野生与养殖花羔红点鲑肌肉营养成分的比较分析

分别对野生与养殖花羔红点鲑Salvelinus malma肌肉中营养成分进行了比较分析.结果表明:(1)野生与养殖花羔红点鲑肌肉的一般营养成分的含量存在差异.野生群体肌肉中水分的含量显著低于养殖群体(P0.05),而粗蛋白质的含量和粗脂肪的含量则显著高于养殖群体(P0.05),野生群体肌肉中粗灰分的含量高于养殖群体,差异不显著(P0.05),野生群体肌肉中无氮浸出物的含量低于养殖群体,差异显著(P0.05).(2)野生与养殖花羔红点鲑肌肉中氨基酸总量(w)分别为(18.01±0.29)%和(16.46±0.15)%.野生群体肌肉中各种氨基酸的含量均高于或等于养殖群体,其中,谷氨酸含量最高.(3)野生与养殖花羔红点鲑肌肉中脂肪酸组成均以油酸(C18∶1)含量最高,硬脂酸(C18∶0)含量最低.亚油酸(C18∶2)、EPA(C20∶5)、二十二碳五烯酸(C22∶5)、DHA(C22∶6)的含量野生群体低于养殖群体,差异显著(P0.05).(4)野生和养殖花羔红点鲑的化学评分分别为0.90和0.87,氨基酸评分分别为0.67和0.64,第一限制性氨基酸都为蛋氨酸.     

Genetic divergence among broodstocks of Arctic charr Salvelinus alpinus in eastern Canada derived from the same founding populations

We examined the amount and distribution of molecular variation at microsatellite loci in 21 broodstocks of Arctic charr Salvelinus alpinus derived from the Fraser River, Labrador and the Nauyuk Lake, Nunavut, Canada. Our goal was to assess the amount of genetic diversity and differentiation as broodstocks are subdivided and propagated in different hatcheries and grow‐out facilities. We observed significant heterogeneity across pairs of ancestral and descendant broodstocks in the mean numbers of alleles at microsatellite loci. We detected a significant decrease in the observed heterozygosity between ancestors and descendants but the amount of decrease did not depend on either the degree of removal from the wild (number of sequential transfers) or the strain (Fraser vs. Nauyuk). Based on allele frequency distributions, there was little genetic evidence of bottlenecks during the creation of subsequent broodstock populations after the initial founding events. All broodstock samples were significantly differentiated from each other but those within the same strain were more similar to each other than to broodstocks from different strains. Broodstocks from the Nauyuk Lake broodstocks showed greater differentiation from each other than did Fraser River broodstocks, which could be attributed to differences in the number of founders.     

Spawning salmon increase brook trout movements in a Lake Michigan tributary

Abstract – Salmon and trout have been introduced to many ecosystems worldwide, yet the ecological impacts of salmonid introductions remain poorly understood. We investigated the effects of introduced Pacific salmon on stream‐resident fish in the Great Lakes basin by monitoring the movements of passive integrative transponder (PIT)‐tagged brook trout in a Lake Michigan tributary receiving a salmon spawning run and in a nearby stream not receiving salmon. Coincident with the September arrival of salmon, an estimated 52% of resident brook trout moved >200 m, while no such movements were detected in the nonsalmon stream. After 3–4 days, however, brook trout movement patterns became similar in the two streams, suggesting that salmon effects on brook trout movements were short‐lived. Movements in the salmon stream were predominantly upstream in direction, with 50% of the tagged brook trout travelling from below to above the stationary PIT tag readers during the study. Declining water temperatures with the onset of fall coincided with low levels of brook trout movement at both sites, likely due to relocation for spawning. Increased brook trout movements coincident with the arrival of salmon spawners could be driven by a combination of interference competition and egg consumption. Using a bioenergetics model, we estimated that the energy lost to movement was likely compensated by the energy obtained from consuming salmon eggs. We conclude that salmon spawners can substantially increase brook trout movement, but in our study, these effects were short‐lived and likely negligible from a bioenergetics perspective.     

花羔红点鲑和白斑红点鲑肌肉营养成分分析

测定了花羔红点鲑(Salvelinus malma)和白斑红点鲑(S.leucomaenis)的肌肉营养成分,并对其进行比较.结果显示:(1)花羔红点鲑肌肉的蛋白质含量、脂肪含量均显著高于白斑红点鲑(P＜0.05),而其灰分含量值则低于白斑红点鲑,但其差异并不显著(P＞0.05)；(2)花羔红点鲑在氨基酸总量、必需氨基...     

