Limnology in Argentina: an historical account.

This short review includes major books, articles and episodes concerned with studies on inland waters that have affected the development of limnology in Argentina.

A photographic record of a pre- and post-lake creation event from World War II at Valley, Isle of Anglesey, UK

The article compares a recent aerial photograph of the lowlands of the Isle of Anglesey area with a German surveillance photograph from 1941. The authors aim to infer the environmental changes made to this sand dune and lake system as a direct consequence of constructing the airfield. Part of Tywyn Trewan, the extensive sand dune system, was completely destroyed in order to create runways and the technical and domestic accommodation to house a strategic airfield. As part of the dredging, six new water bodies with a combined surface area of approximately 6 ha were created.

Conferencias de Limnolog��a

Transcripci��n de 17 conferencias, 13 en castellano, 3 en ingl��s y uno en portugu��s, dictadas durante la Reuni��n Argentina de Limnolog��a (RAL'91)llevada a cabo en la ciudad de La Plata y la que termin�� teniendo car��cter internacional. La mayor��a son revisiones de temas m��s o menos amplios o s��ntesis de la obra del propio autor. Se intent�� dar un cierto orden de distribuci��n de los trabajos por tem��tica.

Duration of unassisted swimming activity for spotted dolphin (Stenella attenuata) calves: implications for mother-calf separation during tuna purse-seine sets

Size-related differences in power production and swim speed duration may contribute to the observed deficit of nursing calves in relation to lactating females killed in sets by tuna purse-seiners in the eastern tropical Pacific Ocean (ETP). Power production and swim-speed duration were estimated for northeastern spotted dolphins (Stenella attenuata), the species (neonate through adult) most often captured by the fishery. Power required by neonates to swim unassisted was 3.6 times that required of an adult to swim the same speed. Estimated unassisted burst speed for neonates is only about 3 m/s compared to about 6 m/s for adults. Estimated long-term sustainable speed is about 1 m/s for neonates compared to about 2.5 m/s for adults. Weight-specific power requirements decrease as dolphin calves increase in size, but power estimates for 2-year-old spotted dolphin calves are still about 40% higher than power estimates for adults, to maintain the same speed. These estimated differences between calves and adults are conservative because the calculations do not include accommodation for reduced aerobic capacity in dolphin calves compared to adults. Discrepancies in power production are probably ameliorated under normal circumstances by calves drafting next to their mothers, and by employing burst-coast or leap-burst-coast swimming, but the relatively high speeds associated with evasion behaviors during and after tuna sets likely diminish use of these energy-saving strategies by calves.

The Dorado-Iconograf��a

Prosiguiendo con la tarea de rescate de documentos realizada por ProBiota, tomamos la iniciativa de editar en este n��mero la iconograf��a de la obra The dorado de J. W. Hills y G. H. Harrison ya que a nuestro entender posee un indiscutible valor hist��rico adem��s de ilustrativo.

Peces continentales de la Argentina: Iconograf��a. Cheirodon interruptus

The goal of this work is to present a collection of drawings and figures depicting the species present in our country. To achieve this, our main sources of information have been the works of Ringuelet et al. (1967), Reis et al. (2003), and L��pez et al. (2003; 2006), as well as the online databases of W. N. Eschmeyer and Fish Base. Each species has an individual factsheet with selected images, including some from anatomical research works. All the works referenced are mentioned in each factsheet. This is an open-ended publication. As such, it will require permanent updating,which will depend on the good will and collaboration of the ichthyological community. As compilers, we understand that this contribution not only provides valuable information, but also highlights the work of men and women who are part of the rich history of our national and regional ichthyology.

Peces continentales de la Argentina: Bibliograf��a. Cheirodon interruptus

The goal of this work is to compile the existing information about the species present in our country. This has been done by means of datasheets that list both local references and reviews by foreign authors that include Argentine taxa. The main information sources consulted were Ringuelet et al. (1967), CLOFFSCA (2003), L��pez et al. (2003; 2006), Liotta (2006) and the online databases of W. N. Eschmeyer and Fish Base. This is an open-ended publication. As such, it will require permanent updating,which will depend on the good will and collaboration of the ichthyological community. With this contribution, we hope to help to build a database of the freshwater fish of Argentina. The completion of this project will provide support to diverse plans emanating from different sectors, as well as promote the diffusion of this field of research and reaffirm Argentina���s sovereign rights over our natural resources.

