NOTE:

CONFIRMATION OF THE OCCURRENCE OF THE CORAL PAVONA CHIRIQUIENSIS GLYNN, MATÉ AND STEMANN (CNIDARIA: ANTHOZOA: AGARICIIDAE) IN THE COLOMBIAN PACIFIC

CONFIRMACIÓN DE LA PRESENCIA DEL CORAL PAVONA CHIRIQUIENSIS GLYNN, MATÉ Y STEMANN (CNIDARIA: ANTHOZOA: AGARICIIDAE) EN EL PACÍFICO COLOMBIANO

Fernando A. Zapata¹, Alberto Rodríguez-Ramírez², Melina Rodríguez-Moreno³, Carlos G. Muñoz¹ and Mateo López-Victoria³

¹Universidad del valle, Departamento de Biología, apartado aéreo 25360, Cali, Colombia. e-mail: fazapata@ univalle.edu.co (FaZ); munozcarlosg@gmail.com (CM)
²Instituto de Investigaciones Marinas y Costeras (InveMar), apartado aéreo 1016, Cerro Punta Betín, Santa Marta. e -mail: betorod@invemar.org.co (arr)
³Justus-Liebig University, Department of animal ecology, Heinrich-Buff-ring 29, 35392, Giessen, Germany. e-mail: sv6683@uni-giessen.de (MrM); sv6682@uni-giessen.de (MLv)

El género Pavona comprende 18 especies de las cuales Pavona chiriquiensis ha sido recientemente descrita y registrada en varias localidades del Pacífico oriental tropical. A partir de observaciones y colecciones realizadas en arrecifes de las islas Gorgona y Malpelo entre 1999 y 2005 se confirma su presencia en Colombia. El tardío registro de P. chiriquiensis en estas islas pudo ser debido a su similitud y confusión con P. varians, o a su reciente colonización del Pacífico colombiano.

PALABRAS CLAVE: Colombia, Corals, Coral reefs, Gorgona I., Malpelo I., Pavona chiriquiensis, Tropical Eastern Pacific.

The scleractinian coral genus Pavona, restricted to but widely distributed within the Indo-Pacific region (Veron, 2000), includes 18 valid species, eight of which occur in the Tropical Eastern Pacific (TEP; Glynn and Ault, 2000; Reyes-Bonilla, 2002). Pavona chiriquiensis Glynn, Mate and Stemann, 2001 is the most recently described species of this genus occurring in the TEP (Glynn et al., 2001). Although this species had been observed since the early 1970’s in shallow rocky outcrops in Panama and was believed to be rare, it is now known to be widely distributed on island sites of the TEP (Glynn et al., 2001). P. chiriquiensis was known to occur in Colombian Pacific waters (Zapata, 2001; Zapata and Vargas-Angel, 2003) but only from anecdotal accounts (H.M. Guzmán, pers. com.; B. Vargas-Angel, pers. com) and a photographic record from Malpelo Island (Garzón-Ferreira and Pinzón, 1999). Here, we confirm the occurrence of P. chiriquiensis at Gorgona and Malpelo Islands (Colombia) based on observations, photographs or specimens collected between 2003 and 2005.

Most observations were made while skin or SCUBA diving on coral reefs located on the eastern, leeward side of Gorgona Island, Colombia (2° 58’ N, 78° 11’ W) during September 11-17, 2004 and October 22-28, 2005. During these periods, extensive observations of the coral communities at La Azufrada and Playa Blanca reefs were made while collecting data for a coral reef monitoring program (SIMAC; Garzón-Ferreira, 1999). Other observations at Gorgona Island were made on October 18-25, 2003 at the Old Pier Reef and La Azufrada, and on October 28, 2005 at El Laberinto, a rocky area composed of large boulders and located southwest of El Horno on the northern tip of the island (see Zapata, 2001 and Zapata and Vargas-Angel, 2003 for maps and description of Gorgona Island coral reefs). Additional observations were made by one of us (M.L.V.) at Malpelo Island (4° 00’ N, 81° 36’ W) on late September 2004. During these periods, we observed several isolated colonies of P. chiriquiensis, some of which were photographed and collected as reference material. This material is now deposited at the Museo de Historia Natural Marina de Colombia (Marine Natural History Museum of Colombia; MHNMC for its Spanish acronym) housed in the Instituto de Investigaciones Marinas y Costeras (INVEMAR) in Santa Marta and at the Marine Biology Reference Collection of Universidad del Valle (CRBMUV) in Cali. We also examined two additional specimens collected by J. Garzón-Ferreira at Malpelo in 1999 (see Garzón-Ferreira and Pinzón, 1999).

