|Scientific Name:||Polycyathus isabela|
|Species Authority:||Wells, 1982|
|Red List Category & Criteria:||Vulnerable D2 ver 3.1|
|Assessor/s:||Chiriboga, A., Hickman, C., Edgar, G., Banks, S. & Vera, M.|
|Reviewer/s:||Stuart, S.N. & Carpenter, K.E. (Global Marine Species Assessment Coordinating Team)|
Recorded as isolated colonies at only three sites on one island (i.e., Punta Albemarle, Punta Vicente Roca and Caleta Iguana). Extensive underwater surveys across Galápagos between 2000 and 2006 have revealed the presence of this species at only two sites. Although assessed here as Vulnerable using the D2 criterion associated with small range size and potential threat from the effects of El Niño, there is also concern that populations of P. isabela have declined in recent decades, as is evident for other local coral species. The population status of the type subpopulation from Punta Albemarle is unknown, although the species has not been sighted in recent searches in that region. The subpopulation from Punta Vicente Roca (sighted in 2003), has not been subsequently seen; despite this location having been surveyed since. While this evidence for decline may suggest listing as Endangered under criteria A or B, the paucity of records for this species makes it difficult to have any degree of confidence in population trends and therefore it is more tenable to assess it as Vulnerable under the D2 criterion which does appear to be well supported by the available evidence.
|Range Description:||Polycyathus isabela is an endemic species for the ETP region, present only around the Galápagos Archipelago. Occurrence known from Punta Albemarle (14 m, holotype); Punta Vicente Roca (10 m), and Caleta Iguana (11 m) at Isabela Island (Wells 1983, Cairns 1991, Reyes-Bonilla 2002, Hickman 2005).|
|FAO Marine Fishing Areas:||
Pacific – southeast
|Range Map:||Click here to open the map viewer and explore range.|
P. isabela is an uncommon species (Hickman 2005), only recorded from three sites at Isabela Island (viz. Punta Albemarle, Punta Vicente Roca and Caleta Iguana). The population status of the type subpopulation from Punta Albemarle is unknown, although the species has not been sighted in recent searches in that region.
The subpopulation from Punta Vicente Roca (sighted in 2003), has not been seen subsequently, despite this location having been surveyed seasonally since that time (Chiriboga, Hickamn and Edgar pers. comms.). In addition, another small colony was sighted in 2004 at Caleta Iguana, Isabela during underwater searches (Chiriboga, Hickman and Edgar pers. comms.).
|Habitat and Ecology:||In recesses or caves with subdued light (Hickman 2005), reported at depths of 10 to 23 m (Cairns 1991, Hickman 2005).|
|Major Threat(s):||Unknown. Presumably El Niño and climate change.|
|Conservation Actions:||Present in one protected area in the ETP region: Galápagos Marine Reserve (IUCN category VI); Galápagos Archipelago Particularly Sensitive Area (PSSA); Galápagos Island World Heritage Site (UNESCO N (i)(ii)(iii)(iv), and Galápagos Island Man and Biosphere Reserve (UNESCO). Included with corals in CITES Appendix II.|
Cairns, S.D. 1991. A revision of the ahermatypic Scleractinia of the Galápagos and Cocos Islands. Smithsonian Contributions to Zoology 504: 32.
Hickman, C. 2005. A Field Guide to Corals of Galápagos. Sugar Spring Press, Lexington, VA. 52 pp.
IUCN. 2007. 2007 IUCN Red List of Threatened Species. Available at: www.iucnredlist.org. (Accessed: 12th September 2007).
Reyes-Bonilla, H. 2002. Checklist of valid names and synonyms of the stony corals (Anthozoa: Scleractinia) from eastern Pacific. Journal of Natural History 36: 1-13.
|Citation:||Chiriboga, A., Hickman, C., Edgar, G., Banks, S. & Vera, M. 2007. Polycyathus isabela. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 24 May 2013.|
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