LABORATORY MEASUREMENT OF INGESTION RATE FOR THE SEA URCHIN LYTECHINUS VARIEGATUS (LAMARCK)(ECHINODERMATA: ECHINOIDEA)

Sea urchins (Lytechinus variegatus) from Biscayne Bay were fed controlled rations (5-cm blades) of turtle grass (Thalassia testudinum) every 48 hours over an 11-day period in 1988. The rations of grass consisted of either unblemished (green) blades or decayed blades. Decayed blades had nearly twice as much dry weight as green blades of the same size. Ingestion times for both types of turtle grass were negatively correlated with sea urchin size (bigger urchins ate faster than smaller urchins). Mean ingestion times for the two types of blades were significantly different (decayed blades < green blades). Sea urchins did not show a preference when offered a green and decayed blade at the same time.