The Corogal: one of the big dredges in Culebra Cut, Panama Canal (ca. 1914)

Leonard Carpenter Panama Canal Collection. Photographs: Dredging, Soldiers, and Ships. [Box 1] from the Special Collections & Area Studies Department, George A. Smathers Libraries, University of Florida.

First U.S. battleships through Panama Canal: Missouri, Ohio, Wisconsin (postcard ca 1914)

Leonard Carpenter Panama Canal Collection. Photographs: Dredging, Soldiers, and Ships. [Box 1] from the Special Collections & Area Studies Department, George A. Smathers Libraries, University of Florida.

Tow boat fleet at Paraiso, Panama Canal (ca. 1914)

Leonard Carpenter Panama Canal Collection. Photographs: Dredging, Soldiers, and Ships. [Box 1] from the Special Collections & Area Studies Department, George A. Smathers Libraries, University of Florida.

View of Paraiso Yard showing dredging equipment, Panama Canal. (ca. 1914)

Leonard Carpenter Panama Canal Collection. Photographs: Dredging, Soldiers, and Ships. [Box 1] from the Special Collections & Area Studies Department, George A. Smathers Libraries, University of Florida.

Emergency dam at Pedro Miguel, Panama Canal (ca. 1914)

Leonard Carpenter Panama Canal Collection. Photographs: Dredging, Soldiers, and Ships. [Box 1] from the Special Collections & Area Studies Department, George A. Smathers Libraries, University of Florida.

Lantern spillway and hydroelectric plant, Panama Canal (ca. 1914)

Leonard Carpenter Panama Canal Collection. Photographs: Dredging, Soldiers, and Ships. [Box 1] from the Special Collections & Area Studies Department, George A. Smathers Libraries, University of Florida.

U.S.S. Ohio, Panama Canal (ca. 1914)

Leonard Carpenter Panama Canal Collection. Photographs: Dredging, Soldiers, and Ships. [Box 1] from the Special Collections & Area Studies Department, George A. Smathers Libraries, University of Florida.

Panama Canal Twenty-fifth anniversary 1914 - Aug. 15 -1939

Leonard Carpenter Panama Canal Collection. Photographs: Views of Panama and the Canal. [Box 1] from the Special Collections & Area Studies Department, George A. Smathers Libraries, University of Florida. Booklet dedication: Published under the direction of a committee appointed by Brigadier General Clarence S. Ridley, Governor of The Panama Canal, to arrange suitable ceremonies, as authorized in Public Resolution No.5, 76th Congress, approved March 28, 1939, to celebrate the twenty-fifth anniversary of the opening of the Panama Canal to commerce. Prepared by Rufus Hardy, Executive Department, The Panama Canal. (120 page document)

Toward identification of larval sailfish (Istiophorus platypterus), white marlin (Tetrapturus albidus), and blue marlin (Makaira nigricans) in the western North Atlantic Ocean*

The identification of larval istiophorid billfishes from the western North Atlantic Ocean has long been problematic. In the present study, a molecular technique was used to positively identify 27 larval white marlin (Tetrapturus albidus), 96 larval blue marlin (Makaira nigricans), and 591 larval sailfish (Istiophorus platypterus) from the Straits of Florida and the Bahamas. Nine morphometric measurements were taken for a subset of larvae (species known), and lower jaw pigment patterns were recorded on a grid. Canonical variates analysis (CVA) was used to reveal the extent to which the combination of morphometric, pigment pattern, and month of capture information was diagnostic to species level. Linear regression revealed species-specific relationships between the ratio of snout length to eye orbit diameter and standard length (SL). Confidence limits about these relationships served as defining characters for sailfish >10 mm SL and for blue and white marlin >17 mm SL. Pigment pattern analysis indicated that 40% of the preflexion blue marlin examined possessed a characteristic lower jaw pigment pattern and that 62% of sailfish larvae were identifiable by lower jaw pigments alone. An identification key was constructed based on pigment patterns, month of capture, and relationships between SL and the ratio of snout length to eye orbit diameter. The key yielded identifications for 69.4% of 304 (blind sample) larvae used to test it; only one of these identifications was incorrect. Of the 93 larvae that could not be identified by the key, 71 (76.3%) were correctly identified with CVA. Although identif ication of certain larval specimens may always require molecular techniques, it is encouraging that the majority (92.4%) of istiophorid larvae examined were ultimately identifiable from external characteristics alone.

Raúl Adolfo Ringuelet (1914 1982): Una síntesis de su trayectoria con énfasis en sus contribuciones a la Ictiología y Limnología.

Historia de la Ciencia fue una materia ofrecida en 2003, por el curso de Posgrado en Ciencias Ambientales (PEA) de la Universidad Estadual de Maringá, PR, Brasil, dictada por la profesora Luiza Marta Bellini. Durante el curso de la misma, se discutía sobre la historia y filosofía de vida de los científicos que brillaron o, por el contrario, pasaron desapercibidos por la historia del pensamiento humano. Al final del término de la materia, se logró compilar un libro llamado Ecólogos e suas histórias: Um olhar sobre a construção das ideas ecológicas (Pelicice et al., 2010). El capitulo diez del libro, es un comentario sobre algunos pioneros que contribuyeron para el desarrollo de la Limnología fluvial en Sudamérica. Dos fueron tratados en ese capítulo, Harald Sioli y Juan José Neiff (ver Arenas‐Ibarra et al., 2010). Sin embargo, la idea principal del capítulo era incluir también a los doctores Argentino Aurelio Bonetto y Raúl Adolfo Ringuelet, pero cuestiones relativas al formato y espacio de cada capítulo, impidieron mantener la integridad original de éste y el mayor conocimiento de las contribuciones de estos dos destacados investigadores argentinos en tierras brasileras. Si bien esta omisión fue compensada en parte por el artículo de Arenas‐Ibarra & Souza‐Filho (2010) en el que se resaltan las figuras de Bonetto y Rzóska como precursores de la Limnología fluvial, quedó aún pendiente este reconocimiento por parte de los autores de este documento a Raúl Ringuelet. Con motivo de que en el transcurso de este año se cumplieron treinta años del fallecimiento del Dr. Raúl Adolfo Ringuelet, decidimos, por invitación de Hugo Luis López, publicar el material recopilado durante la materia cursada en la Universidad Estadual de Maringá (UEM, Brasil), actualizándola con nuevos datos proporcionados por Hugo López y Juan José Neiff. Este trabajo es una síntesis de las ideas de Raúl Adolfo Ringuelet, quien sin duda se encuentra entre los pioneros de la ictio‐limnología local y sudamericana.