Apodida

Apodida
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Euapta godeffroyi
Scientific classification
Kingdom:	Animalia
Phylum:	Echinodermata
Subphylum:	Echinozoa
Class:	Holothuroidea
Subclass:	Apodacea
Order:	Apodida
Families
Family Chiridotidae Family Myriotrochidae Family Synaptidae

The Apodida is an order of littoral to deep-sea, largely infaunal holothurians. This order comprises three families, 32 genera and about 270 known species, called apodids.

Characteristics

These sea cucumbers are vagile holothurians with an elongated shape (up to 3 meters for Synapta maculata), worm or snake-like. Their shape is adapted for burrowing through the sediment, sometimes in a fashion similar to earthworms. Their mouth is surrounded with 10-25 pinnate or peltate tentacles. The absence of tube feet gives the order its name, Apodida meaning without feet : they move by crawling on the sediment, hence they need flat bottoms with few current. Members of this order have a circum-oral ring and tentacles, but do not have tube feet or radial canals. They also lack the complex respiratory trees found in other sea cucumbers, and respire and excrete nitrogenous waste through their skin.

The ossicles, minute calcareous plates embedded in the skin and characteristic of each species, can include wheel and anchor shapes.

List of families

This order contains 3 family, consisting in 32 genera in total, for 270 known species.

• family Chiridotidae Östergren, 1898
• family Myriotrochidae Théel, 1877
• family Synaptidae Burmeister, 1837

• Chiridota heheva.jpg

  Chiridota heheva

• Polycheira rufescens.JPG

  Polycheira rufescens

• Euapta godeffroi.jpg

  Euapta godeffroyi

• Euapta lappa.jpg

  Euapta lappa

• Polyplectana kefersteinii.jpg

  Polyplectana kefersteinii

• Synapta maculata 2.jpg

  Synapta maculata

• Synaptula lamperti (Sea cucumber).jpg

  Synaptula lamperti