We first observed colonies of P. chiriquiensis at Gorgona on the back-reef of the Old Pier Reef and on the reef flat of La Azufrada reef in 2003. These were small (7.5-9.5 cm largest dimension), massive-looking colonies closely resembling unattached colonies of Pavona varians. However, their unusual morphology, sufficiently distinct from that of P. varians, led us to collect two specimens (Catalog Nos. CRBMUV-CORALES 2003001 and 2003002). This material remained unidentified until 2004 when we observed several additional colonies at different sites on La Azufrada Reef.

The first colony observed in 2004 was found on the reef flat of La Azufrada reef at <1 m depth at low tide. This colony was 52 cm long x 47 cm wide x 3-4 cm high, irregularly shaped, massive-looking, and bumpy on the surface (Figure 1a). However, closer examination revealed that it consisted of a thin sheet of coral encrusting pocilloporid coral rubble. The surface exhibited a dense number of hydnophorae and short and low collines (Figure 1b). The live coloration was brown-orange to pinkish with clearly contrasting pale polyp mouths at the center of corallites. The latter characteristic

and the clearly encrusting growth allowed us to tentatively identify this colony as P. chiriquiensis. A number of additional, isolated colonies were later observed at several sites on La Azufrada reef in September 2004. These varied from small (<10 cm diameter) to relatively large (<80 cm) colonies that were almost invariably encrusting dead coral, most often pocilloporid branch fragments, but occasionally dead massive agariciids that were in deeper water (~7 m). All of these exhibited the same basic characteristics described for the first colony although live tissue coloration varied from tan to burned yellow or olive green. Because previous records of the occurrence of P. chiriquiensis at Gorgona were only anecdotal, we photographed and collected several specimens (CRBMUV-CORALES 2004001 and 2004002, and MHNMC -INV-CNI-2954), which were later examined in the laboratory. Corallites of these specimens were small, with indistinct walls and welldeveloped septo-costae in a thamnasterioid arrangement (Figure 1c). The collumella was solid and styliform; the septa were exert and profusely dentate on the sides, but less so on the margins (Figure 1d). These characteristics were compared with descriptions of P. chiriquiensis (Glynn et al., 2001; Maté, 2003) and led us to confirm our tentative field identification. Further confirmation was provided by P.W. Glynn (pers. comm.) after examining some photographs of our specimens. Comparisons with the specimens collected in 2003 revealed that these were also P. chiriquiensis. Examination of specimens collected by J. Garzón-Ferreira at Malpelo Island in 1999 (MHNMC -INV-CNI 234 and 239) and that had been tentatively identified as P. chiriquiensis by P.W. Glynn from a field photograph, confirmed the original report of this species at Malpelo (Garzón-Ferreira and Pinzón, 1999). Since our initial observations in 2003 and 2004, we have observed more colonies of P. chiriquiensis at Gorgona and Malpelo Islands. On September 29, 2004 several colonies (0.5 - 1 m largest dimension) were observed at El Arrecife, in Malpelo Island, at 8-10 m depth, some of them in direct contact and apparent space competition with a colony of Pavona cf. gigantea (M.L.V., pers. obs.). One specimen was collected on this occasion (MHNMC -INV-CNI 2955). On October 28, 2005 several colonies were also observed at El Laberinto in Gorgona Island, at ~10 m depth (F.A.Z., pers. obs.). In both of these cases all colonies were encrusting basaltic rock.

Our findings confirm the occurrence of P. chiriquiensis both at Gorgona and Malpelo Islands. Although not abundant at either locality, at Gorgona P. chiriquiensis is now frequently observed encrusting coral substrates on coral reefs, even though it appears to be more abundant on rocky outcrops as it is elsewhere in the TEP (Glynn et al., 2001; Maté, 2003). The frequency with which P. chiriquiensis is now observed at both localities raises the question as to why, in spite of much work (particularly at Gorgona since 1997), this species had been only rarely observed previously. Although P. chiriquiensis was not described until 2001, it had been observed in Panama since the early 1970’s (Glynn et al., 2001), and the existence of an undescribed species of Pavona under study by P.W. Glynn was known to many since the late 1990’s. The morphological similarity between P. varians and P. chiriquiensis suggests that the latter may have been overlooked by confusion with the former. Alternatively, it is also plausible that P. chiriquiensis may have only relatively recently invaded Colombian Pacific coral communities and that its abundance may be increasing there as it has in other localities in the TEP where it is now more abundant than P. varians (Glynn et al., 2001). Its thin laminar corallum may allow for rapid colony growth. Additionally, short-term aggressive dominance experiments have shown that P. chiriquiensis is more aggressive than P. varians, which in turn is dominant over Pavona frondifera (Maté, 2003). One of the specimens from Gorgona observed in the laboratory was found to have two recently settled recruits of what appeared to be P. chiriquiensis (Figure 2). This is evidence of sexual reproduction and active recruitment and represents an additional mechanism by which P. chiriquiensis may be increasing its population at Gorgona. Thus, P. chiriquiensis appears to be an opportunistic species with a capacity for rapidly colonizing available substrates and invading coral communities. However, P.

