Digestive characteristics and blood chemistry profile of triploid rainbow trout Oncorhynchus mykiss: influence of body size and seasonal variation

2019 ◽  
Vol 85 (6) ◽  
pp. 1001-1010 ◽  
Author(s):  
Yuqiong Meng ◽  
Buying Han ◽  
Changzhong Li ◽  
Kangkang Qian ◽  
Xiaohong Liu ◽  
...  
Author(s):  
Ligia Panasiak ◽  
Karolina Szubert ◽  
Marcin Polonis ◽  
Konrad Ocalewicz

AbstractSomatic growth is considered to affect pace of the telomere attrition in vertebrates. As normally developed and dwarf fish differ in the body size we have decided to compare telomere length in the rainbow trout (Oncorhynchus mykiss) with normal growth and with growth reduced due to the dwarf condition. Examined 1-year-old fish with normal and dwarf appearance were siblings originated from androgenetic fully homozygous doubled haploid (DH) line of rainbow trout. Particular dwarf individuals had body deformities such as humpback, kyphosis, and lordosis. Somatic cells of examined rainbow trout had an average telomere length between 17 and 20 kb, comparable in females and males. Dwarf rainbow trout exhibited significantly lower body length and weight than their normally developed siblings even though no differences in the telomere length were found between these fishes. Statistical analysis did not exhibit any correlation between body size and the telomere length. Equal length of telomeres observed in the studied normal and dwarf rainbow trout suggests morphological and physiological differences in fish with different growth rates do not affect dynamics of telomeric DNA. Or any variation in the telomere length might have been levelled by telomerase that in rainbow trout is active in all tissues irrespective of the individual developmental stage.


1993 ◽  
Vol 50 (3) ◽  
pp. 480-487 ◽  
Author(s):  
Jörgen I. Johnsson ◽  
W. Craig Clarke ◽  
Ruth E. Withler

We tested the hypothesis that hybridization with domesticated rainbow trout (Oncorhynchus mykiss) reduces the seasonal variation in growth in both fresh and salt water in anadromous steelhead trout (O. mykiss). The seasonal variation in freshwater growth was more pronounced in the steelhead trout than in the hybrid and domesticated trout. Consequently, differences in growth rate among groups were considerably higher during winter than in fall or spring. We suggest that high feeding activity during unfavourable winter conditions in natural waters is maladaptive, but is not selected against in protected hatchery environments with a continuous food supply. This may lead to genetic divergence in feeding physiology and/or behaviour between steelhead trout and domesticated rainbow trout. Growth rates in experimental groups transferred to seawater in December relative to groups transferred in April were faster in rainbow and hybrid trout than in steelhead trout. The results support the hypothesis that seasonal variation in seawater growth in steelhead trout is reduced by crossing with domesticated rainbow trout.


2007 ◽  
Vol 64 (12) ◽  
pp. 1770-1780 ◽  
Author(s):  
Joanna Lynne McGarvie Hirner ◽  
Sean P Cox

Stocking lakes with trout to enhance recreational fishing can negatively affect native aquatic species. Our objectives were (i) to compare presence, relative abundance, body size, and developmental stage of amphibians in lakes with and without rainbow trout (Oncorhynchus mykiss) in British Columbia’s southern interior, and (ii) to estimate the size of trout impact for application to amphibian conservation. Presence of long-toed salamander (Ambystoma macrodactylum), Columbia spotted frog (Rana luteiventris), and Pacific treefrog (Pseudacris regilla) was not significantly different between lake types. In contrast, western toad (Bufo boreas) larvae presence and relative abundance were significantly higher in lakes with trout. Relative abundance of salamander larvae was significantly lower in lakes with trout, but hypothesis testing did not provide consistent evidence of significantly lower abundances of spotted frog and treefrog larvae. However, estimated ratios of relative abundance (impact) indicated that larvae of the salamander and two frogs were ≥65% less abundant in lakes with trout. Salamander larvae were significantly smaller in lakes with trout. Although amphibians may currently coexist with trout in our study region, trout stocking policy in British Columbia should consider amphibian conservation because the presence of trout is associated with lower amphibian abundance and body size in individual lakes.


2017 ◽  
Vol 2 (3) ◽  
pp. 91-94 ◽  
Author(s):  
Francesco Fazio ◽  
◽  
Concetta Saoca ◽  
Irene Vazzana ◽  
Giuseppe Piccione ◽  
...  

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