Symbion pandora

Symbion pandora
Scientific classification
Kingdom:	Animalia
Phylum:	Cycliophora
Class:	Eucycliophora
Order:	Symbiida
Family:	Symbiidae
Genus:	Symbion
Species:	S. pandora
Binomial name
Symbion pandora Funch & Kristensen, 1995

Symbion pandora is a jug-shaped microscopic aquatic animal that dwells on the mouth-parts of Norway lobsters. The animals are less than ½ mm wide, with sac-like bodies, and three distinctly different forms in different parts of their three-stage life cycle.

They are so unlike any known animal that its discovery by Danish scientists in 1995 led to the creation of a new phylum. The phylum Cycliophora, from the Greek for 'carrying a small wheel', was named after the creature's circular mouth. Two other members of that phylum have since been discovered.

Symbion refers to the animal's symbiotic relationship with its lobster host while the specific epithet pandora refers to the part of the organism's life cycle that reminded Funch and Reinhardt of the mythical Pandora's box.

Symbion pandora has a bilateral, sac-like body with no coelom. There are three basic life stages:

in this stage. It does, however, have a digestive system which collapses and reconstitutes itself as a larva.

Symbion pandora can reproduce both asexually by budding and sexually. In sexual reproduction the male attaches to a feeding stage and impregnates a budding female. The female then separates from the feeding stage and attaches herself to another host, where the larva in her develops. The female dies, and the larva escapes. The sexual reproductive cycle is triggered when the host crustacean molts its skin in order to grow.

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Wikipedia