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 recently taken an interest in Stauromedusae, having collected two single specimens over the last 10 years.
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. A second, partially digested, specimen was found inside the umbrella of one of 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.
McInnes DE (1989) A Stalked Jellyfish (Stauromedusae) found at Black Rock, Port Phillip Bay.
Among some of these novel communities associated with areas of diffuse flow near active vents are spectacular fields of "stalked jellyfish" (Stauromedusae) up to 10 cm in height (Lutz et al., 1998; Halanych et al., 1999).
Comparatively little effort has been put into determining the systematic relationships within Stauromedusae. As a result, families and genera are recognized by a mosaic of features, many of which are not exclusive, or which suggest contradictory groupings.
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.