The target fishery for the spotted eagle ray Aetobatus narinari in the southern Gulf of Mexico is little known. The landings of four small-scale vessels at two fishing localities were sampled and fishermen were interviewed in 2009. Rays landed at Campeche [mean ± standard deviation (SD) 1204 ± 225.3 mm disc width (DW)], fished at 30-50 km from the shore, were larger than rays landed at Seybaplaya (924 ± 206.5 mm DW), fished at 8-15 km from the shore. Ray catches were male biased off Campeche and female biased off Seybaplaya. Catch rate off Campeche was 6.6 (±4.9) rays per vessel trip and off Seybaplaya was 3.0 (±2.9) rays per vessel trip. Fishermen stated that catches of A. narinari are positively influenced by winter cold fronts, turbidity, low sea temperature, and new moon phase, and negatively influenced by the presence of cownose rays Rhinoptera bonasus. Spatial variation in size composition, and sex and maturity ratios of A. narinari were evident between sites. Catch rates of A. narinari varied with individual fisherman and seasonally between months with winter cold fronts versus warmer months. Fishermen reported a general decline in catches of A. narinari over recent decades in this region.
Information on the occurrence and abundance of the Critically Endangered smalltooth sawfish Pristis pectinata and largetooth sawfish P. pristis across most of their former range is needed for a comprehensive global conservation status assessment. The current presence of both species in Mexico and the rest of Latin America remains uncertain in the absence of dedicated studies. During 2015, we performed the first nationwide study of sawfishes in Mexico. We developed specific materials to survey fishers, raise community awareness, and publicize sawfish conservation needs. We interviewed 794 fishers in 71 localities along the Atlantic and Pacific coasts of Mexico. Additional data from a similar 2010−2011 survey of 39 fishers in Tabasco and Campeche were also included in the analysis. Both species might be nearly extirpated from Mexico. Interviewees reported modal decadal dates of last sighting as the 1980s for the smalltooth sawfish along the Atlantic coast and as the 1970s for the largetooth sawfish along both coasts. No confirmed reports of recent (< 5 yr) sightings were reported. However, a live juvenile smalltooth sawfish was caught in Veracruz in January 2016. Historical importance maps were reconstructed, indicating that both species were distributed along the entire surveyed area; the smalltooth sawfish was especially common in Campeche, Quintana Roo, and Tabasco, while the largetooth sawfish was common in Campeche, Colima, and Chiapas. Both species must be re-categorized in Mexican legislation for species at risk of extinction from 'threatened' to 'endangered'.
High plasticity in cephalopod populations shows dramatic changes in their biological traits. Commercial catches of Mayan octopus (Octopus maya) in six localities of the state of Campeche, Mexico, were sampled monthly for five consecutive fishing seasons (2005–2009) in order to describe variations in population structure and maturation. Octopus maya grows and matures during the fishing season, from August to December. Spent individuals predominate in January and February, revealing a year-long life cycle. However, the presence of a few spent females in all months sampled suggests that a small part of the population shows an extended spawning period. Overall sex ratios did not significantly shift from the expected 1:1 in most samples. Males are mostly mature while the majority of females are immature during the season. Use of illegal fishing gears (spear diving or pots) in central localities accounts for a larger share in mature females. Octopus size showed large interannual and geographic differences. Females mature at a larger size (1024 g body weight, BW; 124 mm mantle length, ML) than males (484 g BW; 91 mm ML). Size at maturity in both sexes varies more between seasons than between localities. Female ML at maturity is larger than the current minimum legal size and implications for current octopus fishing regulations are discussed.
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