174 
THE BOOK OF FISHES 
pose of camouflage to enable it to ap¬ 
proach and capture smaller fish, crabs, 
and shrimps. 
THE PORTUGUESE MAN-OF-WAR HAS A 
FAITHFUL COMPANION FISH 
The Mouse Fish,, for its size, has a 
large mouth and appetite in proportion. 
Many other species hide in the weed 
when young and, as a rule, have colors 
to match at that time of life, though 
later they may be quite different. 
The rainbow-tinted pink, blue, or pur¬ 
ple bubble-like floats of the Portuguese 
Man-of-war (Color Plate, page 178) drift 
at the surface over all tropical oceans and 
are sometimes washed in close to the shore 
in numbers. With them comes an inter¬ 
esting companion, a very small and 
beautiful colored fish called Nomeus^ 
which never strays far from the tentacles 
which stream below the Man-of-war. 
The Nomeus decoys little fishes into his 
protector’s trailing tentacles which sting 
and stun them and thus provide food for 
both. 
When traveling by steamer along the 
Florida coast the writer has watched for 
NomeuSy and from where he stood on 
deck has seen one and sometimes more 
individuals lying suspended in the clear 
water, their blackish ventral fins con¬ 
spicuously spread, always within a 
short distance of a Man-of-war, floating 
above. 
WHEN THE FLYING-FISHES PLAY 
Comparatively few kinds of fishes are 
abundant “off-sounding,” away from the 
influence of the shore-line, and these may 
be divided rather sharply into the hunters 
and the hunted. Mouse Fish and No- 
meus^ belonging to the latter class—the 
one hides, the other lives under the pro¬ 
tection of a powerful companion. 
Flying-fishes, which are abundant, have 
an even more interesting method of es¬ 
caping their enemies, leaping above the 
surface and, with favorable wind condi¬ 
tions, shooting through the air for per¬ 
haps as much as an eighth of a mile, sup¬ 
ported by their long, stiflF breast-fins, 
widely spread at right angles to the body. 
When there is a whole-sail breeze blow¬ 
ing, they seem to fly also for sport. 
A flock of little Flying-fishes no bigger 
than herring, all in the air at once, gleam¬ 
ing blue and white silver in the sun, is 
one of the most beautiful sights of a 
tropical sea. The very thought of it 
takes one back to the broad blue expanse 
of trade-wind ocean, warm decks lurch¬ 
ing under foot, spray singing through 
the shrouds, squawking tropic birds 
and bellying square-sails which swing 
against a background of fleecy cloud 
and sky. 
In spite of their agility. Flying-fishes 
form the chief food of the little schools 
of Oceanic Bonitos, and of the Dolphins, 
swiftest, most graceful, and most highly 
colored of marine fishes, which prowl 
over the high seas. 
THE PRIMEVAL SHARK IS STILL WITH US 
Ages before modern fishes, of which 
we now find such countless variety in 
tropical seas, had been evolved in the 
slow process of evolution, there were 
sharks which differed comparatively little 
from those of the present day. Inter¬ 
mediate forms have become antiquated 
and dropped out, but the primeval shark 
(Color Plate, page 180) is still with us. 
Especially in the tropics they occur in 
great abundance. 
Prowling singly along the edges of the 
reefs, over the shallow flats, or through 
oflF-shore stretches of open water, they 
hunt largely by sense of smell, and con¬ 
gregate in numbers wherever food is 
abundant. 
When a whale is being cut up at sea 
it is astonishing how quickly the slender 
offshore Blue Sharks gather to the feast; 
it would almost seem from nowhere. 
By far the most abundant sharks nu¬ 
merically are the ground sharks {Car- 
charhinus). There is probably no trop¬ 
ical or temperate coast-line where one or 
more species of this genus do not enter 
the bays and inshore water at the proper 
season to give birth to their young. 
SHARKS PROPAGATE UNLIKE MOST 
OTHER FISHES 
Though relics of a bygone age, as far 
as bodily structure is concerned, sharks, 
of all fishes, have the most highly devel¬ 
oped reproductive system. Some lay a 
few large eggs, each one protected by a 
horny shell, but for the most part the egg 
stage is passed through within the body 
of the parent fish, and the young are born 
well grown and able to fend for them¬ 
selves. 
