet on underside enable them to crawl Mouth surrounded by tentacles, filter feeder, sweeps food toward mouth