Ascorbic acid ( Vitamin C ) is an of import food in fish diets and particularly in freshwater fish. In fishes does non happen the biogenesis of Vitamin C hence must be supplied in the nutrient. The fish demands are about 200 mg/kg nutrient but these are related to many factors like influence of emphasis, the growing rate, the size of the fish, temperature of H2O and to the other foods presented in the diet. The measure of vitamin C in the diet is besides related with the presence of diseases in the fish works. The active signifier is ascorbic acid and the inactive dehydroascorbic acid is white crystalline compounds. Besides, a chemically synthesized signifier, L-ascorbate-2-phosphate is readily used by fish as a vitamin C beginning. Cabbage, Citrus fruits, liver, kidneyand largely in glandular tissues there are good beginnings of the vitamin. Besides fish nutrient made from whole fish has good measures of this vitamin. When this food is supplied in the fish repast the nutrient must be protected from aerophilic oxidization which turns ascorbic acid in its inactive signifier. The most of import marks of the lack of vitamin C are anorexia, decrease of growing, reduced bone collagen, hollow-back, scoliosis, haemorrhagies in the fives and in the internal variety meats, jobs in the gill fibrils, eroding of the fives, and increased mortality. Sing the interactions with other foods the vitamin C demand is increased when diets are lacking with tryptophan. Besides this vitamin is really instable to oxidization in presence of elements like Cooper or Fe because addition oxidization and inactive ascorbic acid into dehydroascorbic acid.
Cardinal words: Ascorbic acid, demands, lack.
( Ascorbic acid ) Vitamin degree Celsius can be synthesized by most animate beings in measures sufficient to prolong normal maps of life, but most fishes this phenomenon is non seen because they lack the enzyme L-gloconolactone oxidase that synthesizes vitamin C from glucose ( Darias et al 2011 ) . Therefore, for the above ground vitamin C is indispensable and should decidedly take it with nutrient. Fishs are freshly added to the group of animate beings ( after worlds and birds ) that require vitamin C from the diet ( Dabravski et al 2001 ) . This is because aquaculture is a comparatively new scientific discipline developed largely these last two decennaries ( De Silva, 2001 ) and research in fish eating is besides new. Kitamura et Al. ( 1965 ) were the first to explicate a critical demand for ascorbic acid in trout and four old ages subsequently Halver ( 1969 ) demonstrated the demand for vitamin C in salmon. Subsequently in 2001 Dabrowski prepared a full reappraisal for vitamin C in his book “ Ascorbic acid in aquatic animate beings ” .
Chemical signifiers and its parallels
Vitamin C exists in two signifiers, the decreased signifier ( ascorbic acid ) and the oxidised signifier ( dehydroascorbic acid ) ( Figure 1 ) . Both have vitamin C activity but the 1 that predominates is the decreased signifier. This is called the active signifier of the compound. Besides, both signifiers are frequently reversed. The active signifier ( ascorbic acid ) is a white, crystalline and odorless compound which is soluble in H2O and indissoluble in fat. This decreased signifier is stable in acids but really unstable in alkalic solutions which make the compound to lose its activity. Besides, its activity can be damaged if vitamin C is in contact with the heat and atmospheric oxidization. One derivate like L-ascorbate-2-sulfate ( vitamin C2S ) , is heat immune and can be stored in the tissues of salmonids if they are treated with extra dietary of vitamin C ( Halver, 1985 ) . This immune signifier is besides found in Artemia cysts and in many other animate beings ( when it is in the signifier of sulphate ) ( Tucker and Halver, 1984 ) . Another vitamin C beginnings compound that feed industry industry is interested are synthetized derived functions with other electron-dense groups coupled on the 2-position of ascorbic acid ( Halver 2002 ) .
Figure 1. Two signifiers of the vitamin C ; L-ascorbic acid ( left ) and dehydroascorbic acid ( right ) . ( modified from Halver ( 2002 )
Rainbow trout ( Oncorhynchus mykiss ) is one of the most studied species of fishes associated with demands for vitamin C. It is noted that an sum of 100mg/kg dry weight of ration would be plenty for trout. In trout with muscular hurt should be given five times the normal dosage of 500 mg/kg dry ration to get by with this state of affairs. Besides a high degree of Vitamin C is added in the ration would do the rainbow trout to face with an infective disease ( Halver 2002 ) . Navarre and Halver ( 1989 ) showed that if the trout injected with Vibrio anguillarum they were immune to the agent with an extra dosage of vitamin C in the ration. The same can be said for viral diseases to trout if in ration was added an surplus of ascorbate-2-phosphate ( Anggawati-Satyabudhy et al. 1989 ) . However, Halver ( 2002 ) states that a dosage of 200 mg/kg of dry ration would be sufficient in the instance of rainbow trout. Sing the common carp ( Cyprinus carpio ) Ikeda and Sato ( 1964 ) stress that an grownup person can synthesise little sums of vitamin C, but this is related to the size of the fish. For bigger fishes was expected higher vitamin C synthetization.
