Page 239 - NS-2 Textbook

234 NAUTICAL SCIENCES

Because of the poor visibility, they can be especially dan- Most jellyfish look like big, white, wispy mushrooms.
gerous in murky coastal waters, where they will attack at They swim by water jet propulsion at many depths in the
the slightest movement. oceans. TI,e sea wasp of the tropical seas, and especially
Killer whales are found throughout the oceans, from those of the Australian, Philippine, and Indian Ocean
the Arctic to the Antarctic. They are nearly fearless. They areas, are extremely dangerous. Oftentinles they are seen
reach a length of 15 to 30 feet. In packs, they often attack in huge numbers in the South China Sea.
much larger ,vhales. They are very swift swimmers, Swinlmers who brush against the Porhlguese man-
seeking out seals, walruses, and penguins as prey. De- of-war and jellyfish may be stung by their threadlike ten-
spite their name, attacks against people are rare and are tacles. Sting symptoms may vary from a mild prickiy
thought to be the result of confusion with their natural sensation to a throbbing pain that can render the victim
prey. The only defense against the killer whale is a hasty unconscious. Pain may remain in the area of the sting or
retreat from the water. radiate to the armpit or abdomen. There may be redness
Moray eels have narrow, powerful jaws with knifelike and swelling, blistering, or small skin hemorrhage. TI,ere
teeth. They may reach a length of 10 feet. They can inflict are no specific antidotes, but washing with diluted am-
severe cuts or may hold a bulldog-like grip until death. monia or alcohol and swabbing with mineral oil or bak-
They dwell mostly in crevices and holes under rocks and ing soda may help.
coral in tropical and subtropical seas. Morays seldom The sea wasp jellyfish is very venDInous. It can cause
attack unless provoked, so it is very ,"vise not to poke death in three to eight minutes. Symptoms are almost inl-
around in places where they may be lurking. They are mediate shock, muscular crmnps, loss of sensation, nau-
common along the California coast. sea, constriction of the throat} paralysis, convulsions}
The giant devil ray or manta ray may reach a spread of and, finally, death.
20 feet and a weight of 3,500 pounds. They have a wide There are two members of the mollusk group with a
range in the topical seas. They are very curious and may venomous sting or bite: (1) those with spirally twisted
investigate air bubbles of divers, getting entangled in the single shells, such as snails, and (2) those with no shell,
ail' hose. They have a very coarse skin, which V\Till pro- such as the octopus and squid.
duce severe abrasion on contact. Otherwise, they usually TIlDse with cone-shaped shells are potentially danger-
do not attack humans. ous. They have a head with one or hvo pairs of tentacles,
Stinging Animals. Poisonous marine invertebrates that and a flattened fleshy foot. COile shells are favorites of shell
inflict injury by stinging are divided into four main groups: collectors. There are some 400 species, and most have a
fully developed venom apparatus. They are found in trop-
• Corals, sea anemones, hydroids, and jellyfish
ical waters of the Pacific and Indian Oceans and in the Red
• Mollusks, including octopi and certain shellfish
Sea. They are common on the beaches of the Pacific islands.
• B1oodworms and bristleworms
The venom apparatus of the cone shell lies near the
• Sea urchins
shell opening. The round teeth at the end of a tubelike
Corals and sea anemones have stinging cells that are used appendage are tlU'ust into the victim, and the venom is
to capture food or as a defense against enemies. These forced tmder pressure into the wound. The sting usually
cells inject a paralyzing drug into the victinlS, causing ill- produces numbness and tingling, which quickly spread,
nesses common among skin divers)" sponge fishernlen, becoming especially noticeable about the lips and
and other marine workers. This group includes the elk mouth. Paralysis and coma may follow, with death as the
horn coral of the West lndies and rosy sea anemones of result of heart failure.
the Atlantic. Cone shell wounds must be quickiy cleaned and suc-
Coral cuts and stings are very painful, slow to heal, tion applied to remove poison. Antibiotics may be desir-
and often become ulcerated. The wounds should be able. The patient should be kept warm. Stinlulants may
promptly cleaned and any particles removed. Bed rest, be required, and hospitalization is recommended.
elevation of the linlb, and packing with a mustard pack The octopus has eight arms or tentacles, the squid and
will help. When you are walking on a coral reef, heavy cuttlefish ten, around a muscular central body mass. They
shoes, gloves, and V\Tet Sluts are recommended. have parrotlike beaks and well-developed venom appa-
The hyd1'Oids include poisonous invertebrates like the rahlS. They can move rapidly underwater by water-jet
Portllgllese lIIan-of-war, often wrongly called a jellyfish. propulsion.
The Portuguese man-of-war floats on the surface of all Fortunately, these perilous-looking animals are
tropical oceans and the Mediterranean Sea. Its tentacles tinlid. Octopi hide in holes in the coral and among rocks
trail many feet into the water and can give painful stings. of the continental shelves. TIley are curious but very cau-
The fire coral, a false coral that is sometinles called sting- tious. The danger of the octopus is its bite, and a small
ing coral, is fOtuld anl0ng true corals in the warm waters one can cause as much venom damage as a large one.
of the tropical Pacific, Caribbean Sea, and Indian Ocean. The fear of being grabbed by eight choking arms is un-