Most minerals, occurring in aqueous environments, play a key role in the survival rate of aquatic living organisms. However, life situation of the living organisms would be under attack when the contents of these elements exceed than the specified limit because of various reasons. Bioaccumulation of the elements in living organisms and their excess concentration than standard limit would result in acute and chronic biological impacts in their tissues. ... The experiment was performed in fish farming center of Arab Kheil at the countryside of Amol city for 90 days from July to October 2010. Four diets were prepared for 204 rainbow trout samples. Experimental feeding diets included: the control treatment which contained 29 mg kg^-1 of manganese. This level of manganese occurs naturally in the principle composition of the feeding diets. Treatments 1, 2 and 3 contained 48, 78, and 98 mg of manganese sulphate per kg of food, respectively. ... According to the obtained results, it can be concluded that there is a significant relationship between manganese concentrations in liver, kidney, fatty tissues including muscle of rainbow trout. Manganese mean content is less than the standard limit of FAO which contradicts any interdict in the consumption of rainbow trout. Significant differences were observed among manganese contents in treated fish samples and the control. Manganese content in kidney tissues showed the highest level than other tissues

Emadi, H.

Hosseinzadeh Sahafi, H.

Saeedi, A.A.

Samavat, Z.

Aquatic Commons

Iranian Journal of Fisheries Sciences                   14(2) 523-530                                                      2015 
 
 
 
A comparative study on manganese accumulation in liver, 
kidney, fatty tissues including muscle of rainbow trout 
(Oncorhynchus mykiss) fed with different levels of manganese 
in the diet 
 
Emadi H. 1; Samavat Z.1*; Saeedi A.A.2; Hosseinzadeh Sahafi H.3 
  
Received: November 2012                                  Accepted: December 2014 
 
1-Faculty of Marine Science and Technology, Islamic Azad University, Tehran, Iran. 
2-Caspian Sea Ecology Research Center, Iranian Fisheries Science Research Institute,  
   Agricultural Research, Education and Extension Organization, Sari, Iran. 
3-Iranian Fisheries Science Research Institute, Agricultural Research, Education and   
    Extension Organization Tehran, Iran. 
*Corresponding author’s email: Samavat.a@gmail.com 
 
Keywords: Rainbow trout, Manganese, Muscle, Liver, Kidney, Fatty tissue. 
 
Most minerals, occurring in aqueous 
environments, play a key role in the 
survival rate of aquatic living organisms. 
However, life situation of the living 
organisms would be under attack when 
the contents of these elements exceed 
than the specified limit because of 
various reasons (Amini Ranjbar, 1994). 
Bioaccumulation of the elements in 
living organisms and their excess 
concentration than standard limit would 
result in acute and chronic biological 
impacts in their tissues (Kimmo et al., 
2004). Metals like manganese, copper, 
zinc, and iron are essential elements in 
metabolic activities of living organisms 
at ppm levels and maintaining body 
metabolism as well. Naturally, the 
elements are considered as enzyme 
formers at very poor levels to increase 
fish health status. They should be taken 
through water, food and sediments; 
however, they would lead to intoxication 
when taken at higher levels (Chen et al., 
2008). It has been well documented that 
fishes are considered as good indicators 
for long term monitoring of heavy metal 
bioaccumulation in marine environment 
due to their access to different dietary 
levels (Has-Schon et al., 2008). Mineral 
elements are important from different 
metabolic aspects. Beyond their effects 
on bones strengthening, these elements 
have also beneficial effects on 
homeostasis and maintenance of the fish 
body with their aqueous surrounding 
Short Communication 
524 Emadi et al., A comparative study on manganese accumulation in… 
 