Semblanzas Ictiol��gicas: Roxana Laura Garc��a Liotta

A trav��s de esta serie intentaremos conocer diferentes facetas personales de los integrantes de nuestra ���comunidad���. El cuestionario, adem��s de su principal objetivo, con sus respuestas quiz��s nos ayude a encontrar entre nosotros puntos en com��n que vayan m��s all�� de nuestros temas de trabajo y sea un aporte a futuros estudios hist��ricos. Esperamos que esta iniciativa pueda ser otro nexo entre los icti��logos de la regi��n, ya que consideramos que el resultado general trascender��a nuestras fronteras.

Semblanzas Ictiol��gicas Iberoamericanas: Carlos Arturo Garc��a-Alzate

A trav��s de esta nueva serie tratamos de conocer diferentes aspectos personales de los integrantes de la comunidad ictiol��gica iberoamericana. Esta iniciativa, comparte el esp��ritu y objetivo de las semblanzas nacionales buscando informalmente, otro punto de uni��n en la ���comunidad de icti��logos iberoamericanos���. Quiz��s est�� equivocado en mi apreciaci��n, pero creo que vale la pena este intento, ya que, con la colaboraci��n generosa e insoslayable de los integrantes de este ���universo���, se��alaremos un registro en el tiempo de la Ictiolog��a Neotropical.

La Ictiolog��a Argentina en Im��genes: I-Siglo XIX

ProBiota genera este modesto documento con el prop��sito de compartirlo con el ���Universo ictiol��gico��� y con aquellos que investigan y describen la historia de la ciencia regional. Estas im��genes del pasado y presente de la ictiolog��a nacional conforman un testimonio dirigido al futuro. Aunque, como dijo James Joyce: - No hay pasado ni futuro, todo fluye en un eterno presente -

La Ictiolog��a Argentina en Im��genes: II-SigloXX (1900-1950).

ProBiota genera este modesto documento con el prop��sito de compartirlo con el ���Universo ictiol��gico��� y con aquellos que investigan y describen la historia de la ciencia regional. Estas im��genes del pasado y presente de la ictiolog��a nacional conforman un testimonio dirigido al futuro. Aunque, como dijo James Joyce: - No hay pasado ni futuro, todo fluye en un eterno presente -

Icti��logos de la Argentina: Mirta Lidia Garc��a.

En esta serie se mencionan a todos aquellos que, a trav��s de sus peque��os o grandes aportes, contribuyeron a la consolidaci��n de la disciplina en nuestro pa��s. El plan general de esta contribuci��n consiste en la elaboraci��n de fichas individuales que contengan una lista de trabajos de los diferentes autores, acompa��adas por bibliograf��a de referencia y, cuando ello fuera posible, por im��genes personales y material adicional. Se tratar�� de guardar un orden cronol��gico, pero esto no es excluyente, ya que priorizaremos las sucesivas ediciones al material disponible. Este es otro camino para rescatar y revalorizar a quienes en diversos contextos hist��ricos sentaron las bases de lo que hoy es la ictiolog��a nacional. Considero que este es el comienzo de una obra de mayor magnitud en la que se logre describir una parte importante de la historia de las ciencias naturales de la Rep��blica Argentina.

On the response of Catla catla (Ham) and Cirrhinus mrigala (Ham) to the voltage gradient of electrical field

The threshold body voltage (voltage gradient between head and tail) required for first reaction, electro-taxis and electro-narcosis depended upon species, conductivity of the fish body, nature of current and wave shape. Larger fishes showed first reaction at a lower body voltage than smaller ones. All the three reactions were dependent on the accommodation of nerves to the electrical field and subsequent fatigue of the fishes. No significant change was observed in the period of narcosis and recovery after repeated stimulation.

East African Inland Fisheries Research Organization Annual Report for the year 1948

Introduction The laboratory at Jinja is being developed as a centre for hydro-biological research in East Africa, It has been built and is at present wholly financed from a grant from the Central Research allocation of the Colonial Development Fund. The building contains six laboratories in addition to a library, common room and general office. A maximum number of ten research workers could be given laboratory accommodation. However, shortage of living accommodation will limit the numbers who can work here for the next year or two.