Paper covers rock. Scissors cut paper. Rock dulls scissors. You know the game, right? In the California fish version, called “Rocks, Rainbows, Scorpions” the rainbow scorpionfish beats its California scorpionfish cousin, but the rockfish beats ’em both with its “magnificence.” Read on to learn why — and to decide if you agree with the rules of this made-up game.

The Scorpaenidae family is represented by no less than 56 genera and 421 species, 85 of which can be found off the Pacific Coast. The latter includes two genera of scorpionfish with a total of three species. Only one, Scorpaena guttata, is common here. The other two, Scorpaena mystes and Scorpaenodes xyris, are rare. The genus Sebastes, which includes more than 60 species of rockfish, also belongs to the Scorpaenidae family. 
Most of these fishes spend their days resting on the reefs. Scorpionfishes and rockfishes have similar profiles. Unless sensing danger, the dorsal fin will be folded down, not extended. The California scorpionfish often props itself in place with its large, fan-like pectoral fins. Both species have generous mouths.
Most, if not all Scorpaenidae have venomous anal and ventral fin spines, but while scorpionfish venom can cause excruciating pain, rockfish venom is much less potent and not dangerous to humans.
The three Scorpaenidae described here are from three different genera: Scorpaenodes (rainbow scorpionfish), Scorpaena (California scorpionfish) and Sebastes (black and yellow or hybrid rockfish). 
Rainbow scorpionfish (Scorpaenodes xyris): San Clemente Island’s rocky terrain makes it an ideal lobster habitat. I was seeing a lot of those (all shorts) last August when a sudden movement caught my eye. In a nearby crevice was a small, black fish with an unusual shape. I moved closer and took a photo. The flash revealed a bright red fish with gold accents, a fish I had no idea existed. I managed just two more shots before the fish darted farther into the crevice and out of sight. It wasn’t until I got home and could compare my photos to those in fish ID books that I found out it was a rainbow scorpionfish. Much more common from the Gulf of California to the Galapagos Islands, rainbows are rare in SoCal waters. These little fish only grow to be six inches long and are found from intertidal waters to depths of 160 feet. 
All of the fish identification books point out that the rainbow can be positively identified by “a prominent dark spot on lower rear edge of gill plate.” (Coastal Fish ID: California to Alaska by Paul Humann.) That spot is not visible on my fish, though it may just be obscured by a pectoral fin. The coloring of the rainbow is highly variable. The one shown is a juvenile and will look more like its cousin the California scorpionfish at maturity.
While the rainbow scorpionfish is a shy, reclusive creature, the California scorpionfish and the rockfishes are anything but. Whether they know their camouflage will make them nearly invisible or that their venomous spines will protect them, they are not easily spooked, making them among the easiest fish to photograph. 
California scorpionfish (Scorpaena guttata): Scorpaena comes from the Greek word for scorpionfish and gutta is Latin for speckled. The triangular body of this fish, also called a sculpin, is very distinctive. The head, mouth and pectoral fins are large. The body is covered with intriguingly shaped fleshy filaments that can resemble seaweed along with numerous irregular dark spots. These fish can change colors to match their resting places. What usually gives them away is their large round eyes, a sign that the fish is nocturnal. Although scorpionfishes are easy to photograph because they are reluctant to move, it is hard to make them stand out from their background in pictures because they blend into it so well.
California scorpionfish range from Santa Cruz to Baja. While they prefer shallow rocky environments, they can found as deep as 600 feet. Their diet includes crabs, squid, octopuses, other fishes and shrimp. The largest California scorpionfish recorded by California Fish & Game was 17 inches long. Males can live 15 years or longer, the females, 21. Females are larger than males.
California scorpionfish are oviparous. They are sexually mature at nine inches long and about four years of age. Spawning in mass aggregations takes place from May through August, probably at night. At least some of the fish return to the same place year after year. According to the Fish & Game website: “The eggs are embedded in the gelatinous walls of hollow, pear shaped egg-balloons. The paired egg-balloons, each five to ten inches long, are joined at their small ends. The walls of these ‚äòballoons‚äô are about 0.1 inch thick, transparent or greenish in color, and contain a single layer of eggs. Each egg is about 0.05 inch in diameter. The “balloons” are released at the bottom of the sea and rise rapidly to the surface.” The eggs are fertilized during the ascent.
Pelagic larvae hatch from the eggs within five days and drift with the currents until they settle on the substrate and morph into juveniles. 
Recommended treatment for a scorpionfish wound is immersion in very hot water. Multiple punctures can produce shock, respiratory distress or abnormal heart action and may require hospitalization. The good news is that these fish are not aggressive and most injuries are the result of accidental contact, such as kneeling on one innocently sitting on the bottom or steadying oneself by holding onto a “rock” that really isn’t a rock. 
Black and yellow or hybrid rockfish (Sebastes sp.): The fish depicted here is one whose markings and characteristics make identification difficult. According to Dr. Milton Love, the fish could be either a black and yellow or a hybrid (i.e., a fish whose parents were of different species). Black and yellows are fairly common from Northern California to Baja. This fish was photographed in 38 feet of water at Arch Rock, Santa Cruz Island. Its diet most likely includes crabs and shrimp.
The rockfish genus name, Sebastes, means “magnificent” and the bodies of some but not all of these fish feature interesting patterns and bright colors. 
Rockfish are viviparous and fertilization occurs during a courtship “dance” initiated by the females. Some species may mate with more than one male. The embryos grow inside the mother and when they hatch, the larvae are expelled into the water, where they drift with the currents before morphing into juveniles that are not exact miniatures of their parents but share a resemblance. In ideal conditions, some rockfish can live more than 100 years.
The author wishes to thank Dr. Milton Love, author of Certainly More Than You Want to Know About the Fishes of the Pacific Coast for confirming the IDs of the fish depicted here and once again sharing his vast knowledge of their habits and behaviors. 
Scorpionfish Stats
Phylum: Chordata
Class: Actinopterygii
Order: Scorpaeniformes
Family: Scorpaenidae
Rainbow scorpionfish (Scorpaenodes xyris)
California scorpionfish (Scorpaena guttata)
Black and yellow or hybrid rockfish  (Sebastes sp.)
Reproduction: Spawning (Scorpaenodes xyris, Scorpaena guttata
Sexual (Sebastes sp.)