Abstract:
The influence of a red algae-grazing abalone, Haliotis
asinina from Bolinao Pangasinan, on the density of agarolytic
bacteria in seawater was studied. Three treatments were used in the
experiment: treatment-I contained the abalone and algae;
treatment-1I contained red algae only, and treatment-III with
abalone only. The samples from the seawater were spread plated
on a nutrient agar medium and were cultivated for 2 weeks. The
agarolytic bacteria isolated from the water samples degraded agar
and appeared as yellow-orange colonies with depressions. These
motile, gram-negative bacteria appeared as long rods, ferment
either lactose or sucrose, and are facultatively anaerobic. Results
showed that the number of colony-forming units of agarolytic
bacteria is significantly higher after 24 hours, and has a high
abundance in its fecal pellets. In the second treatment with algae
only, the number of colony-forming units of agarolytic bacteria is
significantly lower. Thus, the presence of an abalone, Haliotis
asinina, increases the density of agarolytic bacteria in water.
