Habitat Preferences of Redband parrotfish (Sparisoma viride) and

Habitat Preferences of Redband Parrotfish (Sparisoma viride) and Stoplight Parrotfish, (Sparisoma
aurofrenatum) as Determined by Fishery-Independent Visual Census Surveys in the Florida Keys
Alison Johnson, Alejandro Acosta and Marie Tellier
Mean Abundance by Size
Stoplight Parrotfish
Reef Rubble (RR)
Stoplight and redband parrotfish were more likely to be observed on
continuous, spur & groove and isolated reef and less likely to be found
on reef rubble and seagrass.
Presence / Absence
Stoplight Parrotfish
Presence / Absence
Redband Parrotfish
Total Number of Surveys = 3542
a Total Number of Surveys = 3549
a
Juvenile Redband Parrotfish
Redband Parrotfish Female
Redband Parrotfish Male
CR
SG
IR
RR
CR
SS
SG
IR
Surveys: 298
Surveys: 865
Surveys: 298
Surveys: 192
Surveys: 863
CR
Surveys: 1031
b
RR
SS
Habitat Type
When present, stoplight and redband parrotfish were equally abundant
across all habitat types.
CR
SG
IR
Habitat Type
RR
SS
a
ab
ab
ab
b
IR
RR
Fish: 330
Fish: 675
Fish: 246
Fish: 447
Fish: 3464
Fish: 2905
SG
SS
Habitat Type
Parrotfish do exhibit habitat preferences but size doesn’t matter!
1) Stoplight and redband parrotfish were more likely to be observed on reef rather
than non-reef habitat.
2) Stoplight parrotfish and redband parrotfish were equally abundant on all habitat
types. Although, statistically, stoplight parrotfish were more abundant on
isolated than contiguous and spur and groove reef whereas redband parrotfish
were more abundant on spur and groove reef than sand and seagrass. This is
likely due to large sample sizes.
Although ontogenetic feeding shifts have been observed for blue and stoplight
parrotfish, this study did not confirm these trends (Overholtzer & Motta 1999;
Bruggemann 1994a).
Literature and photographs were obtained from the following sources:
Bruggemann, J. 1994. Comparative analysis of foraging and habitat use by the
sympatric Caribbean parrotfish Scarus vetula and Sparisoma viride (Scaridae)..
Marine Ecology, 112: 51-66.
Bruggemann JH, van Oppen MJH, Breeman AM (1994a) Foraging by the stoplight
parrotfish Sparisoma viride. I. Food selection in different, socially determined
habitats. Mar Ecol Prog Ser 106:41-55.
Munro, J. L. 1983. Caribbean Coral Reef Fishery Resources. ICLARM, Manila,
Philippines, 276 pp.
Neu, C.W., C.R. Byers, and J.M. Peek. 1974. A technique for analysis of utilizationavailability data. Journal of Wildlife Management 38:541–545.
CR
SG
IR
Habitat Type
RR
Surveys:187
Fish: 1005
Surveys:115
Fish: 693
Surveys:938
Fish: 6369
Overholtzer KL, Motta PJ (1999) Comparative resource use by juvenile
parrotfishes in the Florida Keys. Mar Ecol Prog Ser 177:177–187.
Surveys:762
Fish: 5540
Surveys:56
Fish: 157
Surveys:44
Fish: 96
Surveys:689
Fish: 2232
ab
Number of Surveys with Fish: 2883
Number of Fish: 19447
Surveys:881
Fish: 5840
b
Surveys:487
Fish: 1286
b
ab
a
Mean Relative Abundance
Redband Parrotfish
Mean Number of Fish per Habitat Type
Number of Surveys with Fish: 1760
Number of Fish: 5076
Surveys:484
Fish: 1305
Mean Number of Fish per Habitat Type
Mean Relative Abundance
Stoplight Parrotfish
Fish: 3521
Fish: 2701
Mean Number of Fish per Habitat Type
Fish: 116
Fish: 79
Fish: 17
Fish: 41
SS
Stomach content analysis for stoplight and redband parrotfish has confirmed that
diet consists primarily of algae and to a lesser extent, seagrass (Munro 1983).
Thus, our observations agree with that finding.
This study involved a collaboration between four agencies.
Stoplight and redband parrotfish were identified, enumerated and visually sized to
the nearest cm. ANOVA’s were run on the entire dataset to obtain abundance and
presence / absence values for each species. The datasets were then subdivided
into juveniles and adults and ANCOVA’s were run using “size” as the covariate. For
stoplight parrotfish, all fish 15 cm and over were considered adults, while juveniles
were less than 15 cm. Redband parrotfish 10 cm and over were considered adults
and under 10 cm were considered as juveniles.
RR
How do our results compare with other studies?
Habitat Type
The Florida Fish and Wildlife Commission conducted fish population surveys
during 2008 and 2009 under a collaborative arrangement with the National
Oceanographic and Atmospheric Association, National Parks Service and the
University of Miami’s Rosenstiel School of Marine and Atmospheric Science to
evaluate abundance, spatial distribution, and size structure of reef fishes in the
Florida Keys. The surveys are carried out by SCUBA divers who collect information
on fish abundance as well as other parameters including habitat type.
IR
Juvenile
Adult
3) Ontogeny did not significantly impact habitat preference.
Surveys: 1163
b
b
b
Percent Fish Present
a
Surveys: 1160
Stoplight Parrotfish Male
a
a
Surveys: 1029
Stoplight Parrotfish Female
Percent Fish Present
a
Stoplight Parrotfish Juvenile
SG
Number of Juveniles: 8747
Number of Adults: 10700
Habitat Type
Surveys: 192
Two commonly observed parrotfish were studied.
CR
Fish: 1324
Artificial Reef (AR)
Studies have shown that blue parrotfish (Scarus coeruleus), demonstrate an
ontogenetic feeding shift from algae to sand as they progress from juvenile to
adult. We are interested to see if the stoplight and redband parrotfish also
demonstrate an ontogenetic trend:
Fish: 908
Sand and Seagrass Matrix (SS)
2) When present, which habitats have the greatest abundance of stoplight and
redband parrotfish?
Fish: 1011
Isolated Reef (IR)
Fish: 275
Spur and Groove Reef (SG)
Fish: 923
Continuous Reef (CR)
Mean Number of Fish per Habitat Type
Number of Juveniles: 1623
Number of Adults: 3453
1) In which habitat are you likely to find stoplight and redband parrotfish?
3) Does ontogeny affect stoplight and redband parrotfish abundance in these
habitats?
Mean Abundance by Size
Redband Parrotfish
Fish: 2019
Parrotfish, so called for their tightly packed teeth which form a parrot-like beak are
important herbivores to coral reefs. They use their specialized beak to rasp algae
from dead coral and other substrates thus contributing to bioerosion and controlling
algae. Stoplight and redband parrotfish also consume seagrass such as Thalassia
testudinum and Halimeda opuntia, and are consequently observed feeding in a
wide variety of habitats from coral reefs to seagrass beds. In light of these
dimorphic feeding habits, this study asks two questions:
No ontogenetic trends in habitat preference were observed for either the
stoplight or redband parrotfish.
Fish: 3139
Six distinct habitat types were surveyed, but Artificial Reef was removed
from analysis due to low sample sizes.
Fish: 382
Parrotfish are found in all of the worlds tropical and sub-tropical oceans.
SS
Parrotfish photographs by Reefnet (reefnet.ca).
Habitat photographs by Alison Johnson.