Observaciones sobre las especies de truchas criollas.

The genus Percichthys (Serranidae) includes three nominal species in Argentina, trucha, vinciguerrae and altispinis. The authors of this paper examine materials from: 1: the Río Negro river in its inferior course, in front of Viedma; 2: lake Pellegrini, near Neuquén, where the rivers Neuquén and Limay meet and form the Negro; 3: Plottier, near the place just named; 4: Colorado river, in Fortín Uno; 5: Curacó river, a tributary to the Colorado, now cut into separate sections since years ago on account of the lack of water; this river normally would connect the Colorado with the rivers up to the San Juan where the « trucha » lives; 6: Luro or La Salada lagoon, formed by the Colorado river near its mouth; 7: Argentino lake, in the southern Patagonia. These fishes are known as « trucha criolla » or « native trout » although the old Spanish name was « perca », more appropiate. Percichthys altispinis Regan 1905 is a good species ; it has been re-found in the Colorado river, at Fortín Uno. An illustration of it is given, characters of four specimens and a note on its scales. P. trucha C. V. reveeals itself on close examination as a complex species or linnean species (linneon) ; with several combinations of characters, but even more materials are needed to establish if there are geographical races (subspecies). A new examination of the Chilean materials is required (former authors considered them jointly with the Atlantic versant or Argentine materials). Some of the infraspeciíic forms are prognathous, and low finned ; others, the contrary; the head may be normal, or conical and bony; etc. As to P. vinciguerrae its standing as a valid species is doubtfull; perhaps, with P. laevis Jenyns it is a southern form. In the same reduced habitat (lagoon, or isolated course) diversified forms are present; some show parallelism with those of other places ; it is supposed that they show ecological influences according to the year or season of birth or developpment. A thorough study of the scales is given, with epidological characteristics and general conciusions as to the method of measuring and comparing their « reading». There are some marked differences even in the same habitat.

Ictiólogos de la Argentina: Juan Manuel Cordini.

This series will include all those people who, by means of their contributions, great and small, played a part in the consolidation of ichthyology in Argentina. The general plan of this work consists of individual factsheets containing a list of works by each author, along with reference bibliography and, whenever possible, personal pictures and additional material. The datasheets will be published primarily in chronological order, although this is subject to change by the availability of materials for successive editions. This work represents another approach for the recovery and revalorization of those who set the foundations of Argentine ichthyology while in diverse historical circumstances. I expect this to be the beginning of a major work that achieves the description of such a significant part of the history of natural sciences in Argentina.

Ictiólogos de la Argentina: Francisco Juan José Risso Ceriani.

This series will include all those people who, by means of their contributions, great and small, played a part in the consolidation of ichthyology in Argentina. The general plan of this work consists of individual factsheets containing a list of works by each author, along with reference bibliography and, whenever possible, personal pictures and additional material. The datasheets will be published primarily in chronological order, although this is subject to change by the availability of materials for successive editions. This work represents another approach for the recovery and revalorization of those who set the foundations of Argentine ichthyology while in diverse historical circumstances. I expect this to be the beginning of a major work that achieves the description of such a significant part of the history of natural sciences in Argentina.

Ictiólogos de la Argentina: Juan Carlos Chebez

This series will include all those people who, by means of their contributions, great and small, played a part in the consolidation of ichthyology in Argentina. The general plan of this work consists of individual factsheets containing a list of works by each author, along with reference bibliography and, whenever possible, personal pictures and additional material. The datasheets will be published primarily in chronological order, although this is subject to change by the availability of materials for successive editions. This work represents another approach for the recovery and revalorization of those who set the foundations of Argentine ichthyology while in diverse historical circumstances. I expect this to be the beginning of a major work that achieves the description of such a significant part of the history of natural sciences in Argentina.

Ictiólogos de la Argentina: Aurelio Juan Santiago Pozzi

This series will include all those people who, by means of their contributions, great and small, played a part in the consolidation of ichthyology in Argentina. The general plan of this work consists of individual factsheets containing a list of works by each author, along with reference bibliography and, whenever possible, personal pictures and additional material. The datasheets will be published primarily in chronological order, although this is subject to change by the availability of materials for successive editions. This work represents another approach for the recovery and revalorization of those who set the foundations of Argentine ichthyology while in diverse historical circumstances. I expect this to be the beginning of a major work that achieves the description of such a significant part of the history of natural sciences in Argentina.

