Greater Soapfish, Rypticus saponaceus

Greater Soapfish, Rypticus saponaceus. Fish caught from coastal waters off Ft. Lauderdale, Florida, August 2017. Length: 26 cm (10 inches). Catch, photograph and identification courtesy of Dominick Porcelli, Lighthouse Point, Florida.

The Greater Soapfish, Rypticus saponaceus, is a member of the Grouper or Epinephelidae Family, and is known in Mexico as jabonero grande. The soapfishes are named for their ability to produce a toxic body mucus that forms a slimy, suds like lather when agitated which provides them with a defense to avoid predation. Globally, there are nine species in the genus Rypticus, of which seven are found in Mexican waters, five in the Atlantic and two in the Pacific Ocean.

The Greater Soapfish has an elongated compressed body with a head that has an oblique forehead and a long snout with a prominently projecting lower jaw that has a freshy knob at the front with simple teeth set in bands with a series of pores on the lower jaw. They are a mottled being covered with numerous irregularly distributed small pale blotches and vary from a drab reddish brown to gray with a green or bluish cast. Their anal fin has no spines and 13 to 17 rays; their dorsal fin is rounded and has 3 spines and 23 to 25 rays; and their pectoral fins have 15 to 17 rays. They have 7 to 9 gill rakers. Their skin is smooth to the touch with embedded scales.

The Greater Soapfish is a solitary demersal species that is found over sand and rock substrate and around reefs at depths up to 213 m (700 feet). They are frequently observed lying motionless at the bases of coral colonies and near the mouths of caves. They reach a maximum of 35 cm (14 inches) in length. They are a secretive nocturnal species that feeds on crustaceans and fishes. They are protogynous hermaphrodites with the females able to change sex to males. The Greater Soapfish, although the most common and wide spread of the Soapfishes has been poorly studied and very little is known about their behavioral patterns.

The Greater Soapfish is a resident of all Mexican waters of the Atlantic Ocean including the Gulf of Mexico and the east coast of the Yucatán Peninsula in the Caribbean.

The Greater Soapfish is mostly like confused with the Freckled Soapfish, Rypticus bistrispinus (dark dorsally, pale ventrally, covered with small dense spots), the Reef Bass, Pseudogramma gregoryi (convex forehead, more elongated body), the Spotted Soapfish, Rypticus subbifrenatus (rows of spots behind the eye), and the White-spotted Soapfish, Rypticus maculatus (dark stripe through the eye).

From a conservation perspective the Greater Soapfish is currently considered to be of Least Concern with stable, widely distributed populations. They are utilized by some cultures on a limited basis as a human food fish but are normally covered with slim making them very unappealing.