Although sea slugs are quite common, most are less than two inches in length and often hide beneath rocky ledges, under kelp or in the muddy bottoms of bays. They tend to be solitary and pair up only to breed. Sea slugs are hermaphroditic, maintaining both male and female organs in one animal. When two sea slugs mate, both are fertilized. Each one produces an egg mass which is unique in size, shape and color to that species.
Some sea slugs produce up to a million eggs, others only a few.
This guide contains color photos of over 150 species of sea slugs. Pick up a tide chart at a sporting goods store and look for minus tides for the best viewing opportunities. Animals that can withstand crashing waves are easily crushed underfoot. Look for quiet water rich with plant life. Chica Ecological Reserve Crystal Cove State Park Cabrillo National Monument Bob Garrison is the coordinator of the Department's Interpretive Services.