Little fish make a big contributionCoral reefs represent one of the most biodiverse and rich ecosystems. Such richness conjures up images of coral heads and large colorful reef fishes. Brandlet al.show, however, that one of the most striking and important parts of the reef ecosystem is almost never seen (see the Perspective by Riginos and Leis). Small cryptobenthic fish, like blennies, make up nearly 40% of reef fish biodiversity. Furthermore, the majority of cryptobenthic fish larvae settle locally, rather than being widely dispersed, and have rapid turnover rates. Such high diversity and densities could thus provide the biomass base for larger, better-known reef fish.Science, this issue p.1189; see also p.1128