Estimating thermal exposure of adult summer steelhead and fall Chinook salmon migrating in a warm impounded river

Rising river temperatures in western North America have increased the vulnerability of many Pacific salmon (Oncorhynchus spp.) populations to lethal and sublethal risks. There is a growing need to predict and manage such risks, especially for populations whose life history or geography increases the likelihood of warm‐water exposure. We estimated thermal exposure of adult summer steelhead (O. mykiss) and fall‐run Chinook salmon (O. tshawytscha) as they migrated through a warm (often > 20 °C), 157‐km reach of the impounded Snake River, Washington. Archival temperature loggers and radiotelemetry were used to reconstruct thermal histories for 50 steelhead and 21 salmon. Encountered temperature maxima were mostly inside dam fishways and ranged from 15.8 to 24.0 °C (mean = 19.6 °C) for steelhead and from 18.0 to 21.6 °C (19.9 °C) for salmon. Behavioural thermoregulation was evident for ~50% of steelhead and ~30% of salmon in one of three reservoirs. Degree days (DDs) calculated from archival tags ranged from 74 to 973 DDs (median = 130) for steelhead and from 56 to 220 DDs (133) for salmon. Models using river temperature data and fish migration times accurately estimated total DDs for both species except some steelhead with extended thermoregulation. In a predictive application, we estimated exposure for 10,104 steelhead and 9071 Chinook salmon with passive integrated transponder‐tag detections at dams and found considerable DD variability across individuals, species and years. This estimation method, combined with baseline thermal surveys and existing monitoring infrastructure, can help to address long‐standing questions about how warm‐water exposure affects Snake River salmon and steelhead phenology, bioenergetics, physiology, survival and reproductive success.     

Observations of humpback whales Megaptera novaeangliae in new Caledonian waters during 1991–1993

Recent sightings confirm that humpback whales Megaptera novaeangliae migrate to New Caledonia. Totals of 37 and 73 incidental sightings were made during the winter and spring of 1991 and 1992 respectively. Sightings were distributed widely all around New Caledonia, but concentrated in the south, mainly around Noumea, Ile des Pins and the Southeast Lagoon, areas with the highest human visitation. Very young calves were photographed in some sightings.

Encouraged by the number of sightings, in August 1993 we commenced a programme of photo-identification and behavioural observation in the Southeast Lagoon. In five days of field work, 12 humpback whales were individually identified. One of these was a resight of an animal previously photographed off the coast of Queensland, Australia, in 1991. This supports the hypothesis that humpback whales migrating to New Caledonia are from Antarctic Area V stock.

‘Surface active’ group behaviour, typical of male competition for females in breeding areas, was also noted, and humpback whale song was detected on every day on which it was monitored for in the study area. Several juvenile animals were also observed. We interpret these observations as strong evidence that humpback whales mate and calve in New Caledonian waters.     

Estimation of heritability and genetic correlation for behavioural responses by Gibbs sampling in the Thoroughbred racehorse

Genetic variation of the behaviour of racehorses is one of the major concerns for racehorse breeders. In this study, the heritabilities of behavioural responses to the inspections of conjunctiva, auscultation and blood sampling and the genetic correlations among them were estimated in the Thoroughbred racehorse. The estimation was done with Bayesian analysis with Gibbs sampling based on the univariate or bivariate threshold animal models. The behavioural responses were scored with four categories at the first entrance quarantine in Miho Training Center of Japan Racing Association from 1993 to 1995. The behavioural responses were treated as categorical or binary traits, with both showing similar results. The estimated heritabilities were in the range of 0.23–0.28, suggesting a genetic component in the variation on these traits. The estimated genetic correlations among the traits were very high (approximately 0.9), suggesting that these behavioural responses may be measures of the same trait. Because of the high genetic correlations, repeatability threshold model was applied assuming the responses to be a genetically identical trait measured with three different tests. The estimated heritabilities (approximately 0.23) were at the lower bound of the former estimates. The revealed high repeatabilities (0.97–0.98) suggest a strong contribution of the individual temperament on the behaviour of racehorses.     

Variation in agonistic encounters in a dominance hierarchy of freely interacting red-spotted masu salmon (Oncorhynchus masou ishikawai)

Abstract– Agonistic behaviour and dominance relationships in red-spotted masu salmon, Oncorhynchus masou ishikawai , were observed in a mountain stream pool. A linear, size-structured dominance hierarchy was recognized among individuals, body weight being a more important determinant of dominance status than fish length. Immigrant fish interacted more frequently with residents of similar body size than with larger or smaller fish during the early period following immigration. Thereafter, frequency of interactions rapidly decreased. When a fish was attacked, it reacted in a variety of ways in close accordance with its opponent's dominance rank: responses were to simply flee, flee with lateral display, revolt by performing a counter display or ignore the aggression. Such behavioural modification seems to be established during the successive agonistic encounters, in particular, early encounter periods when frequent interactions took place.     

茉莉花茶抗抑郁的效果

通过观察茉莉花茶对小鼠的体征状态、行为学指标及全脑中去甲肾上腺素（NA）、多巴胺（DA）和5-羟色胺（5-HT）含量的影响,研究茉莉花茶对抑郁模型小鼠的防治作用及其相关机制．首先,对小鼠先后各进行21d的第1次造模和灌胃治疗及第2次造模和灌胃治疗,检测小鼠在第1、2次造模前后的体重、摄食量和糖水偏好程度,发现茉莉花茶对小鼠的体征状态有改善作用（P〈0．05）;其次,在第2次造模前后对小鼠进行悬尾和强迫游泳试验,发现连续使用茶汤灌胃和茶香气处理均能明显缩短小鼠的不动时间（P〈O．01）;最后,检测小鼠全脑中NA、DA和5-HT的含量,发现茉莉花茶能够明显提高NA和DA的含量（P〈O．05）．结果显示,茉莉花茶具有抗抑郁的作用,机制可能与提高NA和DA的含量有关．     

Anaesthetic efficacy of eugenol on various size classes of angelfish (Pterophyllum scalare Schultze, 1823)

Anaesthetic efficacy of eugenol was investigated on Pterophyllum scalare. A total of 130 fish with average weights of 1.0 ± 0.5, 5.0 ± 1.0 and 10.0 ± 1.0 g were subjected to 1.25, 2.5, 4.0, 5.5 and 7.0 mg/L eugenol, and behavioural responses were observed. Induction and recovery times were significantly affected by the interactive effect of eugenol concentration and fish weight (p < .05). Generally, 49.9–128 s after exposure to 1.25–7 mg/L eugenol, fish reached stage 3. Fish entered stage 4 over 55–135 s post exposure to such concentrations. Recovery time was 393.5–597.7 s in all sizes. Any increase in eugenol concentration led to a significant decrease in the induction time with a subsequent increment of the recovery time. Concentrations of eugenol and fish size along with their interactive effects have significantly contributed to the regression models, with concentration recording the highest beta values for stages 1, 2, 3 and 4 (?0.903, ?0.898, ?0.976 and ?0.864 respectively) and the product of size and anaesthetic concentration for full recovery in smaller fish (0.647) and eugenol concentration in larger ones (0.967). Recovery time was fitted to induction time to stage 4 via quadratic and linear regression models in smaller and larger fish respectively. Results revealed the minimal eugenol concentration to induce anaesthesia in various size classes of angelfish in less than 3 min was 1.25 mg/L. Our results showed eugenol as an effective and safe anaesthetic; however, it is not advisable for live fish transportation.     

Assessing the impacts of tourism on the world's largest fish Rhincodon typus at Panaon Island,Southern Leyte,Philippines

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