Spinster Wrasse, Halichoeres nicholsi
The Spinster Wrasse, Halichoeres nicholsi, whose common Spanish name is señorita solterona, is a member of the Wrasse or Labridae Family, known collectively as doncellas, señoritas, and viejas in Mexico. Globally, there are seventy species in the genus Halichoeres, nineteen of which are found in Mexican waters, ten in the Atlantic and nine in the Pacific.
The Spinster Wrasses have elongated compressed bodies with a depth that is 30 to 34% of standard length. Females and males of the Initial Phase (IP) are light green on their upper back and whitish ventrally. They have a short black bar below the base of the front of their dorsal fin that joins a broad diffuse black stripe running along the middle of their flank. Their fins are similar in color to the body except that their caudal fin is yellowish. Terminal Phase (TP) males are bluish-green with a broad black bar behind their head and bright yellow spot just above their pectoral fins. Juveniles are whitish to yellow with irregular black stripes and blotches on their sides; they also have a large ocellated black spot on the middle of their dorsal fin. Their anal and dorsal fins are pinkish with two broken blue bands; their caudal fin is dark with blue specks; their pectoral fins are pinkish-brown with a blue base; and their pelvic fins are half pink and half transparent. Their caudal fin is straight and their dorsal fin has 9 spines and 11 rays. They have a small terminal mouth equipped with two pairs of enlarged canine teeth at the front of both jaws and a large canine at the rear of the top jaw. Their body is covered with large scales.
The Spinster Wrasses are found over sandy or rubble bottoms adjacent to rocky reefs within tidal pools at depths up to 270 feet. They reach a maximum length of 38 cm (15 inches). They are a solitary species that feeds on brittle stars, crabs, mollusks, and sea urchins. They are a small, rare and poorly studied species and very little is known about their behavioral patterns.
In Mexican waters the Spinster Wrasse are found in all waters of the Pacific with the exception that they are absent from along the entire west coast of Baja.
The Spinster Wrasse is most likely confused with the Banded Wrasse, Halichoeres notospilus (numerous bars across back) and the Wounded Wrasse, Halichoeres chierchiae (IP are red dorsally and white ventrally; TP lack black bars).
The Spinster Wrasses are too rare and too small to be of interest to most.
Spinster Wrasse, Halichoeres nicholsi, initial phase (IP) female transitioning to terminal phase (TP) male. Fish caught from shore at Km 21, Cabo Real, Baja California Sur, July 2012. Length: 21 cm (8.3 inches).
Spinster Wrasse, Halichoeres nicholsi, initial phase (IP) female transitioning to terminal phase (TP) male. Fish caught from shore at Km 21, Cabo Real, Baja California Sur, September 2010. Length: 22 cm (8.7 inches).