This fish's name can be confusing because there are several species referred to as yellowtail. Yellowtail are often referred to as kingfish in other countries and are a type of amberjack. This page will focus more on the local yellowtail off the West Coast of the United States and Mexico. These fish range in size from 5 pound "rats" to 40 pound "toads" with larger fish reaching a possible 80 pounds. Their average lifespan is 5-6 years with some individuals living over 10 years. It takes the females 2-3 years to reach sexual maturity in order to spawn. Spawning takes place during the summer months typically June through October.
You can find these fish in kelp beds, rocky reefs, offshore islands and around kelp paddies floating the open ocean. The larger fish are called Home-guards, and stay in the same area year round regardless of water temperature. Most Yellowtail will immigrate from Baja in the winter to Southern California when the water temperatures reach the low 60s and above. Ideal water temperature for these fish are 62-66 degrees, but they can be found in waters reaching the 70s.
Jon Stenstrom with his Baja Yellowtails.
Year round with greater volume of fish occurring in the summer months. Pay attention to the water temperatures stated above. Winter time fish can be found more in the kelp beds and outer Islands rather than an open ocean kelp paddies.
These fish are naturally curious and are easy to bring within range. Then respond well to open/closing your hand at them as well as any noise like tapping on your spear. In kelp or at drop offs, look for blacksmith or other bait fish, and dive just up current on them. The Yellowtails are likely in that same area. Recommended gear really depends on the size of the fish. These fish are excellent fighters and very strong. Shooting a 15 pound fish would not require nothing more than a decent two band speargun with a reel. However, shooting a 40 pound Yellowtail is a whole another story. I would recommend a floatline with a longer speargun around 55" equipped with a slip-tip. In kelp, these fish like to run and scrape themselves on the bottom. They have soft flesh so tear outs do happen which is why I would recommend spectra line on your slip-tip.