First Record of Amphioxus Branchiostoma californiense (Amphioxiformes: Branchiostomatidae) Adjacent to a Shallow Submarine Hydrothermal System at Banderas Bay (Mexico)

Abstract

Shallow submarine hydrothermal vent systems assume differentiated environmental conditions. Some specimens of Branchiostoma californiense were found in the sediments of the influence area of the shallow hydrothermal venting in Punta Mita. This is the only lancelet species registered for the Mexican Pacific. The meristic and morphometric characteristics of the organisms first collected in unconsolidated sediments of this shallow system were reviewed, in order to determine the species. We confirm that it is the same species. This represents the first record of it for both the Banderas bay and in the influence area of a shallow hydrothermal system.