A comprehensive survey of the octopus fauna around the Americas is presented to facilitate and accelerate the assessment of a full understanding of American octopus biodiversity. Brief accounts are provided summarizing research efforts on octopus species taxonomy, diversity and distribution in different regions of North and South America. Octopus americanus and O. insularis are compared and clearly distinguished from each other and from the closely-related European species, O. vulgaris. The use of genus names Paroctopus and Pinnoctopus is clarified. Included is a discussion of the recent application of genus name Paroctopus to warm-temperate and tropical species of small size, along with a cautionary note about species identifications in the light of past errors in misassigning large-to-giant cold-water species to genus Paroctopus. Related to problems with identifying species of Paroctopus, there is an appended note concerning misidentifications and the importance of thorough species descriptions to obtain species information at the levels of both phenotype and genotype. A lectotype is formally designated for Bathypolypus arcticus (Prosch, 1849); and the status of so-called ‘Octopus giganteus’ is reviewed briefly. A supplementary online database, AmeriCeph, provides basic information about all known octopus species of the Americas, including the institutional location of type material and the identification of voucher specimens and their depositories. DNA sequences registered in this database are not all fully compatible with barcoding standards. However, a subset of DNA sequences conforming to strict barcode identifications is provided in a second supplementary table, providing barcode sequences directly applicable also to improving standards of seafood traceability. This in turn contributes to building sustainability of exploited octopus fisheries stocks and identification of species suitable for aquaculture trials to meet the increasing commercial demand for octopus worldwide.

Species are expected to migrate to higher latitudes as warming intensifies due to anthropogenic climate change since physiological mechanisms have been adapted to maximize fitness under specific temperatures. However, literature suggests that upwellings could act as thermal refugia under climate warming protecting marine ecosystem diversity. This research aimed to predict the effects of climate warming on commercial and noncommercial fish species reported in official Mexican documents (>200 species) based on their thermal niche to observe if upwellings can act as potential thermal refugia. Present (2000-2014) and Representative Concentration Pathway (6.0 and 8.5) scenarios (2040-2050 and 2090-2100) have been considered for this work. Current and future suitability patterns, species distribution, richness, and turnover were calculated using the minimum volume ellipsoids as algorithm. The results in this study highlight that beyond migration to higher latitudes, upwelling regions could protect marine fishes, although the mechanism differed between the innate characteristics of upwellings. Most modeled species (primarily tropical fishes) found refuge in the tropical upwelling in Northern Yucatan. However, the highest warming scenario overwhelmed this region. In contrast, the Baja California region lies within the Eastern Boundary Upwelling Systems. While the area experiences an increase in suitability, the northern regions have a higher upwelling intensity acting as environmental barriers for many tropical species. Conversely, in the southern regions where upwelling is weaker, species tend to congregate and persist even during elevated warming, according to the turnover analysis. These findings suggest that tropicalization in higher latitudes may not be as straightforward as previously assumed. Nevertheless, climate change affects numerous ecosystem features, such as trophic relationships, phenology, and other environmental variables not considered here. In addition, uncertainty still exists about the assumption of increasing intensity of upwelling systems.

Ecological theory predicts fluctuations, such as oscillations and instabilities, in populations whose dynamics can be represented by discrete-time surplus production models, whenever the intrinsic rate of population growth (r) is too high. Many fished stocks may have sufficiently high r to undergo fluctuations under fishing. The maximum sustainable yield (MSY) is the fishing harvest rate concept that underlies United Nations Sustainable Development Goals and much of national fisheries administration around the world and yet in fluctuating stocks the MSY does not exist. This is because MSY’s existence necessitates stable zero growth rates and in fluctuating stocks the growth rate switches from positive to negative over regular or irregular cycles, never staying put at zero. A more general surplus production concept is the total latent productivity (TLP). TLP averaged over years of negative and positive productivity has been proposed as a sustainable annual harvest rate for fluctuating stocks. We tested this theory assessing two harvested octopus populations inhabiting the Yucatan Peninsula with a 22-years time series of data, and a two-stages stock assessment methodology, with time-varying parameters at both stages. We find that parameters of the population dynamics changed in both species, dividing the time series in two periods, leading from single-point equilibrium to fluctuating dynamics in one species and increased amplitude and amplitude variability in the other species. These results mean that management based on the MSY would lead to overfishing and collapse of the two octopus stocks, as shown by stochastic projections. Conversely, the average TLP yielded much lower and realistic annual harvest rates, closer to actual landings over the 22-years period. We conclude that average TLP is the correct sustainable harvest rates for fluctuating stocks, which may include cephalopods, other invertebrates and small pelagic fish. This more general concept of surplus production needs to be incorporated in multilateral and national fisheries management policies to avoid overfishing stocks that have fluctuating population dynamics.

