Download 3. literature review

3. LITERATURE REVIEW
Aquarium fishes are rapidly gaining importance due to their immense
commercial value in the export trade, the world over. The demand for good quality
tropical fishes exceeds the supply. There is immense scope for the production of
ornamental fishes. Many studies have well documented the effects of nutrition on
growth in edible fishes (Brett, 1974; Ballestrazzi et al., 1994; Sampath, 1985;
Degani et al., 1985; Nandeesha et al., 1988; James et al., 1993; Khan and Jafri, 1994;
Kelly – Scott et al., 1999; Saroka et al., 2004); but less attention has been paid to
ornamental fishes (Degani and Gur, 1992; Lochmann and Phillips, 1994; Degani and
Yehuda, 1996; James and Sampath, 2002, 2003a).
Generally, fish is a predominant planktonic feeder and when natural
feed is not available in rearing ponds, it is essential to provide supplementary feed. In
India, several fish farms manufacture commercial fish feeds for cultivable fishes
based on the dietary nutritional requirements and feeding behaviour (Rao, 1987;
Seenappa, 1992; Seenappa and Devaraj, 1995). Considerable attention has been given
on the influence of protein levels on growth rate in cultivable fishes (Degani et al.,
1985; Chuapoehuk, 1987; Santiago and Reyes, 1991; Seenappa and Devaraj, 1995).
Machiels and Henken (1985) found that protein requirement of the African catfish
Clarias gairepinus for maximum growth was at 40% protein and this level was high
compared with other species (NRC, 1973). Degani et al. (1989) reported that Clarias
gairepinus showed the highest growth at 40% protein level and the growth rate
declined with decreasing level of protein content (35 and 30%). Juveniles of Asian
seabass, Lates calcarifer fed with diet containing 50% protein and 15% lipid showed
the highest weight gain and specific growth rate (SGR). Lates calcarifer consuming
35% protein and 5% lipid produced the lowest growth rate and showed abnormal
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reddening of fins, indicating deficiency of essential fatty acids (Catacutan and Coloso,
1995). Fry of Salmo trutta fed with 57% protein showed better growth rate than those
fed with 53% protein diet (Arzel et al., 1995).
Ramnarine (1995) reported that the highest growth occurred when
armoured catfish, Hoplosternum littorale was offered with 35% protein diet than
those fed with 25 and 45% protein diets. Khan and Jafri (1994) observed a positive
relationship between the amount of dietary level (upto 35%) and retention of protein
in muscles. Similar changes were observed in RNA concentration and RNA : DNA
ratio in the catfish, Clarias batrachus. Weight gain and specific growth rate of
Heterobranchus bidorsalis fingerlings increased with the increase in dietary protein
level from 25 to 45% but the difference (P>0.05) was not significant between 40 and
45% protein treatments and it suggests that 40% protein was the optimal dietary
protein for H. bidorsalis (Fagbenro et al., 1992). Santiago et al., (1985) found that
Oreochromis niloticus fed with 40% crude protein produced the highest number of fry
and more body weight gain than those fed with 20% protein diet. These observations
were close to the 50% protein requirement of red swordtail.
Many authors have studied the influence of adding new nonconventional ingredients like poultry offal meal, silkworm pupae etc. in the place of
fish meal (Hasan et al., 1988; Hasan, 1991). Sethuramalingam and Haniffa (2002)
observed the substitution of prawn head waste, chicken intestine waste, banana
flower, cauliflower waste and ground nut leaf in the place of fish meal and studied
their effects on feed consumption, growth and digestive enzymes in Labeo rohita.
Recently, protein rich feed formulation enhanced the production cost
of fishes and hence it is essential that alternative protein source has to be found for
use in compounded aqua feeds. In this regard, single cell protein holds promise as
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possible substitute for fish meal because of the possibility of genetically modifying
their nutrient profile within limits to approximate the dietary needs of the cultured
species. Algae are receiving increasing attention as a possible protein source for fish
diets, particularly in tropical developing countries, because of their high protein
content and production rate (Venkataraman et al., 1980). Feeding behaviour studies
have shown that many fish, including carnivorous fish ingest algae as a food source.