environment through nervous system 
and endocrine glands. In addition, these 
elements act as formers of most enzymes 
and pigments and in some metabolic 
activities and energy transportation 
(Heen et al., 1993). Tissues of aquatic 
organisms are very low in manganese 
level; however, most tissues have very 
little manganese accumulation. Bones, 
liver, pancreas and pituitary gland 
showed to have the highest manganese 
concentrations than other organs (Salek 
Yosefi, 2000). As with the magnesium, 
manganese is also considered as enzyme 
activators, as several phosphyt 
transferases and dicarboxylysis are 
activated by this element. Usually, 
aquatic organisms can uptake 
manganese from the water and provide 
the required level of manganese from 
dietary foods (Salek Yosefi, 2000). 
Normally, this element has less toxic 
effect to fish body than iron. Clinical 
symptoms of manganese are hyper-
excitation, imbalanced swimming, 
discoloration of fins and sensory 
barbels. Other symptoms which is 
seldom observed includes fin distortion, 
cataract and the presence of adhesive 
filaments on fish skin. At final stage, the 
fish will paralyses and after a few hours, 
it will convict to the death (Van Duijn, 
2000). This element is necessary for the 
regulation of fish nervous system, bone 
development and reproduction. Also, 
manganese has an efficient role in 
carbohydrate metabolism and is needed 
for fish health enhancement (Malekniya 
and Shahbazi, 1996). Manganese, a 
nutritional element, is essential for the 
survival of all kinds of animal species 
but at a low level. Manganese loss would 
result in a remarkable decline in growth 
rate, abnormal development of the fish 
tail, shortening of the body and 
disturbances in reproduction system of 
rainbow trout. On the whole, the loss of 
manganese in fish body would lead to 
malformation, abnormality of the bones 
and retardation in the synthesis of blood 
cells. In a previous study by Ogino and 
Yang (1980), it has been observed that 
rainbow trout fed with diets containing 4 
mg kg-1 of manganese had less growth 
rate than those fed with diet containing 
13 mg kg-1 of manganese. Recent 
investigations indicate that a few studies 
have been focused on mineral 
bioaccumulation, for example 
manganese, in rainbow trout in Iran. 
This survey aimed to study the 
accumulation of manganese at different 
levels in liver, kidney, fatty tissues 
including muscle of rainbow trout.      
     The experiment was performed in 
fish farming center of Arab Kheil at the 
countryside of Amol city for 90 days 
from July to October 2010. Four diets 
were prepared for 204 rainbow trout 
samples. Experimental feeding diets 
included: the control treatment which 
contained 29 mg kg-1 of manganese. 
This level of manganese occurs naturally 
in the principle composition of the 
feeding diets. Treatments 1, 2 and 3 
contained 48, 78, and 98 mg of 
manganese sulphate per kg of food, 
respectively (Halver, 1988). Feeding to 
the fish was based on 3% of the total 
body weight and conducted three times a 
day (at 8 am, 12 am, and 6 pm) 
according to the water temperature. The 
Iranian Journal of Fisheries Sciences 14(2) 2015                                               525 
 
amount of manganese sulphate in each 
experimental feeding diet was measured 
in accordance to the manganese content 
in the control treatment. Then each 
experimental dose of manganese 
sulphate was mixed well with 1 kg of 
factory prepared food in order to spread 
the manganese homogenously in a given 
diet. After two weeks acclimation, fish 
samples in each treatment with average 
weight of 50 g and density of 51 
individuals in each farming channel 
(100×200×1500 cm3) were fed with 
different feeding diets for three months. 
At the end of the farming period, 
manganese bioaccumulation in liver, 
kidney, fatty tissues including muscle of 
fish samples in treatments and the 
control were compared. Twelve fish 
from each treatment (4 from each 
replicate) were randomly selected and 
then placed into dark polyethylene bags. 
Afterward, samples were frozen at -20ºC 
and transported to the Pasargad 
Research Laboratory in Tehran. After 
transportation, preparation and analysis 
processes on fish samples were 
conducted. To do so, muscle, liver, 
kidney and fatty tissues of the fish were 
separated according to the 
implementation guideline. For heavy 
metal measurement, samples were 
derived into ash (Tacon, 1990): 
 Ash(%) = [
(A+Wb)−Wb
Ws
] × 100 
Where A is the amount of ash; 𝑊𝑏: the 
weight of tiled bowl; 𝑊𝑠: the weight of 
sample.  
Hydrolysis method was applied to 
extract the fat from the muscle tissue 
(Wiehlloughby, 1990):            
Fat (%) = [
Wp − Wf
Ws
] × 100 
Where 𝑊𝑝is the weight of empty petri 
dish; Wf: the weight of petri dish 
containing fat; Ws: the weight of sample. 
To determine manganese content in 
kidney, liver, fatty tissues including 
muscle of the fish, an atomic Philips 
absorption apparatus (Model PU, 9400) 
was used. Data were subjected to the 
One-Way ANOVA using statistical 
software package of SPSS. Mean 
comparisons were performed by 
Duncan’s multiple range test. Data 
calculation and drawing of diagrams 
were done by software package of Excel.    
Temperature averaged between 16 and 
17ºC and it showed no remarkable 
changes during farming period. pH 
value ranged around 7.5 and water flow 
rate was 4 l-1 second-1. Water oxygen 
content ranged from 8.7 to 9.9 mg l-1. 
According to the obtained results, fish 
samples treated by the highest level of 
manganese in dietary food (treatment 3) 
revealed the highest manganese 
accumulation in liver, kidney, fatty 
tissues including muscle, whereas the 
control treatment detected the lowest 
content of manganese. Results 
evidenced the increased accumulation of 
manganese in tissues of 98mg-treated 
fish during a 90-day period. Results of 
One-Way ANOVA indicated significant 
differences (p<0.05) between treatments 
and the control.  
      Results of comparisons of 
manganese content in liver, kidney, fatty 
tissues including muscle are depicted in 
Fig. 1, 2, 3 and 4. Fish samples in 
526 Emadi et al., A comparative study on manganese accumulation in… 
 
