Marine Biology

5. They have fivefold radial symmetry, a calcareous skeleton, and tube feet operated by fluid pressure.
9. sponges
10. distinguished by having a skeleton of cartilage rather than bone, including the sharks, rays, and chimeras.
12. When the sun, moon and Earth are all lined up, the sun's tidal force works with the moon's tidal force
13. produce oxygen and nutrients for other organisms
16. Feed by suction with the help of a round muscular mouth and rows of teeth. Have cylindrical and long bodies
17. radially symmetrical, aquatic, invertebrate animals that have a hollow digestive cavity openinng.

1. small one celled organisms
2. unsegmented body usually enclosed in a calcareous shell
3. a skeleton of bone, and comprising the majority of modern fishes.
4. he moon faces the Earth at a right angle to the sun. When this happens, the pull of the sun and the moon are weak.
6. scales with comb-like edge found in higher order teleost fishes, such as perch and sunfish
7. includes plants and animals that float along the sea's tides and currents, a food staple for many species.
8. toothlike, being made of dentin with a pointed backward projection of enamel, as in sharks and rays.
11. having a segmented body, jointed limbs, and a shell of chitin that is shed periodically.
14. smooth-edged scales predominately found in lower order teleost fishes, such as salmon
15. consisting of two inner bony layers and an outer layer of cosmine