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Figure 1A. Female genital papilla |
Figure 1B. Male genital papilla |
| Livestock Research for Rural Development 23 (11) 2011 | Guide for preparation of papers | LRRD Newsletter | Citation of this paper |
The present study investigated the breeding and feeding performance of goldfish, Carassiusauratus in the subtropical region of Haryana in the laboratory conditions. Male goldfish were divided into three different size classes i.e. small, medium and large, for the study of courtship behaviour. Results from the study of courtship behaviour revealed that large sized males showed highest frequency of courtship behaviour such as nipping and pushing. Female showed preference for large sized males as observed by the association time female spent in the vicinity of differently sized males. The study further investigated the effects of different broodstock sex ratios on seed output, fertilization percentage and hatching success of goldfish in the aquarium. Three different broodstock sex ratios i.e. 1:1, 1: 2 and 1: 3 (male ♂: female ♀) in the goldfish were tested.
Highest fecundity was found in the sex ratio of 1 female: 3 male followed by the 1:2 and 1:1. Under the conditions tested in this study, fry production of goldfish was affected by different broodstock sex ratios and was highest at the sex ratio 1:3 (female: male).Incubation period was found to be irrespective of different sex ratios. Fry produced from the above breeding experiments were further used in a feeding experiment. Effect of three different types of feed i.e. pelleted, live and mixed was studied for the growth performance of fry. The results showed that the growth of fry considerably enhanced in the group fed with mixed feed compared to pelleted and live feed. Mean body weight and specific growth rate was higher in fish that consumed the mixed diet than in those that consumed the other types of feed. Pelleted feed produced the lowest weight gain and specific growth rate. Temperature and other water quality parameters were maintained in optimum range.
Key words: breeding, Carassius auratus, courtship behaviour, feeding, feed, growth, sex ratio
India is the third largest producer of fish in the world and the fishery sector is a major foreign exchange earner. Besides providing affordable nutrition to the rural people, fish simultaneously guarantees the livelihood of millionsof people in the country. Ornamental fish breeding is an emerging sector and can be a world-scale opportunity area for fish farmers in India. The ornamental fish trade earns foreign exchange, besides serving as a source of employment to rural population. It has a significant role in the economy on country and state level (Ahilanet al 2010). Most of the commercially important and commonly available varieties of ornamental fish belong to the family Cyprinidae, Anabantidae, Characidae, Poecilidae and Cichlidae. On the basis of the breeding behaviour ornamental fishes may be categorised in two groups, live bearer and egg layer (Thakur 2004). Among the egg layers one of the most popular ornamental fish suitable for the commercial production in ponds and also in the aquariums is goldfish, Carassiusauratuswhichis a domesticated variety of the common carp, Cyprinuscarpio(Family- cyprinidae).Goldfish spawns easily in captivity, uses wide variety of natural foods as well as formulated feeds, can tolerate poor water quality and grows rapidly at warm temperatures. It is because of these attributes, that goldfish is used in the laboratories where it readily matures and spawns and its reproductive endocrinology and behaviour have been intensively studied (Van Der Kraaket al 1998., Kobayashi et al 2002., Stacey 2003), often as a model for the edible carps (Sokolowskaet al1984).
Success of any culture depends on the assured seed supply which depends on the suitable breeding techniques and brood stock health. Reproductive behaviour in the fishes varies from species to species. Methods of breeding ornamental fish also vary from species to species depending upon their natural breeding pattern. For successful breeding it is a prerequisite to understand the entire behavioural cycle of fish which includes courtship pattern and fertilization method. Reproduction is the basic phenomenon required for the continued existence of living organisms. It has been shown that reproductive success in fish species is influenced by many factors such as the broodstock, sex ratio, stocking density, age, size, nutrition and feeding regime (Salama 1996., Chong et al 2004., Tahoun 2007.,Hammoudaet al 2008 and Ibrahim et al 2008). The operational sex ratio (ratio of fertilizable females to sexually active males at a given time) is a principal factor influencing the intensity of sexual selection and it is a key factor affecting sexual competition and hence maximizing seed production.Broodstock productivity is the most significant constraint on commercial production of fish.
Increased knowledge of the factors regulating broodstock productivity is therefore of great importance to the further development of goldfish culture. In the present investigation courtship behaviour as influenced by the male size along with effect of different sex ratio on the breeding behaviour of goldfish was studied.
