Dimeatus attenuatus Sanamyan 2000

• Main Authors: Sanamyan, K. E., Sanamyan, N. P.
• Format: Text
• Language: unknown
• Published: Zenodo 2002
• Subjects: Biodiversity; Taxonomy; Animalia; Chordata; Ascidiacea; Phlebobranchia; Dimeatidae; Dimeatus; Dimeatus attenuatus; Antarctic; Antarc*
• Online Access: https://dx.doi.org/10.5281/zenodo.5306322; https://zenodo.org/record/5306322

Dimeatus attenuatus Sanamyan, 2000 (®gure 20) Dimeatus attenuatus Sanamyan, 2000. Material examined . St. 4090, 6145±5680 m, about 150 specimens. Remarks . The genus Dimeatus comprises two closely related species, the type D. mirus Monniot and Monniot, 1982 and D. attenuatus . The genus is probably most unusual among Ascidiacea and was originally assigned to the Cionidae. It has two large atrial openings and very peculiar gonads, which do not resemble the gonads of Ciona in any way. In D. mirus , gonads were poorly developed and their structure was not determined, although it was reported that they were in the gut loop (Monniot and Monniot, 1982). The specimens from the present collection all have welldeveloped gonads and the male and female ducts always penetrate the test and open directly to the exterior by multiple openings. In all other ascidians the gonoducts open into the atrial cavity. Dimeatus is the sole genus of the family Dimeatidae Sanamyan, 2000. For further discussion and full description see Sanamyan (2000). Dimeatus attenuatus was found only at one station, but as many specimens. The same is true for D. mirus . Apparently, they form rare compact settlements of many individuals. : Published as part of Sanamyan, K. E. & Sanamyan, N. P., 2002, Deep-water ascidians from the south-western Atlantic (RV Dmitry Mendeleev, cruise 43 and Academic Kurchatov, cruise 11), pp. 305-359 in Journal of Natural History 36 (3) on pages 338-339, DOI: 10.1080/00222930010004232, http://zenodo.org/record/5299679 : {"references": ["SANAMYAN, K., 2000, Dimeatidae, a new family of the Ascidiacea with description of a new species of the genus Dimeatus, Zoosystematica Rossica, 9 (1).", "MONNIOT, C. and MONNIOT, F., 1982, Some antarctic deep-sea tunicates in the Smithsonian collections, Antarctic Research Series, 32, 95 \u00b1 130."]}