Stauromedusae


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Stauromedusae

[¦stȯ·rō·mi′dü·sē]
(invertebrate zoology)
An order of the class Scyphozoa in which the medusa is composed of a cuplike bell called a calyx and a stem that terminates in a pedal disk.

Stauromedusae

 

an order of marine coelenterates of the class Scyphozoa. Stauromedusans greatly differ from the representatives of other orders in terms of structure and life cycle. Apparently, they are scyphistomae that have attained sexual maturity and lost their capacity for asexual reproduction by transverse fission. The body is shaped like a goblet on a stem, standing 2–15 cm high. The edges of the oral side are elongated into eight arms, each of which bears a bundle of small capitate tentacles. Stauromedusans reproduce only sexually. A creeping larva that lacks cilia emerges from the egg. After metamorphosis, it develops into a young stauromedusan. There are approximately 30 species, with 12 species distributed in the USSR. Stauromedusans are benthic and capable of moving by slowly gliding like a hydra.

References in periodicals archive ?
I have corresponded with Claudia Mills at the University of Washington (Mills 2012) and examined the small collection of Stauromedusae available in Museum Victoria.
It was a cold clear sunny day with an excellent low tide, and the Stauromedusae could be seen easily in the shallow still water, attached to Zostera muelleri (Figs.
Interestingly, immediately next to the somewhat sparse beds of Zostera muelleri, in slightly deeper water, there were luxuriant beds of Heterozostera nigricaulis (Kuo 2005) which seemed to be completely devoid of Stauromedusae.
One final observation from this day was of one specimen of the sessile ctenophore, Coeloplana willeyi Abbott, 1902, observed in the field on the same seagrass as the Stauromedusae.
The full life stages of Stauromedusae remain little known and the story of the 'hydropolyp without tentacles', Microhydrula limopsicola (Jarms and Tiemann 1996) is instructive (Miranda et al.
Zagal CJ, Hirano YM, Mills CE, Edgar GJ and Barrett NS (2011) New records of Staurozoa from Australian coastal waters, with a description of a new species of Lucernariopsis Uchida, 1929 (Cnidaria, Staurozoa, Stauromedusae) and a key to Australian Stauromedusae.
Despite their benthic nature, members of Stauromedusae have traditionally been grouped as an order within the cnidarian class Scyphozoa.
The taxonomy of Stauromedusae is further hindered by the fact that many species are rarely encountered.
Combining these data with data from five other species of Stauromedusae, we assess the usefulness of these markers for revealing historical relationships within Stauromedusae and present an initial investigation of stauromedusan phylogeny.
Nematocyst type, size, and location are recorded because these data may be useful for future systematic studies of Stauromedusae.
For the SSU sequences, we excluded regions that could not be reliably aligned across Stauromedusae and the eight outgroup taxa; the resulting alignment is 1746 bases.
Asexual propagation is not known in Stauromedusae, but observations of dense aggregations and a juvenile attached to the base of the peduncle raise the question of whether L.