Thus, the use of algae as a feed additive might help in effective utilization of artificial
diets in cultured fish (Mustafa and Nakagawa, 1995). Spirulina showed that it
improved carcass quality (Liao et al., 1990), growth (Mustafa et al., 1994a) and
sexual maturity (Braun, 1988) in cultivable fishes. However, studies in relation to
impacts of Spirulina on ornamental fishes received sparse attention (Scaria et al.,
2000; James et al., 2006). Detailed and long term studies on assessing the pattern of
growth rate in different stages like juvenile, sexually mature and reproductive stages
and on reproductive potential are lacking. The optimum level of Spirulina may vary
according to its source and target species. There is a need to determine the optimum
level of Spirulina for commercially important ornamental fishes.
The nutritional requirements for the ornamental fishes have been
reported by Swain (1999). Live bearing species of the family Poeciliidae such as
guppies
(Poecilia
reticulata),
platies
(Xiphophorus
maculatus),
swordtail
(Xiphophorus helleri) and molly (Poecilia latipinna and P. sphenops) are popular
ornamental fishes produced in many Asian countries (Chong et al., 2004). The live
bearing fishes breed easily in captivity (Ling et al., 2006) and in view of this farmers
do not pay much attention to provide the fish with nutritionally balanced feed. Owing
to the use of unbalanced feed in guppy farming, problems relating to small brood size,
deformed fry and low survival have been reported by farmers. Madrones et al. (2002)
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observed that immature and broodstock, Placeina placenta (Linnaeus) when fed
microalgae diets (Isochrysis galbana and Tetraselmis tetrahele) attained sexual
maturity and gonad index in short period.
Brood stock nutrition is an important factor governing egg production
and larval survival (Izquierdo et al., 2001). An improvement in broodstock nutrition
and feeding has been shown to improve not only egg quality but also enhance seed
production. Gonadal development and fecundity were affected by certain essential
nutrients (Izquierdo et al., 2001). Dietary protein and lipid play major roles in growth
and reproductive performance (Watanabe, et al., 1984; Watanabe and Kiron, 1995;
Furuita et al., 2002). Ling et al. (2006) proposed the dietary protein and lipid
requirements for optimized growth and reproductive performance of female
swordtails to be at 30% and 42% respectively. Chong et al. (2004) found that a
minimum 30% protein should be included in the diet on female swordtail broodstock.
Dahlgren (1980) conducted an experiment on three types of feed with different
protein levels and recorded higher growth and reproductive performance in the fishes
fed 35% to 47% protein levels. Protein and lipid levels of broodstock diet have been
identified as major dietary factors that determine successful reproduction and survival
of offspring (Jobling, 1998; James and Sampath, 2004a, c). Shim and Chua (1986)
found that the diets with 30 to 40% protein appeared to be the best for gonadal
development.
Spirulina, a freshwater microalgae of the class Cyanophyceae, is a
good source of protein, energy and vitamin supplement to aquaculture diets (Habib et
al., 2008). Nandeesha et al. (1993) reported that Spirulina was valuable feed
supplement for Cyprinus carpio. Several studies have been conducted using dried
Spirulina as a feed supplement (Chow and Woo, 1990; Watanabe et al., 1990). In
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striped jack, Watanabe et al. (1990) observed a significantly lower lipid level in the
dorsal muscle, viscera and liver of fish fed 10% Spirulina diet compared to those in
the control diet. They also found lower level of triglycerides in the dorsal muscle and
liver of fish with 10% Spirulina in the diet. Mustafa et al. (1994b) studied the effect
of a diet supplemented with 2% Spirulina on red sea bream and found that the lipid
content was significantly reduced in fish fed the Spirulina diet compared to those in
the control diet.
