Annotated checklist of marine fishes from the Sanctuary of Bahía Chamela, Mexico with occurrence and biogeographic data.

An annotated checklist of marine fishes of the Sanctuary of Islands and Islets of Bahía Chamela in the central Mexican Pacific is presented. Records of fish species were obtained by different methods including visual census, sampling with anesthetics, fisherman-nets, and trawling with a biological dredge. Additional records were obtained from natural history collections and publications. The list comprises 196 species in 64 families and 141 genera. The Carangidae is the most speciose family with 11 species, followed by the Labridae with 10 and the Pomacentridae with nine. Fourteen species are endemic in Mexican Pacific waters, but none is restricted to Bahía Chamela. The most dominant species recorded during underwater surveys were Epinephelus labriformis, Stegastes flavilatus, and Halichoeres dispilus. Most species are of tropical affinities distributed throughout the tropical eastern Pacific (123), eastern Pacific (23), and Mexican Pacific (14). Other species are known from the eastern and Indo-Pacific regions (18), eastern Pacific and western Atlantic oceans (2), and some are circumtropical (9). A new record of the Gulf Brotula Ogilbia ventralis is provided for the Bahía Chamela and its geographical distribution is extended to Mexican central Pacific

A new species of Websterinereis from the Gulf of California and redescription of Websterinereis foli (Fauvel, 1930) (Annelida, Nereididae)

A new species of Websterinereis Pettibone, 1971, W. pettiboneae sp. n. is described from La Paz Bay, Gulf of California, Mexico. This species is similar to W. foli (Fauvel, 1930) in the neuropodial falcigers shape, but can be separated by the tentacular cirri length, notopodial prechaetal lobe shape, and the size of the notopodial dorsal and ventral ligules on posterior parapodia. Websterinereis foli is redescribed based upon type material. Additional observations on the inter-annual density variation of W. pettiboneae sp. n. during a four-year study are also provided. A key to all species of Websterinereis is included

Riqueza de especies y composición de los ensambles de macroalgas de un arrecife de coral impactado en el Golfo de California, México

Background and Aims: In September 2001, the coral reef of the San Lorenzo Channel, La Paz Bay, Gulf of California, Mexico, was affected by the stranding of the oil tank vessel “Lázaro Cárdenas II”. Soon afterwards, hurricane “Juliette” hit the area with strong winds and water movement, disturbing the reef again. After that, three zones could be observed in the reef: one directly impacted by the shipwreck, one indirectly impacted by the hurricane, which moved and accumulated the coral debris left by the shipwreck, and the third one, which was not impacted. Later, a monitoring program was established to determine the degree of recovery of macroalgal assemblages in both impacted zones compared with the non-impacted one. Methods: From February 2005 to December 2007, macroalgae were collected seasonally by scuba divers in the three zones. In each zone, three to five thalli of all conspicuous algae, five rocks and five fragments of dead coral covered with macroalgal turfs were collected. Species number and composition of macroalgae assemblages were compared between zones and between years. Key results: A total of 117 species were found, 70 belonged to the phylum Rhodophyta, 25 to Ochrophyta-Phaeophyceae, and 22 to Chlorophyta. Macroalgal species richness and composition of the impacted zones were not different from the control zone, even between years. Conclusions: Macroalgal assemblages in the San Lorenzo Channel coral reef were able to recover, regardless of the modification of the substrate caused by the stranding and the hurricane “Juliette” in 2001. Therefore, it is important to implement monitoring efforts in case of anthropogenic or natural disturbance to document the extension of damage, recovery of the communities, and propose mitigation strategies if necessary.  Antecedentes y Objetivos: El arrecife de coral del Canal de San Lorenzo, Bahía de La Paz, Golfo de California, México, se vio afectado por el varamiento del tanque petrolero “Lázaro Cárdenas II” en septiembre de 2001. Poco después, el huracán “Juliette” golpeó el área con fuertes vientos y movimiento de agua que perturbaron nuevamente al arrecife. Después de esto, se pudieron observar tres zonas en el arrecife: una directamente impactada por el encallamiento, otra indirectamente impactada por el huracán, que movió y acumuló los restos de coral que dejó el encallamiento, y la tercera no impactada. Posteriormente, se estableció un programa de monitoreo para determinar el grado de recuperación de los ensambles de macroalgas en ambas zonas impactadas en comparación con la zona no impactada. Métodos: De febrero de 2005 a diciembre de 2007, se recolectaron estacionalmente macroalgas en las tres zonas por medio de buceo. En cada zona, de tres a cinco talos de las especies de macroalgas conspicuas, cinco rocas y cinco fragmentos de coral muerto cubiertos con tapetes macroalgales fueron recolectados. El número de especies y la composición de los ensambles de macroalgas fueron comparados entre zonas y entre años. Resultados clave: Se encontró un total de 117 especies, 70 pertenecientes al filo Rhodophyta, 25 a Ochrophyta-Phaeophyceae y 22 a Chlorophyta. La riqueza de especies y composición de las macroalgas en las zonas impactadas no fueron diferentes de la zona control ni entre años. Conclusiones: Los ensambles de macroalgas en el arrecife de coral del Canal de San Lorenzo pudieron recuperarse independientemente de la modificación del sustrato a causa del varamiento del buque y del huracán “Juliette” en 2001. Por lo anterior, es importante implementar esfuerzos de monitoreo para que, en caso de que ocurra una perturbación antropogénica o natural, se pueda documentar la extensión del daño, la recuperación de la comunidad y proponer estrategias de mitigación si es necesario

