Breeding and moulting locations and migration patterns of the Atlantic population of Steller's eiders Polysticta stelleri as determined from satellite telemetry

This study was designed to determine the spring, summer, autumn, and early winter distribution, migration routes, and timing of migration of the Atlantic population of Steller's eiders Polysticta stelleri . Satellite transmitters were implanted in 20 eiders captured in April 2001 at Vadsø, Norway, and their locations were determined from 5 May 2001 to 6 February 2002. Regions where birds concentrated from spring until returning to wintering areas included coastal waters from western Finnmark, Norway, to the eastern Taymyr Peninsula, Russia. Novaya Zemlya, Russia, particularly the Mollera Bay region, was used extensively during spring staging, moult, and autumn staging; regions of the Kola, Kanin, and Gydanskiy peninsulas, Russia, were used extensively during spring and moult migrations. Steller's eiders migrated across the Barents and Kara seas and along the Kara Sea and Kola Peninsula coastal waters to nesting, moulting, and wintering areas. The majority of marked eiders (9 of 15) were flightless in near-shore waters along the west side of Novaya Zemlya. Eiders were also flightless in northern Norway and along the Kanin and at Kola Peninsula coasts. We compare and contrast natural history characteristics of the Atlantic and Pacific populations and discuss evolutionary and ecological factors influencing their distribution.     

Geographic variation in winter freezing susceptibility in the eggs of the European pine sawfly (Neodiprion sertifer)

Abstract 1 The European pine sawfly, Neodiprion sertifer (Geoffroy) (Hymenoptera, Diprionidae), frequently defoliates Scots pine (Pinus sylvestris L.) forests in northern Europe. It overwinters as an egg. It has been proposed that the high egg mortality caused by low winter temperatures limits the occurrence of outbreaks to the southern part of Fennoscandia. 2 In this study, variation in freezing avoidance by egg supercooling between four Finnish populations (originating between latitudes 60°N and 69°N) of N. sertifer was tested by differential thermal analysis. Offspring of 20 females within each population were selected for the study. The freezing avoidance of parasitized eggs was also examined. 3 The northernmost Inari population was found to be the cold hardiest, and the southernmost (Hanko) was the least hardy population. The within‐population variation between females was greatest in the population from Inari, and the next greatest in the one from Hanko. The inland populations in Eastern Finland had the smallest within‐population variation in freezing avoidance. 4 The high variation in freezing avoidance of eggs will enable N. sertifer to adapt to the predicted climate change and to spread its distribution northwards. This may also change the risk for outbreaks in this area. Parasitized eggs froze at higher temperature than healthy eggs. This observation indicates that N. sertifer may experience reduced egg parasitism in certain winter climate conditions.     

Orexins (hypocretins) and adrenal function.

The recently discovered neuropeptides orexin A and B regulate feeding behavior, neuroendocrine and autonomic functions, and sleep-wakefulness by central mechanisms. The expression of orexins and orexin receptors in various peripheral organs and the presence of orexin A in blood indicate the existence of a peripheral orexin system. In rat and human adrenal glands, both OX (1) and OX (2) receptor subtypes have been described with a predominant expression of OX (2) receptors in the adrenal cortex. In male rats, adrenocortical OX (2) receptors are much higher expressed than in female rats. Various experimental data demonstrate a stimulatory effect of orexins on the secretion of adrenocortical steroids, mainly on glucocorticoids. Some results also suggest the regulation of catecholamine synthesis and release by orexins. Whether the gender-dependent expression of adrenocortical OX (2) receptors has functional correlates awaits future clarification. As plasma orexin appears to rise during hunger and hypoglycemia, orexins may link adrenal functions with energy homeostasis.     

B-cell subsets in blood and lymphoid organs in Macaca fascicularis.

BACKGROUND: Cynomolgus monkeys (Macaca fascicularis) are widely used animal models in biomedical research. However, the phenotypic characteristics of cynomolgus monkey (CM) B cells in peripheral blood (PB) and lymphoid organs are poorly understood. METHODS: FACS analyses of PB-, spleen-, lymph node (LN)-, and bone marrow (BM)-derived B cells were performed. RESULTS: CM peripheral blood B cells have a smaller fraction of CD27(-) (naive) cells ( approximately 40%), as compared to human blood samples ( approximately 70%). Similar to humans, an early activation marker, CD23, is expressed more on CD27(-) CM naive B cells, as compared to CD27(+) B cells. The mean fraction of B cells exhibiting a memory phenotype is similar to that seen in human blood. Unlike humans, CM blood contains a subset of CD20(++)CD80(+)CD21(-)IgM(+/-)CD27(+)CD19(+)FSC(++)BAFF-R(low) B cells that are likely of germinal center origin. Thus, CM blood contains (i) a higher percentage of B cells that express the co-stimulatory molecule CD80, and (ii) a lower fraction of B cells that are CD21(+), as compared to human blood. Due to the relative paucity of information on B-cell subsets in organs of healthy humans, a direct comparison between human and CM lymphoid organ data is limited. The fraction of CD27(+) and CD23(+) B cells appears to be similar, while the fraction of CD80(+) B cells appears to be higher than that seen in human lymphoid organs. CM spleens and to some extent lymph nodes have a distinct subset of CD21(++) cells that are also CD80(+/-)CD23(low)IgM(++)CD27(+/-)FSC(++). This subset is phenotypically similar to the marginal zone B cells present in human spleen and LN samples. We also provide detailed analyses on the fraction of lymphoid organ B cells that express CD21, CD23, CD32, and/or CD80 B-cell markers. CONCLUSIONS: In general, cynomolgus monkey B-cell subsets are similar to those seen in humans, as well as to those seen in other nonhuman primates. However, there are some clear differences between human and cynomolgus monkey B-cell subsets. These findings have direct implications for a variety of in vivo studies in cynomolgus monkeys, ranging from basic research on primate B-cell differentiation to models of infectious diseases and trials of new B-cell targeting therapeutic agents.     

