Echinoderms, Malpelo Fauna and Flora Sanctuary, Colombian Pacific: New reports and distributional issues

A systematic list of echinoderms from Malpelo Fauna and Flora Sanctuary (MFFS) was prepared, based on local sampling, literature review and identification of specimens from Museo de Historia Natural Marina de Colombia (MHNMC) and from National Museum of Natural History, Smithsonian Institution, Washington D. C. (USNM). Standard methodology for monitoring the Eastern Tropical Pacific Seascape was used in December 2006 and March 2007 to sample shallow water echinoderms (1-20 m deep). Malpelo is the richest locality of the Colombian Pacific with 84 species reported (56 % of them deep water organisms), belonging to 22 orders, 42 families and 68 genera, distributed between the surface and a depth of 5000 m. Thirty-six new records for MFFS and Colombian Pacific are reported. In Colombia the shallow water species are widely distributed in the Pacific, while deep forms only occur at Malpelo. The majority of species are mostly related to the Panamanian and Galapagos region showing a possible connectivity. This list increases knowledge on the echinoderm biodiversity from the Malpelo Island in 68 %. Introduction The echinoderms are organisms which are able to feed in a variety of levels, being an important link in the marine trophic networks (Birkeland 1989; Ruppert and Barnes 1995). As group, they play a key role in reef ecosystems, mainly because of the erosion they cause due to the mechanical action (Birkeland 1989). The phylum constitutes at least 90 % of the biomass of the benthic deep-water communities, substantially contributing to the ocean productivity (Birkeland 1989; Brusca and Brusca 1990). The echinoderms of Malpelo Fauna and Flora Sanctuary (MFFS) have been little studied even when continued research has been held in the area. The first scientist that collected the group in the MFSS area was Alexander Agassiz (1892), who led the U.S. Fishing Commission expedition on board of the “Albatross” steamer. Later, Downey (1975) and Birkeland et al. (1975) provided the first inventories of asteroids, ophiuroids and echinoids. Since then, Neira and von Prahl (1986), Neira and Cantera (1988), Pardo-Ángel (1989), Pardo-Ángel and Neira (1990), Neira et al. (1992) and Brando et al. (1992) have extended the knowledge of the richness of species within the MFFS. More recently, Arboleda (2002) and Neira and Cantera (2005) increased the number to 29 species of echinoderms, without considering the Crinoidea class. Some Colombian authors (Cantera and Neira 1987; Cantera et al. 1987; Toro-Farmer et al. 2004; Ortiz 2006; Cohen-Rengifo 2008) also gave important ecological and distributional contributions to the knowledge of echinoderms showing, besides inventory information, data about relationships with environmental factors, biogeography and anthropogenic and natural threats. The current island information related with the assemblage composition of echinoderms is scarce and disperse. Therefore, this inventory was obtained by sampling waters between 7 and 20 m deep and by a comprehensive revision of scientific literature and museum collections. Check List 5(3): 702–711, 2009. ISSN: 1809-127X


Introduction
The echinoderms are organisms which are able to feed in a variety of levels, being an important link in the marine trophic networks (Birkeland 1989;Ruppert and Barnes 1995). As group, they play a key role in reef ecosystems, mainly because of the erosion they cause due to the mechanical action (Birkeland 1989). The phylum constitutes at least 90 % of the biomass of the benthic deep-water communities, substantially contributing to the ocean productivity (Birkeland 1989;Brusca and Brusca 1990).
The echinoderms of Malpelo Fauna and Flora Sanctuary (MFFS) have been little studied even when continued research has been held in the area. The first scientist that collected the group in the MFSS area was Alexander Agassiz (1892), who led the U.S. Fishing Commission expedition on board of the "Albatross" steamer. Later, Downey (1975) and Birkeland et al. (1975) provided the first inventories of asteroids, ophiuroids and echinoids. Since then, Neira and von Prahl (1986), Neira and Cantera (1988), Pardo-Ángel (1989), Pardo-Ángel and Neira (1990), Neira et al. (1992) and Brando et al. (1992) have extended the knowledge of the richness of species within the MFFS. More recently, Arboleda (2002) and Neira and Cantera (2005) increased the number to 29 species of echinoderms, without considering the Crinoidea class. Some Colombian authors Toro-Farmer et al. 2004;Ortiz 2006;Cohen-Rengifo 2008) also gave important ecological and distributional contributions to the knowledge of echinoderms showing, besides inventory information, data about relationships with environmental factors, biogeography and anthropogenic and natural threats.
The current island information related with the assemblage composition of echinoderms is scarce and disperse. Therefore, this inventory was obtained by sampling waters between 7 and 20 m deep and by a comprehensive revision of scientific literature and museum collections.

