The Rock Lobster and Climate Change

Adrift in the Ocean

The rock lobster’s life starts out as one of about 200 000 eggs - of which only one per cent will make it to adulthood - that are glued beneath a membrane on the underside of its mother's tail. After about nine months it will hatch from the egg and be cast adrift on the ocean. 

©Jean Tresfon

There it will spend three or more years bobbing about in the upper surface of the water, where it starts out feeding on plankton and eventually jellyfish. It will moult several times during this period, changing shape slightly each time from transparent bug to armoured adolescent. As the rock lobster (also known as the spiny lobster) approaches its adult form, it will begin to swim up and down between the surface and the ocean floor, scouting about for a future home.

Once it settles into adulthood, the female will first begin to mate at about seven years of age. This is a slow-growing creature that will shrug off its spiny orange carapace once a year, swell out its flesh by absorbing water, wait for its larger shell to set, and then settle back into its new casing. It grows little more than one to five mm per year, if even that.

So it continues until the ripe old age of 40, if it is lucky enough to evade the fishermen's traps or the hungry maws of the octopus, dog sharks and seals. But when the system turns on the rock lobster, it happens in the most spectacular and grizzly fashion.

By Leonie Joubert

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