Discussion on the preceding papers

• Published in: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
• Format: Article in Journal/Newspaper
• Language: English
• Published: The Royal Society 1967
• Subjects: Signy Island; Heywood; Island Lakes
• Online Access: http://dx.doi.org/10.1098/rstb.1967.0026; https://royalsocietypublishing.org/doi/pdf/10.1098/rstb.1967.0026

J. E. Smith. The Anostraca, following the classic studies of Cannon & Manton, are commonly regarded as filter feeders, yet there is evidence that some, including Branchinecta on Signy Island, feed on the bottom. What mechanism is involved and what kind of food is being taken ? R. B. Heywood. In calm weather few Branchinecta giani are visible at the surface, or in mid-water in the Signy Island lakes. They all seem to be browsing on the benthic felts of blue/green algae. The thoracic appendages show slight modification for scraping and Dr Ralph has observed this process in the laboratory. Large masses of blue/green alga are common in the fore-gut of the animals, and we can only conclude that they are general and detritus feeders whose diet is limited largely by particle size. Large pieces of crustacean exoskeleton have been seen in some specimens but these were without musculature and were probably taken in with detritus rather than as the result of predation.