Switch between morphospecies of pocillopora corals

© 2015 by The University of Chicago. All rights reserved. Pocillopora corals are the main reef builders in the eastern tropical Pacific. The validity of Pocillopora morphospecies remains under debate because of disagreements between morphological and genetic data. To evaluate the temporal stability of morphospecies in situ, we monitored the shapes of individual colonies in three communities in the southern Gulf of California for 44 months. Twenty-three percent of tagged colonies of Pocillopora damicornis changed to Pocillopora inflata morphology during this time. This switch in identity coincided with a shift to a higher frequency of storms and lower water turbidity (i.e., lower chlorophyll a levels). Seven months after the switch, P. inflata colonies were recovering their original P. damicornis morphology. All colonies of both morphospecies shared a common mitochondrial identity, but most P. damicornis colonies undergoing change were at a site with low-flow conditions. This is the first in situ study to document switching between described morphospecies, and it elucidates the influence of temporal shifts in environmental conditions on morphologically plastic responses

Estimación del crecimiento individual en elasmobranquios: la inferencia con modelos múltiples

Elasmobranchs play an important role in marine ecosystem and worldwide fisheries. Accurate and quantitative description of growth is crucial in modeling the demography and fisheries stock assessment. This study reviews the quantitative methods (asymptotic, non-asymptotic, and generalized), algorithms, and criteria for the model selection applied for growth modeling in elasmobranchs. We analyzed and contrasted the criteria for model selection, mainly between model selection using r2 and information theoretic approach. In marine organisms, the Akaike information criterion (AIC) has been frequently used as a measure of the relative goodness of fit of different growth models, applied to data from different species such as: Dasyatis americana, Carcharhinus acronotus, Carcharhinus plumbeus, Heterodontus portusjacksoni, Malacoraja senta, Mustelus asterias and Mustelus mustelus. We suggest the use of AIC to select the best growth model in elasmobranchs studies.Los elasmobranquios tienen un papel importante en el ecosistema marino y en las pesquerías mundiales. La descripción precisa y cuantitativa del crecimiento es crucial para evaluar las poblaciones. Este estudio revisa los métodos cuantitativos (asintóticos, no asintóticos y generales), para la modelación del crecimiento individual en elasmobranquios. Se analizan algoritmos y se comparan criterios para la selección de modelos, como los criterios de r2 y la teoría de la información. El criterio de información de Akaike (AIC) ha sido usado frecuentemente como una medida relativa de la bondad de ajuste de diferentes modelos de crecimiento, así como en la comparación de modelos aplicados a datos de diferentes especies: Dasyatis americana, Carcharhinus acronotus, Carcharhinus plumbeus, Heterodontus portusjacksoni, Malacoraja senta, Mustelus asterias y Mustelus mustelus. Se sugiere el uso del AIC para seleccionar el mejor modelo de crecimiento en estudios de elasmobranquios

