CEP). Two-thirds of all CEP echinoderms occur on the continental shelf
(depth \200 m), with a low level of endemism. She found an increase in species
richness from higher to lower latitudes, with peaks of richness in the Gulf of
California, Panama and the Galápagos Archipelago, places that also have a higher
number of endemic species, and are also areas with more research. The Gulf of
California had a greater similarity with the tropics than the Pacific side of the Baja
California peninsula and southern California, while the oceanic island of Cocos
was more similar to the mainland than the Galápagos and Revillagigedo archipelagos. Moreover, she indicated the presence of five faunal transition zones
related to large-scale abiotic parameters. Those transition zones were: (1) the
Galápagos Islands, (2) Gulf of Guayaquil, (3) Costa Rica–Panama, (4) the mouth
of the Gulf of California and (5) Central Baja California outer coast. Seventy
percent of all the 265 CEP shelf restricted species were endemic to the region,
12 % were of a Northeast Pacific affinity (Oregonian and Alaska provinces), 5 %
had a Southeast Pacific affinity (Magellanic and Peruvian provinces), and 13 %
were widespread species. Most species in this last category were transpacific more
than circumtropical, and were species associated with reefs and rocky shores
(Maluf 1988b).
On the Atlantic side, Price et al. (1999) analyzed a database of presence/
absence of the Asteroidea compiled by Clark and Downey (1992) that was based
on records collected over 150 years. They determined geographical patterns of
diversity and make comparisons between coastal and deep-sea diversity for 26
regions of the Atlantic. For 349 species, they found a higher degree of endemism
in coastal waters and a greater level of similarity between regions with increasing
depth. However, the number of species between bathymetrical categories was
similar: 199 species at depths between 0 and 200 m, 135 and 169 species between
200 and 500 m, and 198 species at depths [500 m. The greatest number of species
(81 species) was in the region between Florida and the Yucatan Peninsula, followed by the Bahamas-Caribbean (77 species) and the Caribbean and Guyana
basins together with the Gulf of Mexico region (66 species). This last region
possessed the highest number of endemic species of all the Atlantic Asteroidea (14
species). Regions like Guyanas-Cape Frío, Cape Frío-Río de la Plata, Río de la
Plata-Tierra del Fuego-Falklands islands and the Canary islands had few endemic
species (richness: 48, 22, 43, 26 species respectively; endemism: 1, 1, 8, 0 species
respectively). According to Price et al. (1999) the disparity in sampling efforts is
an important factor which can influence interpretation of geographic patterns.
Alvarado and Cortés (2004), Alvarado et al. (2008, 2010) and Alvarado (2011)
studied the diversity of echinoderms in Central America, covering both Pacific and
Caribbean coast. On both coasts the class Ophiuroidea was the richest with 85
species on the Pacific side and 79 on the Caribbean coast. Panama was also the
richest country in the region on both coasts, with 253 species on the Pacific coast
and 154 species on the Caribbean coast. Alvarado et al. (2010) and Miloslavich
et al. (2010) made an extensive review of published records on echinoderms of the
16 Latin America Echinoderm Biodiversity and Biogeography
517
(depth \200 m), with a low level of endemism. She found an increase in species
richness from higher to lower latitudes, with peaks of richness in the Gulf of
California, Panama and the Galápagos Archipelago, places that also have a higher
number of endemic species, and are also areas with more research. The Gulf of
California had a greater similarity with the tropics than the Pacific side of the Baja
California peninsula and southern California, while the oceanic island of Cocos
was more similar to the mainland than the Galápagos and Revillagigedo archipelagos. Moreover, she indicated the presence of five faunal transition zones
related to large-scale abiotic parameters. Those transition zones were: (1) the
Galápagos Islands, (2) Gulf of Guayaquil, (3) Costa Rica–Panama, (4) the mouth
of the Gulf of California and (5) Central Baja California outer coast. Seventy
percent of all the 265 CEP shelf restricted species were endemic to the region,
12 % were of a Northeast Pacific affinity (Oregonian and Alaska provinces), 5 %
had a Southeast Pacific affinity (Magellanic and Peruvian provinces), and 13 %
were widespread species. Most species in this last category were transpacific more
than circumtropical, and were species associated with reefs and rocky shores
(Maluf 1988b).
On the Atlantic side, Price et al. (1999) analyzed a database of presence/
absence of the Asteroidea compiled by Clark and Downey (1992) that was based
on records collected over 150 years. They determined geographical patterns of
diversity and make comparisons between coastal and deep-sea diversity for 26
regions of the Atlantic. For 349 species, they found a higher degree of endemism
in coastal waters and a greater level of similarity between regions with increasing
depth. However, the number of species between bathymetrical categories was
similar: 199 species at depths between 0 and 200 m, 135 and 169 species between
200 and 500 m, and 198 species at depths [500 m. The greatest number of species
(81 species) was in the region between Florida and the Yucatan Peninsula, followed by the Bahamas-Caribbean (77 species) and the Caribbean and Guyana
basins together with the Gulf of Mexico region (66 species). This last region
possessed the highest number of endemic species of all the Atlantic Asteroidea (14
species). Regions like Guyanas-Cape Frío, Cape Frío-Río de la Plata, Río de la
Plata-Tierra del Fuego-Falklands islands and the Canary islands had few endemic
species (richness: 48, 22, 43, 26 species respectively; endemism: 1, 1, 8, 0 species
respectively). According to Price et al. (1999) the disparity in sampling efforts is
an important factor which can influence interpretation of geographic patterns.
Alvarado and Cortés (2004), Alvarado et al. (2008, 2010) and Alvarado (2011)
studied the diversity of echinoderms in Central America, covering both Pacific and
Caribbean coast. On both coasts the class Ophiuroidea was the richest with 85
species on the Pacific side and 79 on the Caribbean coast. Panama was also the
richest country in the region on both coasts, with 253 species on the Pacific coast
and 154 species on the Caribbean coast. Alvarado et al. (2010) and Miloslavich
et al. (2010) made an extensive review of published records on echinoderms of the
16 Latin America Echinoderm Biodiversity and Biogeography
517