Endemic Fishes of the Cortez Biogeographic Province (Eastern Pacific Ocean)

Abstract

Background. The Cortez Province (CP) is located in the transitional warm-temperate/subtropical region that allows the ichthyological component inhabiting it to be a mixture of elements of different biogeographic affinities. Since the first systematic analysis of the fish fauna of the Gulf of California in the 1960's a major portion of the endemic species was recognized. Subsequently, a total of 31 new endemic species have been described in the CP. This study constitutes an amendment of the fish component of the CP, including the most relevant ecological attributes of the species, along with an updated taxonomic list. Materials and methods. A comprehensive literature review was made, considering current biological knowledge, and taxonomic status of the endemic species from the CP. Those fish species with restricted distribution ranges, falling within the limits of this province, were considered endemic. Additionally, and to recognize the dominant ecological attributes of the CP endemic species, the preferential habitat, bathymetric distribution, the reproduction strategy, and the maximum total length (TL) were recorded. Results. Seventy-nine endemic species were recognized and grouped in 13 orders, 29 families, and 59 genera. Gobiidae (12), Chaenopsidae (8), and Labrisomidae (7) are the families with the highest species richness, and Sebastes (6 species), the most diverse genus. Forty-five percent of the species are associated with coral and rocky reefs, with 35% distributed within the first 10 m depth layer. The dominant reproduction strategies are: oviparous with benthic eggs and pelagic larval phase (48.7%), and oviparous with pelagic eggs (25.6%). More than half of the species (52%) are shorter than 10 cm (total length). Conclusion. The list of endemic species presented in this study is not conclusive, still undescribed species have not been included, detected differences (morphologic and/or genetic) in several species with disjunct populations may increase the diversity of this province.

Diversidad y afinidades biogeográficas de los tiburones, rayas y quimeras (Chondrichthyes: Elasmobranchii, Holocephali) de México

“…A pesar de que la mayoría de las especies de condrictios, en especial las de hábitos pelágicos, tienen una amplia distribución, existen especies restringidas en ciertas áreas marinas, como se observa en Australia, donde al menos el 51 % de las especies de condrictios (Last & Stevens, 2009) son endémicas. Así, en México el 9.4 % de los condrictios son exclusivos de sus mares y representan el 1.6 % del total de especies conocidas a nivel mundial; el mayor endemismo se encontró en el Golfo de México incluyendo la península de Yucatán (5.2 %) y en el Golfo de California (4.2 %) debido principalmente a que en ambos sistemas, bajo el contexto de su historia geológica, se han originado barreras y procesos de aislamiento que han permitido se desarrollen procesos de especiación (Bowen & Avise, 1990;Bernardi & Lape, 2005;McEachran & Fechhelm, 2005;Neigel, 2009;Palacios-Salgado, Burnes-Romo, Tavera, & Ramírez-Valdez, 2012).…”

Patterns of diversity and endemism of soft-bodied meiofauna in an oceanic island, Lanzarote, Canary Islands

“…For example, while the percentage of endemic species in freshwater and terrestrial Hawaiian fauna averages 48%, reaching 95% in some groups, it averages only 11% in the Hawaiian marine fauna (Wagner & Funk 1995;Randall 1998;Paulay & Meyer 2002;Drew & Roderick 2005), though this difference is clouded because the marine fauna (except for fishes) has been less studied. In contrast, the occurrence of marine endemic species in oceanic islands is still significantly higher than what is found in continental marine regions (Meynard et al 2012;Palacios-Salgado et al 2012). This suggests that the same processes leading to a higher level of endemic species might affect both terrestrial and oceanic fauna of islands, and that differences between both realms might depend on the ecological and biological traits of different taxa.…”

Composicion y aspectos biogeograficos del ensamble de peces de la laguna costera Las Guasimas, Sonora, Mexico

“…El número de especies endémicas observadas (3), como Micropogonias megalops, Pleuronichthys ocellatus (Palacios-Salgado et al, 2012) y Leuresthes sardina, es bajo si se considera que en el Golfo de California existen 92 especies endémicas (Thomson et al, 2000). Es poco probable que las especies endémicas sean recurrentes en este ecosistema, debido a que los fondos lodosos y arenosos tienen menos elementos endémicos en comparación con los fondos rocosos, observándose que las familias restringidas a estos hábitats son: Scianidae, Rhinobatidae, Urolophidae, Clupeidae, Engraulidae, Achiridae, Mugilidae, Gerreidae y Centropomidae (Castro-Aguirre et al, 1995), explicando así la dominancia de las familias Sciaenidae, Carangidae, Gerreidae y Engraulidae (Fig.…”