The Fisheries of California [pp. 469-478]

The Fisheries of California.
used as food; or else are used only when
salted or dried by the Chinese, to whose
soups and chowders nothing seems to
come amiss. About twenty of the fresh
water fishes are also food fishes, but
only seven or eight of these have much
value as such.
The distribution of fishes, that is, the
question of the extent of the area inhabited by any particular kind, depends on
a number of different conditions, the
most important of these being the temperature of the water. Most fishes are
extremely sensitive to any change of
heat or cold. Where, as is sometimes
the case, the temperature of the water
changes abruptly at a given point, the
character of the fishes will be found to
change equally. A very little cold is
often sufficient to benumb and paralyze
a fish of the tropics. I have seen in the
West Indies, when the water suffers a
slight chill which brings it down perhaps
to 80 degrees, the cutlass fish, ordinarily
very active, lying stupid and inert on
the surface of the water. On the other
hand, the fishes of cold regions cannot
endure any degree of heat to which they
are not accustomed; and doubtless the
fishes in the depths would be suffocated
by the temperature of the surface water,
even if their lives were not destroyed by
the diminution of pressure.
Another element almost equal in importance is that of depth. The great
majority of the marine fishes that we
know well, or that we recognize as food
fishes, are shore species, inhabiting
depths of from one to fifteen fathoms.
The great variety of oceanic life is found
within this range, through which the
light and heat of the sun readily penetrate. As we go lower we find that the
shore fauna disappears. The greenish
colored shore fishes give place at fifty
to one hundred fathoms to other species,
the prevailing color of which is red.
The green or gray colors match the colors of the sand and kelp; the red ones
harmonize with the red sea-mosses
among which the red fishes live. In still
greater depths, where light and heat
have disappeared, the prevailing hues
are violet or black, the color of darkness.
Of less importance, but still a determining quality for very many fishes, is
the character of the food to be obtained.
Each species thrives best where those
creatures on which it naturally feeds are
most abundant. The herbivorous fishes
live among the tide pools, where they
can feed upon the small sea-weeds; the
crab-eating fishes live among the rocks,
and those which feed upon herrings and
silver-sides flourish best in the open sea.
The character of the bottom is also of
importance. Most of the flounders, for
instance, live on a bottom of sand. The
so-called rock-cod abound about sunken
rocks and banks; while other species
are found only where the bottom is soft
and muddy. I received the other day a
collection of fishes from the harbor of
Swatow, in China. By a simple inspection of these fishes I was enabled to
recognize the fact that the harbor of
Swatow is not a rock basin, but has a
bottom of mud, over which flow the
waters of an estuary. The difference
between the fishes commonly found at
Monterey and at Santa Cruz indicates
clearly the difference in the character
of the bottom at these two different
points on the same bay.
The character of the water is also
an element of importance. About the
rocks of La Jolla and Santa Catalina
the waters are as clear as about a coral
reef in the tropics. In these clear waters are found the same types of fishes
that would be found about a coral bank.
The species are not the same as occur
very far to the south; but the general
character of the fishes is that of a coral
region. On the other hand, in the more
or less muddy waters of the Bay of
San Francisco, only those species are
found to whom the cloudy or muddy
condition of the water is not objectionable; and the brilliant coloration of
1892.]
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