Influence of temperature on larval survival, development and respiration in Chasmagnathus granulata (Crustacea, Decapoda)

Larvae of an estuarine grapsid crab Chasmagnathus granulata Dana 1851, from temperate and subtropical regions of South America, were reared in seawater (32 ‰) at five different constant temperatures (12, 15, 18, 21, 24 °C). Complete larval development from hatching (Zoea I) to metamorphosis (Crab I) occurred in a range from 15 to 24 °C. Highest survival (60% to the first juvenile stage) was observed at 18°C, while all larvae reared at 12°C died before metamorphosis. The duration of development (D) decreased with increasing temperature (T). This relationship is described for all larval stages as a power function (linear regressions after logarithmic transformation of both D and T). The temperature-dependence of the instantaneous developmental rate (D-1) is compared among larval stages and temperatures using the Q10 coefficient (van't Hoff's equation). Through all four zoeal stages, this index tends to increase during development and to decrease with increasing T (comparing ranges 12-18, 15-21, 18-24 °C). In the Megalopa, low Q10 values were found in the range from 15 to 24 °C. In another series of experiments, larvae were reared at constant 18°C and their dry weight (W) and respiratory response to changes in T were measured in all successive stages during the intermoult period (stage C) of the moulting cycle. Both individual and weight-specific respiration (R, QO2) increased exponentially with increasing T. At each temperature, R increased significantly during growth and development through successive larval stages. No significantly different QO2 values were found in the first three zoeal stages, while a significant decrease with increasing W occurred in the Zoea IV and Megalopa. As in the temperature-dependence of D, the respiratory response to changes in temperature (Q10) depends on both the temperature range and the developmental stage, however, with different patterns. In the zoeal stages, the respiratory Q10 was minimum (1.7-2.2) at low temperatures (12-18 °C), but maximum (2.2-3.0) at 18-24 °C. The Megalopa, in contrast, showed a stronger metabolic response in the lower than in the upper temperature range (Q10 = 2.8 and 1.7, respectively). We interpret this pattern as an adaptation to a sequence of temperature conditions that should typically be encountered by C. granulata larvae during their ontogenetic migrations: hatching in and subsequent export from shallow estuarine lagoons, zoeal development in coastal marine waters, which are on average cooler, return in the Megalopa stage to warm lagoons. We thus propose that high metabolic sensitivity to changes in temperature may serve as a signal stimulating larval migration, so that the zoeae should tend to leave warm estuaries and lagoons, whereas the Megalopa should avoid remaining in the cooler marine waters and initiate its migration towards shallow coastal lagoons.

Vertical migration during tidal transport of megalopae of Necora puber in coastal shallow waters during daytime

For meroplanktonic larvae that must settle in coastal areas, their successful return to the shore is determined largely by physical transport processes; however, many organisms perform vertical movements to aid successful recruitment. In this study, daytime tidal vertical migration of megalopae of the velvet swimming crab Necora puber was investigated across two different exposures in the shallow waters of Plymouth Sound. Crabs were collected using a plankton net at the surface and near the bottom during flood and ebb tides. Distribution of the pelagic postlarvae was patchy and the abundance varied spatially in tens and thousands of metres. In temporal scales, the annual pattern was dominated by low occurrence of megalopae, punctuated by episodic peaks of high abundance. Most megalopae were collected at the surface irrespective of the tidal phase. The effect of wave exposure on the vertical migration of megalopae was not clear, although there was a general higher abundance of megalopae on exposed shores. Daytime abundance in the water column appears to be regulated by the tidal cycle, as megalopae were more abundant during flood than ebb tides. Although the megalopae do not appear to make large vertical migrations, this behaviour should produce a net shoreward transport. © 2005 Elsevier Ltd. All rights reserved.

Lima, uma cidade entre a aristocracia e a plebe (1950-1980)

The city of Lima has undergone serious changes over the past sixty years. Until the middle of the last century, Lima retained an urban structure similar to that built in the 18th century, during the final decades of its colonial period. This reality began to change with the abrupt onset of migration from the mountain ranges to the coast in 1946. However, rather than changes in its urban plan, Lima underwent a ethnic and social reconfiguration that would bring new color and new cultural and behavioral norms to the Peruvian capital. The arrival of migrants to the city caused a conservative reaction in the local elites, but it also sparked a need for the intelligentsia to develop new ways of thinking about the place of migrants in the space of the city, and on the other hand, to create new representations of the city itself. From being a city isolated from the rest of the country, Lima came to live with a range of cultural and ethnic references. It did so, however, without creating greater opportunities for the integration of the masses within the urban and social logic of the city, thus making clear the separation between the aristocracy and the general populace.

Two stops in today's new global geographies: shaping novel labor supplies and employment regimes

Includes bibliography

Urban dimensions in rural development

Includes bibliography

O contexto educativo e cultural da pobreza no ensino público municipal em São Bernardo do Campo

Pós-graduação em Artes - IA

Panamá y el proceso de integración centroamericana

Incluye Bibliografía

Um estudo da dinâmica de captura em ressonância de corrotação

Pós-graduação em Física - FEG

Crescimento urbano, pobreza e meio ambiente em Bogotá-Colômbia: uma visão a partir de duas localidades

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Migrantes japoneses: um ciclo migratório : o caso de Londrina-PR

Pós-graduação em Geografia - FCT

CEPAL Review no.82

The devious maze of the international order: the importation of reforms / David Ibarra. -- Foreign banks in Latin America: a paradoxical result / Graciela Moguillansky, Rogerio Studart and Sebastián Vergara. -- A proposal for unitary taxes on the profits of transnational corporations / Andrew Mold. -- Regional integration and macroeconomic coordination in Latin America / Hubert Escaith. -- Import substitution in high-tech industries: Prebisch lives in Asia! / Alice H. Amsden. -- Industrial competitiveness in Brazil ten years after economic liberalization / João Carlos Ferraz, David Kupfer and Mariana Iootty. -- The influence of capital origin on Brazilian foreign trade patterns / Célio Hiratuka and Fernanda De Negri. -- Information and knowledge: the diffusion of information and communication technologies in the Argentine manufacturing sector / Gabriel Yoguel, Marta Novick, Darío Milesi, Sonia Roitter and José Borello. -- Local economic development and decentralization in Latin America / Francisco Alburquerque, in memory of Gabriel Aghón. -- Migrations, the labour market and poverty in Greater Buenos Aires / Rosalía Cortés and Fernando Groisman. -- Households, poverty and policy in times of crisis. Mexico, 1992-1996 / Benjamin Davis, Sudhanshu Handa and Humberto Soto. -- CEPAL Review on the Internet. -- Recent ECLAC publications.

Reestruturação produtiva e imigração laboral nas indústrias de confecção metropolitanas: uma perspectiva comparativa entre São Paulo e Nova Iorque

Pós-graduação em Ciências Sociais - FCLAR

Avaliação biomecânica da fixação das endopróteses com e sem cola biológica e alterações histológicas aórticas. Estudo experimental em porcos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desenvolvimento ontogenético de estruturas sensoriais em Macrobrachium rosenbergii (De Man 1879) (Crustacea, Palaemonidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A influência dos fragmentos florestais na dinâmica de populações de anuros no noroeste do Estado de São Paulo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)