Sea Slugs Part 2

I found so many amazing photos of sea slugs that I needed a second post to fit them all. It never ceases to amaze me how colorful some sea creatures are. I guess if and animal is poisonous enough, it can afford to be flashy.

Sea Turtles

Sea turtles are some of the most graceful and majestic animals in the ocean. They glide through the water effortlessly, flapping their arms like wings. Sea turtles can be found throughout the oceans of the world, from coral reefs to open waters.

Sea turtles have a very unusual life cycle for a marine organism. They spend nearly their whole lives in the ocean but come out onto land to lay their eggs. Sea turtles somehow remember where they are born and will migrate hundreds of miles to return to the exact place they hatched to give birth to the next generation.

A female sea turtle will crawl out onto the beach and dig a hole where she deposits hundreds of eggs which look just like pingpong balls. After incubating in the warm sand, they will all dig their way out of the sand, erupting out of the ground. They make a mad dash towards the waves, running from the many predators that see them as an easy snack.

Baby sea turtles are instinctively attracted to light. The moon naturally points them towards the waves where they will be safe. They will also follow any other light that seems brighter than the moon, including houses and street lamps. This is why many seaside areas are asked to turn thier lights off at night during breeding season. Most species of sea turtles are endangered, but humans are working hard to protect these majestic animals.

Fish

When you think of creatures in the ocean, Fish are probably the first thing that comes to mind. Fish are some of the most populous and successful organisms in the ocean. They are fast, big, and perfectly suited for life in the sea. They are members of the phylum Chordata, meaning they have a backbone and spinal cord. Fish eat anything from algae and plankton to huge marine mammals.

Fish are some of the most diverse and populous organisms on our planet. Fish range in size from tiny fish we can barely see with our naked eye, to the giant whale shark, which dwarfs humans. Fish are spread throughout the oceans of our world and can be found in all seas except the Dead Sea (which is too salty to support any life). Fish can live anywhere from the hot tropical seas to the frigid arctic ocean. Fish have been found from the shallows of tide pools to the deepest reaches of the ocean humans have been able to explore.

I will cover some of the most beautiful, exotic, and bizarre species of fish over the course of this blog. Keep checking for more updates.

Sea Slugs

Nudibranchs, commonly referred to as sea slugs, are some of the most beautiful creatures in the ocean. They are shell-less mollusks related to octopus and clams.

They can be found in oceans throughout the globe, most commonly in shallow tropical waters.

Sea slugs eat a variety of foods, and are usually carnivores. Many species feed on sponges. Some are cannibals.

Sea slugs are often very brightly colored to warn predators that they pack deadly poisons. This kind of coloration advertises that they are bad to eat and keeps predators from trying to make snacks out of them.

Sea slugs are some of the few animals that carry both male and female reproductive organs. They can effectively breed with any other member of their species.

Sponges

Sponges are from the phylum Porifera. They are some of the most simple animals in the ocean. They are huge colonies of cells without a central nervous system. They are really a huge group of individual cells built into a colorful and intricate structure. Sponges come in many different shapes and sizes, and they add splashes of color to a coral reef.

Sponges are full of holes and very porous. This is to allow water to pass through them. They are filter feeders, meaning they pull tiny plankton out of the water and eat the microscopic bits of food that flow in the current. They have tiny hairs that wave in the water, pushing water past them and allowing them to grab bits of passing food. They serve to help keep the water clean.

The household sponges we use today were designed after sea sponges. There used to be a major industry for harvesting sea sponges for use in household cleaning. Because of its destructive effects on the marine habitat, this practice has been replaced by more environmentally friendly synthetic sponges.

Starfish

Starfish are beautiful and delicate sea creatures. We often find them washed up on the beach. While many see them as colorful decorations, they are actually deadly predators to clams and other mollusks. They eat by turning their stomach inside out. If they lose a leg, they can grow it back... and the leg can grow into a new starfish.

Starfish are Echinoderms, related to sea urchins and sea cucumbers. They come in a wide variety of shapes, sizes, and configurations. All starfish are symmetrical and are composed of arms radiating from the center. While most starfish have 5 arms in the traditional star shape, many species have much more.

Starfish are very slow moving animals and spend most of their time stuck to rocks or scooting along the bottom. They actually move using a network of thousands of tiny tubed feet with a single suction cup at the end of them. They have eyes on the tips of their arms and can only see very basic motion.

While they don't move quickly, they are actually predators that feed on clams, mussels, oysters, and other filter feeding mollusks. They stick their suction cups around the shells and pry them slowly open with steady force. When they have a small opening in the shell, the star fish will turn its stomach inside out and push it into the shell. It then digests the mollusk inside its own shell.


Starfish also have amazing regenerative abilities. If a starfish loses any part of an arm, it will simply grow a new one. As long as the core is intact, a starfish can grow back all its limbs. In some species, each limb can actually grow a whole new starfish. There are many varieties of starfish. I will post about them individually later.

Octopus

One of my favorite sea creatures is the octopus. Most people know of them as eight-legged sea creatures, but few know just how fascinating they really are. They are actually very intelligent, perhaps the most intelligent invertebrates in the world. They have been known to learn and solve problems in research laboratories. They have many unique adaptations that allow them to thrive in just about any part of the ocean. They are skilled predators and crafty survivors.


These creatures are mollusks, related to clams, sea shells, and squid. They have a hydroskeleton, which means they are held up by water. They have no bones, and become a limp blob when out of the water. Strangely enough, this doesn't always deter them from slithering up onto land to get to food trapped in tidepools. They can squeeze their bodies into tiny crevices and through holes just a tiny fraction of their size.


They have a large number of defense mechanisms to ward off predators. They camouflage perfectly with their environment and become very hard to see. Their skin is covered in cells that allow them to change colors to match nearly any surrounding. The skin of many species can even change shape to mimic the textures of the world around them. If a predator does spot an octopus, they can spray dark ink into the water. This smokescreen shrouds them from view and allows them to jet away quickly.


Octopus normally crawl along the ocean floor on their eight legs. When necessary, they can force water through their body and out in a strong jet to propel them quickly backwards. It is much like when you let the air out of a balloon. Their legs are covered in suction cups which allow them to stick to surfaces, pick up objects, and hold onto prey. They are fierce and stealthy predators and will pounce on unsuspecting crabs and other small creatures they can catch. There are many interesting species of octopus which I will highlight in later posts.