Coral reefs are home to some of the most studied ecological assemblages on the planet. However, differ- ences in large-scale assembly rules have never been studied using empirical quantitative data stratified along the depth gradient of reefs. Consequently, little is known about the small- and regional-scale effects of depth on coral reef assemblages. Using a large dataset of underwater surveys, we observed that the influence of classic biogeographic drivers on the species richness of coral reef fishes changes significantly with depth, shaping distinct assemblages governed by different rules in mesophotic coral ecosystems. We show that a general pattern of decreased taxonomic and functional richness of reef fish assemblages with depth results from convergent filtering of species composition and trophic strategies on deeper reefs across ocean basins and that at smaller scales deep-reef communities are less influenced by regional fac- tors than shallower reefs.

Depth range
2- 147 m

Mesophotic “mentions”
51 x (total of 5130 words)

Classification
* Presents original data
* Focused on 'mesophotic' depth range
* Focused on 'mesophotic coral ecosystem'

Fields
Community structure
Connectivity
Ecology
Biodiversity

Focusgroups
Fishes

Locations
Bermuda
Brazil - Fernando Noronha
Brazil - St Peter and St Paul Archipelago
Curaçao
French Polynesia
Micronesia - Caroline Islands (Pohnpei)
Micronesia - Guam
Micronesia - Marshall Islands
Philippines
Republic of Palau
USA - Hawaii

Platforms
Rebreather
SCUBA (open-circuit or unspecified)