chiriquiensis has a lower bleaching and mortality threshold during sea warming than P. varians (Maté, 2003) and this may have slowed down its rate of invasion, particularly during the 1997-1998 El Niño warming event, which caused greater bleaching and mortality in massive agariciids than in branching pocilloporids (Vargas-Angel et al., 2001).

ACKNOWLEDGEMENTS

The development and implementation of SIMAC (National Monitoring System for Coral Reefs in Colombia) has been possible at Gorgona and Malpelo thanks to the support of the Instituto de Investigaciones Marinas y Costeras (INVEMAR), the Instituto Colombiano de Ciencia y Tecnología (Colombian Institute of Science and Technology; COLCIENCIAS) through grant Colciencias-BID 2105-09-327-97, the Regional Coordination Unit for the Caribbean of the United Nations Environment Program (UNEPCAR/ RCU), the National Environmental Fund (FONAM) through Environmental Program Agreement BID-7740C/CO, the Special Administrative Unit of the System of National Natural Parks (UAESPNN) of the Ministry of the Environment, Housing and Territorial Development, the Malpelo Foundation and the Coral Reef Ecology Research Group of Universidad del Valle. We are grateful for the decisive support of UAESPNN personnel at Gorgona, particularly Claudia Acevedo, Camilo Gómez and Luis Chasqui. We thank P.W. Glynn for examining photographs and providing literature on P. chiriquiensis and H.M. Guzmán for comments regarding P. chiriquiensis at Gorgona.

LITERATURE CITED

1 Garzón-Ferreira, J. 1999. SIMAC: a new program to monitor coral reef condition in Colombia. Reef Encounter, 25:14-15.        [ Links ]

2 Garzón-Ferreira, J. and J. Pinzón. 1999. Evaluación rápida de estructura y salud de las formaciones coralinas de la Isla de Malpelo (Pacífico colombiano). Bol. Invest. Mar. Cost., 28:137-154.        [ Links ]

3 Glynn, P.W. and J.S. Ault. 2000. A biogeographic analysis and review of the far eastern Pacific coral reef region. Coral Reefs, 19:1-23.         [ Links ]

4 Glynn, P.W., J.L. Maté and T.A. Stemann. 2001. Pavona chiriquiensis, a new species of zooxanthellate scleractinian coral (Cnidaria: Anthozoa: Agariciidae) from the eastern tropical Pacific. Bull. Biol. Soc. Wash., 10:210-225.         [ Links ]

5 Maté, J.L. 2003. Ecological, genetic, and morphological differences among three Pavona (Cnidaria: Anthozoa) species from the Pacific coast of Panama. I. P. varians, P. chiriquiensis, and P. frondifera. Mar. Biol., 142:427-440.         [ Links ]

6 Reyes-Bonilla, H. 2002. Checklist of valid names and synonyms of stony corals (Anthozoa: Scleractinia) from the eastern Pacific. J. Nat. Hist., 36:1-13.         [ Links ]

7 Vargas-Ángel, B., F.A. Zapata, H. Hernández and J.M. Jiménez. 2001. Coral and coral reef responses to the 1997-98 El Niño event on the Pacific coast of Colombia. Bull. Mar. Sci., 69:111-132.        [ Links ]

8 Veron, J.E.N. 2000. Corals of the world. Australian Institute of Marine Sciences and CRR Qld Pty Ltd. Townsville, Vol 2, 429p.         [ Links ]

9 Zapata, F.A. 2001. Formaciones coralinas de Isla Gorgona. 27-40. In: Barrios, L. M. and López-Victoria (Eds.). Gorgona marina: Contribución al conocimiento de una isla única. INVEMAR-Serie Publicaciones Especiales No. 7, Santa Marta.        [ Links ]

10 Zapata, F.A. and B. Vargas-Angel. 2003. Corals and coral reefs of the Pacific coast of Colombia. 419-447. In: J. Cortés (Ed.). Coral reefs of Latin America. Amsterdam: Elsevier Science.        [ Links ]

FECHA DE RECEPCIÓN: 26/04/06                           FECHA DE ACEPTACIÓN: 25/10/06