Thebackboneprotectsthe fish's very delicate andimportantspinal cord.
The spinal cord extends from thebrainalongthe back of the fish to its tail
and is made upofnerve fibres. The sensitive nerves and cells of the spinal
cord are the fish's nervous system, thecontrolcenter for all its body activities.
The long, sharpbones extendingfrom each side ofa vertebra help to
hold the fish's muscles in place.
OBSERVING CIRCULATION OFBLOOD INTHETAILOFAGOLDFISH
Materials:If you have a fishtankwith goldfish, you can carryoutthis
experimenteasily. If not, you may want to buy one at a variety store or a
pet shop. You can see thecirculationof blood in the tailofa goldfishwithout
harmingthe little fish. Besides a fish, you will need a medicine dropper,a
small wadofabsorbentcotton,a saucer, a small fish net and yourmicroscope.
Follow this procedure: Soak the cotton in water from the aquarium.
Carefullycatch a goldfish in the net. While the fish is still in the net, very
gently wrap thesoakedcottonaroundthebodyof the fish, leaving only the
tail uncovered. Place the wrapped fish on a saucer and gently cover the
exposed tail with a glass slide.