Divergence of Salvelinus species from northeastern Asia based on mitochondrial DNA

Abstract –  Phylogenetic analysis of charrs of the genus Salvelinus was performed using PCR-RFLP analysis of mitochondrial DNA (mtDNA). Three fragments of mtDNA (ND1/ND2, ND5/ND6 and Cyt b /D-loop) were amplified by PCR and examined for restriction site variation using 13 restriction endonucleases. Analysis of 313 sites of over 7672 bp of charr mtDNA was conducted. Six phylogenetic lineages of the mtDNA were revealed, corresponding to six separate charr taxa: Salvelinus leucomaenis Pallas; Salvelinus levanidovi Chereshnev, Skopetz & Gudkov; Salvelinus taranetzi Kaganovsky; Salvelinus malma krascheninnikovi Taranetz; Salvelinus malma malma Walbaum and Salvelinus alpinus alpinus . The Levanidov ( S. levanidovi ) and white-spotted ( S. leucomaenis ) charrs represented the most divergent lineages. These are probably closest to a common ancestor of the genus. Salvelinus taranetzi was the next divergent lineage. Salvelinus malma krascheninnikovi was placed between S. leucomaenis and S. taranetzi . Salvelinus malma malma and S. a. alpinus were sister taxa, and were on the last branch to diverge. The divergence between S. m. malma and S. a. alpinus inferred from mtDNA nucleotide sequences was 1.1%; between S. m. malma and S. taranetzi 2.8%; between S. m. malma and S. m. krascheninnikovi 4%; between S. taranetzi , S. m. krascheninnikovi and S. a. alpinus 2.8%. Salvelinus levanidovi and S. leucomaenis were almost equally remote from the other charrs by some 9% and 7%, respectively. The extent of genetic differences between the northern S. m. malma populations and the European S. a. alpinus populations indicates that they diverged recently. The existence of many putative charr species with different divergence times in northeastern Asia suggests that this region may be one of the centres of speciation of the genus Salvelinus .     

Pharmacokinetics of Ivermectin in Salvelinus leucomaenis Following Two Ways of Administration

[目的]研究伊维菌素在白点鲑体内的药动学。[方法]对白点鲑以0．3mg／kg的剂量分别单次口灌和腹腔注射伊维菌素,采用高效液相色谱-紫外检测法（HPLC—UV）于给药后不同时间点连续进行采样检测,通过3p97软件分析药动学参数。[结果]在2种给药方式下,伊维菌素在血浆、肌肉、肝和肾中的药时关系均符合一级吸收一室开放模型。口灌给药方式下,血浆中药动学参数为Tmax=4．503h、Cmax=0．252mg／L、t1/2ka=0．476h、t1/2ka=331．160h、AUC=121．524（mrdL）·h;腹腔注射给药方式下,血浆中药动学参数为Tmax=2．751h、Cmax=0．230mg／L、t1/2ka=0．306h、t1/2ka=153．868h、AUC=51．689（mg／L）·h。[结论]两种给药方式下伊维菌素在白点鲑体内的药动学存在差异,腹腔注射给药比口灌给药吸收快。     

Comparisons of growth and condition of fluvial and resident brook trout within partially migratory populations

Abstract  In partially migratory salmonid populations, growth and condition of migratory fish may be different than that of residents. To ascertain if a similar phenomenon exists in fluvial brook trout, Salvelinus fontinalis (Mitchell), populations, the growth and condition of fluvial and resident brook trout was measured in four Appalachian stream networks. Sites were sampled during summer, cohorts separated via scale analysis and differences in length and condition were investigated. Age-1 and -2 fluvial fish were significantly longer ( P  <   0.001) than residents of the same cohort. Additionally, age-2 fluvial fish had significantly greater condition ( P  <   0.005) than resident fish of the same cohort. This suggests that the use of spatially segregated resources can result in growth and condition advantages. However, potentially greater rates of mortality as suggested by low abundance in main stem sites may limit the fitness advantages of this energetically profitable, but ultimately risky, behaviour.     

Offspring or ornaments? Is carotenoid‐based ornamentation in female Arctic charr,Salvelinus alpinus (L.), condition‐dependent and traded off against offspring?

Abstract –  In several carotenoids-based ornamented species, females invest carotenoids also into their gametes to increase the quality of the rapidly growing zygote. The extra carotenoids demand may cause females to trade-off valuable carotenoids between ornament and eggs. This may be one reason why females are less showy ornamented than males. In our study-population of Arctic charr, individuals of both sexes vary in degree of conspicuousness of their red abdomen and fins. None of the two carotenoids-based ornaments was significantly associated with either (i) the amount of carotenoids in the egg, although being negative and close to significance, or (ii) potential condition-dependent parameters like relative density of leucocytes, condition-factor and parasitism. This study does not support the 'direct selection hypothesis' to explain the existence of female ornaments, and gives equivocal support for the hypothesis of asymmetrical investment of carotenoids into gametes to explain the less showy ornaments in females when compared with males.