Study on Spawning Fecundity and its Relation with Body Size of Rainbow Trout (Oncorhynchus Mykiss) from Hatchery of Kashmir Himalayas
Asim I Bazaz, Irfan Ahmad*, Tasaduq H Shah, Farooz A. Bhat, Oyas A Asimi, Bilal A. Bhat, Nafhat-ul-Arab,Zarka Yousuf and Nakeer Razak
Division of Fisheries Resource Management, Faculty of Fisheries, SKUAST–Kashmir
Division of Fish Genetics and Biotechnology, Faculty of Fisheries, SKUAST–Kashmir
Division of Aquatic Environmental Management, Faculty of Fisheries, SKUAST–Kashmir
Division of Fish Nutrition and Biochemistry, Faculty of Fisheries, SKUAST–Kashmir
Division of Social Sciences, Faculty of Fisheries, SKUAST–Kashmir
Received Date: 26/03/2022; Published Date: 19/04/2022
*Corresponding author: Irfan Ahmad, Division of Fish Genetics and Biotechnology, Faculty of Fisheries, SKUAST, Kashmir, India
Cite this article: Asim I Bazaz¹, Irfan Ahmad2*, Tasaduq H Shah¹, Farooz A. Bhat¹, Oyas A Asimi⁴, Bilal A. Bhat⁵, Nafhat-ul-Arab³, Zarka Yousuf¹ and Nakeer Razak².Study on Spawning Fecundity and its Relation with Body Size of Rainbow Trout (Oncorhynchus Mykiss) from Hatchery of Kashmir Himalayas
The present investigations were carried out at Trout Culture Farm Laribal, Srinagar (J&K Govt.) in the month of December 2020. Relationship between length-weight, spawning fecundity and relative fecundity was observed in rainbow trout (O. mykiss). The mean length of male rainbow trout (38.77±1.38 cm) while as, mean length for female rainbow trout (38.05±1.32cm) was observed. The mean weight of male and female rainbow trout recorded was 794.6±49.3g and 766.3±64.3g respectively. The spawning fecundity per female ranged from 2002 to 2804 eggs. The relative fecundity ranged from minimum of 2.26/gm body weight to maximum of 3.49/ gm body weight with mean value of 3.13±0.12/gm body weight. The present study recorded a significant positive correlation between total body length and total body weight of male rainbow trout (r= 0.938, p<0.05) and total body length and total body weight of female rainbow trout (r=0.989, p<0.05). Similarly, a significant positive correlation between total body length and spawning fecundity (r=0.897, p<0.05), total body weight and spawning fecundity (r=0.845) was observed. Relative fecundity showed a significant negative correlation between total length, total weight and spawning fecundity. (r= -0.839, p<0.01), (r= -0.900, p<0.01) (- 0.537, p<0.01) respectively.
Keywords: Oncorhynchus mykiss, spawning fecundity, length, weight, relative fecundity
The rainbow trout (Oncorhynchus mykiss), introduced in Kashmir in the year 1912, has thrived well since then and is now established in almost all the cold-water streams, lakes and rivers of the valley. Fecundity refers to the number of mature eggs in a female fish's ovary prior to spawning. Fish stock fecundity is a prominent feature of fishery biology as it has a direct impact on fish production, stock recruitment, and stock management, Bagenal and Braum . Estimating fecundity is important not only for these criteria, but also for acquiring knowledge about different races, as different races have different fecundities and egg diameters, which helps identify whether a population is homogeneous (with a single species) or heterogeneous (with multiple species) . Egg size, diameter, or unit volume of number of eggs spawned, or expressed as the weight of eggs spawned, is a key factor in determining brood stock fecundity . By artificially stripping the eggs from the fish at full maturity, the number of ripe or mature eggs released by salmonid brood fish can be easily determined; this number is known as fecundity. Fecundity is often referred to as total or absolute fecundity, or simply fecundity, when expressed in terms of the number of eggs produced per brood fish. Alternatively, relative fecundity is defined as fecundity expressed per unit body weight of post-stripped fish. There are scientific objections to using relative fecundity because the number of eggs produced for each unit increase in weight varies significantly [4,5]. With increasing age of the fish, both fecundity and egg size also increase  although it is considered that these changes are due mainly to the generally larger size of older fish.
