Background:

Amphioxi (Cephalochordata), are a group of marine organisms of great relevance and interest in evolutionary studies, due to their phylogenetic position; inhabit the sandy bottoms of coastal waters around the world. Two species Branchiostoma elongatum and B. californiense are widely distributed throughout the Tropical Eastern Pacific.

Objectives:

The objective of this work is to document the occurrence of Branchiostoma californiense, in a lagoon-estuarine system from Chiapas, Mexico.

Methods:

The specimens were collected from the sandy bottom between 50 and 90 cm deep, using a stainless-steel sieve in the estuarine channel of the estuarine-lagoon system La Joya-Buenavista.

Results:

A total of 19 specimens of B. californiense were collected. The specimens collected were juvenile stages less than 10mm in length (3.1-5.9 mm).

Conclusions:

These records indicate the first record of this species in the inland waters of Chiapas and represent the southernmost records of this species in the Mexican Pacific.