treatment 3 had the highest mean level of 
manganese accumulation in their tissues 
as compared to the control fish. 
Moreover, comparison of manganese 
content in the studied tissues revealed 
significant differences (p<0.05) among 
various treatments and the control.  
 
 
 
Figure 1: Comparison of manganese concentration (mean±SD) in liver of rainbow trout (Different 
characters show significant difference at p<0.05 using Duncan’s multiple range test). 
 
Figure 2: Comparison of manganese concentration (mean±SD) in kidney tissue of rainbow trout   
                 (Different characters show significant difference at p<0.05 using Duncan’s multiple range  
                  test).  
                  
 
Iranian Journal of Fisheries Sciences 14(2) 2015                                               527 
 
 
Figure 3: Comparison of manganese concentration (mean±SD) in fatty tissue of rainbow trout  
                 (Different characters show significant difference at p<0.05 using Duncan’s multiple range  
                  test). 
 
 
 
Figure 4: Comparison of manganese concentration (mean±SD) in muscle tissue of rainbow trout  
                (Different characters show significant difference at p<0.05 using Duncan’s multiple range  
                 test). 
  
Regarding to the obtained results, 
manganese accumulation in body tissues 
increased parallel with increase in its 
concentration in dietary foods. Results 
of statistical analysis using One-Way 
ANOVA revealed significantly (p<0.05) 
lower content of manganese in control 
fish samples as compared to other 
treatments. Fish samples in treatment 3 
indicated the highest level of manganese 
528 Emadi et al., A comparative study on manganese accumulation in… 
 