Lista de los peces de la provincia de San Juan

Esta serie tiene como finalidad dar a conocer las especies presentes en los diferentes estados provinciales. Tomando como base los trabajos de López et al., (2003); Reis et al., (2003); Liotta (2006) y Ferraris (2007) hemos actualizado el elenco ictiofaunístico en cada territorio provincial, siguiendo la macrosistemática de Nelson (2006). No se realizan, con excepción del nombre vulgar y localidad tipo, comentarios ni observaciones sobre las especies señaladas ya que estos se encuentran en la bibliografía adjunta. Se incluyen dos tablas que contienen información sobre especies introducidas y de aquellas de presencia dudosa o que requieren confirmación en el territorio provincial. En este último caso se cita el trabajo que las menciona por primera vez. Consideramos que este modesto aporte contribuirá a precisar el conocimiento ictiofaunístico regional ya que además de la lista de especies, presentamos el marco biogeográfico e hídrico correspondiente. Por otra parte, entendemos que la participación de autores involucrados en la región considerada, le da un verdadero sentido federal a esta contribución, además de reforzar vínculos entre los protagonistas de nuestra especialidad. En este nuevo número, presentamos la provincia de San Juan que se encuentra enclavada en el centro-oeste de nuestro territorio, limitada por las provincias de La Rioja, Mendoza y San Luis. Se presenta por primera vez una lista exhaustiva de la ictiofauna de la provincia de San Juan basada en la revisión bibliográfica y de material de referencia de las colecciones Ictiológicas de la Universidad Nacional de San Juan y del Museo de La Plata. Se citan 21 especies, de las cuales 15 no habían sido mencionadas con anterioridad (Arratia et al., 1983; Murúa y Acosta, 1997; Liotta, 2006). Ocho especies han sido introducidas principalmente con fines deportivos. Se menciona la presencia de Percichthys chilensis, lo que constituiría el primer registro formal de esta especie ya que López-Arbarello (2004) la menciona para el Río Tunuyán (Mendoza), sin material de referencia.

Ictiólogos de la Argentina: Juan Carlos Vidal

This series will include all those people who, by means of their contributions, great and small, played a part in the consolidation of ichthyology in Argentina. The general plan of this work consists of individual factsheets containing a list of works by each author, along with reference bibliography and, whenever possible, personal pictures and additional material. The datasheets will be published primarily in chronological order, although this is subject to change by the availability of materials for successive editions. This work represents another approach for the recovery and revalorization of those who set the foundations of Argentine ichthyology while in diverse historical circumstances. I expect this to be the beginning of a major work that achieves the description of such a significant part of the history of natural sciences in Argentina.

Semblanzas Ictiológicas: Juan Martín Díaz de Astarloa

A través de esta serie intentaremos conocer diferentes facetas personales de los integrantes de nuestra “comunidad”. El cuestionario, además de su principal objetivo, con sus respuestas quizás nos ayude a encontrar entre nosotros puntos en común que vayan más allá de nuestros temas de trabajo y sea un aporte a futuros estudios históricos. Esperamos que esta iniciativa pueda ser otro nexo entre los ictiólogos de la región, ya que consideramos que el resultado general trascendería nuestras fronteras.

Fish consumption by harbor seals (Phoca vitulina) in the San Juan Islands, Washington

The harbor seal (Phoca vitulina) is a large-bodied and abundant predator in the Salish Sea ecosystem, and its population has recovered since the 1970s after passage of the Marine Mammal Protection Act and the cessation of bounties. Little is known about how this large predator population may affect the recovery of fish stocks in the Salish Sea, where candidate marine protected areas are being proposed. We used a bioenergetics model to calculate baseline consumption rates in the San Juan Islands, Washington. Salmonids (Oncorhynchus spp.) and herring (Clupeidae) were the 2 most energetically important prey groups for biomass consumed by harbor seals. Estimated consumption of salmonids was 783 (±380 standard deviation [SD]) metric tons (t) in the breeding season and 675 (±388 SD t in the nonbreeding season. Estimated consumption of herring was 646 (±303 SD) t in the breeding season and 2151 (±706 SD) t in the nonbreeding season. Rockfish, a depressed fish stock currently in need of population recovery, composed one of the minor prey groups consumed by harbor seals (84 [±26 SD] t in the nonbreeding season). The variables of seal body mass and proportion of prey in seal diet explained >80% of the total variation in model outputs. Prey groups, such as rockfish, that are targeted for recovery may still be affected by even low levels of predation. This study highlights the importance of salmonids and herring for the seal population and provides a framework for refining consumption estimates and their confidence intervals with future data.

Semblanzas Ictiológicas: Juan José Rosso

A través de esta serie intentaremos conocer diferentes facetas personales de los integrantes de nuestra “comunidad”. El cuestionario, además de su principal objetivo, con sus respuestas quizás nos ayude a encontrar entre nosotros puntos en común que vayan más allá de nuestros temas de trabajo y sea un aporte a futuros estudios históricos. Esperamos que esta iniciativa pueda ser otro nexo entre los ictiólogos de la región, ya que consideramos que el resultado general trascendería nuestras fronteras.

Semblanzas Ictiológicas: Juan Manuel Molina

A través de esta serie intentaremos conocer diferentes facetas personales de los integrantes de nuestra “comunidad”. El cuestionario, además de su principal objetivo, con sus respuestas quizás nos ayude a encontrar entre nosotros puntos en común que vayan más allá de nuestros temas de trabajo y sea un aporte a futuros estudios históricos. Esperamos que esta iniciativa pueda ser otro nexo entre los ictiólogos de la región, ya que consideramos que el resultado general trascendería nuestras fronteras.