Biology Quiz - Starfish Flashcards
What are Sea Stars
Sea Stars (Starfish) are echinoderms, which are an unusual group of marine animals
Radial Symmetry
Circular body plan in which there is a central disk (Circular body region) with elements (Arms, normally 5 (Pentamerous)) that radiate from the central region
Exosceleton
The skeleton of the sea star is located beneath/within the skin; sometimes referred to as a dermal endoskeleton
Madreporite (Sieve Plate)
Opening (Inlet) for water entering the water vascular system. Also transfors water to the stone canal
Mouth
Opening into the digestive system
Tube Feet
Structures that are used for locomotion and capturing food
The tube feet have a medicine dropper shape
Pyloric (Hepatic) Caeca or Digestive Gland
Structures of the digestive system that produces enzymes for the digestion of food
Gonads
There are a pair of gonads in each arm; the male and female gonads are difficult to distinguish when preserved; external fertilization in water
Pyloric Stomach
The portion of the 2 part stomach that
lies closest to the aboral (opposite mouth) surface of the
central disk. Connected to pyloric caeca by ducts.
Note: Thin walled; this structure is
often damaged when the endoskeleton is removed.
Madreporite (Sieve Plate)
Opening (inlet) for water entering the water vascular system
Stone Canal
Transfers water from madreporite to the ring canal
Ring Canal
Transfers water from stone canal to the radial canals
Radial Canals
Transfers water from ring canal to the tube feet
Ampulla
A bulbous like structure at the top of each tube foot. Circular muscles contract around each ampulla forcing water down the tube foot. Longitudinal muscles along the tube feet contract forcing water back into the ampulla, causing a cuplike suction at the distal end of the tube foot.
