The object of this project was to collect foam produced by two species of frog, Physalaemus pustulosus, which lays its foam nest on or near the surface of small pools of standing water, and Leptodactylus fuscus, which lays its foam nest in mud burrows immediately adjacent to pools. Foam was collected, under Roger Downie's specialised guidance, the eggs removed, and the foam frozen for return to Glasgow for analysis. The separation was carried out either by hand (laboriously carried out by Isla and Ross Kennedy - with help from Freya Kennedy, who also played a major role as morale booster) or by gentle centrifugation. Centrifugation also compresses the foam and provides a liquid which is easier to analyse than a foam.
A comprehensive analysis of this unusual biological material requires a team effort.....
Roger Parton (Infection and Immunity) helps in the search for anti-microbial compounds, Les Fixter, John Kusel and John Beeley (Biochemistry and Molecular Biology) look for lipids, carbohydrates and surface-active compounds in the foams, and Alan Cooper (Chemistry), Malcolm Kennedy (I&I) - assisted by Tennie Videler and Emma Wilson - along with Nick Price in Stirling University, examine the biophysical properties of proteins purified from the foams. The work is supported by a grant from the Wellcome Trust under a new scheme (Sir Henry Wellcome Commemorative "Showcase" Awards) to support unusual research directions.
Our colleagues may think we are crazy even thinking about this project, but not as crazy as Trinidadians thought we were collecting frog nests from dirty ditches and ponds in a graveyard! Perhaps they will all be proved correct.
Click for some pictures of the Trinidad 1997/8 foam collection expeditions.
Click for a video clip of the foam nesting process.