The typical bidirectional pattern of subtidal flow observed at the mouths of estuaries is produced by inflows during high-tide (flood) and outflows during low-tide (ebb) periods. This flow pattern can be modulated in the presence of a strong river discharge, as observed for the Alvarado Estuary (western Gulf of Mexico) during the rainy season. Herein, six transect repetitions were obtained using a towed Acoustic Doppler Current Profiler (ADCP) at an average speed of approximately 2 m/s during a diurnal tidal cycle from September 20 to 21, 2009. The water column during this period was strongly stratified at the mouth of the estuary due to the amount of discharge from the Papaloapan River. Furthermore, the temperatures within the estuary were directly related to the distance from the Papaloapan River. Based on salinity data obtained at four locations along the estuary, the Alvarado Estuary could be considered for the first time as a transitional system from oligohaline to mesohaline (salinities between 5 and 18). The currents and backscatter intensities of the ADCP revealed concentrated areas of suspended particles in the deepest area of the estuary during flood tide periods. During ebb tide periods, estuarine water primarily exited through its mouth (-90%), followed by the artificial channel (-10%) located in the northernmost area of the estuary. The residence time during this season was 3.99 days. Finally, the typical estuarine flow pattern observed during flood and ebb tide periods was only depicted near the bottom of the mouth of the estuary. However, the near-surface flow was always toward the ocean (outflow), regardless of the tidal stage.

Production of octopus fisheries is highly variable typically due to their sensitivity to environmental conditions. Using data from four scientific research cruises conducted in 2016 and 2017, we studied the influence of the environment on the relative abundance and distribution of two co-occurring octopus species, Octopus americanus (merobenthic) and O. maya (holobenthic), at the eastern part of the continental shelf of the Campeche Bank, a tropical upwelling area. By means of fitting hierarchical Bayesian spatio-temporal models, we found that the relative abundance of both species decreased with depth and when salinity and temperature were higher. The residual spatial distribution showed that variability in space for both species differed between seasons. In summer, when upwelling conditions dominate, O. americanus was abundant at the eastern part of the continental shelf, while O. maya dominated in the north-east and the coastal zone of Yucatan. In winter, when mixing conditions characterize the water column, O. americanus was abundant in coastal waters of Quintana Roo towards the north-west, whereas O. maya occurred mostly to the north-east. Additionally, the body weight of O. americanus decreased with depth, rocky bottoms and winter, while O. maya was smaller in shallower waters, sandy bottoms and summer. Overall, both species showed greater affinity for less saline and cooler waters, indicative of upwelling conditions. The spatial distribution differed between species and between sizes. We suggest that the ontogenetic differences would be associated with their distinct dispersal capacity during their early stages that would be under the influence of the Loop Current.

The Mayan octopus (Octopus maya) and the American octopus (O. americanus) are the two species that support the octopus fishery on the Campeche Bank. The large-scale fleet catches both species. However, landings are recorded as American octopus in the official statistics, and this causes a problem for the management of the fishery. The large-scale octopus fishery on the Campeche Bank was studied using a model based on data from interviews with skippers. A total of 180 valid interviews were conducted in the base ports of Progreso and Yucalpeten (Yucatan), representing 51.1% of the skippers in the fleet in 2019. This information was used for the first time to estimate catch per unit effort (CPUE) and total catches for each octopus species. The mean CPUE ranged between 50 and 500 kg day-1, with minimums of 10 kg day-1. The mean estimated potential catches ranged from 5069 to 3456 t per year for O. maya and from 4113 to 2805 t per year for O. americanus. The relationship between official landings and estimated catches showed a significant correlation (rxy=0.898). The total estimated catches were on average 20% lower than the official landings of O. americanus. The origin of this discrepancy is discussed.