Although, breeding is the most important aspect for successful culture of animals, feeding is also essential for maintenance. Feeding constitutes a major factor as growth of fishes mainly depends upon quality of feed for achieving better growth and good survival rates. Research developments in larviculture and early rearing technology have allowed 90% of currently marketed freshwater ornamental fish to be cultured (Tlusty 2002).
Fish larvae are the smallest self-supporting vertebrates and in order to increase their chances of survival, they need to complete their morpho-functional systems to escape predation and to obtain food (Osseet al 1997). Transition from endogenous to exogenous feeding is one of the most critical stages in freshwater fish culture and the availability of suitable food is essential for a high rearing success on commercial scale (Gulbrandsen 1993 and Jähnichen and Kohlmann1999).
Hence, present study further investigated the effect of different feed types on the growth performance of fry. For the feeding practices workers have used formulated feeds or combinations of formulated feeds and live feeds in feeding trials with different species of fish larvae. In most studies, live foods (e.g., Artemia, rotifers, copepods) produced better results in terms of growth and survival than inert diets. However, in some studies mixed feed promotes better growth performance (James and Sampath2004.,KumarguruVasagamet al 2007). In the present work three different types of feed used were pelleted, live and mixed feed.
The aim of the present work therefore was to investigate the effects of broodstock sex ratio on the reproductive performance of goldfish and to study the growth performance of fry fed with different feed types. These aspects may be of great help to the farming community venturing into the breeding and culture of ornamental fish species. Management strategies for breeding and rearing of goldfish can be easily adopted by hatcheries to improve seed production.
The study was carried out in the Department of Zoology and Aquaculture in the CCS HAU, Hisar. Brood stock of goldfish was obtained from Sultan Singh fish farm, Nilokhedi, Karnal, Haryana. They were acclimated under laboratory conditions in the aquarium filled with chlorine free water. Aquatic vegetation (hydrilla) was introduced into the aquarium for hiding purpose and holding the adhesive eggs.
Male and female were selected by sexual dimorphism exhibited by goldfish during the breeding season. Female goldfish was easier to spot, as the belly of a mature female is plump and it has a protruding genital papilla (Fig. 1A). Male was found to be streamlined and having concave genital papilla. When males were ready for spawning they developed breeding tubercles on the head and pectoral fins (Fig. 1B). These breeding tubercles were used during breeding when the male nudged the female with its head and fins in order to stimulate female for spawning. Males were divided into three different size groups prior to experiment. Male and female were paired and were released into the aquarium (24x12x12) in five replicates. Brood fishes were fed with supplementary feed containing 40% protein and fedadlibitium.
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Figure 1A. Female genital papilla |
Figure 1B. Male genital papilla |
Length and weight of the male and female brood fish were taken before initiation of experiment. Males were separated into three distinct size classes (small, medium and large) and paired with female. Behaviour of both the male and female goldfish was keenly observed for courtship behaviour. Various courtship behaviour patterns like chasing, nipping and pushing were recorded for different size groups of male for half an hour on an average. Female association time in the vicinity of differently sized male was also recorded as female matechoicepreference. Male and female goldfish were grouped according to different sex ratios in the five replicates. Breeding performance of the goldfish as affected by the different sex ratio was recorded. Breeding performance was measured according to the following standard formulae:
(i) Fecundity = Total number of eggs
Total number of fertilized eggs
(ii) Total fertilized eggs (%) = –––––––––––––––––––––––––––––– x 100
Total number of eggs produced
Number of eggs hatched
(iii) Hatching (%) = –––––––––––––––––––––––––––– x 100
Total number of eggs produced
(iv) Incubation period = Time gap between fertilization of eggs and hatching.
