Ecology of the rocky shore
| The rocky shore biome is characterized by relatively shallow water
swirling with waves of varying intensity. The temperature is about 60 degrees,
cooler than the estuary biome but not as cold as the open ocean. The depth
of the water varies from zero (where the land protrudes above the surface)
to about 10 feet at the deepest tidal pools. |
There are no significant tidal flows because Arida has no moon. The
water is relatively clear (there is not much mud or sediment) allowing
sunlight to penetrate through to the rocky bottom in most places. |
| Primary producers
There and
three primary producers living in the rocky shore biome:
feathers,
big red and heliotropic.
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| Feathers are 2 to 3 feet tall, brownish on the bottom
and green at the top. The live in the shallowest waters where their holdfasts
cling to the rocky bottom. They obtain energy from the sun and convert
it to nutrients through photosynthesis. |
Heliotropic floats near but just underneath the surface of the
water. It is a smooth, slippery plant with long tendrils snaking downward,
somewhat like kelp on Earth. It also obtains most of its nutrients through
photosynthesis but can also absorb microscopic organism that float through
the water. Heliotropic is yellow at the top and dark brown at the bottom,
and is about six inches wide with the tendrils extending 5 to 6 feet below
it in the water. |
Big Red is the largest of the primary producers,
growing as tall as 10 feet and in some cases protruding above the surface
of the water by as much as one foot. It is green at the top and reddish
brown at the bottom, where its holdfasts cling to the rocky bottom. |
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Primary
consumers
There are two primary consumers living in the rocky shore
biome. They are Pelagris and Flapello. Both of these are herbivores that
obtain their nutrients by eating plants and converting the calories into
energy. Both have limited mobility; flapello moves by flapping its eight
tails against the water to obtain forward motion whereas Pelagris is a
jelly like substance that moves by undulation.
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| Pelagris, which is about 12 inches wide, feeds on both feathers and
heliotropic. Since its movement is relatively limited, it does not venture
into the deeper waters. |
Flapello, however, is more mobile so it is able to feed on feather,
heliotropic and big red. It is only about 6 inches long, so it does not
consume huge quantities of food but survives on a relatively meager diet. |
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Secondary
consumer
At three to four meters in length, the Ray Gun is the largest
animal living in the rocky shore biome. It is a strong swimmer that tracks
down and overpowers its prey using its swimming power. Ray Guns feed on
the much smaller Flapello and Pelagris; using its brown color as a camouflage,
the Ray Gun often hides amongst the rocks partially covered with sand,
and waits to spring on its prey. Ray Guns are voracious carnivores, and
are the top secondary consumers in the rocky shore biome.
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