Sunset Wrasse, Thalassoma grammaticum
Sunset Wrasse, Thalassoma grammaticum, Juvenile Transitioning To Initial Phase (IP) Female. Fish caught from shore at Km 21, Cabo Real, Baja California Sur, December 2014. Length: 14.0 cm (5.5 inches).
Sunset Wrasse, Thalassoma grammaticum, Initial Phase (IP) Female. Fish caught from shore at Km 21, Cabo Real, Baja California Sur, December 2018. Length: 16.2 cm (6.4 inches).
Sunset Wrasse, Thalassoma grammaticum, Terminal Phase (TP) Mmale. Fish caught from shore at Km 21, Cabo Real, Baja California Sur, November 2009. Length: 18.0 cm (7.1 inches).
Sunset Wrasse, Thalassoma grammaticum, Terminal Phase (TP) Male. Fish caught from shore off Roca de Ian, Bahia de Los Muertos, Baja California Sur, December 2019. Length: 18.0 cm (7.1 inches). Catch and photograph courtesy of Brad Murakami, Surrey, British Columbia, Canada.
Sunset Wrasse, Thalassoma grammaticum, Terminal Phase (TP) Male. Underwater photograph taken in the greater Los Cabos area, Baja California Sur, October 2019. Photograph courtesy of Bob Hillis, Ivins, Utah.
The Sunset Wrasse, Thalassoma grammaticum, is a member of the Wrasse or Labridae Family, and is known in Mexico as señorita crepúsculo. The Sunset Wrasse is a truly gorgeous fish. Globally, there are twenty-eight species in the genus Thalassoma, four of which are found in Mexican waters, one in the Atlantic and three in the Pacific Ocean.
The Sunset Wrasse has an elongated compressed body with a depth that is 28% to 32% of standard length. Females and males of the Initial Phase (IP) are greenish-yellow with a faint red band on their head. Terminal Phase (TP) males are greenish-blue and have a pinkish head with narrow greenish bands radiating from their eyes across their cheeks. Their anal and dorsal fins have purple stripes along the base; their caudal fin has purple stripes along the top and bottom edges; and their pectoral and pelvic fins are a uniform green color. Juveniles are greenish-brown dorsally and white ventrally with a black mid-lateral stripe that breaks into spots toward the rear and ends in a black spot at the base of their caudal fin. They have a small terminal mouth equipped with one pair of canine teeth at the front of both jaws. Their anal fin has 3 spines and 11 rays; their caudal fin vary from being rounded in juveniles to is strongly concave with the tips becoming more elongated in TP males; their first dorsal fin has 8 spines; their second dorsal fin has 13 or 14 rays, and their pectoral fins have 15 to 17 rays. Their body is covered with large scales. Their lateral line is continuous and bends abruptly down under the rear of the second dorsal fin.
The Sunset Wrasse is found in and around rocky and coral reefs within tidal pools at depths up to 66 m (215 feet). They reach a maximum 32 cm (13 inches) in length. They are a solitary species that feeds on brittle stars, crabs, mollusks, and sea urchins. The Sunset Wrasse 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 Sunset Wrasse 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 southwest coast of Baja, from Loreto, Baja California Sur, southward along the southeast coast of Baja, and sporadically along the coast of the mainland being more abundant in southern locations.
The Sunset Wrasse is not easily confused with any other species due to its head markings, but is very similar in shape to the Emerald Wrasse, Thalassoma virens (lacks the prominent lines on the head).
From the conservation perspective the Sunset Wrasses is currently considered to be of Least Concern with stable, widely distributed populations. They are too rare and too small in stature to be of interest to most. I catch these fish with some regularity mid-day during low tides using a Carolina rig, size 6 hooks, baited with cut squid. They are a “catch-and-release.”