Longjawed Mackerel Try Tasting Very Large Jellyfish

Longjawed mackerel are a very unusual fish with an unusual feeding behavior. They are rapid swimmers and they school in large numbers, quickly cruising through the open ocean with their mouths open wide and their lower jaws extended. This allows them to scoop up zooplankton in large numbers, feeding on the tiny organisms that we can barely see. They have visible teeth and impressive jaws, making it look like they are more equipped for chasing down and eating bait fish.

Longjawed mackerel are lightly colored and very reflective, making them difficult to see in sunlight. Although they cruise over reefs and sandy areas, they are as likely to be found out in the deep, suspended far from other objects and surfaces, making them a somewhat rare sight for scuba divers and snorkelers.

This scuba diver was returning from the deeper waters in Fiji when he saw a large jellyfish drifting along over the coral ledge. He drifted with the bizarre creature, filming it as it pulsed and undulated with the current, making its way along the reef. A school of longjawed mackerel surrounded the diver and the jellyfish, racing back and forth as they gathered food. A few of the hungry mackerel decided to test out the jellyfish for tastiness. They darted at it and bit quickly, retreating with a flash. It seemed that the jellyfish was either deemed inedible, or else the fish were stung. Jellyfish are actually a type of zooplankton so it actually makes sense that the fish would recognize the jellyfish as possible food. After a few attempts, the fish did not try to bite the jellyfish anymore. They swam around it curiously for a few minutes more and then they were off in search of more suitable food.

For a diver to get a glimpse of such feeding behaviors close up is a rare treat. Normally, the presence of a human makes the fish reluctant to venture close and focus their attention on food. This was an occasion where moving as slowly as possible and being patient paid off. The ocean is a fascinating world and the creatures there are part of a complex relationship where they are predators one minute and prey the next. It is a delicate balance and to see it play out on front of your eyes is very interesting. Scuba divers should always remember that they are guests in this domain and that improper behavior can have immediate consequences. People are wise to keep in mind that they are observers and should not try to interfere with this balance in any way.