Nutrient requirements of all animals vary in their life cycle. The
changes that occur in the morphology and physiology of aquatic animals between
hatching and maturity lead to a number of important variations in feeding and
nutritional requirements through the larval, fingerling and adult stages. These
variations occur in the morphology of the digestive organs, the digestive process and
the feeding behaviour (Silva and Anderson, 1995).
Color is one of the major factors, which determines the price of
aquarium fish in the world market (Saxena, 1994). Ornamental fishes are acceptable
to consumers if they have striking and vibrant colors. Fish are capable of producing
some pigments. Since fish, like other animals are unable to synthesize carotenoids de
novo (Goodwin, 1984). However, dietary sources of pigments also play a role in
determining some pigments. The carotenoid pigmentation of fish results from the
pigment present in the diet (Hata and Hata, 1973). Skin color is highly dependent on
the carotenoids presents in the diets of most fish. Hence, a direct relationship between
dietary carotenoids and pigmentation exists in them (Halten et al., 1997). Color
enhancing diets may contain additional natural pigments to enhance colors of
ornamental fish. People involved in the trade of ornamental fish are constantly
exploring methods of enhancing skin coloration. Many studies have proved that the
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fish can be pigmented by supplementation of plants sources (Ibrahim et al., 1984;
Boonyaratpalin and Phromkunthong, 1986; Ahilan and Prince Jeyaseelan, 2001;
Kowsalya et al., 2001). Ahilan et al. (2008) investigated that effect of three plant
additives (coriander, mint and amaranth leaves) on growth and body coloration in
gold fish.
Color enhancement through the use of carotenoids in feed has been
confirmed by the previous authors (Kiessling et al., 2003; Alagappan et al., 2004).
Baron et al. (2008) studied that effect of dietary pigments on the coloration and
behaviour of flame red dwarf gourami (Colisa lalia) and addition of synthetic
astaxanthin significantly increased red coloration in males. Sinha and Asimi (2007)
reported that the China rose (Hebiscus rosasinensis) petal is a potent natural
carotenoid source for gold fish (Carassius auratus) to enhance its color. Ezhil et al.
(2008) reported encouraging results on coloration of red swordtails (Xiphophorus
helleri) fed diet containing marigold petal meal. They also found that the dietary
marigold powder accelerated gonadal development (Sinha and Asimi, 2007) in
ornamental fish. Scanning the literature revealed that rare studies are available on the
timing and duration of feeding astaxanthin on the efficiency of pigmentation in
rainbow trout, Oncorhnchus mykiss (Nickell and Bromage, 1998). However such
studies has not been investigated in ornamental fishes. The present study is designed
to examine the effects of timing and duration of Spirulina supplementation on growth,
color retension and fecundity in X. helleri.
Growth is a complex process that represents the outcome of
interactions among abiotic and biotic factors operating a behavioural and
physiological processes (Weatherly and Gill, 1987; Jobling, 1994). Food consumption
is a major limiting biotic factor affecting growth rate in fishes (Brett, 1974) and
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information on the relationship between food consumption and growth is a necessary
foundation for the development of pisciculture. Different physiological activities are
influenced by the amount of food consumed (i.e. feeding rates or ration size) were
studied by many workers (Beamish, 1972; Ponniah and Pandian, 1977; Kelly – Scott
et al., 1999).
Several authors have studied the effects of varying ration size on
growth, food consumption, conversion efficiency and body composition of many
species (Arunachalam and Ravichandra Reddy, 1981; Das and Ray, 1989; Cui et al.,
1994 and Fontaine et al., 1997).
Most of the workers fixed the ration size based on percentage of the
live body weight per day (Arunachalam and Ravichandra Reddy, 1981; Hung et al.,
1995; Fontaine et al., 1997) or on dry weight of fish (Wurtsbaugh and Davis, 1977).
Elliott (1976) argued strongly that ration should be expressed as a percentage of
maximum ration instead of percentage of body weight. Therefore, in the present
study, ration size was fixed based on ad libitum feeding following Andrews (1979).
