Luidia

Luidia is a genus of starfish in the family Luidiidae in which it is the only genus. Species of the family have a cosmopolitan distribution.

==Characteristics== Members of the genus are characterised by having long arms with pointed tips fringed with spines. Their upper surfaces are covered with paxillae, pillar-like spines with flattened summits covered with minute spinules. The upper marginal plates are replaced by paxillae, but the lower marginal plates are large and covered with paxillae. The tube feet do not have suckers, but have two swollen regions. A mouth, oesophagus, and cardiac stomach are seen, but no pyloric stomach or anus is present. The gonads are underneath the sides of each arm.