''Haliclystus'' is a genus of

stalked jellyfish Stauromedusae are the stalked jellyfishes. They are the sole living members of the class Staurozoa and belong to the medusozoa subphylum of Cnidaria. They are unique among medusa jellyfish in that they do not have an alternation of polyp and med ...

that contains 11 species and one

nomen nudum In Taxonomy (biology), taxonomy, a ''nomen nudum'' ('naked name'; plural ''nomina nuda'') is a designation which looks exactly like a scientific name of an organism, and may have originally been intended to be one, but it has not been published ...

(''

Haliclystus sanjuanensis ''Haliclystus sanjuanensis'' is a species of small (~4 cm) stalked jellyfish found in the Pacific Ocean along the west coast of North America. This species can be found in shallow waters at low tide on soft substrates such as seagrass ('' P ...

''). It is the largest genus in the order Stauromedusae. Members of this genus are found in the Pacific, Atlantic, Indian, Arctic, and Southern oceans. Two members of this genus, '' Haliclystus kerguelensis'' and ''

Haliclystus antarcticus ''Haliclystus antarcticus'' is a Stauromedusae, stalked jellyfish which lives on rocky shore lines in the Southern hemisphere. Description The original type specimens for this species have been lost. however the species was re-described in 2009 ...

'', are found in the Southern hemisphere only. The remaining 9 members are found in the Northern hemisphere only. Species in this genus have four longitudinal planes of symmetry. They have eight arms which are tipped with clusters of secondary tentacles. The number of these secondary tentacles is reported to vary across the different species. Species in this genus also have eight large pads known as anchors located between the arms. These vary in size and shape and currently play in important role in differentiating one species from another. Some, but not all, species in this genus have prominent white

nematocyst A cnidocyte (also known as a cnidoblast) is a type of cell containing a large secretory organelle called a ''cnidocyst'', that can deliver a sting to other organisms as a way to capture prey and defend against predators. A cnidocyte explosively ...

clusters. The 'stalk' or peduncle in this genus is four chambered. At least one group of scientists have suggested that the taxonomy of this genus needs to be revised.

References

External links

* Haliclystidae Medusozoa genera {{Staurozoa-stub