89
4 Spawning Aggregations in Reef Fishes; Ecological and Evolutionary Processes
4.2 Coral Reef Fishes, Diversity, Habitat Structure
and Biogeography
Fishes are the most diverse group of vertebrates with a total of 31,319 species
(Table 4.1 ) (Eschmeyer and Fong 2010) . Nearly 70% of the world’s marine fi sh species occur in only 8% of the ocean habitat and, more dramatically, coral reefs with a
Fig. 4.1 ( a ) Resident aggregation of the humphead wrasse, Cheilinus undulatus , in Palau. Small
numbers of males and females travel frequently to specifi c sites for extended periods in the year
and spawn in pairs during the day according to the tides. ( b ) Transient aggregation of twin-spot
snapper, Lutjanus bohar, in Palau. Large numbers of fi sh gather for brief periods for a short time
each year and spawn in groups; picture shows fi sh returning to substrate after releasing eggs and
sperm (Photos: Mandy Etpison, Nial McCarthy)
4 Spawning Aggregations in Reef Fishes; Ecological and Evolutionary Processes
4.2 Coral Reef Fishes, Diversity, Habitat Structure
and Biogeography
Fishes are the most diverse group of vertebrates with a total of 31,319 species
(Table 4.1 ) (Eschmeyer and Fong 2010) . Nearly 70% of the world’s marine fi sh species occur in only 8% of the ocean habitat and, more dramatically, coral reefs with a
Fig. 4.1 ( a ) Resident aggregation of the humphead wrasse, Cheilinus undulatus , in Palau. Small
numbers of males and females travel frequently to specifi c sites for extended periods in the year
and spawn in pairs during the day according to the tides. ( b ) Transient aggregation of twin-spot
snapper, Lutjanus bohar, in Palau. Large numbers of fi sh gather for brief periods for a short time
each year and spawn in groups; picture shows fi sh returning to substrate after releasing eggs and
sperm (Photos: Mandy Etpison, Nial McCarthy)