Coffroth,-M.A.  Mucous sheet formation on poritid corals: An 
	evaluation of coral mucus as a nutrient source on reefs.  
	MAR.-BIOL. 1990. vol. 105, no. 1, pp. 39-49.

Fluid mucus and mucous sheets were collected from Porites 
astreoides, P. furcata, P. divaricata  during 1986 and 1987 
on reefs in the San Blas Islands, Panama, La Parguera, Puerto 
Rico and the Florida Keys, USA. Mucus samples were collected 
from Indo-Pacific poritids (P. australiensis, P. lutea, P. 
lobata  and P. murrayensis ) on the Great Barrier Reef during 
1985. Biochemical analyses of the fluid mucous secretions, 
and the derivative mucous sheet, indicate that the mucus is 
primarily a carbohydrate-protein complex. Porites  fluid 
mucus had a mean caloric content of 4.7 cal/mg ash-free dry 
weight (AFDW), while mucous sheets contained 3.5 cal/mg AFDW. 
68% of the mucous sheet was ash, while fluid mucus was 22% 
ash. The high ash and low organic contents suggest that 
mucous sheets have a low nutritional value. C:N ratios varied 
(range 6.9 to 13.7 for fluid mucus, and 4.8 to 5.9 for mucous 
sheets), but were similar to typical C:N ratios for marine 
organisms. Bacterial numbers and chlorophyll a concentrations 
were higher on mucous sheets than in the surrounding water. 
Although bacteria aggregate on mucous sheets, bacteria 
accounted for < 0.1% of the carbon and nitrogen content of 
the mucous sheet.