35
rapidly in omnivorous
fishes than in carnivores.
The coef-
ficient of variation of total radioactivity, calculated for
various tissues of 12 families of reef fish, differed between
tissues and between families.
The greatest variation within
families occurred in the goatfish and mullet,
possibly due to
the movement of schools of these fish along the open,
sandy-
bottom areas of the reef in contrast to the more limited range
of the majority of the other reef fish.
Other biological
variables suggested, which would contribute to the variation,
were mortality and the influx and outflow of breeding popula-
tions and their young.
Hiatt and Strasburg (1960) have presented an extensive
treatment of the ecological relationships of the fish fauna
on the coral reefs of the Marshall Islands.
observations on the food habits,
Included are
type of digestive apparatus
and habitat of the common reef fishes of this area.
of the reefs was divided into five trophic levels:
producers,
and (3),
the algae;
(2) primary consumers,
(4) and (5) secondary,
The life
(1) primary
the herbivores;
tertiary and quaternary con-
sgumers, carnivorous fish divided according to habitat and
feeding habits.
Using this classification,
a food web was
depicted in which the organisms of the pelagic and benthic
divisions were linked largely through the broad classification