Striped murrel (Channa striata) stands out as a delectable freshwater fish highly preferred across Southeast Asia and the Indian subcontinent. The flesh of the striped snakehead is highly nutritious and is also recognized for medicinal values (Sahu et al., 2012). It is a fish with great economic values because of the large market demand as food fish resulting from the appealing flavor and lesser abundance of intramuscular spines than most fish (Kumar et al., 2012 and Dayal et al., 2013). Despite its potential, fish farming in India predominantly revolves around carps, shrimp and tilapia, highlighting an urgent need for species diversification in aquaculture. With its culinary appeal and economic potential, it presents a promising opportunity for aquaculture diversification, particularly within the Indian context. Globally, murrel culture remains underdeveloped, with only 21,721 tons produced through aquaculture in 2016 out of a total production of 92,523 tons, indicating that nearly three-fourths of the supply still comes from capture fisheries (FAO, 2016). Despite the significant demand for fish, many farmers encounter challenges in successfully cultivating Murrel. This is primarily due to the lack of access to quality hatchery seeds, commercial feeds and efficient nursery and grow-out rearing techniques. In India, a large proportion of murrel farming relies on wild seeds, which are only available seasonally (Marimuthu and Haniffa, 2007; Kumar et al., 2017; Damle et al., 2023). Notably, many states of the country lack certified hatcheries producing murrel seeds. This not only limits reliable seed availability but also exerts pressure on natural stocks. A primary constraint in expanding murrel aquaculture is the species’ inability to spawn naturally under captive conditions, necessitating the establishment of reliable induced breeding protocols (Marimuthu and Haniffa, 2007; Dayal et al., 2013). The induced breeding trials have been attempted by using Pituitary Gland Extract (Haniffa et al., 2000; Roy et al., 2016), hCG (Haniffa et al., 2000; Kumar et al., 2021b; Kumar and Mohanty, 2018; Nam et al., 2011), Ovatide/ Ovaprim (Haniffa et al., 2000; Kumar and Mohanty, 2018; Dayal et al., 2013) and WOVA FH (Pati et al., 2004). The optimal dosages of different agents for induced spawning vary widely among different authors. The present study comparatively evaluates the effectiveness of traditional pituitary gland extract (PGE) and modern synthetic hormone formulations such as WOVA-FH under captive condition.

Broodstock collection and transportation and management
 
The present study was carried out at advanced research farm facility, of Dr. MGR. Fisheires college and research institute, Ponneri, Tamil Nadu during the year 2025. Wild brooders were collected from lakes and swampy habitats during pre- and post-monsoon months when water levels were low. Prior to transport, Syntex tanks were disinfected, filled with source water and covered with mesh to prevent jumping. Brooders were transported under ambient aeration. Brood fish were weighed, examined for external parasites and gradually acclimatized by suspending them in pond water in holding nets. Broodstock were reared in disinfected lined ponds of 400 m² area filled with borewell water (zero salinity freshwater). The stocking density was maintained at 70-80 kg per 400 m², equivalent to 2000-2500 kg/ha. Initially, the broodfish were fed with live tilapia juveniles and subsequently transitioned to a floating formulated feed containing 42% crude protein at a feeding rate of 3% of body weight, administered twice daily. Weekly partial water exchange was carried out along with routine monitoring of water quality parameters (Table 1) using standard procedure (APHA, 2005) to maintain optimal rearing conditions. Broodstock maturity was assessed through abdominal pressure test, freely milt and egg oozing fishes were selected for breeding.


 
Breeding system
 
The breeding system consisted of rectangular earthen breeding pools measuring 5 × 10 ft with a water depth maintained between 1.5 and 2.0 m. Prior to stocking, the pools were thoroughly cleaned and disinfected using potassium permanganate (KMnO₄) at a concentration of 5 ppm to eliminate pathogenic organisms and maintain hygienic breeding conditions. After disinfection, the pools were filled with borewell water up to a depth of approximately 1 m and allowed to stabilize before the introduction of broodfish. To simulate the natural breeding habitat of murrel, nearly 50% of the water surface area was covered with thoroughly washed aquatic macrophytes, Eichhornia. (Fig 1). These floating aquatic plants provided shelter, reduced stress and created a favourable microenvironment for courtship, spawning and egg protection. The vegetation also served as a substrate for bubble nest formation and helped maintain relatively stable water conditions within the breeding pools. The breeding pools were provided with protective fencing around the perimeter to prevent the escape of broodfish and to avoid the entry of predators, unwanted organisms and external contaminants. Regular monitoring of water quality parameters and pool hygiene was carried out throughout the breeding period to ensure optimal environmental conditions for successful spawning and seed production.