Tab. 1. Vitamin C demands for different fish species in flesh outing stage of growing. Requirements are expresed as milligram of L-ascorbic acid per kilogram dry diet. WG – weight addition ; ADS – absence of lack marks ; FCR – upper limit provender transition ratio ; S – increased endurance
Rainbow trout ( Oncorhynchus mykiss )
Atlantic salmon ( Salmo salar )
Lall et Al. 1989
Yellowtail ( Seriola dumerili )
Turbot ( Psetta upper limit )
Merchie et Al. 1996
European sea bass ( Dicentrarchus labrax )
Merchie et Al. 1996
Gilthead sea bream ( Sparus aurata )
( see r. trout )
Nile Tilapia ( Oreochromis niloticus )
WG, ADS, FCR, S
Soliman et Al. 1994
Common carp ( Cyprinus carpio )
Grey mullet ( Mugil cephalus )
El – Dahhar, 2006
Oscar ( Astronotus ocellatus )
Frasalossi et Al. 1998
Kuruma runt ( Marsupenaeus japonicus )
Shigueno and Itoh 1988
Goldfish ( Carassius auratus )
James and Vasudhevan
Channel Catfish ( Ictalurus punctatus )
Lim and Lowell 1978
Guppy ( Poencilia reticulata )
WG, ADS, FCR, S
Mehrad and Sudagar 2010
Cobia ( Rachycentron canadum )
96.6 – 386.5
Zhou et Al 2012
For the Atlantic salmon ( Salmo salar ) the demands for H2O soluble vitamins are lower than those referred in old plants. To acquire a liver storage and a good enzymatic activity should increase vitamin C dose beyond the degrees we give to merely increase the weight. There is grounds in research lab that the addition in diet of vitamin C has a positive consequence on opposition to disease and a better unsusceptibility response. Ascorbic acerb protects phagocytic cells and besides defends tissues from oxidization ( Gatlin, 2002 ) .
Sing gilthead sea bream ( Sparus aurata ) , there is no quantitative informations on demands for vitamin C. If seabream ration consists on fishmeal, there is non necessary any addendum of vitamin C that affect on growing public presentation ( Henrique et al. , 1998 ) , but auxiliary degrees are recommended for holding opposition to emphasize, nephritic map and wound-healing ( Alexis, Karanikolas and Richards, 1997 ; Henrique et al. , 1998 ) . Harmonizing to NRC ( 1993 ) the recommendations for salmonids may be applied to sea bream excessively. Woodward ( 1994 ) , suggest that that, without specific informations, the vitamin demands established for salmonids can be applied to other teleost.
Besides the information for vitamin demands for European sea bass ( Dicentrarchus labrax ) are highly scarce. There are studies that sea bass demands for vitamin C are below 50mg/kg dry diet. For persons in flesh outing these demands are reduced to less than 10 mg/kg, but to hold a sufficient content in the liver the diet must hold higher measures than that ( Fournier et al. 2000 ) . Kaushik et Al. ( 1998 ) suggest that the vitamin C demands for the sea bass like for sea bream would mention to the demands of rainbow trout.
For the on turning grey mullet ( Mugil cephalus ) El-Dahhar ( 2006 ) applied one experiment with different degrees of ascorbic acid in the diet and concluded that dietetic demands for the best growing, endurance and feed use of this species was 40-mg/kg dry diet. While, at intercrossed Tilapia ( Oreochromis niloticus x Oreochromis aureus ) higher degrees of vitamin C in the diet can save the add-on of vitamin E.
Problems of lack
When the fish has a diet deficient in vitamin C, by and large discernible marks associated with faulty collagen formation. Therefore, was observed hyperplasia of collagen and gristle tissue, humpback, scoliosis, hollow-back, resorbed opercula, malformations and hyperplasia of jaw hapless regeneration of the lesions, ( Halver et al. , 1969 ) . Different writers observed the same marks in different fish species like ; rainbow trout ( Falahatkar et al 2011 ) , Atlantic salmon ( Halver 2002 ) , yellowtail ( Kanazawa et al 1992 ) , zebra danio ( Newsome and Piron 2006 ) , common carp ( Dabrowski et al.,1989 ) , Tilapia ( Stickney et al 2009 ) , gilthead sea bream ( Alexis et al 1997 ) Atlantic halibut ( Lewis mcCrea and Lall 2010 ) , Rachycentron canadum ( Zhou et al 2012 ) .
