Major Ocean Life Zones 283Dante Fenolio/Science Source Images© E. Widder/HBOI/Alamya. Found at dark depths of 700 to 3000 m (2300 to 9840 ft), the
spiky fanfin anglerfish attracts prey with its glowing lure. Its fin
rays allow it to sense movement in the dark water. Photographed
in Monterey Bay Canyon, California.
b. Unlike other fish species in the ocean’s depths, the
dragonfish can see red light. The pockets of red light
shining beneath each of its eyes allow it to detect other
organisms without being seen.feeders, scavengers, and predators. Many are invertebrates,
some of which attain great sizes. The giant squid measures
up to 18 m (59 ft) in length, including its tentacles.
Fishes of the deep waters of the oceanic province
are strikingly adapted to darkness and scarcity of food
(Figure 11.10). An organism that encounters food
infrequently must eat as much as possible when food
is available. Adapted to drifting or slow swimming,
animals of the oceanic province often have reduced
bone and muscle mass. Many of these animals have
light-^ producing organs to locate one another for mat-
ing or food capture.- What are the four main life zones in the ocean,
and how do they differ from one another?
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The Oceanic Province: Most of the Ocean
The oceanic province is the largest marine environment,
representing about 75 percent of the ocean’s water; it
is the open ocean that does not
overlie the continental shelf.
Most of the oceanic province is
loosely described as the “deep
sea.” (The average depth of the
ocean is 4000 m, more than 2 mi.)
All but the shallowest waters of
the oceanic province have cold temperatures, high pres-
sure, and an absence of sunlight. These environmental
conditions are uniform throughout the year.
Most organisms of the deep waters of the oceanic prov-
ince depend on marine snow, organic debris that drifts down
into their habitat from the upper, lighted regions of the oce-
anic province. Organisms of this little-known realm are filter
What other adaptations might this
species have to its extreme environment?Think Criticallyoceanic province
The part of the pelagic
environment that
overlies the ocean
floor at depths greater
than 200 m (650 ft).