Differential effect of formalin preservation on yolk and tissue of young chinook salmon (Oncorhynchus tshawytscha Walbaum)

1981 ◽  
Vol 59 (8) ◽  
pp. 1608-1611 ◽  
Author(s):  
T. A. Heming ◽  
R. P. Preston

Preservation in 5% neutral formalin for periods up to 50 days differentially increased the yolk and tissue weight of young chinook salmon (Oncorhynchus tshawytscha). Yolk gained relatively more weight than tissue. As a result, intact alevins showed a net weight gain during preservation, the magnitude of which was related to the amounts of yolk and tissue present at preservation. No single correction factor was generally applicable to compensate for weight changes in preserved alevins. On the other hand, preservation had little effect on weight of intact chinook eggs, regardless of egg composition. Presumably, increases in yolk and tissue weights of preserved eggs were masked by loss of perivitelline fluid.

2005 ◽  
Vol 119 (4) ◽  
pp. 591 ◽  
Author(s):  
Jeffrey S. Gleason ◽  
Ryan A. Hoffman ◽  
James M. Wendland

We report observations of Beavers (Castor canadensis) foraging and feeding on discarded Chinook Salmon (Oncorhynchus tshawytscha) carcasses within the confines of the Susitna River drainage in southcentral Alaska on three separate occasions between 1999 and 2004. In all three instances, Beavers were observed actively seeking out freshly discarded carcasses or transporting “fresh” salmon carcasses in their mouths. In one instance, Beavers were seen using their dextrous forefeet to “handle” chunks of salmon while hunched over carcasses and in this case we actually witnessed Beavers “chewing” and ingestion was assumed. In the other two instances, Beavers were observed swimming with salmon carcasses in their mouths. Though unique within the framework of Beaver foraging ecology, we suggest this behavior may be a fairly common strategy employed by Beavers in Alaskan streams and rivers to take advantage of a seasonally superabundant source of protein.


1974 ◽  
Vol 31 (7) ◽  
pp. 1211-1214 ◽  
Author(s):  
Edward M. Donaldson ◽  
J. R. McBride

Injection of a chinook salmon (Oncorhynchus tshawytscha) gonadotropin preparation into gonadectomized sockeye salmon (Oncorhynchus nerka) did not result in any increase in the plasma concentration of cortisol or cortisone, nor did it stimulate the activity of the interrenal tissue. On the other hand, injection of mammalian ACTH (Acthar) did result in an increase in the plasma concentration of cortisol and cortisone, and stimulated the interrenal tissue. The salmon gonadotropin preparation, however, elicited an increase in thyroid activity. The results suggest that in the salmon, ovulation is not caused by gonadotropin induced interrenal corticosteroidogenesis.


2015 ◽  
Vol 72 (11) ◽  
pp. 1749-1759 ◽  
Author(s):  
Cyril J. Michel ◽  
Arnold J. Ammann ◽  
Steven T. Lindley ◽  
Philip T. Sandstrom ◽  
Eric D. Chapman ◽  
...  

Outmigration survival of acoustic-tagged, hatchery-origin, late-fall-run Chinook salmon (Oncorhynchus tshawytscha) smolts from the Sacramento River was estimated for 5 years (2007–2011) using a receiver array spanning the entire outmigration corridor, from the upper river, through the estuary, and into the coastal ocean. The first 4 years of releases occurred during below-average river flows, while the fifth year (2011) occurred during above-average flows. In 2011, overall outmigration survival was two to five times higher than survival in the other 4 years. Regional survival estimates indicate that most of the improved survival seen in 2011 occurred in the riverine reaches of the outmigration corridor, while survival in the brackish portions of the estuary did not significantly differ among the 5 years. For the 4 low-flow years combined, survival rate in the river was lower in the less anthropogenically modified upper reaches; however, across all regions, survival rate was lowest in the brackish portion of the estuary. Even in the high-flow year, outmigration survival was substantially lower than yearling Chinook salmon populations in other large rivers. Potential drivers of these patterns are discussed, including channelization, water flow, and predation. Finally, management strategies are suggested to best exploit survival advantages described in this study.


1987 ◽  
Vol 65 (11) ◽  
pp. 2672-2681 ◽  
Author(s):  
C. B. Murray ◽  
T. D. Beacham

Chinook (Oncorhynchus tshawytscha) and chum salmon (O. keta) embryos were initially incubated at 4, 8, or 12 °C and then maintained at the same temperature or systematically transferred at completion of epiboly (early transfer) or complete eye pigmentation (late transfer) to each of the other incubation temperatures. For both species initial incubation at 8 or 12 °C resulted in higher embryo and alevin survival rates than initial incubation at 4 °C. Increasing or decreasing temperature regimes had little effect on embryo and alevin survival rates. Transfers after epiboly or completion of eye pigmentation had little influence on subsequent survival rates, except the early and late transfers of chinook salmon embryos from 4 to 12 °C, which resulted in an increase in alevin mortality. Hatching and emergence times varied inversely with temperature, and chum salmon generally hatched and emerged sooner than chinook salmon. Decreasing temperature regimes produced longer and heavier chinook salmon alevins and fry, but constant incubation at 8 °C or early or later transfers to 8 °C resulted in longer and heavier chum salmon alevins and fry. Temperature regimes that simulate those experienced by a species during natural incubation tend to enhance survival and alevin and fry size. Different trends in embryo and alevin developmental characters between species and among families within a species were assumed to reflect adaptations to variable natural incubation conditions.


