Phylum Echinodermata (Starfish)

Gallery 

Large starfish

Morphology of a starfish (1)

Morphology of a starfish (2)

INTERESTING FACTS 

·        Although their name is starfish, they not related to fish at all.
·        Their star-like shape is the reason why they were named starfish
·        Vary in size
·        Commonly their body radially symmetrical
·        Ability to regenerate. This process is slow
·        Carnivores. Likes to eat clams, shells and mussels.
·        Mouth located on the underside of its body
·        Anus located upper side of body
·        Move using tube feet, consists of hundreds projections underside their body. Used for walking and catching prey
·        Do not have brain. Do not have blood
·        Surface of body covered with bony skeleton which often contains different kind of thorns and spikes
·        Predators of starfish : sea otters, rays, sharks, seagulls, different types of fish
·        Reproduce sexually or asexually
·        Not hermaphrodites
·        Can survive up to 35 years in wild

cCLASSIFICATION 

1. Class Asteroidea 

2. Class Holothuroidea 

• Holouthurians measure generally between 10 and 30 centimetes long, with extremes of some millimeters for Rhabdomolgus ruber and up to more than 3 meters for Synapta maculata 
• Holothurians do not look like other echinoderms at first glance, beccause og their tubular body, without visible skeleton nor hard appendixes.

3. Class Echinoidea 

• Urchins typically range in size from 6 to 12 cm, although the largest species can reach up to 36cm. The lower half of sea urchin's body is referred to as the oral surface, because it contains the mouth, while the upper half is the aboral surface. 

VIDEO LINKS 

1.     https://youtu.be/FO6k-8mNfvU (Starfish walking on sand) 

2.     https://youtu.be/4dkieg7F37c (Starfish eating a clam) 

3.    https://www.youtube.com/watch?v=uYLAYcyeNsY (starfish eating a lobster)