A Na pump with reduced stoichiometry is up-regulated by brine shrimp in extreme salinities.

Brine shrimp () are the only animals to thrive at sodium concentrations above 4 M. Salt excretion is powered by the Na,K-ATPase (NKA), a heterodimeric (αβ) pump that usually exports 3Na in exchange for 2 K per hydrolyzed ATP. express several NKA catalytic α-subunit subtypes.

Temperature-dependent RNA editing in octopus extensively recodes the neural proteome.

In poikilotherms, temperature changes challenge the integration of physiological function. Within the complex nervous systems of the behaviorally sophisticated coleoid cephalopods, these problems are substantial. RNA editing by adenosine deamination is a well-positioned mechanism for environmental acclimation.

Oxygen supply capacity breathes new life into critical oxygen partial pressure (Pcrit).

The critical oxygen partial pressure (Pcrit), typically defined as the PO2 below which an animal's metabolic rate (MR) is unsustainable, is widely interpreted as a measure of hypoxia tolerance. Here, Pcrit is defined as the PO2 at which physiological oxygen supply (α0) reaches its maximum capacity (α; µmol O2 g-1 h-1 kPa-1). α is a species- and temperature-specific constant describing the oxygen dependency of the maximum metabolic rate (MMR=PO2×α) or, equivalently, the MR dependence of Pcrit (Pcrit=MR/α).

Convergent and parallel evolution in a voltage-gated sodium channel underlies TTX-resistance in the Greater Blue-ringed Octopus: Hapalochlaena lunulata.

The natural history and pharmacology of tetrodotoxin (TTX) has long intrigued biologists. This toxin has a remarkable distribution that spans two domains of life (Bacteria and Eukarya). Within Eukaryotes, TTX has only been identified in animals but is known to be present in over five-dozen species of phylogenetically distant Metazoans.

Ocean acidification does not limit squid metabolism via blood oxygen supply.

Ocean acidification is hypothesized to limit the performance of squid owing to their exceptional oxygen demand and pH sensitivity of blood-oxygen binding, which may reduce oxygen supply in acidified waters. The critical oxygen partial pressure (), the  below which oxygen supply cannot match basal demand, is a commonly reported index of hypoxia tolerance. Any CO-induced reduction in oxygen supply should be apparent as an increase in In this study, we assessed the effects of CO (46-143 Pa; 455-1410 μatm) on the metabolic rate and of two squid species - and - through manipulative experiments.

Do squid breathe through their skin?

Squid are thought to obtain a large portion of their oxygen via simple diffusion across the skin in addition to uptake at the gills. Although this hypothesis has support from indirect evidence and is widely accepted, no empirical examinations have been conducted to assess the validity of this hypothesis. In this study, we examined cutaneous respiration in two squid species, and , using a divided chamber to physically separate the mantle cavity and gills from the outer mantle surface.

Experimental determination of the spatial scale of a prey patch from the predator's perspective.

Foraging theory predicts that predators should prefer foraging in habitat patches with higher prey densities. However, density depends on the spatial scale at which a "patch" is defined by an observer. Ecologists strive to measure prey densities at the same scale that predators do, but many natural landscapes lack obvious, well-defined prey patches.