in their body tissues. Also, mean 
comparisons of manganese content 
showed significant (p<0.05) differences 
among various treatments.  
     In this study liver, kidney, fatty 
tissues including muscle of the rainbow 
trout were examined. Based on the 
results obtained in the present study, 
addition of manganese to the fish dietary 
food increased the accumulation of this 
element in their body tissues in 
comparison to the control treatment. As 
fish muscle tissue is of importance for 
human consumption, the tissue was 
studied here. Other fish tissues were also 
examined in order to investigate any 
absorptive differences with muscle 
tissue. There was a significant 
relationship between manganese 
concentration in body tissues and 
feeding diets. Previous studies 
demonstrated that mean concentration of 
manganese is different in various 
tissues. Results of the present work 
presented that fish samples in treatment 
3, which had received the highest level 
of manganese in their feeding diet, had 
the most content of manganese in their 
studied tissues than other treatments and 
the control. Furthermore, manganese 
level was less than the allowable limit 
admitted by the World Health 
Organization, implicating no problem in 
the quality of fish meat (Sing and Ferns, 
1978). Approximately, 5-10 mg day-1 of 
manganese is recommended as the safe 
range for the human health. Manganese 
might cause fish intoxication by the 
absorption from the feeding diets. As 
expressed by previous researchers, 
drinking water contains 100 µg l-1 of 
manganese is recommended for human 
health and there would be inevitable 
issues such as psychosis, mental and 
nervous disturbances as well as a 
considerable decline in the absorption of 
other minerals like calcium, copper, 
iron, magnesium and zinc.  
      Manganese absorption in human 
body depends on the age, feeding diets, 
iron content and other minerals. Around 
3 to 8 % of manganese is taken in by 
means of alimentary duct. Totally, daily 
manganese uptake by means of feeding 
diets, drinking water and respiration is 
estimated to be 3-8 µg, 0.1 to 24, and 400 
ng, respectively. It has been reported that 
manganese is absorbable to human body 
by respiration system (Heen et al., 
1993). Manganese might cause fish 
intoxication by the absorption from the 
feeding diets. As expressed by previous 
researchers, drinking water contains 100 
µg l-1 of manganese. Lethal 
concentration of manganese in rainbow 
trout fish is 0.1 g l-1 and this metal 
exhibited its toxicity effects in fish body 
when adding as manganese sulphate (0.5 
g l-1) and manganese chloride (0.33 g l-1) 
(Heen et al., 1993). Having been entered 
to the blood circulation, manganese 
influxes to the brain before it is 
metabolized in the liver. Therefore, this 
element causes undesirable effects on 
central nervous system. As manganese 
can be excreted by means of bilious 
system, the element poissesses more 
simple mechanism in feeding system 
(Esmaeli Sari, 2002). 
 Generally, differences in metal 
accumulation of various body tissues 
might be due to the differences in their 
Iranian Journal of Fisheries Sciences 14(2) 2015                                               529 
 
ecological demands and metabolic 
activities. According to the presented 
results, more bioaccumulation of 
manganese in body tissues of those fish 
treated by 98 mg kg-1 might be attributed 
to the high content of manganese in their 
feeding diets. In a previous research by 
Yamamoto et al., (1983), manganese 
bioaccumulation showed a direct 
relationship with the weight of rain bow 
trout fish samples. Based on the results 
obtained here, the most level of 
manganese accumulated in kidney 
tissues of the rainbow trout than other 
tissues. Like other minerals, manganese 
can accumulate in some fish tissues. 
Many previous researchers 
demonstrated that manganese 
bioaccumulation in fish muscle is less 
than the accumulations of minerals like 
iron, copper, zinc, and magnesium (Sing 
and Ferns, 1978).  
     This element can aggregate in body 
tissues including heart, kidney, gills, 
muscle, intestine, and liver (Stranah and 
Andreji, 1998). Freshwater fish can 
retain ions in their kidney and excrete 
excess water from their bodies in order 
to survive. In addition, organs like heart 
and kidney are the locations in which 
trace elements can accommodate in most 
fish species (Olsson, 1998).  
       In the surveys on heavy metal 
concentrations of zinc, iron, copper, 
manganese, nickel and cadmium (dry 
weight) in west white leg shrimp caught 
from northwest coast in Mexico, it has 
been declared that most heavy metals 
can accumulate in hard tissues and 
muscle. Several investigators believe 
that heavy metals can accumulate in 
various body tissues of the living 
organisms but the animal tissues can 
tolerate against the excess 
bioaccumulation of these elements as 
much as possible if metal content 
exceeds the threshold level (Rogers and 
Richards, 2003). 
      According to the obtained results, it 
can be concluded that there is a 
significant relationship between 
manganese concentrations in liver, 
kidney, fatty tissues including muscle of 
rainbow trout. Manganese mean content 
is less than the standard limit of FAO 
which contradicts any interdict in the 
consumption of rainbow trout. 
Significant differences were observed 
among manganese contents in treated 
fish samples and the control. Manganese 
content in kidney tissues showed the 
highest level than other tissues. Until 
now, several studies have been focused 
on the accumulation of manganese in 
rainbow trout fish throughout the world. 
In addition, no research has been 
conducted on manganese 
bioaccumulation in body tissues of 
rainbow trout fish so far in Iran.   
   