Seagrass Halodule wrightii as a new habitat for the amphioxus Branchiostoma californiense (Cephalochordata, Branchiostomidae) in the southern Gulf of California, Mexico

The first record of the amphioxus Branchiostoma californiense on seagrass patches of Halodule wrightii in the Gulf of California is reported. Sixty individuals (19 males, 18 females, and 23 undifferentiated) were collected in May 2017 at Bahía Balandra, Gulf of California, from subtidal seagrass patches at a depth of 0.5 m at low tide. The length and weight ranged from 15.88–28.44 mm and from 0.01–0.11 g for females and 11.7–27.9 mm and 0.01–0.09 g for males, respectively. The minimum size of sexually mature individuals was 11.70 mm for males and 15.88 mm for females; 62% of the specimens were sexually mature. Analysis of the total length-weight relationship suggested an allometric growth pattern among females, males and undifferentiated individuals, whereas an analysis of the entire sample suggested an isometric growth pattern. Typical and additional morphological characters were used to identify the amphioxi. High morphological variability between individuals was found, suggesting the presence of several morphotypes. Branchiostoma californiense had been previously reported as exclusively associated with bare sandy areas, but our study shows that this species can also be found in seagrass patches, using them as breeding and feeding grounds. Thus, seagrass patches are evidenced as suitable habitats for amphioxus

Morphological variation and different branch modularity across contrasting flow conditions in dominant Pocillopora reef-building corals

© 2015, Springer-Verlag Berlin Heidelberg. Pocillopora corals, the dominant reef-builders in the Eastern Tropical Pacific, exhibit a high level of phenotypic plasticity, making the interpretation of morphological variation and the identification of species challenging. To test the hypothesis that different coral morphospecies represent phenotypes that develop in different flow conditions, we compared branch characters in three Pocillopora morphospecies (P.damicornis, P. verrucosa, and P. meandrina) from two communities in the Gulf of California exposed to contrasting flow conditions. Morphological variation and branch modularity (i.e., the tendency of different sets of branch traits to vary in a coordinated way) were assessed in colonies classified as Pocillopora type 1 according to two mitochondrial regions. Our results can be summarized as follows. (1) Pocillopora type 1 morphospecies corresponded to a pattern of morphological variation in the Gulf of California. Overall, P.damicornis had the thinnest branches and its colonies the highest branch density, followed by P.verrucosa, and then by P.meandrina, which had the thickest branches and its colonies the lowest branch density. (2) The differentiation among morphospecies was promoted by different levels of modularity of traits. P.verrucosa had the highest coordination of traits, followed by P.damicornis, and P.meandrina. (3) The variation and modularity of branch traits were related to water flow condition. Morphology under the high-flow condition was more similar among morphospecies than under the low-flow condition and seemed to be related to mechanisms for coping with these conditions. Our results provide the first evidence that in scleractinian corals different levels of modularity can be promoted by different environmental conditions

Distribución del coral arrecifal Pocillopora inflata (Scleractinia) en el Pacífico Mexicano y comentarios sobre su situación taxonómica