For most salmonids these measures of fecundity are readily made because eggs are artificially stripped from each female at spawning. For many other species of fish, particularly wild populations, which either cannot be stripped or are not readily accessible throughout their life cycles, fecundity has to be estimated from counts of the number of ripe eggs, either in microscope sections of the ovary or in samples of ovary where the oocytes have been separated in Gilson's fluid. This study was aimed to describe the length-weight relationship and spawning fecundity of the fish from Dachigam hatchery in Kashmir valley.
Materials and Methods
The present study was conducted in the month of December 2020. Healthy parent stocks of male and female rainbow trout were collected from Trout Culture Farm, Laribal, Srinagar (J&K Govt.), which is located around 20 kms from district Srinagar. Relationship between total body length, total body weight, spawning fecundity and relative fecundity was determined. The data were recorded from an aesthetized fish.
Male and female rainbow trout were segregated before stripping. Eggs were stripped in a dry, clean plastic bowls by applying gentle pressure to the abdomen of female rainbow trout. Spawning fecundity was determined by counting total number of stripped eggs per female rainbow trout (Oncorhynchus mykiss).
It was calculated as total number of stripped eggs divided by weight of fish.
Estimation of total length and total weight
The total length of male and female rainbow trout was determined using a Vernier caliper (Trusize absolute digimatic) (Plate 1). The total weight was calculated using a weighing balance (Thomson electronic weighing scale, D-112) (Plate 2).
Plate 1: Total length measurement of rainbow trout using a vernier caliper.
Plate 2: Total weight measurement of rainbow trout using a digital weighing balance.
Results and Discussion
The total length of male rainbow trout ranged from 30.3cm to 45.1cm with a mean value of 38.77±1.38 cm while as for female rainbow trout, the length ranged from 34.5cm to 47.4cm with a mean value of 38.05±1.32 cm. The observed total weight of male rainbow trout ranged from 623g to 1065g with a mean value of 794.6±49.3g while as the female rainbow trout weighed in the range of 635g to 1237g with a mean value of 766.3±64.3g (Table 1, Figure 1&2). The spawning fecundity per female ranged from 2002 to 2804 eggs and the mean spawning fecundity of 2337.4±92.33 eggs was observed. The relative fecundity ranged from minimum of 2.26/gm body weight to maximum of 3.49/ gm of body weight with mean value of 3.13±0.12 per gram of body weight somatic weight (Table 3).
Figure 1: Minimum, maximum & mean values of length of male &female Rainbow trout
Figure 2: Minimum, maximum & mean values of total weight of male & female rainbow trout
Table 1: The data provides the (descriptive) statistical of total length and total weight of male and female O. mykiss.
Table 2: Pearson’s correlation between total length and total weight of male and female rainbow trout.
** Significant at 0.01 level of significance
The Pearson’s correlation between total length and total weight of male and female rainbow trout is given in (Table 2) below. It was found that there was a significant positive correlation between total length and total weight of male rainbow trout (r= 0.938, p<0.01) and total length and total weight of female rainbow trout (r=0.989, p<0.01). The Pearson’s correlation between total length, total weight and fecundity of rainbow trout is given (in Table 4), there was significant positive correlation between total length and fecundity (r=0.897, p<0.01), total length and total weight (r=0.968, p<0.01) as well as between total weight and fecundity (r=0.845, p<0.01).
Figure 3: Scatter plot of correlation between spawning fecundity and length, spawning fecundity & total weight.
Figure 4: Scatter plot of correlation between total length & total weight.
Figure 5: Scatter plot of significant correlation between total length & relative fecundity
Figure 6: Scatter plot of significant correlation between spawning fecundity & relative fecundity.
Table 3: The data provides the (descriptive) statistical of total length, total weight, spawning fecundity and relative fecundity of O. mykiss.
Table 4: Pearson’s correlation between total length, total weight and fecundity of rainbow trout.
** Correlation is significant at 0.01 level.
Table 5: Pearson’s correlation between total length, total weight and relative fecundity of rainbow trout
* Correlation is significant at 0.01 level.
