Staurozoa

Staurozoa Temporal range:
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Cnidaria
Subphylum:	Medusozoa
Class:	Staurozoa Marques & Collins, 2004
Orders
†Conulatae Stauromedusae

Staurozoa is a class of Medusozoa, jellyfishes and hydrozoans. It has one extant order: Stauromedusae (stalked jellyfishes). A fossil group called Conulariida has been proposed as a second order, although this is highly speculative. The extinct order is largely unknown and described as a possibly cnidarian clade of marine life with shell-like structures, the Conulariida. Staurozoans are small animals (1–4 cm or 0.4–1.6 in) that live in marine environments, usually attached to seaweeds, rocks, or gravel. They have a large antitropical distribution, a majority found in boreal or polar, near-shore, and shallow waters. Few staurozoans are found in warmer tropical and subtropical water environments of the Atlantic, Indian, and Pacific Ocean basins, but most are known from the Northern Hemisphere. Over the years their number of species has increased, thus right now it is said to have an estimated 50 species. Information on Staurozoa, is one of the least studied groups within Cnidaria. It is often neglected, but correctly recognizing the characters of this class is crucial for understanding cnidarian evolution.

• During the metamorphosis of a stauropolyp into an adult stauromedusa, the eight primary tentacles

1. Disappear by resorption.
2. Metamorphose into adhesive interradial and perradial rhopalioids.
3. Remain as primary tentacles but with a modified shape.
4. Migrate and cluster together with the secondary tentacles.

Gallery

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  Haliclystus sp.
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  Haliclystus antarcticus
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  Haliclystus sanjuanensis
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  Manania handi