Pteraster Tesselatus (Cushion Sea Stapr

Body Plan- Sea stars are made up of their Pyloric stomach, Cardiac stomach, Rectal gland, Madreporite, Anal ring, Optic Cushion, Ampulla, Gonad, Ampulla,Pyloric caeca, and tube foot.

Pteraster Tesselatus (Cushion Sea Star)

Evolution

and

human effects

The full classification order of a Cushion sea star is as follows:

Animalia- Echinodermata- Asteroidea- Velatida- Pterasteridae- Pteraster- Pteraster tesselatus

They have a sister group called the hemichordates. (acorn worms, extinct graphtolites, and pterobranchs.)together they form a clad called ambulacraia. This species is important to humans because their bodies contain a nonstick material with the ability to treat inflammatory human diseases such as arthritis and hay fever. Humans are effecting Cushion sea stars by polluting their habitats. This drives the sea stars to evolves apart. Conservation is being administered to help this species.

Place in Ecosystem

Citations

• What ecosystem are the most commonly found in?- ocean floors or coral reefs were there is shallow sea grass
• They are heterotrophic.
• Cushion sea stars do not live in symbiosis with other organisms.
• Slime stars are mostly prey. Some predators are large fish and Triton Gastropods. However, they're omnivores, and some of their prey includes small fish and plankton.
• Place in food web?- primary or secondary consumer
• Place in food chain?- Primary, secondary, and tertiary consumer
• They can eat up to twice their body weight in one day depending on what they are doing

General Information

Anatomy

General Body Plan-

• Phylum Name- Pteraster Tesselatus
• Common Name- Cushion Sea Star or Slime Star
• Where?- Pacific Ocean
• What ecosystems?- aquatic habitats where shallow sea grass is found
• What do they look like and what do they do?

Asteroids. (n.d.). Retrieved May 15, 2015.

Descriptions and articles about the Cushion Star (Pteraster tesselatus) - Encyclopedia of Life. (n.d.). Retrieved May 15, 2015.

GBIF.org. (n.d.). Retrieved May 15, 2015.

Starfish - Sea Stars Features. (n.d.). Retrieved May 15, 2015.

Two Cushion sea stars move away from each other over a grassy.. (n.d.). Retrieved May 15, 2015.

Vic High Marine. (n.d.). Retrieved May 15, 2015.

Photos and Videos

Features

This is how Cushion Sea Stars move

Systems

A distinguishing feature of Pteraster Tesselatus are their vision and their skin. Also, they are Echinoderms. Each has a specific sex, but it's not able to determine it from the phenotype. Something that makes them different than other species in their phylum is their size. They're larger than normal sea stars are. Cushion sea stars symmetry is bilateral. This means that if you draw a line down the middle, they're almost exactly the same on both sides. Starfish are segmented, but it's not along a longitudinal axis because of their radio symmetry. The way cushion sea stars walk is similar top that of a starfish. THEY WALK. They have tube feet (which are basically small legs under their legs) that move them along the ocean floor. The life cycle of a cushion sea star looks like this:

Egg Larvae Live as part of plankton

Adult Lecithotrophic

The skeleton composition is made of calcium carbonate plates, known as ossicles. Cushion Sea Stars digest food through their mouth witch is in the middle of their underside and the annus circle on the upper side. Food comes through the stomach, mouth, or tube feet. These organisms breathe through small, finger-like skin gills. Their nervous system is spread throughout their arms. Sea water is used to move nutrients through their bodies. Some other systems unique to the phylum are eye spots. They reproduce through releasing their eggs and sperm into the water near a sea star of the opposite sex, allowing fertilization to occur externally.