Elliott (1975a, b) studied the growth rate of brown trout fed on
maximum rations and reduced rations separately. Ali et al. (1998) who attempted to
find out the effect of random fluctuations in daily ration on growth rate of juvenile
three spined stickleback concluded that fish can buffer the effect of random variations
in daily food supply effectively and attain the same growth performances as fish on
constant rations.
Knowledge on the optimum ration of fish is important since feeding at
this rate provides maximum conversion efficiency per unit feed cost. Estimations of
optimal ration can be based on the theoretical considerations of growth and feed
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conversion (Smith, 1973) or on individual determinations of feed intake. Many
experimental studies have shown that food intake and conversion efficiency strongly
depend on many extrinsic and intrinsic factors; water temperature and fish size are the
main factors that determine the nutritional requirements (Brett and Groves, 1979).
Effect of ration size and temperature on oxygen consumption and pattern of nitrogen
excretion in sockeye salmon was studied by Brett and Zala (1975) whereas their effect
on gastric evacuation in plaice was attempted by Jobling and Davies (1979).
Elliott (1976), Cui and Wootton (1988) and Xie and Sun (1992)
studied the interrelated effects of ration size, temperature and body size on food
consumption, growth, digestibility, gastric evacuation, nitrogen excretion and body
composition. However, there is paucity of information on the effect of ration on
growth and reproduction in ornamental fishes (Nagarajan et al., 2009). There is a need
to determine the optimum level of ration size on growth, gonad weight and
reproductive potential as a function of body weight / life stage in ornamental fishes.
Understanding the physiology of any organisms is very essential for
successful culture. Metabolic studies give an idea about the general physiology.
Oxygen consumption is a broad index of metabolism of the animal (Prosser and
Brown, 1965). Most of the studies on metabolism estimated through oxygen
consumption are pertaining to aquatic fishes. Oxygen consumption of organisms is
affected by various factors both intrinsic and extrinsic. Body size is one of the
important intrinsic factors. Physiological activities are also influenced by the amount
of food consumed (Ponnaiah and Pandian, 1977) which inturn depends on quality of
food. The respiratory quotient, the ratio between the volume of carbondioxide
released to the volume of oxygen consumed varies according to the composition of
diet (Prosser and Brown, 1965). In general, protein is required by fish in large amount
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and the requirement changes in relation to the stage of fish which inturn reflects on
oxygen consumption.
Scanning the literature makes it clear that most of the works on the
oxygen consumption in cultivable fishes (Hughes and Singh, 1970a and b; Johansen,
1970). Impact of protein rich diet Spirulina on ornamental fishes are restricted and
such studies are necessary to understand the influence of Spirulina diets on oxygen
consumption. Studies on determination of optimum level of Spirulina diet on
metabolic estimates are wanted in ornamental fishes and such studies would greatly
help to the culture of ornamental fishes.
The form of nitrogen waste produced by protein catabolism. In general,
the correlation between kind of excretory product and availability of water is so good
that nitrogen excretion appears to be an important character. Nitrogen excretion is a
labile character, and the excretory pattern may change with stage in the life cycle,
body weight, availability of water, nutrition, and other influences. Nitrogen excretion
in individual animals is also modifiable with diet and osmotic stress (Prosser and
Brown, 1965).
Previous studies were done on the effects of body size (Jobling, 1981),
stocking density (Sampath, 1985) and density and water change (Sampath and
Pandian, 1984) on ammonia excretion in cultivable fishes. The depletion of dissolved
oxygen and accumulation of ammonia and other toxic products of metabolism are the
major two constraints in high density fish culture (Sampath, 1985). However, there is
paucity of information in ornamental fishes (James and Sampath, 2006). A detailed
study of Spirulina diets on metabolic and excretory rates and proximate composition
in ornamental fishes are lacking and such studies are necessary to understand the
influence of Spirulina diets on the above physiological and biochemical parameters.
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