Photo by Ettienne Kotze	Longsnout pipefish Syngnathus temminckii. Over the last few weeks the pipefish population at locations such as A-Frame, Windmill, and deeper reefs, seems to have increased dramatically, and in some areas large numbers can be seen. At A-Frame, the grass-green caulerpa beds on the sea-ward site of the rocks, are especially full of these juvenile pipefish. Here they swim in groups resembling schools just above the caulerpa, swaying back and forth in the surge. Even further inshore on the sand large numbers have been observed, lying on the bottom, and darting up to nab one or two small mysids (small shrimp-like crustaceans) from the school swimming above the sand. The question is, why are they doing this? Rudie Kuiter, who has written a guide book on pipefishes and seahorses, and is an expert on the subject, had this to say: "The pipefish explosion has been observed in a number of species. Personally I've seen massing of Dunckerocampus in Indonesia and in Australia, on occasion, large groups of certain species congregate in southern Australian water. Sometimes adults appear in large numbers and produce even larger numbers of juveniles. It has happened with 2 species of seahorses as well and resulting in a large increase of their populations that lasts for many years. The photograph you sent appear to represent large juveniles. If this is so, I would suggest that they school for protection to enable them to move around more freely in search for food. It may well be that food has become more scarce due to their own success and made it necessary to come out of hiding. In Australia we have such roaming groups of the genus Stigmatopora that are found in seagrass areas. These will only appear along the edges in close-swimming aggregations, whilst in other times they spread out in their habitat." The longsnout pipefish, incidentally, is given as Syngnathus acus in Smiths' and Two Oceans. This is incorrect. It was thought that S. temminckii was the same as S. acus, but it can be differentiated by a different head shape and general colour, apart from being smaller. S. acus can be found from the north-east Atlantic to islands off the north-east African coast and the Mediterranean. S. temminckii's distribution is limited to southern Africa.
References: Thanks to Rudie Kuiter for information. Seahorses, Pipefishes and their relatives, RH Kuiter, 2000. Smiths' Sea Fishes, MM Smith and PC Heemstra, 1986. Two Oceans, a guide to the marine life of Southern Africa, GM Branch, CL Griffiths, ML Branch and LE Beckley, 1994. Coastal Fishes of Southern Africa, PC Heemsta and E Heemstra, 2004.
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