Dabrowski et Al. ( 1995 ) observed ascorbic acerb lacks related with generative maps in in Tilapia, rainbow trout, pod and xanthous perch. These lacks were observed during whole vitelogenesis, but embryologic viability was observed merely in rainbow trout and Tilapia. Besides, was detected a lessening of rainbow trout fruitfulness and egg production. In a parallel survey by the same writer was observed that diets with lacking vitamin C had a decrease of yolk in the eggs of rainbow trout.
In Tilapia ( Tilapia aurea ) feeding with a diet with lower than 25mg/kg vitamin C were observed pathological alterations like scoliosis hemorragies in the oral cavity, fives and swim vesica ( Stickney et al 2009 ) . For discus fish ( symphysodon spp. ) for many old ages the vitamin degree Celsius lack was related with the cause of the parasitic disease hole in caput. This guess led to the fact that adding vitamin degree Celsius in the fish diet the disease desapeared. In fact, subsequently was seen that hole in caput was non related to vitamin C, but its consequence mending lesions caused the healing of the lesions of the Hole in caput ( Lowel 1989 ) . In grey mullet degrees of vitamin C which accumulates in liver, gill and encephalon may be depleted significantly if the fish is exposed to Cd ( Thomas et al 2006 ) .
Feeding the Walleyes Stizostedion vitreum with a vitamin C – free diet caused high mortality rate and retarded growing for the remainder of the group. Besides were presented the classical marks of vitamin C lack explained above for other fish species ( Macconnell and Barrows 1993 ) . While in vitamin C free-diets was observed increased mortality, retarded growing and bad provender transition rate for juvenile loanblend striped bass ( Sealey and Gatlin 2002 ) .
In Atlantic halibut ( Hippoglossus Hippoglossus ) the most presented marks of vitamin C lack were scoliosis and hollow-back largely in the haemal part of the vertebras. These experimental findings were similar with marks found in commercial halibut hatcheries ( Lewis-McCrea and Lall 2010 ) .
Interaction with other foods
D-ascorbic acid, 6-deoxy-L-ascorbic acid and L-glucoascorbic acid are isomers of the active signifier ( ascorbic acid ) , but have really low or no activity. Because of their close similarity these compounds compete with the active signifier for the sites of different enzymes and chemical reactions in being ( Halver 2002 ) .
Lim et Al ( 2000 ) investigated the interaction between vitamin C and Fe if they are supplemented in the diet of mudcat ( Ictalurus punctatus ) . If the vitamin C was supplemented in high doses ( 3000 mg/kg ) there was a important consequence on endurance. Besides there are studies that mention the of import function of the combination of vitamins D and C ossification procedure in fishes and in formation of skeletal distortions ( Darias et al 2011 ) . There is besides an interaction between ascorbic acid and T4 which was investigated in fresh water mudcat, ( Heteropneustes fossilis ) . If the fish is exposed to the organophosphate pesticide chlorpyrifos, the activity of different enzymes is reduced drastically. When the combination of tetraiodothyronine ( T4 ) and vitamin C was administered to the fish, the activities of enzymes returns in the degrees of control ( Tripathi and Shasmal 2010 ) .
Another interaction between vitamins C and E is reported in Atlantic salmon from Hamre et Al. ( 1997 ) . From the consequences of the survey these writers says that diets with vitamins C and E have two different mechanisms of interaction: a interactive consequence against oxidization on H2O and lipid stages and a regeneration consequence of vitamin E from its extremist by ascorbic acid. For a interactive consequence in the interaction between vitamins C and E was besides reported in immune system of gilthead sea bream by Ortuno et Al ( 2001 ) . Harmonizing to the consequences of the survey both vitamins produced a interactive consequence on the respiratory explosion activity of the scavenger cells of the fish. The same combination of vitamins C and E in the diet increased growing rate, and seeds quality in xanthous perch, ( Perca flavescens ) ( Jun Lee and Dabrowski 2004 ) . Meanwhile, Frischknecht et Al ( 2006 ) reports that there is a correlativity between vitamins C and E, but need to work more on mechanisms of these interactions.
There are studies for effects of interaction of vitamins C and E besides on generative public presentation of different fishes. Therefore, the add-on of vitamins C and E by injection effects on reproduction of the Nipponese eel ( Anguilla japonica ) ( Furuita et al 2009 ) . After the injection the hatchling rate and the survival rate of larvae increased. Besides increased the accretion of vitamin in broodstock and eggs. In a recent survey Nguyen et Al ( 2012 ) showed another consequence of combination between vitamins C and E on generative public presentation, of kuruma runt ( Marsupenaeus japonicas ) . These writers suggest that the diet of kuruma runt must incorporate the addendum of vitamins C and E in because their combination gives better egg hatchability and better quality of larvae.
The vitamin C is an indispensable food in fishes and therefore must be supplied in the diet.