Background:

Placozoa is a phylum with only one species:Trichoplax adhaerens (F. E. Schulze, 1883); recent genetic studies suggest, however,that several haplotypes inhabit tropical and subtropical waters around the world. Placozoans have been found usually close to littoral zones where mangrove forests occur.

Goals:

To provide the second record of this species from the coasts of Mexico and describe a new filament structure observed in the upper epithelium.

Methods:

Photographic images were taken of Placozoans found in glass slides introdu ced in marine aquariums. Some specimens were collected and stained with Mito Tracker, DAPI and Lyso Tracker fluorescent dyes according to the manufacturer instructions.

Results:

Puerto Morelos in the Mexican Caribbean Sea and Florida in the Atlantic coast are the closest places to the Gulf of Mexico were Placozoans have been recorded. We report here the first record of Trichoplax adhaerens in the Gulf of Mexico. The organisms were found in sea water aquariums built with materials, water, and invertebrates obtained from the Tuxpan reef (21.016667 N, 97.186389 W), an emerged platform that belongs to the Lobos-Tuxpan Reef System.

Conclusions:

This finding is the first record of Trichoplax for the coasts of the western Gulf of Mexico and includes the description of a filament structure in the upper epithelium not reported before.