Chameleon wrasse

Halichoeres dispilus is a wrasse, family Labridae, from the tropical eastern Pacific, described by Günther in 1864 ^[1]. In Peru it is known as «doncella», «señorita», «san pedrano» or «sanpedrano» ^[2]. It lives over rocky or coral reefs with patches of sand, between 2 and 76 m deep, and grows to about 25 cm total length ^[2]. The IUCN Red List classes it as Least Concern ^[3].

The genus name, Halichoeres, combines the Greek roots hals, meaning salt, and choiros, meaning pig ^[2]. Günther described the species in 1864 in a different genus, as Platyglossus dispilus, a combination now treated as a synonym ^[1].

FishBase gives a maximum length of 25 cm total length for the species ^[2]. The IMARPE photographic catalogue of otoliths, however, figures a specimen labelled «doncella» that measured 32.0 cm total length and whose sagitta, the largest otolith, measured 4.0 mm ^[4].

Its genetic identity is under study. In a DNA barcoding survey based on the mitochondrial COI gene, among the species analysed, the one closest to the northern Peruvian specimens was Halichoeres notospilus, at a distance of 14.7 %, yet divergence within the species itself reached 2.51 %, above the 2 % threshold the authors use to flag a possible taxonomic split ^[5]. The delimitation analysis separated 3 lineages: one with individuals from Costa Rica and one from Baja California Sur; another with individuals from the Galápagos, one from Isla Foca and one from central Peru; and a third with individuals from northern and central Peru together with samples from the Pacific coast of Panama ^[5]. The authors suggest this may be a complex of cryptic species formed by parapatric speciation, a hypothesis that, in their view, needs more genetic markers and sampling across the whole range ^[5].

In another study, the Galápagos population differed by 3.3 % from the Panama population in its mitochondrial sequence ^[6]. Its sister species is Halichoeres insularis, an endemic wrasse discovered in the Revillagigedo Archipelago, Mexico, in 1991, from which it differs by 7.6 % in COI ^[7].

It ranges through the eastern Pacific from the Gulf of California to Bahía Independencia, Peru, including the Galápagos Islands ^[2]. A study of tropical eastern Pacific wrasses and damselfishes assigned it a range that includes Baja California, the Revillagigedo Islands, Cocos Island, Panama, the Galápagos and mainland Ecuador, spanning about 5192 km, which places it, by the authors' definition, among the region's widespread species ^[8].

It lives in shallow water over rocky or coral reefs broken up by sandy areas, and has been recorded between 2 and 76 m deep ^[2].

A DNA barcoding study of rocky-reef fishes from northern Peru, collected at Isla Foca, which the authors place in the transition zone, along the coast between Cabo Blanco and Los Órganos and at Punta Sal in Tumbes, analysed several specimens of the species from northern Peru, one of them from Isla Foca, together with sequences from individuals from central Peru ^[5]. Further south, at the Lobos de Afuera Islands, its DNA was detected in seawater sampled in November 2018, and the species also appears there in historical reports ^[9].

Its planktonic larval stage is long: in 147 specimens aged from the daily rings of their otoliths, the mean duration was 39.4 days, with a minimum of 30 and a maximum of 50 ^[8].

Its larvae can travel far from shore. A sample taken in open water over the Galápagos Rift held 4 larvae of the species, 9.4 to 13.5 mm standard length, and the DNA sequence obtained from one of them matched the Panama population, about 1000 km away, rather than the Galápagos one ^[6].

During the breeding season it forms well-defined pairs ^[2]. When disturbed, and also at night to sleep, it buries itself in the sand ^[2].

It is a solitary fish that eats small invertebrates it finds in the sand; in the Gulf of California, large individuals also take small blennioid fishes ^[2]. A diet-based model assigns it a trophic level of 3.9 ^[2].

The authors of the Peruvian genetic study stress that its long pelagic larva is exposed to shifting ocean circulation and that, even without barriers to gene flow, genetic breaks can form within a continuously distributed species ^[5].

The IUCN Red List assesses it as Least Concern, in an assessment from 2007 ^[3]. FishBase estimates its vulnerability to fishing as low to moderate, 30 out of 100 ^[2].

The Lobos de Afuera Islands, where its DNA was detected, are a marine protected area within the Guano Islands, Isles and Capes National Reserve ^[9].

Not medical advice. For a sting, a poisoning or an allergy, seek medical care.

FishBase classes it as harmless to people ^[2].

It is of minor commercial importance in fisheries, is sold fresh in local markets and is also traded for aquariums ^[2].

At the Lobos de Afuera Islands, about 32 nautical miles off the northern coast, its DNA turned up in seawater sampled in November 2018; the authors note that the distance from the coast and the complex seabed limit access to these islands ^[9].

A study published in 2025 analysed specimens of the species from rocky reefs in northern Peru, one of them from Isla Foca; its sampling covered Isla Foca, the stretch between Cabo Blanco and Los Órganos in Piura, and Punta Sal in Tumbes, under a permit from the Ministry of Production issued in 2020 ^[5].