24 
EANHS Bulletin 30<1) 
animals living and working together 
Each animal is called a polyp, and die 
group is called a colony The polyps 
all share the same food from one 
digestive area. Each violet tentacle is 
a protective polyp It contains stinging 
cells to catch food and protect the 
colony. One large feeding polyp is 
shaped like a mouth Other polyps arc 
reproductive polyps; they bud of tiny 
medusae which will grow into new 
Velella colonies. This strange 
arrangement is a little like a termite 
colony Termites have workers, 
soldiers, and reproductive adults, all 
shoring the same home and food 
Porpita 
Porpita is another Hat. Boating, violet- 
coloured hydrozoan of the ocean 
surface that may be washed to shore 
Fire Coral 
Fire coral ( Millepora spp.) colonies 
look like underwater ferns or 
branching corals. There is a big 
difference, however: fire corals sting! 
The stings are painful but not usually 
dangerous. 
Portuguese Man-of-War 
Sometimes a storm at sea blows 
Portuguese men-of-war ( Physalia 
phy sails) to the beach. They look like 
tiny polythene bags full of air. with 
trailing violet threads. Each of them 
is a hydrozoan colony 
Out on the open ocean some 
Portuguese men-of-war grow large 
The gas- filled Boat may be up to 30 
centimetres long, and tinged with blue 
red or purple colours. Under the Boat 
are feeding, stinging and reproductive 
polyps The stinging polyps become 
tentacles up to fifteen metres long 
To British sailors of long ago. the 
bright Boats looked like the sails of 
Portuguese warships. A warship was 
called a "man of war", sometimes said 
"man o' war" The animals Boated in 
the same waters that the Portuguese 
ships explored. 
The violet tentacles of Portuguese 
men-of-war have powerful stinging 
cells. The long tentacles stun and catch 
fish and other animals that swim past 
them They can also sting people 
severely. Even a small man-of-war can 
give you a painful sting If you get 
stung, get out of the water. Do not 
wash with fresh water, as fresh water 
triggers the stinging capsules! Rub 
alcohol on the stings. The stings may 
leave scars for several days, but they 
will eventually lade. 
Hydra 
In tresh water, tiny hydra live attached 
to rocks and plants. Each hydra is a 
separate animal, about one centimetre 
long. Ii has a cylindrical body and 
about six long tentacles. The hydra can 
