RESUMEN
El nor-occidente del Golfo de Urabá, Colombia, abriga los arrecifes más meridionales del Mar Caribe, sometidos a altas turbulencias y condiciones fluctuantes de turbidez y salinidad. Se presenta una lista sistemática anotada de esponjas (Porifera) de esta área. Un total de 77 especies de la clase Demospongiae, 3 especies de la clase Homoscleromorpha y 1 especie de la clase Calcarea fueron encontradas en litorales rocosos y áreas arrecifales por encima de los 20 m de profundidad. Algunas especies en Urabá presentan espículas silíceas con dimensiones superiores a las registradas en otras áreas del Caribe, debido probablemente al aporte adicional de sílice de las grandes descargas de los ríos en el interior del Golfo. Este trabajo incluye, adicionalmente, la descripción taxonómica formal de 15 especies, que representan nuevos registros para el Caribe Colombiano.
Palabras clave: Esponjas, Porifera, Demospongiae, Calcarea, Caribe, espículas hipersilicilicadas.
ABSTRACT
The North-West Gulf of Urabá, Colombia, harbors the southernmost Caribbean reefs, exposed to high turbulence and fluctuating turbidity and salinity. An annotated systematic check-list of sponges from this area is presented. A total of 77 demosponge species (class Demospongiae), 3 homoscleromorph species (class Homoscleromorpha) and 1 calcareous species (class Calcarea) were found to inhabit rocky shores and reefs, above 20 m in depth. Some species in Urabá bear siliceous spicules larger than in other Caribbean areas, probably owing to additional silicon input from heavy river discharge in the gulf. This work provides, additionally, the formal taxonomic description of 15 species, which are new records for the Colombian Caribbean.
Key words: Sponges, Porifera, Demospongiae, Calcarea, Caribbean.hipersilicified spicules.
ANNOTATED CHECKLIST OF SPONGES (PORIFERA) FROM THE SOUTHERNMOST CARIBBEAN REEFS (NORTH-WEST GULF OF URABÁ), WITH DESCRIPTION OF NEW RECORDS FOR THE COLOMBIAN CARIBBEAN
Introduction
The continental coast of Colombia in the Caribbean Sea has particular ecological and geological features that differ markedly from other intensively explored areas of the Caribbean (see Hajdu et al.. 1995). This is especially true for the Gulf of Urabá, an area near the Colombia-Panama border that represents the southernmost portion of the Caribbean Sea. That area was part of the deep ocean corridor that connected the eastern Pacific to the Caribbean Sea before the rising of the Isthmus of Panama. Currently it is greatly influenced by large amounts of sediments and fresh water discharged by the Atrato River (Chevillot et al., 1993; Duque-Caro. 1990). Moreover, at the North-West margin of the Gulf, fringing and patch reefs flourish in conditions of fluctuating high turbulence, turbidity and salinity (Diaz et al., 2000). In spite of these environmental and geological features, the knowledge of the flora and fauna of the Gulf of Urabá is very poor, even compared to other areas of the Colombian Caribbean (Bula-Meyer & Schnetter, 1988, Alvarado, 1992; Zea, 1998).
The systematic study of sponges in Colombia is very recent, covering only the last three decades. In the Gulf of Urabá, surveys have been carried out on rocky shores and reef environments, less than 20 m in depth, along the coastline of Capurgana and Sapzurro towns,...