Chromium oxyselenide solid solutions from the atmospheric pressure chemical vapour deposition of chromyl chloride and diethylselenide

A new chromium oxyselenide solid-solution series Cr(2)O(3-x)Se(x) (x = 0, 0.1, 0.15, 0.2, 0.3, 0.4, 0.5, 0.7, 1.5, 2.15) was formed by the atmospheric pressure chemical vapour deposition of chromyl chloride and diethylselenide at 600 degrees C. The level of selenium incorporation was directly related to the gas-phase molar flows of reagents. There was a crossover in structure type adopted by the chromium oxyselenide with selenium incorporation, at x = 0-0.2 the solid solution crystallises in the Cr(2)O(3) structure type, at x = 0.3-2.15 it adopts the Cr(2)Se(3) structure type. All of the chromium oxyselenides were antiferromagnets. They showed a variation in Neel temperature with composition with a minimum temperature of 11 K observed for x = 0.7

Influence of seasonal and latitudinal temperature variation\ud on early life-history traits of a coral reef fish

Temporal and latitudinal gradients in ocean temperature may be useful for predicting the likely responses of marine species to accelerating global warming. Here, we examined seasonal variations in early life-history traits of the reef fish Pomacentrus moluccensis at Lizard Island on the Great Barrier Reef (GBR). Latitudinal variations were then compared among three locations from Kimbe Bay in Papua New Guinea to the southern GBR (18° latitude). At Lizard Island, a 4°C temperature rise from spring to summer was correlated with a 0.13 mm day⁻¹ increase in pre-settlement growth rates and a 3.28-day decrease in pelagic larval duration (PLD). The latitudinal comparison revealed a non-linear relationship where growth rate and settlement size declined and PLD increased at Kimbe Bay where temperature was the highest of all the study sites. Furthermore, the slopes of latitudinal variations in life-history traits as a function of temperature within the GBR were significantly steeper than those in the temporal analysis. These latitudinal patterns were likely to be shaped by (1) the species thermal reaction norm, (2) local adaptation or (3) location-specific environmental and demographic characteristics. The significant correlations of early life-history traits with natural temperature gradients emphasise the potential sensitivity of reef fish larvae to global warming

Retention of a transgenerational marker ((137)Barium) in tissues of adult female anemonefish and assessment of physiological stress

Recently it was shown that female fish injected with enriched stable isotopes maternally transmit a chemical signature to larval otoliths. Validation of this larval marking technique requires laboratory experiments to determine appropriate injection concentrations and to assess any negative effects on larval and adult condition. This study investigated the temporal profile of (137)barium assimilation and retention in tissues of adult female anemonefish Amphiprion melanopus (Pomacentridae) following intraperitoneal injection with either 2 or 4 mu g Ba-137 g(-1) body mass. Mean barium isotope ratios (Ba-138:Ba-137) in the two groups of treated fish were not significantly different from each other, but were significantly different from those in the control group up to 56 days post-injection. This pattern of Ba-137 retention was consistent across gonad, muscle, liver and bone tissues. Mean plasma cortisol concentration (an indicator of non-specific physiological stress) was not significantly different among groups and was considered to be representative of unstressed fish. Together, these results indicate that (1) A. melanopus suffer minimal physiological stress and cope well after treatment with Ba-137, (2) Ba-137 is retained in female A. melanopus for a prolonged period (at least 56 days), such that multiple clutches of offspring are likely to be marked with an isotopic signature, and (3) a lower dosage of 2 mu g Ba-137 g(-1) appears sufficient for transgenerational marking. It is concluded that Ba-137 is suitable for use as a transgenerational marker and is a powerful tool to resolve long-standing enigmas such as larval dispersal distances and the fishery benefits of marine reserves