The octopus fishery on the Campeche Bank (Yucatán, Mexico) is considered the third largest in the world. In Yucatán, two fleets target this resource: an artisanal fleet and a semi-industrial fleet. The artisanal fleet only catches Octopus maya, while the semi-industrial fleet catches two species, O. Maya and O. “vulgaris” Type II, because it operates at deeper waters ( > 30 m). Since there is no information on the abundance of O. “vulgaris” Type II, management is based only on O. Maya. In order to generate information about the abundance of this species, four fishing research cruises were carried out in the northeastern area of the continental shelf off the Yucatán Peninsula. Four methods (a stratified random method, a swept area, geostatistics and a weighted swept area) were applied and compared to determine the instantaneous abundance and biomass of both species in the study area. The lowest potential biomass was calculated with the geostatistical method, with values between 18.5% and 36.7% lower than the other three methods. O. “vulgaris” Type II showed the lowest biomass (37.8±3.36 t) during May and July and the highest (189.56±11.6 t) in December. Our findings revealed that the total abun­dance of both species was similar in the study area, with a geographic overlap whose amplitude changed throughout the year according to the geographic position: O. Maya dominated at approximately 88°W, while O. “vulgaris” Type II dominated towards the southeast at 87°W.

The regulatory framework of the red octopus (Octopus maya) fishery includes total allowable catches (TAC), which are based on studies conducted on the population that occurs in shallow waters. In fact, most of the biological studies of this species refer to the fraction of the population that occupies waters less than 30 m deep; however, O. maya can occur up to a 60 m depth. The aim of this study is to assess the stock of O. maya that occupies waters between 30 m and 60 m deep. Four research cruises were carried out during the closed and fishing seasons, from May 2016 to January 2017. An average of 29 sampling sites were surveyed in each cruise (+/- 2 sampling sites) using a commercial vessel with a uniform sampling effort. In each sampling site, the swept area, the total number of octopuses captured, the total weight of the catch, and the individual weight of octopuses were recorded. Biomass was obtained with four methods: stratified random method, swept area method, geostatistical biomass model, and an unpublished method of weighted swept area. The four methods provided consistent results. The distribution pattern of species was in patches, although before the fishing season started it was more homogeneous. The fraction of the population that occurs between 30 m and 60 m deep consisted mostly of adult organisms, so it could be contributing significantly to the recruitment of the entire population, even to the fraction that is exploited.

The annual variation of total nitrogen, dissolved oxygen, salinity, temperature, Chlorophyll-alpha and density time series in the surface layer (1 and 5 m depth) were analyzed in a tropical coral reef system, under the influence of city drainage and river discharges. It is important to fully understand the temporal variation of such parameters throughout the world since they are related to biological processes. Furthermore, most tropical coral reef systems, such as the Veracruz Reef System (VRS, Mexico), developed in areas where the reefs are under stress due to the influence of fresh water input during the rainy season, and sediments coverage (vertical mixing) during the northern winds (cold front) season. In addition to the atmospheric temporal variability at mesoscales in the western Gulf of Mexico (dry, rainy and northern wind seasons), the VRS exhibited two transition months between seasons, in contrast to the three months transition period expected from the atmospheric variability. Finally the system was found to be more productive than its surrounding areas due to nutrient input from rivers and city drainage.

The “Parque Nacional Sistema Arrecifal Veracruzano” (PNSAV), a coastal reef system located in the corridor of the southwestern Gulf of Mexico, is an ecosystem with different environmental characteristics when compared to most tropical coral reefs. The current study aims to describe the hydrological variation of temperature, salinity, density, oxygen, nitrogen and chlorophyll-a from March, 2011 to March, 2012. A total of 13 sampling stations distributed along the PNSAV were used to describe the temporal variation of the physicochemical characteristic of the area. There was a good correlation between the physicochemical and biological variables according to a multivariate statistical analysis (cluster and PCA) performed using all variables. The correlation value among the physicochemical and biological variables was about the same for all stations despite the differences in coral coverage. It was found that the PNSAV had different seasons (dry, rainy, northern and transition seasons or southern and northern wind seasons) depending on the variables used to perform the analysis. Finally, some stations depicted a hypoxic area in front of the Jamapa River owing to bacterial activity, which maybe one of the explanation of the absence of coral reef structures in this area.

During July to November of 2008, the artisanal fisheries captured juvenile sharks belonging to the Carcharhinus and Sphyrnidae family in the Veracruz Reef System (south western Gulf of Mexico).The three most abundant organisms were of the species Sphyrna lewini, Carcharhinus brevipinna and Rhizoprionodon terraenovae.Local fisherman recognized five captured areas of sharks as a direct way or bycatch.Some of these areas are located near to eddies formations and river discharges (high productivity areas).These top predators fed on benthic and demersal prey of coastal and reef habits had been the Teleost group the most important item in its diet.However it is possible to observe differences in its feeding tendency.