DIVE LOG DECEMBER 25 ISSUE 415

whilst simultaneously flopping over from left to right. This is a swimming pattern designed to confuse and confound any would be predators and make it difficult to be eaten or photographed. The closer you get, the faster it wriggles! Some people think it resembles a tumbling piece of weed that does not arouse any interest from a hungry predator. Another wriggler is the juvenile Sweetlip fish. The only solution here is to use a long lens and take plenty of time. You will get many failures but you might eventually get the fish in a good position. Larger territorial fish will remain in a home range. Many Damselfish will have a clearly defined territory. I teach a course called The Marine Biology of fish where I get divers to observe the territory of a White Eared Parma, our most common Damselfish. Observing marine life does open up a great deal of understanding about their behaviour and

personalities. This knowledge is useful to learn.

These Damselfish from Sydney live as if they were inside an invisible box one metre high, one metre deep and two metres across. If you do not believe me, watch them for five minutes and see for yourself. They will rarely leave this territory. It is as if there is an electric fence around it. If they are harassed by a predator and get distracted, their neighbour will attack them. The entire sea floor is real estate, complete with boundaries that fish are very aware of. If they cross the boundary, they are attacked by their neighbour. Similarly, any intruder entering their territory is violently driven off. It is a deadly world down there.

The only thing missing from these very clearly defined territories are picket fences and letter boxes.

Male Weedy Sea Dragon

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Dive Log Australasia #415 DECEMBER ’25

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