Materials and Methods
The MFFS (3°51'07'' N, 81°35'40'' W) is located 490 km west of Buenaventura port in the Colombian Pacific. The island emerges from a volcanic submarine mountain called the Malpelo ridge that extends in northeast-southwest direction being 241.4 km long and 80.5 km wide (Graham 1975). Its range goes from abyssal depths to 360 m above sea level with an extension of 1.2 km 2 of land and 8574 km 2 of marine protected area This project was carried out at the IV and V Scientific Research Cruises of the ''Fundación Malpelo y otros Ecosistemas Marinos'' and the assistance of UNESCO Seascape project, CI Seascape project (Walton Family Foundation) and Marine Management Area Science project (Gordon and Betty Moore Foundation). The samplings were part of a regional study of the islands within the Marine Conservation Seascape of the Eastern Tropical Pacific (MCSETP) that seeks to evaluate the shallow water marine ecosystems.
Quantitative censuses using underwater visual techniques from the standard Edgar et al. (2004)  Every echinoderm seen over and between the corals, rocks, and crevices was counted, photographed and identified during immersions.

Results and Discussion
The systematic list was composed by 22 orders, 42 families, 68 genera and 84 species (Table 1). The Holothuroidea class was the richest with 24 species while the Ophiuroidea class showed the lowest richness with 18. From the total, 26 species were identified during immersions, while the remaining 58 were obtained from literature during the second stage of the project ( The shallow water starfishes Narcissia gracilis malpeloensis and Tamaria stria are endemic to the island and were described by Downey (1975) in The Biological Investigation of Malpelo Island from the Smithsonian Institution expedition in 1972. Also, N. g. malpeloensis is well represented in the USNM with six museum specimens.
At national level, according to Arboleda (2002) and Neira and Cantera (2005), Malpelo is one of the richest eco-regions with 39 shallow water species (0-200 m), followed by the eco-regions Gorgona and Pacific Ocean (IVEMAR 2000), both with 47 species. However, this study places Malpelo as the richest with a total of 84 shallow and deep water species.
Despite the results for the country, MFFS shows the lowest richness from the Topical Eastern Pacific (TEP) islands, in comparison with the 114 shallow species from Galapagos, Ecuador (Maluf 1991) and 67 from Cocos Island, Costa Rica (Unpublished data from Juan José Alvarado). For example, for Malpelo only five ophiuroids were found, compared with a total of 11 from Galapagos (Hickman 1998) and 17 from Cocos Island (Unpublished data from Juan José Alvarado). This notorious difference could be the consequence of the methods used, which for this study did not include nocturnal immersions or rock removal in order to find cryptic and nocturnal organisms, where species such as Astrodictyum panamense, Ophiocoma aethiops and O. alexandri are considered present and even fairly common in other regions (Unpublished data from Juan José Alvarado; Hickman 1998).
When comparing the distribution of the echinoderms reported herein with those from other regions in the Pacific off the coast of Colombia, we can see the following particularity:  (Neira and Cantera 1988;Pardo-Ángel 1989;Pardo-Ángel and Neira 1990;Neira et al. 1992;Arboleda 2002;Neira and Cantera 2005).  (Neira and von Prahl 1986;Neira and Cantera 2005).

The sea cucumbers
3. The other species, mostly deep-sea ones, are only distributed at Malpelo.
Echinoderms found in MFFS are considered widespread, distributed from the Gulf of California, Galapagos islands, Peru and Chile (Maluf 1988;1991;Hickman 1998;Edgar et al. 2004;Solís-Marín et al. 2005), being also related to the Panamanian and Galapagos region. Starfishes as Acanthaster planci, Eremicaster pacificus, E. crassus gracilis and the holothurians H. keffersteini, H. fuscocinerea, and I. horrens also occur in the Indo-Pacific region, indicating a possible connectivity between the eastern and western Pacific Oceans.
Based on the estimation made by Maluf (1991) who informed the presence of 50 species, this research enhanced the knowledge richness of MFFS in 68 %. Thus, the value of Malpelo as a World Heritage Site is established, where constant research on the marine ecosystems will not only create more tools of judgment and evidence in order to fulfil the statements of the Biological Diversity Convention, but will set the basis for the formulation of biodiversity conservation plans.

Acknowledgements
We thank Juan Jose Alvarado for his ongoing dedication, patience and support. Thanks also to Jaime Cantera for sharing his knowledge, to Milena Benavides Serrato for offering valuable assistance in the identification of museum individuals at INVEMAR as well as Graham Edgar for helping in the field identification. We appreciate the help of Cleveland Hickman for sending his 'Field Guide to Sea Stars and other Echinoderms of Galapagos', and Cynthia Ahearn for sending the Malpelo reference list from the USNM, which has been extremely useful. A special thanks to our friends from ProCAT-Colombia for their dedication to the revision of this paper. We would also like to thank the anonymous reviewers for their comments and help with the manuscript.