Molecular identification of the first Galapagos fur seal (Arctocephalus galapagoensis) reported on the central coast of Oaxaca

Abstract

Several sightings of different pinniped species have been recorded outside their typical areas of distribution. In May 2019, pinniped yearlings were sighted on 4 occasions on the central coast of Oaxaca, Mexico. One of them was found injured in La Escobilla (Oaxaca, Mexico) and was transported immediately to the Centro Mexicano de la Tortuga for rehabilitation. Visual identification of the species was inconclusive, as young individuals of several fur seal species can be very similar. A molecular analysis was thus performed to confirm the species. DNA was extracted from the individual, and a fragment of the mitochondrial DNA control region was sequenced and aligned with several sequences of other fur seal species. A parsimony analysis was performed, and the tree revealed that the individual was a Galapagos fur seal, Arctocephalus galapagoensis. This is the first record of this species on the central coast of Oaxaca. The atypical presence of this species in the country could be related to high sea surface temperatures associated with events such as El Niño.

Northernmost record of the Chilean torpedo Tetronarce tremens from tropical coastal waters of the Mexican Pacific

“…Most notably, the distribution of Tetronarce tremens by 2050 is predicted to extend northwards to central Mexico, based on the IPCC RCP8.5 global warming scenario (Kaschner et al ., 2019). Nevertheless, considering records of species of Tetronarce in the open ocean (Ebert et al ., 2015; Morales-Serna et al ., 2019), the specimen studied here could have been driven into shallow waters of the Mexican Tropical Pacific by favourable oceanographic processes (Tamayo-Millán et al ., 2021).…”

“…Atypical records of vertebrates beyond their native distribution ranges in South America have recently occurred in Oaxaca, Mexico (Villegas-Zurita et al ., 2016; Tamayo-Millán et al ., 2021). Here, we report the first finding of the Chilean torpedo Tetronarce tremens in the Mexican Pacific, based on a single specimen captured by artisanal fishermen off the coast of Oaxaca.…”

A Systematic Review of Global Marine Mammal Rehabilitation and Refloating, 2000–2023

“…Rehabilitation of endangered otariids included the Galápagos fur seal (Arctocephalus galapagoensis) and Galápagos sea lion (Zalophus wollebaeki). Four of the five reports on the rehabilitation of these species reported on extra-limital occurrences of single individuals [22][23][24][25]. While the Galápagos species are vulnerable to climatic changes and anthropogenic activity, including entanglement in fishing gear and refuse, oil spills, and introduced pathogens, rehabilitation efforts currently appear to be limited to in situ responses [26].…”