Since there is such a wide range of reproductive patterns in teleosts, an accurate definition of fecundity that is acceptable in all circumstances has not been established, nor is it simple to do so. Individual or absolute fecundity is defined as the number of ripening eggs found in the female shortly prior to spawning. Fecundity estimates for teleosts range from a few hundred to several lakhs. Fish that live-in cold-water streams and lakes have a lower fecundity than those that live in warm water streams and lakes Das and Subla (1969) recorded the fecundity of Crossocheilus diplocheilus from 6424 to 21432 in the fish length group of 95mm to 128mm. Fecundity estimates of Tor putitora from Kumaon lakes revealed that the fish measuring 339 to 517mm in length possessed 7076 to 18525 eggs . The fecundity estimates of brown trout (Salmo trutta fario) have been described by several workers. Absolute fecundity of brown trout ranged from 160 to 761 eggs per female . Brown and Kamp  found that the average number of eggs produced was 1,285 in brown trout which had an average total length of 388.6mm (15.3 inches). Taube (1975) found that in the length range of 202-354mm (8-14 inches), the average number of eggs produced per female trout by inch group ranged from 241 to 936. When present results are compared with these fecundity estimates, rainbow trout appears to be equally productive having an average fecundity of 2337.4±92.33 in an average total fish length of 38.77±1.38 cm. Fish fertility is usually related to the length, weight, and age of the fish, as well as the length, weight, and volume of the ovary. A straight-line correlation between fish weight and fecundity was found by several researchers [10-13]. In Salmo trutta fario also various workers including [14-17] correlated the fish weight and fecundity Allen  found this relationship to be linear. Mc Fadden  found a direct relationship between egg weight and fish weight. In Oncorhynchus mykiss this relationship is also found to be linear. Linear relationships of fecundity with body measurements were also reported by [19-21]. The findings of the present work are in agreement with these observations.
Bagenal stated that the fecundity increases with the increase in the body measurement in all the cases, a liner relationship was observed between the fecundity and the body parameters. The value of the coefficient of correlation indicated that fecundity was more directly related to ovary weight (r = 0.996) and fish length (r = 0.859) then the ovary length (r = 0.828) and the fish weight (r = 0.653). In the present study, the positive correlation between length and fecundity (r=0.897), between length and weight (r=0.968) as well as between weight and fecundity (r=0.845) was found. Hence, both the studies are in proximity with each other. Mohammad et al. 2018, reported relative fecundity showed a significant negative correlation with weight, length and absolute fecundity (r=-0.747, p<0.01; r=-0.419, p<0.05and r=-0.460, p<0.05 respectively). The close relationship between absolute fecundity and fish length demonstrated here is supported by the works of [22,23,24] and many others. Fecundity generally increased with total length in several fishes. A positive correlation has been observed between total length of females with their fecundity of Mugil parsia  Osteogenesis militaria  Polynemus paradiscus , and Labeo rohita [28-31]. These results are in conformity with the present study as relative fecundity showed a significant negative correlation between total body weight & relative fecundity; total length & relative fecundity; spawning fecundity & relative fecundity (r= - 0.900, p<0.01; r= - 0.839, p<0.01; r= - 0.537, p<0.05 respectively).
These findings are important with respect to reproduction life history of the species and many to be interpreted as the species response to improve fitness relating to habitat variations. Overall results of present study demonstrated that spawning fecundity increased with increase in fish length & weight. There was positive correlation between length and fecundity, length and weight as well as between weight and fecundity.
Conceptualization and designing of research work (AIB/ THS); Execution of field/lab experiments and data collection (AIB); Analysis of data and interpretation (AIB/ IA); Preparation of manuscript (AIB/NUA).
- Bagenal T B and Braum E (1978) Eggs and Early Life History. IBP Hand Book No. 3, 3rd Edn. Blackwell Scientific Publication, Oxford, pp: 106.
- Shafi S (2012) Study on fecundity and GSI of Carassius carassius (Linneaus, 1758) from Dal Lake Kashmir. Journal of Biology, Agriculture and Healthcare. 2: 3.
- Bromage N, Cumaranatunge PRC (1988) Egg Production in the Rainbow Trout. In: R.J.Roberts and J.F. Muir Eds. Recent Advances in Aquaculture. Vol. 3, Croom Helm, London, pp. 65-137
- Bagenal TB (1973) Fish fecundity and its relations with stock and recruitment. Rapp. P.-V. Reun. Cons. Int. Explor. Mer, 164: 186- 198.
- Bromage N, Hardiman P, Jones J, Springate J, Bye V (1990) Fecundity, egg size and total egg volume differences in 12 stocks of rainbow trout. Aquacult. Fish. Manage 21: 269- 284.
- Springate JRC, Bromage NR (1984) Broodstock management: egg size and number, the ‘trade off. Fish Farmer 7: 12-14.
- Pathani SS (1981) Fecundity of mahseer, Tor putitora (Ham.). Proc Indian Acad. Sci (Anim.Sci) 90: 253-260.
- Garcia A, Brana F (1988) Reproductive biology of brown trout (Salmo trutta L.) in the Allen River (Austurias, Spain). Polish Archives of Hydrobiology 35(3): 373.
