RESUMEN
Species of the genus Octopus from the northeastern Pacific are ecologically and economically important; however, their taxonomy is confusing and has not been comprehensively assessed. In this study, we performed a taxonomic evaluation of these species considering the morphological characteristics of the original descriptions, a molecular analysis of partial COI-gene sequences, and a traditional morphometry analysis of nine body measurements. Several interesting findings were obtained with our results: for instance, we updated the diagnoses of some species by including characters such as the number of lamellae per demibranch and the presence of chromatophores in the visceral sac; we deposited partial COI-gene sequences of species that had not been incorporated into the GenBank repository; and according to the morphometric analysis, we confirmed that the lengths of arms I-IV are relevant to discriminate the species under study. The taxa evaluated were morphologically, molecularly and morphometrically well-delimited; however, features such as funnel organ shape and arm length proportions in regard to dorsal mantle length are either not included in the diagnosis of the genus Octopus or overlap with other genera. Hence, this information, combined with the results obtained from the molecular analysis, supports the generic re-assignation of two of the species evaluated.
RESUMEN
Se presenta una descripción general del patrón estacional de la clorofila a (Chl-a) y temperatura superficial del mar (TSM) en la región occidental del Golfo de México (Tamaulipas, Veracruz, Tabasco, Campeche, Yucatán y Quintana Roo), así como el análisis de la variabilidad interanual en los estados de Tabasco y Campeche como estudios de caso. Las series de tiempo se estimaron a partir de imágenes de satélite derivadas de los sensores OCTS-SeaWiFS (1996-2007) y AVHRR (1996-2006). Se identificaron dos periodos donde predominaron las condiciones cálidas (1997-1999) y frías (2000-2001), los cuales podrían relacionarse con cambios en la estructura del ecosistema de esta región.
A general description of the seasonal pattern of chlorophyll a (Chl-a) and sea surface temperature (SST) in the Western Gulf of Mexico (Taumalipas, Veracruz, Tabasco, Campeche, Yucatan and Quitana Roo) is presented, as well as an analysis of the inter-annual variability in the states of Tabasco and Campeche, as case studies. The time series were estimated from satellite images obtained with the OCTS-SeaWiFS (1996-2007) y AVHRR (1996-2006) sensors. Two periods when warm conditions (1997-1999) and cold conditions (2000-2001) predominated were identified, which could be related to changes in the regional ecosystem.
Apresenta-se uma descrição geral do padrão estacional da clorofila a (Chl-a) e temperatura superficial do mar (TSM) na região ocidental do Golfo do México (Tamaulipas, Veracruz, Tabasco, Campeche, Yucatán e Quintana Roo), assim como a análise da variabilidade interanual nos estados de Tabasco e Campeche como estudos de caso. As séries de tempo se estimaram a partir de imagens de satélite derivadas dos sensores OCTS-SeaWiFS (1996-2007) e AVHRR (1996-2006). Identificaram-se dois períodos onde predominaram as condições cálidas (1997-1999) e frias (2000-2001), os quais poderiam relacionar-se com mudanças na estrutura do ecossistema desta região.
RESUMEN
Se analiza, desde la perspectiva socioeconómica, el desempeño de la pesquería de camarón y calamar gigante en la región noroeste de México. Se ubica a estas dos pesquerías en el contexto de sus orígenes y orientación exportadora, argumentando que estos dos elementos han marcado el ritmo de explotación de esos recursos. Se describe el comportamiento de las capturas y los ingresos generados por las dos pesquerías. Se concluye que, a pesar que estos dos recursos son fuente de empleo e ingreso, no resuelven los problemas estructurales de la pesca en la región, ya que existen factores biológicos y de mercado que deben ser considerados para que estas dos pesquerías sean ambientalmente sustentables y económicamente eficientes.