"You probably never realized before," said Mr. Choate, "that in the warm waters of the Gulf Stream, between Miami and Key West, more than 600 varieties of fish are to be found.  They vary in size all the way from the tiny sea-horse, the size of a baby's little finger, to the great tarpon and killer-whale, the latter a vicious creature weighing many tons and large enough to swallow a good-sized boy without scraping the buttons off his jacket."