- Brown CJD, Gertrude C Kamp (1942) Gonad measurements and egg counts of brown trout (Salmo trutta) from the Madison River, Montana. Trans. Amer. Fish. Soc., 71(1941), pp. 195-200.
- Bagenal TB (1957) The breeding and fecundity of the long rough dab, Hippoglossoides platessoides (Fabr.) and the associated cycle in condition. J. Mar. Biol. Assoc, UK 36: 339-375.
- Singh HR, Nauriyal BP, Dobriyal AK (1982) Fecundity of hillstream minor carp Puntius chilinoides (Mc Clelland) from Garhwal Himalaya. Proc Indian Acad Sci. (Anim. Sci.) 91(5): 487-491.
- Pokhriyal RC (1986) Fishery biology of Crossocheilus latius latius (Ham.). From the Grahwal Himalaya. D. Phil. Thesis. Garhwal University, Srinagar, Garhwal.
- Nautiyal P (1985) Fecundity of the Garhwal Himalayan mahseer Tor putitora (Ham.). J. Bombay Nat Hist Soc 82 (2): 253-257.
- Allen KR (1951) The Horokiwi stream, a study of a trout population. Newzealand Marine Department, Fisheries Bulletin 10: 238.
- Nicholls AG (1958) The egg yield from brown and rainbow trout in Tasmania. Aust J Freshw Res 9(4): 526-536.
- Alp A, Kara C, Buyukcapar HM (2003) Reproductive biology of brown trout, Salmo trutta macrostigma Dumeril 1858, in a tributary of the Ceyhan River which flows into the eastern Mediterraneansea. J. Appl. Ichthyol 19: 346-351.
- Bagenal TB (1969) The relationship between food supply and fecundity in brown trout, Salmo trutta L. Journal of fish biology, 1: 169-182.
- Mc Fadden JT, Cooper EL, Andersen JK (1965) Some effects of environment on egg production in brown trout (Salmo trutta). Limnology and Oceanography, 10: 88-95.
- Swarup K (1962) The fecundity of Indian Shad, Hilsa Ilisha. J Zool Soc13: 108-112.
- Rao C, Nagendra NR, Rahman KVK (1979) An analysis of the fecundity in the Cyprinid fish Puntius dorsalis (Jardon).All India seminar on Icthyology p. 11.
- Bhuiyan AS, Islam K, Zaman T (2006) Fecundity and ovarian characteristics of Puntius gonionotus. J Biol Sci 14: 99-102.
- Joshi SN, Khanna SS (1980) Relative fecundity of Labeo gonius (Ham.) from Nanak Sagar reservoir. Proceeding of India Academic Science Animal Science. 89(5): 493-503.
- Treasurer JW (1990) The annual reproductive cycle of pike, Esox lucius L., in two Scottish lakes. Journal of Fish Biology. 36:29-46.
- Dobriyal AK (1988) Fecundity of the Chinese silver carp Hypophthalmichthys molitrix (Val.) from Gujartal fish farm. Jaunpur, UP. Proceeding Indian Academy of Sciences. 97(2): 169-173.
- Sarojini KK (1957) Biology and fisheries of the grey mullets of Bengal. I. Biology of Mugil parsia Hamilton. Indian Journal of Fisheries. 4(1):160-207.
- Pantulu VR (1963) Studies on the age and growth, fecundity and spawning of Osteogenesis militaris (Linn). Journal of Cons. Int. Explor 28: 295-315.
- Gupta MV (1968) Observation on the fecundity of Polynemus paradism L from the highly estuarine system. Proceeding of National Institute Science India. 34(B): 330-345.
- Varghese TJ (1973) The fecundity of the rohu, Labeo rohita (Hamilton). Proceedings of the Indian Academy of Sciences - Section B. 77(5): 214-224.
- Das SM, Subla BA (1969) The mechanism of feeding in nine Kashmir fishes with a comparative account of the standard mechanism in a herbivore, an omnivore and a carnivore. Kash Sci 4(1-2): 121-130
- Mohammad I, Bhat FA, Balkhi MH, Shah TH, Bhat BA, Wali A (2018) Relationship among body weight, body length, ovary weight and the fecundity of Cyprinus carpio Var. communis in Kashmir Himalaya. Journal of Pharmacognosy and Phytochemistry 7(6): 2018-2020.
- Taube CM (1975) Sexual maturity and fecundity in brown trout of the Platte River. Fish Res Rep p. 14.