Functional traits, mechanistic bioenergetics and microclimatic downscaling of marine ectotherms

Ocean acidification and elevated temperature negatively affect recruitment, oxygen consumption and calcification of the reef-building Dendropoma cristatum early life stages: Evidence from a manipulative field study

Expected temperature rise and seawater pH decrease may affect marine organism fitness. By a transplant experiment involving air-temperature manipulation along a natural CO2 gradient, we investigated the effects of high pCO(2) (similar to 1100 mu atm) and elevated temperature (up to +2 degrees C than ambient conditions) on the reproductive success, recruitment, growth, shell chemical composition and oxygen consumption of the early life stages of the intertidal reef-building vermetid Dendropoma cristatum. Reproductive success was predominantly affected by temperature increase, with encapsulated embryos exhibiting higher survival in control than elevated temperature conditions, which were in t…

The functional trait-based approach to investigate life history traits in marine invertebrates to predict effects of global climate change on ecosystems

Coping with cyclic oxygen availability: evolutionary aspects

Both the gradual rise in atmospheric oxygen over the Proterozoic Eon as well as episodic fluctuations in oxygen over several million-year time spans during the Phanerozoic Era, have arguably exerted strong selective forces on cellular and organismic respiratory specialization and evolution. The rise in atmospheric oxygen, some 2 billion years after the origin of life, dramatically altered cell biology and set the stage for the appearance of multicelluar life forms in the Vendian (Ediacaran) Period of the Neoproterozoic Era. Over much of the Paleozoic, the level of oxygen in the atmosphere was near the present atmospheric level (21%). In the Late Paleozoic, however, there were extended times…

Taking the acid test: Mediterranean limpets face up to climate change

Impacts of climate change involve the interactions of multiple stressors on intertidal organisms, but rarely are the impacts of these stressors examined together. Many tests are also conducted in artificial, controlled laboratory conditions, without making use of natural opportunities to test performance of organisms under different environmental stressors. Given its small tidal range, the Mediterranean Sea provides such an opportunity, with a very fine scale environmental gradient and species living very close to each other over the tidal gradient. The vertical distribution of the limpets, Patella rustica and P. caerulea overlap in Palermo, Sicily, but despite this they have different ther…

Effects of ocean acidification on embryonic respiration and development of a temperate wrasse living along a natural CO2gradient

We assessed rising CO2 effects on metabolism and development of a nesting wrasse by reciprocal transplant experiments in the field. Offspring brooded under different CO2 conditions exhibited similar responses. However, embryos from High-CO2 site were resilient to a wider range of pCO2 levels than those belonging to current-day conditions.

Structural properties, conformational stability and oxygen binding properties of Penaeus monodon hemocyanin

Hemocyanin sequences allineament shows the presence of highly invariant regions especially in the active site and in the tight intersubunits interaction sites. Comparing the aminoacids in contact regions between monomers is possible to interpret the stability of hexamers.

The importance of thermal history: costs and benefits of heat exposure in a tropical, rocky shore oyster.

Although thermal performance is widely recognized to be pivotal in determining species' distributions, assessment of this performance is often based on laboratory acclimated individuals, neglecting their proximate thermal history. The thermal history of a species sums the evolutionary history and, importantly, the thermal events recently experienced by individuals, including short-term acclimation to environmental variations. Thermal history is perhaps of greatest importance for species inhabiting thermally challenging environments and therefore assumed to be living close to their thermal limits, such as in the tropics. To test the importance of thermal history the responses of the tropical…

Intertidal oyster and mussel beds in a global warming perspective. Trade offs and microclimatic downscaling

Concurrent environmental stressors and jellyfish stings impair caged European sea bass (Dicentrarchus labrax) physiological performances

9 pages, 5 figures, 4 tables

The molecular heterogeneity of hemocyanin: Structural and functional properties of the 4×6-meric protein of Upogebia pusilla (Crustacea)

The structural properties of the hemocyanin isolated from the Mediterranean mud shrimp, Upogebia pusilla (Decapoda: Thalassinidea), were investigated. Our intent was to make use of the U. pusilla case to perform a structural comparison between crustacean and chelicerate 4×6-meric hemocyanins. The thalassinidean hemocyanin appears similar in size but different in structural organization compared to the chelicerate 4×6-mer. Ultracentrifuge analyses on the purified protein revealed a sedimentation coefficient of 39S, typical of 4×6 hemocyanins. Electron micrographs are in agreement with a model in which four 2×6-meric building blocks are arranged in a tetrahedron-like quaternary structure and …

Symposium on “Climate Change and Molluscan Ecophysiology” at the 79thAnnual Meeting of the American Malacological Society

Climate change has already had many observable effects on Earth. On land, glaciers and snowpacks have shrunk, tropical forests are being replaced by savannahs, and coastal areas have increased risks of flooding (e.g., IPCC 2007, Allan and Soden 2008, Dai 2010, NOAA 2010, Chen et al. 2011). In addition to sea-surface warming, climate change has altered the physical and chemical nature of the marine environment, including ocean acidification and expanding hypoxia. The scope and scale of future environmental change that individuals will undergo on land and in the sea will fundamentally influence the ecological and evolutionary responses of populations and species, dependent on their evolved ph…

Closely related crabs from opposite niches adopt different mechanisms to adjust oxygen transport

The successful colonization of new environments is often achieved through adaptations or key innovations of existing physiological or biochemical mechanisms. The oxygen supply in marine invertebrates represent a complex and deeply integrated system which plays a fundamental role in animal adaptive plasticity. In particular, species which inhabit highly stochastic environments as shallow water or intertidal bands, have to cope with extremely different regimes of oxygen availability and effectively maintain a stable aerobic metabolism. Within this framework, we have focused on comparative physiology of Portunid Crabs hemocyanin, to evaluate the role molecular heterogeneity and functional plas…

Unusual oxygen binding behavior of a 24-meric crustacean hemocyanin.

Abstract Hemocyanins from Crustacea usually are found as 1 × 6 or 2 × 6-meric assemblies. An exception is the hemocyanin isolated from thalassinidean shrimps where the main component is a 24-meric structure. Our analysis of oxygen binding data of the thalassinidean shrimp Upogebia pusilla based on a three-state MWC-model revealed that despite the 24-meric structure the functional properties can be described very well based on the hexamer as allosteric unit. In contrast to the hemocyanins from other thalassinidean shrimps the oxygen affinity of hemocyanin from U. pusilla is increased upon addition of l -lactate. A particular feature of this hemocyanin seems to be that l -lactate already enha…

Effects of ocean acidification on embryonic respiration and development of a temperate wrasse living along a natural CO2 gradient

Volcanic CO2 seeps provide opportunities to investigate the effects of ocean acidification on organisms in the wild. To understand the influence of increasing CO2 concentrations on the metabolic rate (oxygen consumption) and the development of ocellated wrasse early life stages, we ran two field experiments, collecting embryos from nesting sites with different partial pressures of CO2 [pCO2; ambient (400 µatm) and high (800-1000 µatm)] and reciprocally transplanting embryos from ambient- to high-CO2 sites for 30 h. Ocellated wrasse offspring brooded in different CO2 conditions had similar responses, but after transplanting portions of nests to the high-CO2 site, embryos from parents that sp…