Starfish Dissection

Starfish Dissection

Starfish live in ocean on the sea bottom. Starfish breathe through their feet. Their feet are made of thin tissue that gases can easily move through. Starfish’s tubed feet and tiny bumps all over their bodies transport the oxygen from the seawater to their tissues. Starfish mainly eat clams, oysters’ sand dollars and mussels.

Fun FACT

A starfish can regenerate lost arms. This is useful if the sea star is threatened by a predator. Starfish house most of their vital organs in their arms, so some can even regenerate an entirely new sea star from just one arm and a portion of the star’s central disc. It takes almost a year for this to happen

function of external structures 

 ring of oral spines- spines around the mouth

Central dics- holds all the arms of the starfish 

arms- help with movement and capture prey

Ambulacral groove-contains the tube feet on the oral side and used to pry open the shells of bivalves

  tube feet-  used for feeding, movement, and a little for respiration

eyespot- Senses Light And Dark

madreporite- where water enters in the water vascular system

Spines-  helps protects the starfish

mouth-stomach that is pushed out to eat food

 

function of internal structures

pyloric ceeca-secretes enzymes for digestion and absorption of nutrients

gonads-  make sperm or eggs

ampulla -Fill up with water and then release to tube feet

ossicles - Plates That Fuse To Form Skeleton

stone canal- a short canal that connects the madreporite to the ring canal around the mouth

ring canal- Circular canal in the center disk

lateral canal-  Branches off of radial canal all the way down the arm and leads into the ampulla

Incision Guide

Dissection video