236
Coral Reef Fish
6.3.3 Benthovore and Piscivore Fish
The guild of fish feeding on various groups of zoobenthos is the most
numerous by number of species (Tables 6.10, 6.12). The total number of
species it includes (counting in the omnivorous bottom fish) comprises 40 to
80% of all communities of the reef ichthyofauna. But their share in the
whole fish biomass is less (20-30%), because their species populations are
less numerous and their trophic specialization is higher in comparison with
other guilds (Goldman and Talbot 1976; Harmelin-Vivien 1981; Williams
and Hatcher 1983). The share of their food ration varies from 15% of the
total ration of the fish community in lagoonal biotopes to up to 50% in those
of reef slopes. This guild could be subdivided into three main groups,
depending on the level of their trophic specialization and on their preferred
food: (1) fish feeding on large sessile benthic animals: ascidians, sponges,
hydroids, zoantharians, sessile polychaetes; (2) fish feeding on large vagile
fauna with firm exoskeleton: large crabs, barnacles, gastropods, bivalves,
urchins, asteroids, holothurians, chitons; and (3) fish feeding on small vagile
zoo benthos of soft sediments and on the infaunal benthos of the hard rocks
and rubble: bottom crustaceans, small crabs, ostracods, stomatopods,
amphypods, polychaetes and other worms. Fish from the first two groups
consume also significant amounts of plant material, and those from the last
group also small fish. Inside each of these group each species is specialized
to feed on definite kinds of prey, which reflects the morphology of its mouth
parts (Hiatt and Strasburg 1960).
Within the group of fish feeding on sessile benthos there are species
which feed mostly on sponges and ascidians, like the balisitid Cantherines,
the puffer Arothron, the ostraciontid (boxfish) Acanthostracion, the
chaetodontids (angelfish) Holacanthus, Pomacanthus, and the butterfly fish
Chaetodon ephippium. The large wrasse Lachnolaimus and the ogcocephalid
Ogcocephalus nasutus prefer the barnacles, the balistid Alutera scripta feeds
on strongly defended hydrocoral Millepora with poisonous nematocysts,
while the sergeant fish pomacentrid Aboefduf saxatilis is specialized for
feeding on zoantharians. Many species of the butterfly chaetodontid fish also
feed on polyps of the scleractrinian, corals, octocorals and zoantharians and
also pick up the filtering cones of serpulid polychaetes (Birkeland and
Neudecker 1981; Wylie 1988). Some of them have special "sucking"
construction mouth parts to suck out the polyps of scleractinians and
octocorals (Reese 1981). Among the pomacentrids there are species adapted
to scraping off the coral mucus they feed on from living colonies of
scleractinians. Among these are the pomacentrids Chromis caeruleus,
Pomacentrus sufflavus and the butterfly fish Chaetodon vagabundus (Benson
and Muscatine 1974). Corals are grazed directly by some scarids: Scarus
quacamaia, S. croicensis, S. coelestrinus, Sparisoma aurofrenatum, the surge
on-fish Acanthurus chirurgus and the pomacentrid Microspathodon chrysurus. Their stomachs contains the swallowed pieces of hard corals (Randall
Coral Reef Fish
6.3.3 Benthovore and Piscivore Fish
The guild of fish feeding on various groups of zoobenthos is the most
numerous by number of species (Tables 6.10, 6.12). The total number of
species it includes (counting in the omnivorous bottom fish) comprises 40 to
80% of all communities of the reef ichthyofauna. But their share in the
whole fish biomass is less (20-30%), because their species populations are
less numerous and their trophic specialization is higher in comparison with
other guilds (Goldman and Talbot 1976; Harmelin-Vivien 1981; Williams
and Hatcher 1983). The share of their food ration varies from 15% of the
total ration of the fish community in lagoonal biotopes to up to 50% in those
of reef slopes. This guild could be subdivided into three main groups,
depending on the level of their trophic specialization and on their preferred
food: (1) fish feeding on large sessile benthic animals: ascidians, sponges,
hydroids, zoantharians, sessile polychaetes; (2) fish feeding on large vagile
fauna with firm exoskeleton: large crabs, barnacles, gastropods, bivalves,
urchins, asteroids, holothurians, chitons; and (3) fish feeding on small vagile
zoo benthos of soft sediments and on the infaunal benthos of the hard rocks
and rubble: bottom crustaceans, small crabs, ostracods, stomatopods,
amphypods, polychaetes and other worms. Fish from the first two groups
consume also significant amounts of plant material, and those from the last
group also small fish. Inside each of these group each species is specialized
to feed on definite kinds of prey, which reflects the morphology of its mouth
parts (Hiatt and Strasburg 1960).
Within the group of fish feeding on sessile benthos there are species
which feed mostly on sponges and ascidians, like the balisitid Cantherines,
the puffer Arothron, the ostraciontid (boxfish) Acanthostracion, the
chaetodontids (angelfish) Holacanthus, Pomacanthus, and the butterfly fish
Chaetodon ephippium. The large wrasse Lachnolaimus and the ogcocephalid
Ogcocephalus nasutus prefer the barnacles, the balistid Alutera scripta feeds
on strongly defended hydrocoral Millepora with poisonous nematocysts,
while the sergeant fish pomacentrid Aboefduf saxatilis is specialized for
feeding on zoantharians. Many species of the butterfly chaetodontid fish also
feed on polyps of the scleractrinian, corals, octocorals and zoantharians and
also pick up the filtering cones of serpulid polychaetes (Birkeland and
Neudecker 1981; Wylie 1988). Some of them have special "sucking"
construction mouth parts to suck out the polyps of scleractinians and
octocorals (Reese 1981). Among the pomacentrids there are species adapted
to scraping off the coral mucus they feed on from living colonies of
scleractinians. Among these are the pomacentrids Chromis caeruleus,
Pomacentrus sufflavus and the butterfly fish Chaetodon vagabundus (Benson
and Muscatine 1974). Corals are grazed directly by some scarids: Scarus
quacamaia, S. croicensis, S. coelestrinus, Sparisoma aurofrenatum, the surge
on-fish Acanthurus chirurgus and the pomacentrid Microspathodon chrysurus. Their stomachs contains the swallowed pieces of hard corals (Randall