Biology Reference
In-Depth Information
including fleshy macroalgae, algal turfs, and encrusting coralline algae (Hay
1997
;
Mumby
2009
). Algal turfs are easily digested and have a high energetic and protein
value relative to other macroalgae and are thus the preferred food of many herbiv-
orous fish, in both the Caribbean Sea and other tropical habitats (Bruggemann et al
.
1994
; Kopp et al
.
2010
). Based on their experiments in the Caribbean
(Guadaloupe), Kopp et al
.
(
2010
) determined that
Acanthurus coeruleus
(Blue
tangs) and
Sparisoma aurofrenatum
(Redband parrotfish) graze preferentially on
algal turfs, while
Sparisoma rubripinne (Redfin parrotfish)
and
Sparisoma viride
(Stoplight parrotfish) are more inclined towards
Halimeda
spp. while
Acanthurus
bahianus
(Ocean surgeon) prefer Phaeophytes. Their results also revealed the
aversion of herbivorous fish towards
Dictyota
spp., a brown macroalgae that uses
chemical compounds as a grazing deterrent (Hay
1997
; Paul et al
.
1990
). On the
GBR, Mantyka and Bellwood (
2007a
) report that grazers of macroalgae on the reef
crest of Pioneer Bay are composed of six reef fish species (two rabbitfishes, three
parrotfishes, and one damselfish) which display species-specific feeding behavior.
For example, the rabbitfishes,
Siganus doliatus
feed heavily on
Hypnea
spp
.
while
Siganus canaliculatus
feed intensively on
Sargassum,
and the three parrotfishes
Chlorurus microrhinos
,
Hipposcarus longiceps,
and
Scarus rivulatus
were the
dominant grazers of calcified
Halimeda
spp. (
H. cylindracea
,
H. discoidea
,
H. opuntia)
, and
Amphiroa
spp. During their experiment,
Chlorodesmis fastigiata
and
Galaxaura
spp. were least affected by herbivory, suggesting a reduced palat-
ability owing to their chemical deterrence and calcareous structures (Paul et al
.
1990
). More recently, Cvitanovic and Bellwood (
2009
) have reported that the
dominance of herbivorous fish over macroalgae species and specific reef areas
can show local variability. In an experiment conducted on the Orpheus Islands,
they found similar rates of macroalgae removal in three separate bays; however,
three different species of herbivores were responsible for the grazing control. They
also found that
Kyphosus vaigiensis
(Brassy chub) were responsible for high rates
of removal of
Sargassum
spp., although past studies had identified
Siganus
canaliculatus
(White spotted spinefoot) and
Platax pinnatus
(Dusky batfish) as
the dominant grazers of
Sargassum
spp. in Pioneers Bay
(
Mantyka and Bellwood
2007b
). Most recent studies highlight the importance of herbivore richness and
diversity (Burkepile and Hay
2010
) as well as abundance and biomass (Mumby
et al
.
2006
; Kopp et al
.
2010
) in maintaining reef macroalgae community structure,
reducing fleshy macroalgal blooms and enhancing coral reef recovery and resil-
ience. For example, Burkepile and Hay (
2010
) determined that complementarity
feeding among fish species not only impacted structure of macroalgal communities,
but also enhanced coral survivorship and growth on reefs in the Caribbean Sea
(Florida Keys, USA). The authors observed that fast grazing by ocean surgeonfish
(
Acanthurus bahianus
) and princess parrotfish (
Scarus taeniopterus
) kept
macroalgae communities dominated by short, filamentous algae and crustose cor-
alline algae, both algal states that do not suppress coral growth. Conversely, within
the established benthic communities, the authors observed that the redband
parrotfish (
Sparisoma aurofrenatum
) played a vital role in the removal of upright
macroalgae cover which can be detrimental for coral growth and survival. To
