COVER ILLUSTRATION. Spawning whitebelly damselfish, Amblyglyphidodon leucogaster, in Sinai, Egypt
Photographed by Alexander Mustard
Most marine fish reproduce by releasing eggs and sperm into the water column; so begins their perilous adventure to the next generation. Eggs hatch and larvae develop, drifting along as part of the plankton for a few weeks before metamorphosing into miniature versions of their parents. Parental care is non-existent, save for producing the astronomic numbers of eggs required to overcome the lottery-winning odds of survival.
Damselfish are one of a handful of families that form a minority group among marine fishes by adopting a different strategy. These fish lay their eggs in nests on coral reefs. Far fewer eggs are laid, and energy is instead diverted to their protection during the first weeks of life.
These whitebelly damselfish were photographed in the Red Sea. Most coral reefs are found close to the equator, but the Red Sea represents a uniquely northern extent of their range in the Indian Ocean. This high latitude means that Red Sea reefs are peculiarly seasonal, and to take this photograph I had to visit the rejoin in the summer; the breeding season on the whitebelly damselfish starts at the end of May, when the water is warmer than 22°C.
To mate, the males must stake out territories on the reef, clean their nest sites and defend them from other males before they can set about attracting females. The females spend most of their time feeding in open water on crustacean zooplankton, dedicating energy to producing eggs. Females periodically take a break from feeding in the water column and parade past the males' nests. Spawning typically involves one female and one male, but in this unusual photo the 'fortunate' chap had attracted three females simultaneously!
As a photographer, I am keen to record these everyday events in the underwater world that are seldom noticed, even by scuba divers who regularly explore the coral reefs. Such behaviours are the cogs and gears that drive the system. This type of photography is also rewarding for another reason: being able to capture animals going about their everyday lives and witnessing their natural behaviour is as good a reassurance as any that my presence in their home is not an intrusion.
Alexander Mustard
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