pink staghorn or pink robe sponge Microxina benedeni

Microxina benedeni is found throughout Antarctica, South Georgia Island, and the Falkland Islands from 30 to 1,266 meters depth [1,4,7,9]. The body of M. benedeni can be tubular, gradually thickening near the distal end and shaped like a club (clavate), or split into branches [3,6].



Microxina benedeni has a narrowed base that can be a stalk [3]. The surface of M. benedeni is bristly with numerous conules [3,6]. The color of M. benedeni is straw, grayish yellow and brown [3,6].



Microxina benedeni has been collected at sizes up to 18 centimeters high [3].

M. benedeni is typically found in the third benthic zone of Cape Armitage below 33 meters depth [5]. M. benedeni is uncommonly seen, being 0.08% of the benthic surface cover at a Cape Armitage site [2].



Here's a closer view of Microxina benedeni.

The body of M. benedeni can harbor an isopod that sometimes kills the sponge [5].

An extract from M. benedeni has antibacterial and antiyeast activity [2].



Microxina benedeni may host diatoms within its food- capturing cells that line the passages through which the sponge circulates water; these endobiont diatoms live by consuming carbohydrates produced by the sponge and also by photosynthesis [10]. This symbiotic adaptation by the diatoms enhances their survival in the low light levels found down deep under the ice (as well as the dark months of winter) [10].

Taxonomic Note: Systema Porifera has Microxina as the genus [8].

1: B.A.N.Z. Antarctic Research Expedition, 1929-1931, under the command of Sir Douglas Mawson, Kt., O.B.E., B.E., D.Sc., F.R.S., Reports -- Series B (Zoology and Botany). Volume 9, part 4. Porifera -- Part 1: Antarctic Sponges. VM Koltun. Adelaide : Mawson Institute for Antarctic Research, University of Adelaide, 1976; 2: Antarctic Science 4(2):179-183, 1992; 3: Sponges of the Antarctic. I. Tetraxonida and Cornacuspongida. VM Koltun. IN: Biological reports of the Soviet Antarctic Expedition, 1955-1958 (Rezultaty biologicheskikh issledovanii Sovetskoi antarkticheskoi ekspeditsii, 1955-1958). Volume 2. EP Pavlovskii, ed. Jerusalem : Israel Program for Scientific Translations. 1966. pp.6-131; Appendix, Index of Latin Names on pp. 443-448 (synonymy noted in Appendix); 4: Hooper, JNA & Wiedenmayer, F. Porifera. IN: Zoological Catalogue of Australia. Volume 12. Wells, A, ed. Melbourne : CSIRO Australia, 1994; 5: Ecological Monographs 44(1):105-128, 1974; 6: Ross Sea Expeditions 1987-1988 and 1989-1990, Straits of Magellan Expedition 1991, Data Report Part 3, Physical, Chemical and Biological Oceanography. F Faranda and L Guglielmo, eds. Genova : Repubblica Italiana, Ministry of the University and Scientific and Technological Research, National Scientific Commision for Antarctica, 1994. pp.67-100; 7: Polar Biology 12:559-585, 1992; 8: Systema Porifera. JNA Hooper and RWM Van Soest. New York: Kluwer, 2002; 9: Antarctic Science 9(4):3921- 398, 1997; 10: Biological Bulletin 198:29-33, 2000

ID of inv177 as Gelliodes benedeni (Topsent, 1901) (Haplosclerida, Niphatidae) by Walentina de Weerdt and Rob van Soest (provided without specimens for checking microscopic details). Text ©Peter Brueggeman. Photographs ©Norbert Wu & Jim Mastro. Photographs may not be used in any form without the express written permission of Norbert Wu or Jim Mastro. Norbert Wu no longer grants permission for uncompensated use of his photos under any circumstances whatsoever; want more info?