Photo by Peter Southwood Photo by Peter Southwood Drawing by Gary Williams	This unidentified organism (Peter suggested "dreadlocks" as a name) has been seen at Tafelberg reef on a few occasions. It appears to be some kind of soft coral. Gary Williams, of the California Academy of Sciences, had this to say: "The only kind of organisms that comes to mind without having a specimen to examine, are certain kinds of hydroids - some may have manubriums with capitate tentacles (white fingerlike structures) and grape-like clusters of gonophores (red processes). Or alternatively, the white fingerlike structures could represent manubriums while the basal red processes could be filiform tentacles. Some anemones have grape-like auxiliary processes in addition to the tentacles (like Actineria spp.), but I am more inclined at this point to go with the hydroid option. Whatever it is, my guess is that it is a new taxon." Further investigation by Gary Williams has led him to look at hydroids, and he has come up with a suggestion as to what the various bits and pieces are, as shown on the sketch. Update! 31 July 2005. Gary Williams and Charles Griffiths researched the literature more, using Gary's suggestion that it is a hydroid, and they have come up with a very likely candidate. It is called Myriothela tentaculata, and has been described from a single specimen dredged up from 43 m near Slangkop. Specimens have been sent to Gary for confirmation. If you look in Two Oceans, pages 34 and 35, you will see what many hydroids look like, and none look like this one. Looking through the reference Gary and Charles were using we were surprised at how different hydroids can actually look - from the plant-like colonies shown in Two Oceans, to single individuals 2 meters in length! The latter one is a deep-sea species, and not likely to be encountered by us. Hydroids are more interesting than one would expect. The form we see is just the sesile polyp stage. To reproduce they form medusae, which resemble small, free-swimming, jellyfish; they in turn reproduce sexually, and the larvae produced create the next generation of polyps. By having a free-swimming stage they are able to colonize other areas. As with jellyfish hydroids have stinging cells, which may be used to differentiate the various genera. The common ones on our divesites, for example, the smoky feather-hydroid, Lyptocarpus filamentosus and the yellow toothed feather hydroid, Alaophenia pluma, definitely do sting - inadvertently touching them with your gloves may result in the stinging cells (nematocysts) adhering to your glove, and only discharging when you touch, for example, your face. While it is not particularly painful, the area where I was stung swelled up for days. Each nematocyst is a cell, and contains the sting tightly coiled up inside it. To fire it the cell contracts, and the pressure inside cause the hollow sting to be everted, and it shoots out. Have you seen this? Have you photographed it? Please let us know where, when, and how deep, so we can start building up a better picture of where it can be found. Once we have more information, and hopefully a definitive identification, we will post this on the SURG website.
References: The living shores of Southern Africa, M Branch and G Branch, 1981. Two Oceans, a guide to the marine life of Southern Africa, GM Branch, CL Griffiths, ML Branch and LE Beckley, 1994. Monograph on the Hydoridea of Southern Africa, NAH Millard, Annals of the South African Museum, Volume 68, 1975 Thanks to Professor Charles Griffiths (UCT) and Gary Williams (California Academy of Sciences) for information.
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