 
Selection of brooders and induced breeding procedure
 
Selection of suitable brooders for induced breeding was carried out based on the external secondary sexual characteristics and gonadal maturity status of the broodfish. Sex differentiation in striped murrel (Channa striata) was performed during the spawning season using morphological characteristics. Females were identified by the presence of a soft and bulging abdomen due to ovarian development, along with a reddish, oval-shaped genital pore. In contrast, males possessed a comparatively slender body, a rounded head and a smaller genital papilla (Fig 2 and Fig 3).




       
Sexual maturity in murrel could be attained even at smaller body sizes ranging from 250-300 g. Based on the earlier studies, male brooders weighing 300-600 g and female brooders weighing 400-800 g were selected for the induced breeding trials. Healthy, active and disease-free brooders were chosen and conditioned under suitable captive conditions prior to hormone administration. The induced breeding experiment was designed with one control and six treatments, each maintained in triplicate. The hormone doses were selected based on earlier reports and preliminary observations. Murrel pituitary extract (prepared scarifying the mature murrel fishes and following the similar procedure as preparation of carp pituitary extract) was administered intramuscularly at doses of 10+50 mg, 10+ 100 mg and 10+150 mg, while WOVA-FH was tested at doses of 0.2, 0.4 and 0.6 ml/kg body weight. The control group was maintained without hormonal induction. For hormone administration, the selected brooders were held gently to minimize stress and the hormone extract was injected intramuscularly (Fig 4) behind the dorsal fin above the lateral line (Fig 4). Females received two injections, consisting of a preparatory dose (6.00 PM) followed by a resolving dose (10.00 PM), with an interval of approximately four hours between injections. Male brooders received only a single injection at the time of the second dose administered to females. Following hormone administration, the injected males and females were immediately released into the prepared breeding pools at 1:1 (Male: Female) sex ratio.


       
The brooders were continuously observed for courtship behaviour, pairing activity and spawning response. Particular attention was given to the release of gametes into the water under captive conditions. The parameter such as latency period, number of Spawned Eggs, fertilization rate, hatching rate and survival rate (at 30DPH) were recorded. The data obtained were subjected to one-way ANOVA using SPSS software. When significant differences were observed among the treatments, Duncan’s multiple range test (DMRT) was performed for mean comparison at the appropriate significance level.

The present investigation clearly demonstrated that hormonal induction significantly influenced the reproductive performance of striped murrel, Channa striata, particularly with respect to latency period, egg production, fertilization, hatching and larval survival (Table 2). The findings revealed that the application of exogenous hormones effectively stimulated spawning activity, whereas no spawning response was observed in the untreated control group. Similar observations have been reported by earlier researchers who stated that induced breeding is essential in murrels because natural spawning under captive conditions is generally poor due to the absence of suitable environmental cues and reproductive stimulation (Haniffa et al., 2004).


       
The mean male brooder weight ranged from 433.33± 28.28 g in the control group to 467.17±23.71 g in T6 (WOVA-FH 0.6 ml kg^-1). Female brooders exhibited mean body weights ranging from 641.33±35.01 g to 654.33±13.94 g. ANOVA revealed no significant difference among treatments for male body weight (p>0.05) and female body weight (p>0.05), indicating uniformity of brooders among experimental groups. The non-significant variation observed in male and female brood weights among treatments confirmed the uniformity of experimental brooders used in the study. The comparable body weight of brood fish among treatments eliminated possible size-related bias and ensured that the differences observed in breeding performance were mainly due to hormonal effects. Similar experimental standardization has been reported in induced breeding studies of murrels by Haniffa et al., (2004) and Marimuthu et al., (2009), who emphasized that uniform broodstock selection is necessary for reliable evaluation of hormonal treatments. Since murrels are monogamous, mating with a single partner during spawning, a sex ratio of 1:1 is considered optimal for successful captive spawning of striped murrel (Haniffa et al., 2000; Kumar and Mohanty, 2018; Kumar et al., 2021).
 
