Coral reefs in La Parguera are distributed in three parallel lines: (1) inshore, (2)
mid-shelf and (3) outer shelf (Almy and Carrión-Torres 1963, Acevedo and
Morelock 1988). The length and the wide range of the reef’s depths produce
physical, chemical and biological gradients providing a highly productive, structurally complex, and biologically diverse ecosystem (Morelock et al. 1977,
Acevedo and Morelock 1988). The most common mangrove species is Rizophora
mangle (L.) Laguncularia racemosa (L. Gaertn. f.) is less common. Extensive sea
grass beds are well established in La Parguera. Thalassia testudinum (Banks ex
König) and Syringodium filiforme (Kützing) are the most common and widely
distributed species. Also, most extensive sea grass beds are found at a depth of two
meter around mangrove islands (García et al. 2003).
With the goal to characterize the echinoderms fauna in two major communities
in La Parguera, Benavides-Serrato (2006) collected and described echinoderms
associated with coral reefs and seagrass communities during several field trips
(February of 2005 to January of 2006) at eleven different localities (Fig. 14.4).
As a result of this study, 32 species were found at La Parguera. Thirty-one
species of echinoderms were identified from sampling stations from the seagrass
beds. The most abundant classes were Echinoidea (mean abundance varied
between 0.22 ind m
-2 at Caballo Blanco to 5.89 ind m
-2 at San Cristobal, represented by L. variegatus, E. lucunter and E. viridis) and Ophiuroidea (mean
abundance varied from 0.31 ind m
-2 at Caballo Blanco to 3.99 ind m
-2 at San
Cristobal, principally represented by Ophiocoma echinata (Lamarck), Ophiactis
savignyi (Müller and Troschel), Ophiothrix (Ophiothrix) angulata (Say) and
Ophiothrix (Ophiothrix) orstedii (Lütken).
Twenty-four species of echinoderms were identified from the coral reef community. Ophiuroidea had the highest number of species (14). The composition of
the different classes at different depths showed that ophiuroid and echinoid species
were widely distributed from depths of 0 to 20 m. Crinoids only appeared at
depths greater than the 10 m. On the other hand, asteroids were absent from the
shallow water habitats (0–5 m). The crinoids Davidaster discoidea and D. rubiginosa (Pourtalès) were only found at The Buoy at a depths of 20–30 m.
14.3.1 Asteroidea Distribution
A total of seven species of sea stars within the Order Valvatida have been documented in Puerto Rico. These include Oreaster reticulatus (Linnaeus) in the
family Oreasteridae. This is probably one of the most significant and ubiquitous
sea stars of seagrass communities in Puerto Rico. It has been commonly documented across the entire shelf on seagrass bottoms and sandy patches from nearly
sea level to about 25 m depths, but is particularly abundant on shallow water
(depth \ 10 m) seagrass communities adjacent to Vieques, Culebra Island, La
Cordillera, and Fajardo, off northeastern Puerto Rico. Populations have locally
disappeared over the last three to four decades from many locations across the
14 Review of Echinoderm Research in Puerto Rico
455
mid-shelf and (3) outer shelf (Almy and Carrión-Torres 1963, Acevedo and
Morelock 1988). The length and the wide range of the reef’s depths produce
physical, chemical and biological gradients providing a highly productive, structurally complex, and biologically diverse ecosystem (Morelock et al. 1977,
Acevedo and Morelock 1988). The most common mangrove species is Rizophora
mangle (L.) Laguncularia racemosa (L. Gaertn. f.) is less common. Extensive sea
grass beds are well established in La Parguera. Thalassia testudinum (Banks ex
König) and Syringodium filiforme (Kützing) are the most common and widely
distributed species. Also, most extensive sea grass beds are found at a depth of two
meter around mangrove islands (García et al. 2003).
With the goal to characterize the echinoderms fauna in two major communities
in La Parguera, Benavides-Serrato (2006) collected and described echinoderms
associated with coral reefs and seagrass communities during several field trips
(February of 2005 to January of 2006) at eleven different localities (Fig. 14.4).
As a result of this study, 32 species were found at La Parguera. Thirty-one
species of echinoderms were identified from sampling stations from the seagrass
beds. The most abundant classes were Echinoidea (mean abundance varied
between 0.22 ind m
-2 at Caballo Blanco to 5.89 ind m
-2 at San Cristobal, represented by L. variegatus, E. lucunter and E. viridis) and Ophiuroidea (mean
abundance varied from 0.31 ind m
-2 at Caballo Blanco to 3.99 ind m
-2 at San
Cristobal, principally represented by Ophiocoma echinata (Lamarck), Ophiactis
savignyi (Müller and Troschel), Ophiothrix (Ophiothrix) angulata (Say) and
Ophiothrix (Ophiothrix) orstedii (Lütken).
Twenty-four species of echinoderms were identified from the coral reef community. Ophiuroidea had the highest number of species (14). The composition of
the different classes at different depths showed that ophiuroid and echinoid species
were widely distributed from depths of 0 to 20 m. Crinoids only appeared at
depths greater than the 10 m. On the other hand, asteroids were absent from the
shallow water habitats (0–5 m). The crinoids Davidaster discoidea and D. rubiginosa (Pourtalès) were only found at The Buoy at a depths of 20–30 m.
14.3.1 Asteroidea Distribution
A total of seven species of sea stars within the Order Valvatida have been documented in Puerto Rico. These include Oreaster reticulatus (Linnaeus) in the
family Oreasteridae. This is probably one of the most significant and ubiquitous
sea stars of seagrass communities in Puerto Rico. It has been commonly documented across the entire shelf on seagrass bottoms and sandy patches from nearly
sea level to about 25 m depths, but is particularly abundant on shallow water
(depth \ 10 m) seagrass communities adjacent to Vieques, Culebra Island, La
Cordillera, and Fajardo, off northeastern Puerto Rico. Populations have locally
disappeared over the last three to four decades from many locations across the
14 Review of Echinoderm Research in Puerto Rico
455