Q: Is there any difference between the striped marlin found off the Pacific coast of Mexico and those found on the other side of the Pacific? Have striped marlin ever been caught in the Atlantic? -Wes Henredon, Rosemont, California A: The striped marlin is the most widely distributed of all Pacific billfishes, yet studies show that the genes of populations from separate parts of the ocean differ slightly from each other. A striped marlin from Mexico or Ecuador, for example, has DNA markers different from those of a striped marlin from Hawaii or New Zealand. On the other hand, as a species the striped marlin is almost identical genetically to the Atlantic white marlin. Genetic evidence suggests that striped marlin either stick very close to home or return to a home area each year to spawn; however, striped marlin are known to travel great distances. Although theoretically residents only of the Pacific and Indian oceans, some striped marlin do occasionally round the southern tip of Africa and are caught on the Atlantic side of the Cape of Good Hope. According to records, one stray individual was caught off Angola, West Africa. Studies are under way to determine if striped marlin should be placed under stricter regulations to preserve their genetic diversity. How often fish from populations in various parts of the Pacific migrate and interbreed is a key question. Like other billfishes, striped marlin tend to follow warm-water masses for food. Under the right water conditions, it's possible for a striped marlin to end up almost anywhere.