Northernmost record of dusky dolphin &lt;i&gt;Lagenorhynchus obscurus&lt;/i&gt; in coastal waters off northern Peru (4°S)

Ana Paula Suárez,Belén Alcorta,Vanessa Jaramillo,Aldo S Pacheco

doi:10.22370/rbmo.2018.53.3.1365

Abstract

Dusky dolphin Lagenorhynchus obscurus is distributed primarily in cool coastal waters at several continental margins and island borders in the Southern Hemisphere. Off Peru, the northernmost record of this species has been in front of the coast of Salaverry (ca., 6°S). In this paper, we report for the first-time a pod of dusky dolphin at the coast of Los Órganos (4°9.517’S; 81°11.958’W) northern Peru, thus extending the potential distributional range ca., 350 km towards the equator. A group of between 10 to 20 adult individuals was sighted on 17 October 2017, during a whale-watching excursion. Digital photographs and film allowed us to confirm the species based on body morphology and coloration. The sighted group was moving around the area without heading to a given direction. This record constitutes the northernmost record of dusky dolphin in Peru and arguably in the Southern Hemisphere.

Highlights

The dusky dolphin Lagenorhynchus obscurus (Gray, 1828) is a relatively small delphinid distributed in the waters of the Southern Hemisphere (Jefferson et al 2015) and characterized by having a conspicuous areal behavior (Würsig & Whitehead 2009)
We report the presence of dusking dolphin of the coast of Los Órganos (4°S) constituting the first extra-limit record closest to the equator
Dolphins were positive identified as Lagenorhynchus obscurus after a careful examination of photographs and film

Summary

Introduction

The dusky dolphin Lagenorhynchus obscurus (Gray, 1828) is a relatively small delphinid distributed in the waters of the Southern Hemisphere (Jefferson et al 2015) and characterized by having a conspicuous areal behavior (Würsig & Whitehead 2009). Along the southeast Pacific coast, the distribution seems to be disjoint with continuous range from central Peru to central Chile with a gap between 33° and 46°S (Van Waerebeek 1992) range extended down to the Patagonian region (Jefferson et al 2015). Along the southeast Pacific coast of Peru, earlier Van Waerebeek (1992) proposed Chimbote (9°S) as the northern limit of the distribution of dusky dolphin. Multiple new records (Van Waerebeek et al 1997, Reyes 2009, Tzika et al 2010, Llapapasca et al 2018) indicated that Salaverry (6°S) should be considered the northern limit. We report the presence of dusking dolphin of the coast of Los Órganos (4°S) constituting the first extra-limit record closest to the equator

Materials and methods

Results and discussion

Literature cited