The Rockfish and Scorpionfish Family – Scorpaenidae

This page is separated into three sections: Rockfish, Scorpionfish and Thornyheads. Many professionals include the Rockfish from the Sebastidae Family as members of the Scorpaenidae Family. Others believe that the Rockfish are a standalone family separate from the Sebastidae. For organization purposes, I have included the Rockfish Family with the Scorpionfish Family in this website.

PART I.  ROCKFISH.  Fifty-four different Rockfish reside in Mexican waters of the Pacific Ocean and forty-three are included in this website.

FROM THE PACIFIC (43):

Other Rockfish Residents of Mexican Waters of the Pacific (photos needed).

PART II.  SCORPIONFISH – Nineteen Scorpionfish reside in Mexican waters of the Atlantic Ocean and seven are included in this website. Twelve Scorpionfish reside in Mexican waters of the Pacific Ocean and ten are included in this website.

FROM THE ATLANTIC (7):

FROM THE PACIFIC (10):

PART III.  THORNYHEADS – Two Thornyheads reside in Mexican waters, with both being found in the Pacific Ocean and both are included in this website.

FROM THE PACIFIC (2):

The Rockfish and Scorpionfish or Scorpaenidae Family is estimated to have  four hundred thirty individual species that have been placed into sixty-seven genera. The majority are found in the Indo-Pacific Ocean. In Mexico they are known collectively as escorpiónes and/or lapóns. The family is large, heterogeneous, and includes many poorly characterized small fish that have been divided into three subfamilies, rockfish, scorpionfish and thornyheads. Rockfishes, placed in the Genus Sebastes, are found only along the West Coast of North America with the majority being deep water species. Scorpionfish, placed in the Genus Pontinus, Scorpaena and Scorpaenodes, are found in all temperate and tropical seas, primarily inshore, and live in rocks, coral reefs, and seaweed at various depths from shallow tidal pools to the oceanic abyss. Thornyheads which are in their own subfamily Sebastolobinae and in the Genus Sebastolobus have three known species of which two are found in Mexican waters of the Pacific Ocean.

The Rockfish, Scorpionfish and Thornyheads are small to medium-sized bottom-dwelling fish. Rockfish and Scorpionfish are highly variable in color. Inshore species are mostly brown or mottled and feature bars with dark pigments on a lighter background and often have a pale or reddish belly. Deeper water species are normally red, often with darker red, brown, or black spots with white skin filaments. Thornyheads are a uniform red color. Adults range in size from 5.0 cm (2.0 inches) to 91 cm (3 feet 0 inches) with most being between 8.0 cm (3.1 inches) and 30 cm (12 inches). They have weakly compressed bodies with widths that are 23% to 41% of standard length and very large bulbous spiny heads that are 37% to 50% of standard length. Most Rockfish, Scorpionfish, and Thornyheads have cirri above their eyes. The eyes and snout length vary by species. Their mouths are moderate to large, terminal, oblique, protractile, and are equipped with small conical teeth. They have a spiny, longitudinal ridge under their eyes that extends posteriorly and is firmly attached to their gill cover. Their gill cover has 1 or 2 spines and its margin has 3 to 5 spines. Additional spines are scattered on their head. All Rockfish, Scorpionfish, and Thornyheads have anal fins with 2 to 4 spines and 5 to 14 rays, caudal fins that are straight or rounded, a single dorsal fin that is strongly notched at the rear with 8 to 18 strong venomous spines and 4 to 14 soft rays, large pectoral fins with a broad fan-like base, and pelvic fins with 1 spine and 5 rays. Their bodies are covered with scales of varying consistency, being generally small and smooth to rough.

Most Rockfish, Scorpionfish and Thornyheads are secretive reef species that dwell in caves and crevices during the daytime. They are extremely well camouflaged and excellent ambush predators feeding primarily at night on crustaceans and fish. In general, they are solitary and only aggregate for reproduction. A few reproduce vivparous. The majority, however are ovoviviparous with fertilization and embryo development internal, and female rockfish give birth to live larval young. Larvae are found in surface waters, and may be distributed over a wide area extending several hundred miles offshore. Each female produces between 20,000 to over 2,000,000 eggs. Larvae and small juvenile rockfish may remain in open waters for several months, being passively dispersed by ocean currents. Larval rockfish feed on cladocerans, diatoms, dinoflagellates, and tintinnids; juveniles consume copepods and euphausiids of all life stages; and, adults eat demersal invertebrates and small fishes, including other species of rockfish, associated with kelp beds, pinnacles, rocky reefs and sharp drop-offs. Most Scorpionfish are ovoviviparous producing between a few hundred to a few thousand eggs.

The Rockfishes, of adequate stature, and Thornyheads are considered to be deluxe food fishes. All Scorpionfish are edible but most are very small and dangerous to handle and therefore are not considered to be valuable food fish. The larger and more abundant species, caught primarily as a by-catch of deepwater trawlers, are sold commercially in some regions of the world. The flesh is white and considered an excellent food. Many Scorpionfish are utilized by the aquarium trade.

CAUTION! Most Rockfishes and Thorneyheads have sharp anal, dorsal, head, and pelvic spines that can inflict painful puncture wounds. The Scorpionfish have anal, dorsal, head and pelvic spines that are venomous. Worldwide, scorpionfishes rank second only to stingrays in total number of envenomations, with an estimated occurrence of approximately 40,000 to 50,000 cases annually. Scorpionfish poison is produced by glandular tissue in longitudinal grooves on each side of their spine. Wounds from these spines vary from bee-sting intensity to unbelievable agony with significant swelling. Medical reports indicate that these wounds are not life-threatening and treatment involves soaking the affected area for 30 to 90 minutes in water between 110^o and 112^o. The Scorpionfish toxins are peptides that are broken down by human enzymes into non-toxic fragments; this process is significantly enhanced by heat. Although wounds from Scorpionfish typically do not cause complications, these fish should be treated as “extremely hazardous” and released as soon as possible, being careful not to allow their poisonous spines to penetrate the skin. Medical treatment should be sought for any wounds that cause significant pain or other symptoms. A fairly recent publication by F.V. Campos, et al., Journal of Venomous Animals and Toxins, 22:35 (2016) has identified one of the major toxin in  Scorpaena plumieri as a 130 kDa two subunit glycoprotein named cytolytictoxin (SP-Ctx).

For an excellent reference on Scorpionfish and their close relatives the Rockfish and the Thornyheads, please consult “A Guide To The Rockfishes, Thornyheads, and Scorpionfishes of The Northeast Pacific” by John L. Butler, Milton S. Love and Tom E. Laidig, University of California Press, 2012, which includes several of my Scorpionfish photos. I can also refer you to “The Rockfishes of the Northeast Pacific” by Milton S. Love, Mary Yoklavich, and Lyman Thorsteinson, University of California Press, 2002.