1992 ◽  
Vol 14 ◽  
pp. 81-89 ◽  
Author(s):  
ML Kent ◽  
J Ellis ◽  
JW Fournie ◽  
SC Dawe ◽  
JW Bagshaw ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Manit Srisurapanont ◽  
Sirijit Suttajit ◽  
Surinporn Likhitsathian ◽  
Benchalak Maneeton ◽  
Narong Maneeton

AbstractThis study compared weight and cardiometabolic changes after short-term treatment of olanzapine/samidorphan and olanzapine. Eligible criteria for an included trial were ≤ 24 weeks, randomized controlled trials (RCTs) that compared olanzapine/samidorphan and olanzapine treatments in patients/healthy volunteers and reported weight or cardiometabolic outcomes. Three databases were searched on October 31, 2020. Primary outcomes included weight changes and all-cause dropout rates. Standardized mean differences (SMDs) and risk ratios (RRs) were computed and pooled using a random-effect model. This meta-analysis included four RCTs (n = 1195). The heterogeneous data revealed that weight changes were not significantly different between olanzapine/samidorphan and olanzapine groups (4 RCTs, SDM = − 0.19, 95% CI − 0.45 to 0.07, I2 = 75%). The whole-sample, pooled RR of all-cause dropout rates (4 RCTs, RR = 1.02, 95% CI 0.84 to 1.23, I2 = 0%) was not significant different between olanzapine/samidorphan and olanzapine groups. A lower percentage of males and a lower initial body mass index were associated with the greater effect of samidorphan in preventing olanzapine-induced weight gain. Current evidence is insufficient to support the use of samidorphan to prevent olanzapine-induced weight gain and olanzapine-induced cardiometabolic abnormalities. Samidorphan is well accepted by olanzapine-treated patients.


Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1359
Author(s):  
Noga C Minsky ◽  
Dafna Pachter ◽  
Galia Zacay ◽  
Naama Chishlevitz ◽  
Miriam Ben-Hamo ◽  
...  

Since the outbreak of COVID-19, billions of people have gone into lockdown, facing pandemic related challenges that engender weight gain, especially in the obese. We report the results of an online survey, conducted during Israel’s first quarantine, of 279 adults treated in hospital-based obesity clinics with counseling, medications, surgery, endoscopic procedures, or any combination of these for weight loss. In this study, we assessed the association between changes in dietary and lifestyle habits and body weight, and the benefits of receiving weight management care remotely through telemedicine during lockdown. Compared to patients not receiving obesity care via telemedicine, patients receiving this care were more likely to lose weight (OR, 2.79; p = 0.042) and also to increase participation in exercise (OR, 2.4; p = 0.022). While 40% of respondents reported consuming more sweet or salty processed snacks and 33% reported less vegetables and fruits, 65% reported more homemade foods. At the same time, 40% of respondents reported a reduction in exercise and 52% reported a decline in mood. Alterations in these eating patterns, as well as in exercise habits and mood, were significantly associated with weight changes. This study highlights that lockdown affects health behaviors associated with weight change, and advocates for the use of telemedicine to provide ongoing obesity care during future quarantines in order to promote weight loss and prevent weight gain.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lujiao Huang ◽  
Ju Zhang ◽  
Hong Sun ◽  
Hongli Dong ◽  
Run Li ◽  
...  

Abstract Background Cesarean section (CS) is a rising public health issue globally, and is particularly serious in China. Numerous studies have suggested that gestational weight gain (GWG) control may be an effective way to reduce the rate of CS. However, rare study has examined the association between GWG and CS among women in Southwest China. We proposed to examine their association based on a prospective birth cohort, and further to explore the optimal GWG range. Methods We retrieved data from a prospective birth cohort from Sichuan Provincial Hospital for Women and Children, Southwest China. Unconditional multivariable logistic regression was used to examine the association between GWG and CS by adjusting for potential confounders. In one analysis, we incorporated the GWG as a categorical variable according to the Institute of Medicine (IOM) recommendation, similar to the method used in the majority of previous studies. In the other analysis, we directly incorporated GWG as a continuous variable and natural cubic splines were used to characterize the potential nonlinear exposure-response relationship, aiming to identify the optimal GWG. We further stratified the above analysis by pre-pregnancy BMI and GDM, and then a heterogeneity test based on a multivariate meta-analysis was conducted to examine whether the stratum specific estimations agreed with each other. Results A total of 1363 participants were included. By adopting the IOM recommendation, the adjusted OR of CS was 0.63 (0.47, 0.84) for insufficient GWG and 1.42 (1.06, 1.88) for excessive GWG. After stratification by pre-pregnancy BMI, we found a higher risk of CS in associated with excessive GWG in the stratum of underweight compared with the other strata, which implied that pre-pregnancy BMI may be an effect modifier. By applying a flexible spline regression, the optimal GWG levels in terms of reducing the CS rate based on our data were more stringent than those of IOM recommendation, which were 9–12 kg for underweight women, < 19 kg for normal weight women and < 10 kg for overweight/obese women. Conclusions These results suggested that a more stringent recommendation should be applied in Southwest China, and that more attention should be given to underweight women.


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