Being tube-shaped,
the ameboids wiggled across the ocean floor eating microscopic
organisms that landed on the bottom of the ocean. The ameboids
reproduce asexually. From this multicelled organism animal life
in the ocean took off!
These
microscopic organisms obtained their nutrients by consuming other
cells, Unicos and Lumers. Pikriyotics were anaerobic and reproduced
asexually. In order to increase their chances of catching nutrients,
Pikriyotics began meshing together to create more surface area
for Unicos to float into, increasing their chances of getting
food. This began a series of mutations that lead toward the beginning
of multicelled animal organisms. Since only some of the Pikriyotics
would actually devour Unicos when they would float into the mass,
some Pikriyotics died of starvation. However, over time the Pikriyotic
masses began cell specialization.
The specialization of the Pikriyotic mass evolved
into the ameboid. The ameboids were soft bodied, tube-like organisms.
They had a mitochondrian, for aerobic respiration. Because of
the weight of all the Pikriyotics clinging together, they sank
to the ocean floor. Being tube-shaped,
the ameboids wiggled across the ocean floor eating microscopic
organisms that landed on the bottom of the ocean. The ameboids
reproduce asexually. From this multicelled organism animal life
in the ocean took off!
This evolutionary process has
filled Entropolia's oceans with a variety of animal life. Among
these are various soft and hard-bodied invertebrates and vertebrates.
Also included are many microscopic life forms, most of which serve
as food for the larger aquatic life forms.
The microscopic ocean lifeforms are the most
important life forms in the ocean. These single-celled organisms
are the base of the ocean food pyramid. These organisms are suspended
in the water at various depths providing a source of food for
many larger animals. These organisms are in abundant supply and
can be found throughout Entropolia's ocean due to strong oceanic
currents carrying the floating microscopic organisms. These organisms
all evolved from mutations of the single-celled Pikriyotic organism.
From the ameboid, evolution brought to the ocean many soft-bodied creatures. This group includes worm and snake-like creatures. Most of these creatures appear to be bottom scavengers, mud feeders or micropredators. They reproduced asexually. One of most interesting is the Hallucigenia. It had a single row of tentacles along its back and a double row of seven legs on which it walked. The Hallucigenia is the beginning of hard-shelled organisms. The spines along the back are made of calcium carbonate and serve as protection against predators.
From the Hallucigenia, hard-shelled creatures arose. Worm-like
creatures developed exoskeletons. These shield-like exoskeletons
were shed many times as they grew. 
It is
assumed that exoskeletons arose from the increased amount of oxygen
making it possible for larger animals to evolve, and with this
development came the need for the increased protection afforded
by some sort of hard outer shell or exoskeleton. Among the shelled
animals is the Lobopod. Lobopods live on the slopes of the continental
shelf. It has a circular shelled exoskeleton with a soft-bodied
underside. It lives in rocky regions where it blends in with the
surrounding topography. It reproduces sexually. In the presence
of another Lobopod, the female will turn over exposing her underside
with eggs attached. The male will squirt sperm over the area attempting
to fertilize the eggs. The female buries eggs for incubation.
It feeds on microscopic particles that fall
to the ocean floor. The average weight of an adult is 3 g, with
sizes ranging form 12-15 cm. It is multicolored to blend with
the surrounding rocks.
Swimming animals evolved from the Pikriyotic masses that fell
to the ocean floor due to the organisms' small tails being unable
to keep it afloat. As mentioned earlier some Pikriyotic masses
turned into ameboids. Others continued to try to swim and over
time their tails grew longer living it the ability to swim. 
Swimy
was the first swimming animal in Entropolia's ocean. From Swimy
arose all fish found in the ocean today. One of the fish types
found on Entropolia is the Hirson. Hirson's grew on average to
be 2 meters in length, 15-20 kg and able to capture all but the
largest fish with its jaws. This predator is big with a long whipping
tail. It has two dorsal and two pectoral fins. It varies in color
from red to orange depending on the region in which it is found.
They are found in the deep cold oceans of Entropolia. They reproduce
sexually.
Other fish found in the oceans vary from the Elephantus herbivore found dwelling in Hydrocoselenia forests. Also, the Salosucker is a scavenger fish that dwells on the ocean floor sucking up decomposing plant and animal material.
It is the varied life that is found in the oceans of Entropolia that provide a flourishing biome for both plants and animals. It is an intricate web of life that enables all this diversity to coexist and depend on one another.
Photo credits: crabs = Eyewitness Books, starfish, jellyfish, fish = Grolier's