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 Iberoamericanas: Iván Danilo Arismendi Vidal.

A través de esta nueva serie tratamos de conocer diferentes aspectos personales de los integrantes de la comunidad ictiológica iberoamericana. Esta iniciativa, comparte el espíritu y objetivo de las semblanzas nacionales buscando informalmente, otro punto de unión en la “comunidad de ictiólogos iberoamericanos”. Quizás esté equivocado en mi apreciación, pero creo que vale la pena este intento, ya que, con la colaboración generosa e insoslayable de los integrantes de este “universo”, señalaremos un registro en el tiempo de la Ictiología Neotropical.

Catalog of Osteological Collections of Aquatic Mammals from Mexico

This paper compiles available information on osteological and other anatomical specimens of at least 51 species of aquatic mammals (34 extant, one recently extinct and 16 fossil) collected in Mexico between 1868 and 1990 and housed in 29 scientific institutions (18 in the USA, nine in Mexico, one in the Netherlands, and one in England). These collections contain a total of 1427 specimens representing 10 families of odontocetes (Squalodontidaet , Rhabdosteidaet , Pontoporiidae, Albireonidaet , Monodontidae, Phocoenidae, Delphinidae, Ziphiidae, Kogiidae, and Physeteridae), three of mysticetes (Cetotheridaet , Eschrichtiidae, and Balaenopteridae), three of carnivores (Otariidae, Phocidae, and Mustelidae) and one of sirenians (Trichechidae). Of the aquatic mammals recorded from Mexico, seven species are not represented by specimens (Stenella frontalis, Lagenodelphis hosei, Feresa attenuata, Hyperoodon sp., Eubalaena glacialis, Balaenoptera borealis, and Enhydra lutris). (PDF file contains 40 pages.)

Caribbean corals in crisis: record thermal stress, bleaching, and mortality in 2005

Background: The rising temperature of the world’s oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin. Methodology/Principal Findings: Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers’ field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles. Conclusions/Significance: Thermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch’s Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate

Changes in size and age at maturity of the northern stock of Tilefish (Lopholatilus chamaeleonticeps) after a period of overfishing

The modern fishery for Tilefish (Lopholatilus chamaeleonticeps) developed during the 1970s, offshore of southern New England, in the western North Atlantic Ocean. The population quickly became over exploited, with documented declines in catch rates and changes in demographic traits. In an earlier study, median size at maturity (L50) of males declined from 62.6 to 38.6 cm fork length (FL) and median age at maturity (A50) of males declined from 7.1 to 4.6 years between 1978 and 1982. As part of a cooperative research effort to improve the data-limited Tilefish assessment, we updated maturity parameter estimates through the use of an otolith aging method and macroscopic and microscopic evaluations of gonads. The vital rates for this species have continued to change, particularly for males. By 2008, male L50 and A50 had largely rebounded, to 54.1 cm FL and 5.9 years. Changes in female reproductive schedules were less variable among years, but the smallest L50 and youngest A50 were recorded in 2008. Tilefish are dimorphic, where the largest fish are male, and male spawning success is postulated to be socially mediated. These traits may explain the initial rapid decline and the subsequent rebound in male L50 and A50 and less dramatic effects on females. Other factors that likely contribute to the dynamics of maturity parameter estimates are the relatively short period of overfishing and the amount of time since efforts to rebuild this fishery began, as measured in numbers of generations. This study also confirms the gonochoristic sexual pattern of the northern stock, and it reveals evidence of age truncation and relatively high proportions of immature Tilefish in the recent catch.

Record of cestode parasites from Penaeid prawns of Ratnagiri

Studies on the cestode parasites of commercially important prawns are few. So far only four species of larval cestodes have been recorded from penaeid prawns of Florida (Woodburn et al., 1957, Sparks and Mackin, 1957, Hutton et al, 1959 and Kruse, 1959). So far there are no records of larval cestodes from prawns of India. For the first time the authors have been able to collect six forms of larval cestodes from penaeid prawns of Ratnagiri.

Some bacteria isolated from marine plankton and mud

57 bacterial strains isolated from marine plankton and mud from the inshore waters of Cochin, are described. The flora of the plankton was dominated by chromogens while mud sample and failed to produce chromogens. The different strains are divided into five arbitrary groups for the convenience of description. The flora is similar to that of Mandapam (east coast) while it differed from the flora of Calicut (west coast) in the paucity of Bacillus and other spore formers.

Ecology and production in two sandy beaches of Goa. Part (A) Distribution of bacteria in Colva and Siridaon in relation to certain environmental parameters

Qualitative and quantitative studies on the bacterial flora of two beaches viz., Colva and Siridaon at high tide, mid-tide and low tide levels during the pre-monsoon period were made. Estimations of important nutrients, like inorganic phosphates and nitrates and organic carbon have been made and correlation with the bacterial counts is being attempted. Definite correlation between bacterial population and organic carbon is seen however, no correlation is observed between bacterial counts and other physicochemical parameters.

Bacteria in the inshore environment at Karwar and Vengurla

Qualitative and quantitative studies of the bacterial population in two stations, Karwar and Venguria, have been made for a period of eight months, which revealed the pattern of distribution to be almost similar to that from east coast and west coast.

Fish muscle structural proteins

Based on the differences in their physico-chemical properties proteins are broadly categorised as sarcoplasmic or fibrillar. The properties are important in fish technology. The authors review some of these physico-chemical properties of the proteins which have distinguished themselves as 'structural' or 'textural' proteins. As denaturation in these proteins caused by a variety of factors manifests itself in terms in the quality attributes of the product, relevant mechanisms have been particularly highlighted.

Studies on Thiobacilli spp. isolated from sandy beaches of Kerala

Occurrence, isolation and oxidative activity of Thiobacilli spp. from some sandy beaches of Kerala are reported. These organisms were encountered in polluted beaches and were dominant during monsoon in all the beaches.