New distributional data and biometrics of some moray eel species (Muraenidae) in the Canary Islands and Western Sahara (east-central Atlantic)

Abstract

Over the last five centuries, moray eels (Muraenidae) have been subject to artisanal fishing in the waters of the Canary Islands and Western Sahara by Canarian fishermen, gaining culinary interest in the Canary Islands. This study updates the geographical distribution of some Muraenidae species in this region (27-23ºN), including cases of latitudinal and longitudinal migration. In the Canary archipelago, the natural expansion of Gymnothorax vicinus from El Hierro (2008) – the westernmost island with the warmest coastal waters – to the central islands is now confirmed. This species, potentially native to the region, has been observed in both the northern (more temperate) and southern (warmer) sectors of the archipelago, likely due to its broad habitat use and its aggressiveness. The presence of Gymnothorax miliaris – typically restricted to the western islands – at the easternmost end of the archipelago (Fuerteventura) is now documented. Muraena melanotis, first reported in Tenerife in 2018, has now expanded to El Hierro, as evidenced by the capture of a mature female. Current data suggest that this thermophilic species may have established a small population in the warmer western sectors of the archipelago. Additionally, unpublished biometric data on Canarian samples of G. miliaris and G. polygonius are provided. In Western Sahara, the first record of the amphi-Atlantic species Gymnothorax polygonius on the African continental coast is now documented. The presence of Gymnothorax afer and Muraena robusta at 23º32’N, the new northern distribution limit for both species, is now confirmed.