Spawning aggregations and reproductive behavior of reef fishes in the Gulf of California

Spawning aggregations numbering up to tens of thousands of reef fishes have disappeared throughout the tropics due to fishing, causing the collapse of their populations and of commercial fisheries in many regions. Although there is a wealth of information on spawning aggregations in the Caribbean and the Indopacific, there are almost no data on spawning aggregations of commercial reef fishes in the Tropical Eastern Pacific. Here we describe aggregations and the reproductive behavior of eight species of reef fishes in the Gulf of California, Mexico. The serranids Mycteroperca prionura and M. rosacea, the snapper Lutjanus novemfasciatus, and the jacks Caranx sexfasciatus and Seriola lalandi form spawning aggregations of 12 to > 1000 individuals on islands, exposed coastal rocky reefs, and seamounts. The serranids Paranthias colonus and the snapper L. argentiventris spawn in schools with densities similar to these during non-reproductive periods. We observed aggregations of the serranid M. jordani but (lid not observe spawning. Some spawning aggregations of these and other species (such as Epinephelus itajara and Stereolepis gigas) have now disappeared from the Gulf of California due to fishing. Our findings suggest the existence of undocumented spawning aggregations throughout the Tropical Eastern Pacific that sustain varied levels of fishing pressure. These spawning aggregations must be identified and protected in order to ensure the replenishment of fish populations.