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Coral reef fishes form one of the most species-rich vertebrate communities globally, with over 4000-4500 species across seven key families. Investigate the latitudinal and longitudinal richness patterns, explore the relationship between reef area and fish diversity, and understand how factors like sea-level changes and currents influence species distribution. Discover the unique biodiversity hotspots in the Western Pacific and unravel the mysteries behind the lower richness in the Atlantic. Join an expedition to the Coral Triangle, a hub for discovering new coral reef fish species.
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Coral reef fishes The most species-rich vertebrate communities known
Seven important families of coral reef fish • Gobiidae • Serranidae • Labridae • Chaetodontidae • Zanclidae • Acanthuridae • Tetraodontidae
4000-4500 species worldwide, comprising 25% of the known species of marine fish
Latitudinal gradient in species richness holds for all marine fishes • Possibly a result of the high number of coral reef fishes, which are found only in the tropics
However, do coral reef fishes show such a gradient within the tropical and subtropical regions? • Not clearly, and their species richness is not clearly linked with reef area, which does show a gradient within the tropical and subtropical regions (more reef area at the equator)
Longitudinal patterns of coral reef fish species richness • Most species-rich areas are in the western Pacific, which also has the highest richness of coral species • Investigators have assumed that this is the center of origin of the group
Also, a general pattern of less species richness in the Atlantic as compared to the Pacific exists
The relationship between reef area and fish diversity longitudinally is clearly demonstrated
The high species richness in the western Pacific could be because of • Sea-level changes during the period 5-2 mya, resulting in basins of water being isolated, where allopatric speciation of fishes could then take place • High endemism levels in western Pacific support this idea, although high endemism is also found in Arabian Sea, Hawaii, and the Red Sea
Low species richness of eastern Pacific may be because of • Westward-flowing currents • Lack of stepping stones across the Pacific
Lower species richness of Atlantic compared to Pacific may be because of • Lack of suitable refuges during times of environmental stress leading to • Generalist species and • Lack of specialists • Ex. Parrotfish
Take-home message • Reef area and current patterns explain some, but not all, patterns in coral reef fish species richness