Who are these fish and why are they
Jumping?

Fish are know to ‘jump’ for numerous reasons, some of which are: 1) to escape predators, 2) to move greater distances more quickly (flying fish) 3) to catch prey, or 4) maybe just to have ‘fun’. However, this fish has quite a different reason!

The Spanish mackerel, Sierra mackerel, Pacific mackerel and possibly other species of mackerel make their home in the Golfo de California (Sea of Cortez), the Bahia de La Paz, and the marinas and shallows around the Ciudad de La Paz. Checking out the jumping fish at the Marina CostaBaja has identified them as the Pacific mackerel.

As for why they are jumping day and night, and week in and week out think of man’s best friend - Fido. No they don’t have fleas but they do have “fish-lice”. Fish-lice are small parasites that attach them selves on and between the scales of this fish.












Alexandrium cyst from Invertebrate Biology

Studies have shown that the fish are ‘itching’ themselves. As they have no paws, and no beaks as with birds, or companions as with monkeys they jump and splash down trying to dislodge these copepod parasites.

Are they successful?; well as with Fido and his fleas the sea-lice are very well attached and research has show that some are dislodged but not all. But it must provide some relief or why continue? So the Pacific mackerel keeps jumping.

Research by:
Bill & Jean Martin
SV Talaria