Three types of feed i.e. pelleted feed, live feed and mixed feed were used for the study of growth performance of goldfish larvae. All treatments were set in five replicates and in each replication 20 fry were introduced. A comparison was made to assess the best growth among the three different feeding treatments. Pelleted feed was made with groundnut oil cake, rice bran, wheat flour and soybean. All the ingredients were ground and powdered prior to the preparation of feed. Wheat flour was used as binder to make the diets water stable and chromic oxide (Cr2O3) was added as an external digestibility marker. Nutrient and energy content of the various ingredients of pelleted feed is given in Table 1.Composition and proximate composition of pelleted feed is given in Table 2.
| Table 1. Ingredient content and compositions of various ingredients of pelleted feed. | |
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Ingredients |
Contents (g/kg dry weight) |
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Groundnut oil cake (GNOC) |
58.00 |
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Rice Bran (RB) |
0.75 |
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Wheat Flour (WF) |
0.75 |
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Processed soybean (HPS) |
38.50 |
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Chromic oxide (Cr2O3) |
1.00 |
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Mineral Premix and Amino-acids (MPA) |
1.00 |
| Table 2. Proximate Composition of pelleted feed | |
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Proximate composition % |
Pelleted feed |
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Crude protein (%) |
45.50 |
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Crude Fat (%) |
12.00 |
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Crude Fiber (%) |
5.00 |
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Total Ash (%) |
7.15 |
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Nitrogen free extract (NFE) (%) |
30.35 |
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Gross energy kJg-1 |
20.40 |
Live feed was given in the form of live zooplankton of various types. Zooplanktons were cultured in FRP (Fibre reinforced plastic) tanks in screen house of Department of Zoology and Aquaculture using cattle manure, mustard oil cake and poultry manure in ratio of 1:1:1. After 10 days of inoculation of zooplanktons from the fish pond the population of the zooplankton increased and this zooplankton was used for feeding the fry. For mixed feeding pelleted feed and live zooplankton both were fed to the fry in the ratio 50:50.
Daily observations were made on the survival and health. Fifty percent of water from the treated aquaria was renewed at a 15 days interval time and uneaten feed was removed daily from the aquarium to avoid fouling of the water. Dead fry were removed from the aquarium and a record was maintained for each aquarium. The growth performance parameters were calculated according to the following equations:
Live weight gain
Weight gain = W2 – W1
Specific growth rate (SGR)
In W2 – ln W1
SGR = –––––––––––– × 100
t
Where,
W1= Initial weight
W2= Final weight
t = Duration of experiment (No. of days)
Survival (%) = Final fish number/ initial fish number x 100
Water quality parameters were also analysed weekly following APHA (2005). For Statistical analysis all the data were subjected to one-way analysis of variance to determine significant differences between the treatments.
Courtship behaviour involves all the behavioural interaction between female and male which lead up before the fertilization. In the present study it was observed that courtship behaviour in goldfish started with the event of male chasing the female rapidly (Figure. 2A), often nudging her flanks with his snout and attempting to lead her to a spawning site. Male sometimes tried to attract the female by encircling the female in order to retain her in a given area. Due to the encircling by the male female could not avoid the male and male touched the vent of the female (Figure. 2B) and sometimes head of the female also (Figure. 2C). These patterns of chasing and nudging (touch and push) females by the male was found to be in agreement with DeFraipont and Sorensen (1993) and Kobayashi et al (2002).
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| Figure 2A. Male chasing the female | Figure 2B. Male hitting the vent of the female | Figure 2C. Male touching the head of the female |
During the present study courtship behaviour was recorded for different size categories ofmales i. e. small, medium and large from the standardised chasing, nipping and pushing frequency per trial of 30 minute observation period (Table 2). Results showed that large sized males exhibitsthe highest frequency of chasing which was found to be 23.4±0.60 minutes. Chasing, nipping and pushing frequencies followed similar trends, although the chasing frequency was significantlyhigher than the nipping and pushing frequency (Figure 3).
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Figure 3. Mean frequency of courtship behaviour by different size of male goldfish, C. auratus |
Figure 4. Association time (%) of female goldfish spentwith big, medium and small sized males |
Nipping and pushing frequency was 16±0.70 and 7±0.89 minutes respectively which was also highest for large sized males. However, for small sized males the frequency of chasing, nippingand pushing was lowest. Further in the goldfish for female mate choice association time was also taken as measurement and it was observed that female spent more time associating with large sized males followed by medium and least time in association with small sized males(Table 3). Female on an average spent 68% of the total observation time in association with large sized males, 36% in association with medium sized males and only 5% time in the vicinity of small sized males (Figure 4).
