White-blooded fish
There are 25 species of icefish in the Southern Ocean. They
are the only
vertebrates
without hemoglobin in their blood.
This substance carries oxygen throughout the body. Hemoglo-
bin also makes blood red. So icefish have colorless blood. Their
bodies even look like ice!
Lions of the sea
The lion’s mane jellyfish is the world’s largest jellyfish. A jelly-
fish body is called a bell. The lion’s mane’s bell can be wider
than six feet (1.8 m) across. It has eight clusters of sticky
tenta-
cles
. Each cluster can contain more than 100 tentacles. These
tentacles can be more than 100 feet (30.5 m) long.
INFINITE WONDERS
8
F
or me, the most interesting creatures that live in the polar sea are the Ant-
arctic icefish. These fish live without oxygen transporting hemoglobin. They
produce antifreeze proteins that prevent their blood and tissues from freezing.
Some of them die of heat stress at only 57.2
°
F (14
°
C).
— Dr. Markus Frederich, Marine Scientist, University of New England
ASK A
SC I ENT I ST
What do you think is the most interesting
creature that lives in the polar sea?
