Diatom assemblages associated with Sphaerotylus antarcticus (Porifera: Demospongiae)
Sphaerotylus antarcticus is a common Antarctic sponge characterized by a dense spicule fur that covers its surface. This sponge has been sampled at Terra Nova Bay from 22 November 2001 to 29 January 2002 at weekly intervals. On its spicules, a rich assemblage of benthic diatoms has been observed, ma...
| Published in: | Journal of the Marine Biological Association of the United Kingdom |
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| Main Authors: | , , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Cambridge University Press (CUP)
2005
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1017/s0025315405011720 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0025315405011720 |
| Summary: | Sphaerotylus antarcticus is a common Antarctic sponge characterized by a dense spicule fur that covers its surface. This sponge has been sampled at Terra Nova Bay from 22 November 2001 to 29 January 2002 at weekly intervals. On its spicules, a rich assemblage of benthic diatoms has been observed, mainly composed of Hyalodiscus sp., a centric sessile diatom, forming short colonies. The temporal trend of the abundances of these diatoms showed a maximum of 115×10 6 cells g −1 dry weight (dw) at the end of December. Almost all the diatom frustules observed in the sponge choanosome belonged to the planktonic species Fragilariopsis curta , which displayed a peak (50×10 6 cells g −1 dw) in the second half of January. Diatoms that were observed in the choanosome were of a size comparable to that of the inhalant pores, suggesting that sponges actively engulf diatoms, due to the pumping activity of their choanocyte chambers. Sponges, as active filter feeders, therefore represent one important vector in the transfer of energy from planktonic to benthic trophic chains in Antarctic habitats. |
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