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Table 3: Physicochemical parameters of aquarium water during the breeding experiments |
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Sr. No. |
Parameters |
Range |
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1 |
Temp.(0C) |
23-28 |
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2 |
Dissolved oxygen (DO)(mg/l) |
6.0-6.8 |
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3 |
pH |
7.4-7.8 |
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4 |
Alkalinity (mg/l) |
227-245 |
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5 |
Total hardness (mg/l) |
189-195 |
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6 |
Free CO2 (ppm) |
1-1.5 |
Cyprinid fishes in general, exhibits some common patterns in their courtship and reproductive behaviour as reported by earlier studies on the reproductive behaviour of different members of family cyprinidae. Male goldfish exhibited swimming movements in pairs, circling and pushing the female on the abdomen during courtship as observed during the present study was also reported in Danioaequipinnatus (Vincent and Thomas 2008)and Puntiuschola (Kharbuliet al 2004, Turner 1993). However, temporal sequences of each behaviour pattern may vary widely in different genera and/or between species.
Breeding performance of goldfish at variable sex ratio of male and female were studied.Three different sex ratios taken in the present study were 1:1, 1:2 and 1:3 (female: male). The highest seed per female was significantly high (1004.60 ± 8.95)the third sex ratio (1 female: 3 males) followed by the second (1 female: 2 male) and the first sex ratio (406.20 ± 7.10) (sex ratio 1 female: 1 male), respectively.These results are supported by an earlier study carried out by Khalfalla et al (2008).
The difference in fertilization percentage between the different sex ratios was significant. Highest fertilization percentage was recorded in the sex ratio of 1female: 3 male (72%) followed by 1: 2 (64%) and lowest rate of fertlization (57%) in the 1:1.No significant differences were found in hatching percentage between sex ratio of 1:1 and 1:2. Results revealed that hatching percentage(81%) was also significantly high in the group having 1female: 3 male followed by 1:2 (74%) and 1:1 (71%) male to female ratio. Brood stock sex ratio did not affect survival rates significantly and the survival percentage ranged between 65-70 % for all treatments. The reason for the highest seed production at sex ratio of 1female: 3 male may be the higher number of males per female leads to the complete expulsion of the ova from the ovary of the female and hence maximum fertilization. Similar resultshave beenreported by earlier studies on the carps (Kobayashi et al2002 Jhaet al 2005, Haniffaet al 2007). Lowest fecundity, fertilization (%), and hatching (%) was found in the group with 1:1 (female: male). Incubation period ranged between 32-40 hrs for all the treatments irrespective of various sex ratios. These results are in agreement with studies in goldfish by Kobayashi et al 2002 and Jhaet al 2005.Survival percentage of hatchlings remained unaffected by the different sex ratios.
The present research work further carried out the rearing aspect of goldfish using different types of feed. Study was conducted to investigate the effect of three different feed types on the growth performance and survival of goldfish larvae Initial weight of the goldfish larvae for all the three treatment ranged between 0.15-0.17g. In the present study feeding experiment was for 60 days and final growth parameters were measured after 60 days of initial stocking. The final weight, weight gain and specific growth rate were significantly affected by different types of feed, with the highest values obtained in fry fed mixed feed.Larvae fed with mixed feed were show significantly higher growth of 1. 978±0.031g compared to fish fed either the live or pelleted feed (Figure 5). Survival was also significantly affected by feed. It was also higher in fish fed mixed feed and live feed than in those fed the pelleted feed. Fry fed with pelleted feed had significantly lowest final weight (1.005±0.18g) than those fed with the live and mixed diet. Specific growth rate was also highest in the group fed with mixed feed (Figure 6). Mixed feed promoted the growth of goldfish larvae and the best growth performance of larvae of goldfish obtained through early rearing with mixed and live feed as observed in the present investigation. It was found to be in agreement with the earlier studies on the goldfish conducted by the Kestemont (1995) and Krejszeff (2008) who achieved the best growth rate in intensively reared goldfish by feeding fish a mixed diet. Rottmannet al. (1991) also reported that a feeding program comprising of a combination of live food items and a dry diet would be superior to a dry diet alone because it would meet more completely the nutritional requirements of the larvae for maximum growth and survival and provide a range of nutrients to ensure consistent growth.