References 
Amini Ranjbar, G., 1994. A survey on 
heavy metal accumulation (Zn, Cu, 
Pb, and Cd) in surficial sediment of 
Anzali Wetland. Iranian Journal of 
Fisheries Sciences, 3, 5-26. (in 
Persian). 
Chen, Z.N., Zhang, L., Zhuo. and 
Tang, B., 2008. Catalytic kinetic 
methods for photometric or                           
fluorometric determination of heavy 
530 Emadi et al., A comparative study on manganese accumulation in… 
 
metal ions. Journal of Microchim 
Acta, 164(3-4), 311- 336.    
Esmaeli Sari, A., 2002. Pollutants, 
hygiene and standards in natural 
environment. Naghsh Mehr         
Publication. Tehran. pp. 149-156. 
Halver, J.E., 1988. Fish nutrition. 
academic press. United State of 
Amireca. 494P. 
Has-Schon, E., Bogut, I., Rajkovic, V., 
Bogut, S., Cacvic, M. and 
Horvatic, J., 2008. Heavy metal 
distribution in tissues of six fish 
species included in human diet, 
inhabiting freshwaters of the nature 
park (Bosnia and Herzegovina). 
Journal of Arch Environmental 
Contamination Toxicology, 54, 75-
83. 
Heen, K., Monahan, R.L. and Utter, 
F., 1993. Salmon aquaculture. 
Fishing News Books. 278P.  
Kimmo, A.M., Pentinen, O.P. and 
Jussi, V.K., 2004. Pentachlorophenol 
bioaccumulation and effect on heat 
production on salmon eggs at 
different stages of development. 
Aquatic Toxicology, 68,75-85. 
Malekniya, N. and Shahbazi, P., 1996. 
General biochemistry. Tehran 
University Publication. Tehran, pp. 
87-104. 
Ogino, C. and Yang, G.Y., 1980. 
Requirement of rainbow trout for 
dietary zinc. Bulletin of the 
Japanese Society of Scientific 
Fisheries, 44, 1015-1018. 
Olsson, P.E., 1998. Disorders 
associated with heavy metal 
pollution in fish disease and 
disorders.  Vol. 12. Noninfectious 
disorders. Neatherland 
J.F.WOO.P.T.K.(Eds). CAB 
International Publishing, Oxford, 
England. 386P. 
Rogers, J.T. and Richards, J.G., 2003. 
Ion regulatory distruption as the 
acute toxic mechanism for rainbow 
trout. Aquatic Toxicology, 64, 215–
234. 
Salek Yousefi, M., 2000. Feeding of 
farming aquatics (coldwater, warm 
water and shrimp), Cultural Institute 
of Alani Publications, Tehran, 
318P. 
Sing, S.M. and Ferns, P.N., 1978. 
Accumulation of heavy metals in 
rainbow trout Salmo gairdneri on a 
diet containing activated sewage 
sludge. Journal of Fish Biology, 13, 
277–86. 
Stranah, I. and Andreji, J., 1998. 
Levels of cobalt, nickel, copper and 
manganese in fish the  Danub River. 
Slovak. 66P. 
Tacon, A.G.J., 1990. Standard methods 
for the nutrition and feeding of 
farmed fish and shrimp. Argent 
Laboratories Press. pp. 4-24. 
Van Duijn, J.R.C., 2000. Diseases of 
fishes. Narendra Publishing House. 
Delhi, India. 174P. 
Wiehlloughby, S., 1990. Salmonid 
farming. Fishing News Books. 
329P. 
Yamamoto, H., Satoh, S., Takeuchi, T. 
and Watanabe, T., 1983. Effect on 
rainbow trout of   manganese or 
trace element from fish meal diet. 
Bulletin of the Japanese Society of          
Scientific Fisheries, 49, 287 – 293.  
 


Short communication: A comparative study on manganese accumulation in liver, kidney, fatty tissues including muscle of rainbow trout (Oncorhynchus mykiss) fed with different levels of manganese in the diet

http://aquaticcommons.org/22795/1/IFRO-v14n2p523-en.pdf

Short communication: A comparative study on manganese accumulation in liver, kidney, fatty tissues including muscle of rainbow trout (Oncorhynchus mykiss) fed with different levels of manganese in the diet

Abstract

Similar works

Full text

Available Versions

Aquatic Commons