Sea Urchins of the Philippines 
Rich Mooi i and Angelica Munguia 2 
^ Department of Invertebrate Zoology & Geology, California Academy of Sciences, 
55 Music Concourse Drive, San Francisco, CA 94118; Email: rmooi@calacademy.07g 
2 University of California at Davis, Davis, CA 95616; Email: anmimguia@ucdavis.edu 
A list of 210 species of echinoids recorded from the Philippines was developed using 
data from the literature, the 2011 Hears! Philippine Biodiversity Expedition, and 
ancillary sources such as collections at the California Academy of Sciences and the 
National Museum of Natural History at the Smithsonian Institution. The list was 
then taxonomically updated using the World Echinoidea Database. The Philippines is 
home to more species of echinoids than any other comparable region in the world. 
Ongoing discovery of new Philippine records and species new to science indicate that 
present species richness estimates for the Philippines are conservative. Analysis of 
the list suggests that the unsurpassed Philippine cchinoid diversity is best explained 
by the center of overlap hypothesis. Several of the echinoid species encountered dur¬ 
ing the Expedition have the potential of dramatically increasing our understanding 
of their evolution, behavior, and ecological significance. 
Keywords: Echinoidea, species list, systematics, center of overlap hypothesis, biodiver¬ 
sity, bathymetry 
Accurate esthnates of species richness are crucial to arguments made in favor of policies 
intended to protect specific marine regions, and for analyzing the status of species in threatened 
areas. However cmcial these inventories might be, the value of their contribution to both science 
and policy-making remam at the mercy of data quality. Resources such as GBIF, iNaturalist, post¬ 
ings by underwater photographers, and even commercial websites such as eBay allow data to accu¬ 
mulate, but require vetting by taxonomists. For these reasons, collaborative expeditions and sur¬ 
veys in which specialists in a variety of taxa are represented will continue to provide important 
data. These data act as a sort of “ground-truthing” for the scientific and lay community alike 
because their dependability is higher than what is often encountered in relatively unreviewed, sec¬ 
ondary resources such as those listed above. 
The Echinodemiata (sea lilies, stai'fish, brittlestars, sea cucumbers, and sea urchins) compris¬ 
es an entirely marine clade of about 6,500 species. Most members of the group are relatively large, 
usually common, and conspicuous members of the marine biota. Among these, the sea urchins 
(Echinoidea) are arguably the best-known and most thoroughly studied of the major extant clades. 
In spite of this, and the fact that they are often reported by divers, photographei*s, amateurs, and 
professionals visiting or working in the Indo-Pacific, they are frequently misidentified or their 
reported nomenclature is not congiuent with cuirent usage. Nevertheless, with appropriate taxo¬ 
nomic quality control, echinoids can be usefrd indicators of relative species richness among differ¬ 
ent oceanic ecoregions, particularly as their nomenclature and taxonomy are now starting to be bet¬ 
ter understood through efforts such as those represented by the World Echinoidea Database (2011). 
Echinoids are morphologically disparate and ecologically diverse. The familial* epibenthic, 
rocky substrate “regular” sea urchms constitute a polyphyletic assemblage (Kroh and Smith 2011) 
that includes slate pencil urchins (cidaroids), fire urchins (echinothurioids), and other “true” sea 
urchins (diadematoids, camarodonts and other carinacean forms) with large spines and a subspher- 
ical body, or test. All of these groups possess an Aristotle‘s lantern, a large, heavily muscled jaw 
apparatus equipped with five hard, sharp teeth used for chewing and rasping at food sources, or for 
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