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Figure 5. Weight gain (g) by fry of goldfish fed with pelleted, live and mixed feed |
Figure 6. Specific growth rate (SGR) by fry of goldfish fed with pelleted, live and mixed feed |
Mixed schedules were superior to single high protein schedules because nitrogen retention was higher in the fish fed the mixed schedules. Results of the present work revealed that overall growth performance of the goldfish larvae higher in fish fed with mixed feed followed by the live feed and the pelleted feed. These findings are in agreement with the earlier studies conducted on the Poeciliasphenops (KumarguruVasagam 2007, Kruger et al 2004) and Clariasgariepinus (Olurin and Oluwo 2010) which obtained higher growth of the fish when fed with mixed diet.
The present investigation further reported the suitability of live feed in comparison to pelleted feed. Live feed also produced high specific growth rate and growth, perhaps because large size, movement, and high protein content stimulated the predatory responses of the fish. Live feed provide more protein than pelleted feed and all the amino acids essential to fish. Also, live zooplankton contains enzymes (Bengtsonet al 1991) that help in initial digestion of juvenile fishes and apparently enhance their appetite, feed intake, and growth. Likewise, coho salmon (Oncorhynchuskisutch) fry fed on live feed grew faster than those fed pelleted feed. The present findings were also supported by the study conducted by Degani (1990) in juvenile of Trichogastertrichopterus which reported that juveniles fed live feed grew faster than those fed formulated feed because of the palatability, high consumption and chemical composition of the live feed. Similarly a study by Chakarbartyet al.(2008) who investigated the effect of feeding dry earthworm instead of live feed along with dry feed revealed that the feed consumption and growth were better in fish fed with mixed feed (dry earthworms and pellets). Swimming and feeding behaviour patterns were normal in all treatments irrespective of feed type.
Water quality plays an important role in the survival of the fish and during the present work all the parameters as monitored on weekly interval were in optimum range (Table 6). The range of the water quality parameters recorded during the present work was in agreement with earlier studies on goldfish (Kestomont 1995, Krejszeff 2008)
The global ornamental fish trade has been increasing and hence in recent years, research and development on breeding and seed production of ornamental fishes has also gained momentum. Despite the huge potential offered by the rich diversity and environment, export of ornamental fish from India continues to remain negligible.
Development of this sector requires strategies involving sustainable exploitation of the existing natural resources and breeding of native and exotic varieties under controlled conditions. Presently the industry is not organised and the earning potential of the sector is not being exploited in a technology driven manner in harmony with nature. With concerted efforts towards ornamental fish breeding and culture it may be possible to put India on the world map of ornamental fish trade.
Ornamental fish seed production provides additional income to the fish farmers and help in their socioeconomic development. If the work of ornamental fish breeding and rearing in aquaria and garden pools is adopted along with some allied activities (live feed production, artificial feed production and equipments business) it can be a boon for the thousands of unemployed youths and women. Women can run small home units of ornamental fish breeding or rearing or both as it can be practiced in rural areas as well as in urban areas with little alteration of backyard or even the roof of a dwelling. Women can improve their family economy and nutrition and thereby their improved position in the family owing to their contribution to the family economy. At the first stage of starting of an ornamental fish breeding unit very sophisticated or complicated equipment is not necessary. Ornamental fish farming can be a promising alternative for many people and it has the potential to contribute to the economic growth of states concerned and the sustainable development of aquatic resources. Ornamental fish breeding can be done successfully with high yield at low cost. Different capital cost, variable cost and profit obtained from the unit of ornamental fish breeding in a year is given below.
A. Fixed capital
1. Low cost shed of 300 sq. ft area 10000
2. Glass tanks (24’'X12"X12") 20000
3. Bore-well with 1 hp pump 8000
4. Oxygen cylinder with accessories 5000
5. Aerators 5000
6. Nets, mugs, buckets etc. 5000
Sub-total 53000*
*This fixed capital cost is for 10 years
Cost for 1 year 5300
B. Variable cost
1. Cost of fish brooders 15,000
2. Cost of feed, manures, chemicals 10,000
3. Maintenance charges 5,000
4. Miscellaneous charges 2,000
Sub- total 22000
Grand total (Capital cost of 1yr+variable cost) 27300
Sale of 3000 nos ornamental fish @ Rs.3/fish 90000
Net Profit 62700
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Received 7 May 2011; Accepted 11 October 2011; Published 4 November 2011