The smallest known free-living white shark (Carcharodon carcharias)

The Smallest Known Free-Living White Shark Carcharodon carcharias (Lamniformes: Lamnidae): Ecological and Management Implications

Omar Santana-Morales, Alicia Abadía-Cardoso, Mauricio Hoyos-Padilla, Gavin J. P. Naylor, Shannon Corrigan, Luis Malpica-Cruz, Marc Aquino-Baleytó, Rodrigo Beas-Luna,  Chugey A. Sepulveda, Jose L. Castillo-Géniz

Copeia 108(1), 39-46 (2020)

DOI: https://doi.org/10.1643/OT-19-233

Abstract

The White Shark (Carcharodon carcharias) is a top predator cosmopolitanly distributed and heavily protected worldwide. Identification and information pertaining to White Shark nursery areas is limited yet crucial for the protection of sharks during their most vulnerable life stages. Here, we present morphometric, skeletal, and haplotypic characteristics of the smallest free-living White Shark reported to date (1066 mm TL). These characteristics correspond to a newborn White Shark smaller than those previously reported in an embryonic state but displaying the same number of rows of functional teeth as an adult. The individual was caught incidentally by an artisanal fishery operating along the Pacific coast of Baja California, near the international border between Mexico and the United States (USA). We found no genetic divergence between Isla Guadalupe and central California, two aggregation sites that have been proposed as a possible source for newborn sharks in this area. The newborn White Shark displayed the most common haplotype present among individuals at both aggregation sites. These findings provide evidence suggesting the presence of an extended nursery habitat in the Northeast Pacific, a transnational region between Mexico and USA. 

Keywords: Ecology, management, nursery area, newborn