Twice-spotted Soapfish, Rypticus nigripinnis
Twice-spotted Soapfish, Rypticus nigripinnis. Fish provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, November 2011. Length: 12.5 cm (5.0 inches).
Twice-spotted Soapfish, Rypticus nigripinnis. Fish provided by the commercial fishermen of Bahía Kino, Sonora, March 2015. Length: 12.8 cm (5.0 inches). Photograph and identification courtesy of Maria Johnson, Prescott College Kino Bay Center, Kino Bay, Sonora.
The Twice-spotted Soapfish, Rypticus nigripinnis, is a member of the Grouper or Epinephelidae Family, that is also known as the Blackfin Soapfish and in Mexico as jabonero doble punteado. 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 Twice-spotted Soapfish has an elongated, and very compressed body. They are overall a dark brown color and covered with numerous yellow-tan spots with dark centers extending into the fins. Their caudal fin is dark. They have an oblique forehead, a short snout, and a slightly projecting lower jaw that does not have a fleshy knob at the tip. Their median fins are thick and fleshy. Their anal fin lacks spines but has 14 to 18 rays; their caudal fin is rounded; their dorsal fin has 2 spines, providing a key to identification, and 24 to 28 rays; and, their pectoral fins are rounded with 15 to 17 rays. They have 7 to 10 gill rakers.
The Twice-spotted Soapfish is found within rocky reefs sheltering in caves and crevices and over soft bottoms near beaches and estuaries, at depths up to 70 m (230 feet). They reach a maximum of 35 cm (13.8 inches) in length and less than 450 grams (1 lb) in weight. They are protogynous hermaphrodites with the females able to change sex to males. The Twice-spotted Soapfish is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.
The Twice-spotted Soapfish is a resident of Mexican waters of the Pacific Ocean but has a limited distribution being found from Magdalena Bay, Baja California Sur, southward along the southeast coast of Baja, in the lower three-fourths of the Sea of Cortez, and along the coast of the mainland south to Guatemala.
The Twice-spotted Soapfish can be easily confused with the Mottled Soapfish, Rypticus bicolor (3 dorsal spines; fleshy knob at tip of snout).
From a conservation perspective the Twice-Spotted Soapfish is currently considered to be of Least Concern with stable, widely distributed populations. They are small in stature and too rare to be of interest to most.