The Pacific Ocean has the lowest diversity of ophiuroids of all Mexican waters,
with only 63 species distributed in two orders, 12 families and 28 genera. Only 23
species are restricted to the Mexican Pacific Coast and the rest (40 species) are
common to the Pacific Ocean and the Gulf of California. The order Ophiurida is
the richest from the class Ophiuroidea, with nine families. The most speciose
Fig. 2.8 a Euapta godeffroyi (Semper, 1868), central Gulf of California. b Holothuria arenicola
Semper, 1868, Jalisco, Mexican Pacific. c Labidodemas cf. macullochi (Deichmann, 1958),
Jalisco, Mexican Pacific. d Holothuria kefersteini Selenka, 1867, south of Gulf of California.
e Pentamera chierchia (Ludwig, 1887), Guerrero, Mexican Pacific. f Holothuria cf. inhabilis
Selenka, 1867, central Gulf of California. Images a by Offer Keter, b and c by Francisco Solis,
d by Luis Carballo, e by Valeria Mas and f by Carlos Sanchez-Ortiz
2 The Echinoderms of Mexico
23