External Anatomy:
The external anatomy of a starfish consists of a central disc that includes
the anus and the madreporite, which are located on top of the starfish. The madreporite is a plate that brings water into
the water-vascular system. (Zoology Book)
Starfish usually have 5 arms, but some starfish have more. Each arm has spines,
tubed feet, ambulacral grooves, and sensory tentacles on the tip of the arm. An ambulacral groove is found in the ambulacral
area, which runs from the mouth on the oral side of each arm to the tip of the arm. They are then surrounded by hundreds of
tubed feet and movalbe spines. The tubed feet and spines work together that allow the starfish to move and suck to a plantation.
They also use the tubed feet and spines to help stick to their prey, which allows them to consume. The starfishes also have
eyespots on the tip of their arms that allow them to see their way. (Zoology Book)
Internal Anatomy:
The internal anatomy of a starfish consists of a water-vascular system, which one
of its unqiue characteristics, the madreporite, anus, intestinal cecum, gonad, ambulacral ridge, ampulla, cardiac stomach,
pyloric stomach, pyloric duct, and pyloric cecum. (Zoology Book)
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