open sand flat for comparison. The radius of each individual was measured. They
also recorded the coloration pattern to distinguish juveniles from adults. Their
results showed that O. reticulatus density varied among sites. It was lowest at the
seagrass bed and highest at sand bottom, while intermediate densities were
recorded at mangrove and fringing reef sites. They noted that asteroid populations
in mangrove and coral habitats were mainly composed of juveniles, but lowest in
the seagrass beds and intermediate on the sand flat. Based on the abundance of
juveniles on mangrove banks and in fringing reefs, they concluded that these are
important habitats for recruitment and serve as nurseries for O. reticulatus.
Furthermore, they proposed that species such as O. reticulatus may serve as
sentinels of ecological change, and they may have broad-ranging effects in the
health of coastal ecosystems.
Pacific
Guzman and Cortés (1989), as part of a study of the coral reefs at Caño Island,
indicated the presence of the sea star Acanthaster planci. This species was found in
densities between 0.4 and 1.8 ind ha
-1 , and feeding mainly on the corals Pavona,
Psammocora and Pocillopora. Acanthaster planci was also observed at Cocos
Island, where it had densities of 10.4 ± 3.1 ind ha
-1 in 1987. It fed on Porites
lobata, a coral that was not part of its diet (Guzman and Cortés 1992). Guzman and
Cortés (2007) reported densities of 7.4 ± 2.3 ind ha
-1 in 2002. Alvarado and
Chiriboga (2008) reported a density of 0.02 ind m
-2 on only two of 19 study sites
around the island. In other studies the seastar was present in four of five reefs
studied (Guzman and Cortés 1992, 2007).
Ophiuroid Ecology
Caribbean
During the 1990s, Richard B. Aronson evaluated the impact of hurricanes and
storms on predator–prey dynamics in Caribbean coral reefs. Aronson (1991)
assessed predation, physical disturbance and sublethal arm damage in ophiuroids
(Ophioderma spp.) in Belize and Jamaica in order to compare to Jurassic-Present
trends. This study supported the hypothesis that predation on ophiuroids increased
when durophagous teleostean fishes and decapods crustaceans diversified in the
Late Mesozoic.
Aronson (1992) investigated predation intensity experienced by Ophiothrix
oerstedi within and among back reef sites in Jamaica, Barbados and Belize, and
provided assessment of the impact of severe storms on predator–prey interactions
in back reef habitats. Aronson (1998) evaluated the ecology of predation on
ophiuroids in the Caribbean on two temporal scales: seasonally over a 3 years
period and annually over a decade. His research suggests that some ecological
3 Central America Echinoderms: Diversity, Ecology and Future Perspectives
77
also recorded the coloration pattern to distinguish juveniles from adults. Their
results showed that O. reticulatus density varied among sites. It was lowest at the
seagrass bed and highest at sand bottom, while intermediate densities were
recorded at mangrove and fringing reef sites. They noted that asteroid populations
in mangrove and coral habitats were mainly composed of juveniles, but lowest in
the seagrass beds and intermediate on the sand flat. Based on the abundance of
juveniles on mangrove banks and in fringing reefs, they concluded that these are
important habitats for recruitment and serve as nurseries for O. reticulatus.
Furthermore, they proposed that species such as O. reticulatus may serve as
sentinels of ecological change, and they may have broad-ranging effects in the
health of coastal ecosystems.
Pacific
Guzman and Cortés (1989), as part of a study of the coral reefs at Caño Island,
indicated the presence of the sea star Acanthaster planci. This species was found in
densities between 0.4 and 1.8 ind ha
-1 , and feeding mainly on the corals Pavona,
Psammocora and Pocillopora. Acanthaster planci was also observed at Cocos
Island, where it had densities of 10.4 ± 3.1 ind ha
-1 in 1987. It fed on Porites
lobata, a coral that was not part of its diet (Guzman and Cortés 1992). Guzman and
Cortés (2007) reported densities of 7.4 ± 2.3 ind ha
-1 in 2002. Alvarado and
Chiriboga (2008) reported a density of 0.02 ind m
-2 on only two of 19 study sites
around the island. In other studies the seastar was present in four of five reefs
studied (Guzman and Cortés 1992, 2007).
Ophiuroid Ecology
Caribbean
During the 1990s, Richard B. Aronson evaluated the impact of hurricanes and
storms on predator–prey dynamics in Caribbean coral reefs. Aronson (1991)
assessed predation, physical disturbance and sublethal arm damage in ophiuroids
(Ophioderma spp.) in Belize and Jamaica in order to compare to Jurassic-Present
trends. This study supported the hypothesis that predation on ophiuroids increased
when durophagous teleostean fishes and decapods crustaceans diversified in the
Late Mesozoic.
Aronson (1992) investigated predation intensity experienced by Ophiothrix
oerstedi within and among back reef sites in Jamaica, Barbados and Belize, and
provided assessment of the impact of severe storms on predator–prey interactions
in back reef habitats. Aronson (1998) evaluated the ecology of predation on
ophiuroids in the Caribbean on two temporal scales: seasonally over a 3 years
period and annually over a decade. His research suggests that some ecological
3 Central America Echinoderms: Diversity, Ecology and Future Perspectives
77