The family Batrachoididae is represented by 25 genera and 78 species occurring worldwide (^{Greenfield, Winterbottom, & Collete, 2008}). In the Gulf of Mexico there are 3 genera and 4 species (^{McEachran & Fechhelm, 2005}). The species of this family are found in tropical to temperate waters; most are coastal but some reside in freshwater and others occur on continental shelves up to 250 m. All species are benthic, generally on sandy to muddy bottoms (^{McEachran & Fechhelm, 2005}).

Sanopus reticulatus Collete, 1993 is reported only on the Yucatán state coast. There are 3 previous reports of its presence: in Progreso (^{Collette, 1983}), Sisal (Badillo-Alemán, Gallardo-Torres, & Chiappa-Carrara, 2013), and the Madagascar reef (^{Zarco-Perello, Moreno-Mendoza, & Simões, 2014}).

During the events of algal bloom presented on August 17-20, 2015 in Las Coloradas, Yucatán, and September 27, 2015 in Telchac, Yucatán, 8 dying specimens of S. reticulatus were collected and photographed. In Las Coloradas no organisms were collected because of the advanced state of decomposition. Additionally, we collected 2 adult S. reticulatus in Celestún while scuba diving on September 26, 2015. The specimens were deposited in the Colección ictiológica regional de referencia UMDI Sisal (Semarnat Yuc-Pec 239-01-11) of the Unidad Académica Yucatán, Universidad Nacional Autónoma de México, under collection numbers Yuc-pec-356 and 357.

Taxonomic identification of these specimens was based on the reticulate pattern on the body and head (Fig. 1), and branched chin barbels that are more deeply divided than in other species of the genus (Collete, 1983). The sex of the specimens was determined by direct observation of the gonad. Total length (TL) was measured with the aid of an ichthyometer (±0.1 mm) and total weight with a high precision balance (±0.5 g). The specimens were fixed with 10% formaldehyde and 70% alcohol for preservation.

Figure 1 Collected specimen of Sanopus reticulatus, dorsal view (Yuc-pec-356). 

The presence of S. reticulatus in Celestún and Las Coloradas extends the known distribution of this species to about 75 km southwest of Celestún and about 200 km of Las Coloradas (Fig. 2) from its previous known range from Sisal to Progreso, Yucatán (^{Badillo-Alemán, Gallardo-Torres, & Chiappa-Carrara, 2012}).

Figure 2 Distribution map of Sanopus reticulatus on the Yucatán state coast, locations with previous records (white circles) and locations with new records (dark circles). 

The specimens collected in Celestún were 2 males, caught in the morning at an average depth of 3 m in burrows in hard substrate. Their length ranges from 399 to 410 mm and weight from 863.5 to 966.1 g. The S. reticulatus collected and photographed on the beach of Las Coloradas and Telchac is ranges from 115 to 242 mm in total length and from 15.4 and 182.1 g in weight. In the latter locations we collected 3 males and 4 females.

These results suggest that S. reticulatus has a continuous distribution along the Yucatán coast. Currently, this species is evaluated on the red list of IUCN under the category of endangered B1ab(iii), meaning a high risk of extinction in the wild, because of a limited distribution. The information provided in this study will contribute to a better assessment of the current status of this species endemic to Mexico.

We are grateful to David de Anda Fuentes from the Centro Regional de Investigación Pesquera de Yucalpetén, Joaquín Cauich Flores and Leonardo Pech for their support in field activities, Maribel Badillo-Alemán and Luis Salinas Peba for photographs, and the Colección ictiologica regional de referencia UMDI Sisal for housing specimens. This paper was financed by the Instituto Nacional de Pesca through the project number 07.