Background. The geographic distribution of reef corals in the eastern Pacific is well documented. However, field surveys still produce new geographic records of the taxa. Goals. The objective of this paper is to present a detailed compilation of the areas of occurrence of the Pocillopora inflata in Mexico, provide observations on its distribution range and comment on the taxonomic validity of the records of this species in the country. Methods. Data regarding distribution of the species in the Eastern Pacific and Mexican Pacific were gathered from published sources and field logs. Results. The distribution of P. inflata ranges from the southern Gulf of California (including new records for four locations of Baja California Sur, along the 24°N parallel), Nayarit, Colima, Guerrero and Oaxaca (to Huatulco Bays; 15°N). This new data call for a modification of the distribution map for the taxon in the Red List of the International Union for Conservation of Nature. Conclusions. Repeated observations in the Gulf of California revealed that, due to the remarkable phenotypic plasticity of another species (P. damicornis), confusion may arise with the identification of P. inflata in the field, since the general form of this species, is quite similar to the branches of P. damicornis affected by storms.Antecedentes. La distribución de los corales del Pacífico Oriental está bien caracterizada, sin embargo prospecciones de campo siguen arrojando nuevos registros geográficos de los taxa. Objetivos. Presentar una recopilación detallada de las zonas de presencia del coral Pocillopora inflata, en México, aportar observaciones que extienden su ámbito de distribución y discutir algunos aspectos sobre la validez taxonómica de los registros de la especie en el país. Métodos. Se compilaron datos de distribución de la especie en el Pacífico Oriental y datos de campo del taxón en el Pacífico mexicano. Resultados. Los resultados indican que la distribución de P. inflata comprende el sur del Golfo de California (incluyendo nuevos registros en cuatro localidades de Baja California Sur, dentro del paralelo 24°N), Nayarit, Colima, Guerrero y Oaxaca (hasta Bahías de Huatulco; 15°N). Los nuevos datos modifican el mapa de distribución reconocido para el taxón en la Lista Roja de la Unión Internacional para la Conservación de la Naturaleza. Conclusiones. Observaciones llevadas a cabo repetidamente en el Golfo de California evidencian que debido a la gran plasticidad fenotípica de otra morfoespecie (P. damicornis), puede haber confusiones al identificar P. inflata en el campo, ya que la forma general de esta especie y la de las ramas de P. damicornis afectadas por tormentas, llega a ser muy similar

Taxonomic identity of Distaplia stylifera (Tunicata, Ascidiacea), a new arrival to the eastern Pacific displaying invasive behavior in the Gulf of California, Mexico

A colonial ascidian of the genus Distaplia caused a mass mortality of the pen shell Atrina maura (Sowerby, 1835) during June 2016 in the southwest of the Gulf of California (Mexico), with a significant socio-economic cost. Tentatively identified in previous works as Distaplia cf. stylifera, a precise taxonomic determination was still lacking. In the present work, based on a detailed morphological study, it is confirmed that this aggressive species is Distaplia stylifera (Kowalevsky, 1874). Originally described from the Red Sea, the species currently has a wide circumtropical distribution (with the exception of the Eastern Pacific to date) and is reported as introduced in parts of its range. The present account thus represents an important range extension of this species. However, when revising the original description and later observations, the reported variability of several characters makes it likely that the binomen is in fact a complex of species, as is common in other ascidians with wide distributions. A complete morphological and genetic study including populations from the entire range of distribution would be necessary to settle the status of D. stylifera. Taxonomic uncertainties hinder a correct interpretation of biogeographical patterns and inference on the origin of the studied population. Nevertheless, the known introduction potential of the species, coupled with an explosive growth in an anthropized environment, and the lack of any previous reports in the Eastern Pacific, strongly suggest that the investigated population represents yet another instance of ascidian introduction. From the point of view of management, its invasive behavior is cause for great concern and warrants mitigation measures

Contribución al conocimiento del origen y relaciones de la ictiofauna de agus profundas del Golfo de California, México

A review of the state of knowledge on the origin, relationships and distribution of the depp water ichthyofauna of the Gulf of California es presented. We conclude there is no sharp difference between the ichthyofaunal assemblages of the Gulf and most of the Eastern Pacific because most of the species are shared. The first representative check list of deepwater fich of the recorded species, including 193 species belonging to 143 genera and 83 families, is provided.Se hace una revisión del estado de conocimiento del origen, relaciones y distribución de la ictiofauna de aguas profundas del Golfo de California. Se concluye que  no existe una clara diferenciación entre los conjuntos ícicos del Golfo y lso del resto del Pacífico oriental dado que la mayoría de las especies son compartidas. Se proporciona la primera lista representativa de las especies registradas en este tipo de ambientes, la cual incluye 195 especies repartidas en 143 géneros y 83 familias