scholarly journals Low-Lipid Diets Fed at Reduced Ration: Effects on Growth, Body Composition, and Survival of Juvenile Chinook Salmon

2019 ◽  
Vol 10 (2) ◽  
pp. 500-508
Author(s):  
Karen M. Cogliati ◽  
Julia R. Unrein ◽  
Wendy M. Sealey ◽  
Frederic T. Barrows ◽  
Olivia Hakanson ◽  
...  

Abstract There is a growing demand within research and conservation hatcheries to rear fish that more closely approximate the smaller size and leaner body composition of their wild counterparts. Low-lipid diets may help achieve this goal as they can provide all the nutritional needs of young fish and can lead to slower growth and leaner bodies. We compared growth of Chinook Salmon Oncorhynchus tshawytscha fed three experimental low-lipid diets (11–12, 8–9, 4–6% lipid) at the onset of feeding with a commercially available high-lipid diet (18–20%) and an experimentally formulated high-lipid control (13.9% lipid). After 5 mo on their respective treatments, the size, growth rate, and daily growth index of fish on the commercial diet were significantly higher than those on the three low-lipid diets. We also compared whole-body lipid content across our five diet treatments. Whole-body lipid content was significantly different across the five diets, with fish fed the commercial diet having, on average, an almost twofold higher lipid content over fish fed the lowest lipid diet formulation. We present comparable data from a limited sample of wild juvenile conspecifics as observations. We suggest that low-lipid starter diets can be used to produce healthy fish that more likely emulate some of the variations in size and body composition of wild fish.

1985 ◽  
Vol 63 (1) ◽  
pp. 22-27 ◽  
Author(s):  
G. H. Geen ◽  
J. D. Neilson ◽  
M. Bradford

Chinook salmon (Oncorhynchus tshawytscha) eggs, alevins, and fry were reared in pH 4.5, 5.0. 5.5, 6.2 (control), and 7.0 water from the eyed stage of development. Survival through hatching was >90% in all instances. Alevin mortality was high at pH 4.5 and 5.0. Fry were more tolerant of low pH than alevins. Growth rates of alevins and fry held at or above pH 5.0 and 4.5, respectively, were not affected by pH, nor did exposure to acidic water retard otolith development or result in their resorption. One otolith daily growth increment was formed every 24 h in alevins and fry irrespective of pH. Widths of otolith daily growth increments decreased when fry were transferred to pH 4.5 water and increased on their return to higher pH indicating changes in growth rate. Transfer of fry from pH 6.2 to pH 5.0 or 5.5 had no effect on increment widths.


1982 ◽  
Vol 39 (10) ◽  
pp. 1340-1347 ◽  
Author(s):  
John D. Neilson ◽  
Glen H. Geen

The effects of photoperiod, feeding frequency, and water temperature on formation of otolith daily growth increments in juvenile chinook salmon (Oncorhynchus tshawytscha) were examined. Feeding frequency influenced both increment number and width, whereas photoperiod and temperature affected only increment width. Fish fed once/24 h produced one increment every 24 h on average, while fish fed 4 times/24 h produced more than one increment every 24 h. Wider increments were produced in fish exposed to warmer water (11 °C) or 24 h of darkness. The ratio of otolith size to fish size remained constant throughout and between the photoperiod, temperature, and feeding frequency experiments, regardless of the number or width of increments produced. Although otolith growth is isometric with respect to increase in fish length under these experimental regimes, otolith microstructure will differ in fish of the same size reared under different environmental conditions. An understanding of factors affecting otolith increment production is required before increment number and width can be used to assess growth rates.Key words: otolith, daily, growth increments, chinook salmon


Diversity ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 71 ◽  
Author(s):  
Hards ◽  
Gray ◽  
Noël ◽  
Cunjak

Slimy sculpin (Cottus cognatus) are increasingly being used as indicator species. This has primarily entailed measuring their condition, the assumption being that condition can be used as a surrogate for lipid content. While there is evidence to suggest this assumption is applicable to some fish, it has yet to be validated for C. cognatus. Further, there are several means by which one may calculate condition, the most commonly employed of which are indirect measurements of lipid content (namely, Fulton's K, somatic K (Ks), and Le Cren's relative condition factor (Kn)). We compared the ability of each of these morphometric indices to predict whole-body lipid content in C. cognatus. There was a moderate degree of evidence that Fulton's K, Ks, and Kn are reliable predictors (Ks and Kn in particular). Of the latter we recommend Kn be used because, unlike Ks, it does not require that fish be killed. And while Fulton's K did not perform quite as well, we consider it a sufficient substitute if the data necessary to calculate Kn are unavailable.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Qin Tang ◽  
Chunfang Wang ◽  
Congxin Xie ◽  
Jiali Jin ◽  
Yanqing Huang

An 8-week feeding trial was carried out with juvenile yellow catfish to study the effects of dietary available phosphorus (P) on growth performance, body composition, and hepatic antioxidant property. Six pellet diets were formulated to contain graded available P levels at 0.33, 0.56, 0.81, 1.15, 1.31, and 1.57% of dry matter, respectively. Triplicate tanks with each tank containing 60 juveniles (3.09 ± 0.03 g) were fed one of the six experimental diets for 8 weeks. Specific growth rate, feeding rate, and protein efficiency ratio were significantly higher at 0.81% dietary available P. Efficiency of P utilization distinctly decreased with increasing P level. Body lipid content significantly decreased while body ash and feces P content significantly increased with increasing P level. Quadratic regression analysis indicated that vertebrae P content was maximized at 1.21% dietary available P. Fish fed 1.57% dietary available P had highest activity of hepatic superoxide dismutase and catalase and malonaldehyde content. In conclusion, decreasing dietary available P increased P utilization efficiency and body lipid content while decreased vertebrae P content. Juvenile yellow catfish were subjected to oxidative damage under the condition of high dietary P content (1.57%), and the damage could not be eradicated by their own antioxidant defense system.


Sign in / Sign up

Export Citation Format

Share Document