The influence of prey consumption and demographic stochasticity on population growth rate of Isle Royale wolves Canis lupus

The relationship between the rates of prey capture and predator population growth is a fundamental aspect of predation, yet it is rarely measured for vertebrate predators. For the isolated wolf population on Isle Royale, annual variation in kill rate explains 22% of the variation in wolf population growth rate. From the slope of this relationship, we estimate that the production efficiency (ratio of production to respiration) of wolves is between 0.5% and 1.5%. More generally, we assess the relative extent to which wolf population growth rate is affected by density dependence, prey availability (moose, Alces alces ), winter weather, and demographic stochasticity. Prey availability explains the most variation in wolf growth rate (42%), but this is only recognized after accounting for the influence of a disease-induced population crash and age structure of the prey population (i.e. number of vulnerable moose, >9 years of age). Demographic stochasticity accounts for approximately 30% of the variation in wolf growth rate. This recognition is important, but not surprising, given that the average population size of Isle Royale wolves is 22. Previous work indicates that the effect of winter climate, as mediated through prey vulnerability and kill rates, is substantial. This work indicates that the direct effect of winter climate is weak, and explains only about 4% of the variation in wolf growth rate (P=0.10).     

A comparative study of the performance of family groups of Atlantic salmon reared in tanks and released in a river

A study was conducted in in the Dale River as a part of a stock enhancement programme. The aim was to compare growth and the incidence of precocious maturation between offspring from precocious and large maturing males, and to study genotype‐environment interactions. River and hatchery performance was compared for 5 × 2 maternal half‐sib family groups, which were stocked as 0+ juveniles or maintained in the hatchery throughout. To identify the offspring, the broodfish were characterized by DNA‐fingerprinting (eight microsatellite markers). Smolt size of 1+ hatchery‐reared smolt and fish caught in a smolt trap, and the size and incidence of precocious maturation among 1+ hatchery‐reared parr and 1+ and 2+ parr caught in the river are compared between the families.     

Population biology and status of exploitation of introduced garfish Belone belone euxini (Günther, 1866) in the Black Sea

The garfish Belone belone euxini (Günther, 1866) is a commercially important pelagic fish species in Sinop artisanal fishery, which is showing a decreasing trend in catch results. As a basis for fisheries management a sampling program was carried out between October 2000 and September 2001 along the Turkish coast of the Black Sea, to study the population structure, growth, and reproduction cycle of garfish in the area, and to achieve a rough estimate of exploitation. The length–weight relationship and von Bertalanffy growth parameters were estimated as W = 0.00076 L^3.137, L_∞ = 74.64 cm, K = 0.13 year^?1, t_o = ?3.67, respectively. First sexual maturity was estimated at age 2 and at a total length of 38.8 cm for females. The spawning period was from May to September. The total fecundity–length relationship was estimated as F = 0.0041 L^4.1086 (r² = 0.92). Mortality rates were Z = 1.24 year^?1, M = 0.23 year^?1and F = 1.01 year^?1 for total, natural, and fishing mortality, respectively. The exploitation ratio E = 0.81 indicates that the population is heavily exploited.     

Effects of dietary soybean meal and photoperiod cycle on osmoregulation following seawater exposure in Atlantic salmon smolts

Atlantic salmon Salmo salar juveniles were fed either fishmeal-based diets (FM) or diets in which soybean meal (SBM) partly replaced the FM from first feeding on. The fish were kept at continuous daylight during the juvenile stage. During the last 3 weeks before reaching 100 g body mass, all fish were subjected to 12L:12D. Starting at 100 g body mass, groups of 60 fish from each feeding background were subjected to continuous light for 12 weeks (short winter), or a square-wave photoperiod cycle to stimulate parr to smolt transformation with 8L:16D during the first 6 weeks, and then continuous light during the last 6 weeks (long winter). After the 12 weeks, 20 fish from each treatment were subjected to 0, 24 or 96 h seawater exposure at a water salinity of 34. Hypo-osmoregulatory ability at seawater exposure was assessed by mortality, intestinal pathology, plasma ion concentrations and osmolality, gill Na⁺/K⁺-ATPase activity and element concentrations in the cytoplasm of distal intestinal enterocytes using X-ray microanalysis. The hypo-osmoregulatory capacity was higher in fish kept at short winter than at long winter, apparently due to more rapid development of gill Na⁺/K⁺-ATPase activity. Fish fed SBM suffered typical soybean meal-induced histological alterations of the distal intestine and apparent reductions in digestive function in the more proximal gastrointestinal regions. The net osmoregulatory capacity of these fish was maintained, as indicated by higher gill Na⁺/K⁺-ATPase activity and lower plasma Na⁺, Ca²⁺ and osmolality compared to the FM-fed fish. Thus, feeding SBM did not impair the hypo-osmoregulatory ability of the Atlantic salmon following seawater exposure.