Latency period
 
Latency period (Fig 5) varied significantly among the induced breeding treatments (p<0.001). The highest latency period was observed in T1 (15.25±0.48 h), followed by T4 (15.00±0.58 h). Moderate latency periods were recorded in T2 (13.50±0.43 h) and T5 (12.67±0.33 h). The shortest latency periods were observed in T3 (8.83±0.31 h) and T6 (8.67±0.21 h), indicating rapid spawning response at higher hormone dosages. No spawning response was observed in the control treatment. These findings indicate that increasing hormone dosage significantly reduced the latency period in striped murrel breeding.


       
The significant variation in latency period among hormonal treatments indicates a dose-dependent response to hormonal induction. The shorter latency periods observed at higher doses of PGE and WOVA-FH are consistent with previous reports that latency period varies with the type and dosage of hormone administered (Sahoo et al., 2005). Haniffa et al., (2004) reported latency periods of 10-14 h in induced breeding of striped murrel using pituitary extract, while Marimuthu et al., (2009) reported reduced spawning latency with increasing doses of Ovaprim. The reduced latency at higher hormonal doses may be associated with enhanced stimulation of the reproductive endocrine axis, accelerated final oocyte maturation and subsequent ovulation (Kumar et al., 2021).
 
Spawned egg production
 
The spawned eggs are tiny, golden yellow in colour floating between the aquatic weeds (Fig 6). Significant variation was observed in the number of spawned eggs (Fig 7) among treatments (p<0.001). The highest egg production was recorded in T5 (4231.67±130.40 eggs), followed by T2 (3746.67±203.92 eggs). Intermediate egg production was observed in T1 (2575.00±342.48 eggs) and T6 (2468.33±169.44 eggs). Lower egg production was recorded in T3 (2113.33±217.25 eggs) and T4 (1810.00±276.10 eggs). No spawning occurred in the control group. The results suggest that WOVA-FH at 0.4 ml kg^-1 was the most effective hormonal treatment for maximizing fecundity.




       
However, the reduction in latency period was not accompanied by a proportional increase in reproductive output. WOVA-FH at 0.4 ml kg^-1 (T5) produced the highest number of spawned eggs, fertilization rate, hatching rate and larval survival, despite the shorter latency being recorded at the higher WOVA-FH dose of 0.6 ml kg^-1 (T6). This indicates that an optimum rather than a maximum hormonal dose is required for efficient reproductive performance. Similar dose-dependent responses have been reported in Pangasianodon hypophthalmus (Legendre et al., 2000), Anabas testudineus (Mandal et al., 2016) and Channa striata (Bagra et al., 2024). Excessive hormonal stimulation may accelerate ovulation without necessarily improving egg quality and spawning efficiency, potentially resulting in premature ovulation, over-ripening and reduced reproductive output.
 
Fertilization rate
 
Fertilization rate differed significantly among treatments (p<0.001). The highest fertilization rate was observed in T5 with 73.00±1.53%, followed closely by T2 with 70.00± 1.41%. Lower fertilization percentages were observed in T6 (45.33±1.76%), T3 (42.50±1.73%), T4 (41.33±3.18%) and T1 (39.75±4.37%). No fertilization was observed in the control treatment due to absence of spawning. The results clearly demonstrate the superior efficiency of WOVA-FH 0.4 ml kg^-1 and PGE 10+100 mg kg^-1 in achieving higher fertilization success.
       
The higher fertilization and hatching rates recorded in T5 may reflect better synchronization of spawning and improved gamete quality at the optimum hormonal dose. Fertilization success is influenced by egg quality, sperm quality and synchronization between male and female brooders. Similar fertilization rates of 65-80% have been reported for induced breeding of murrels using synthetic hormones and pituitary extracts (Marimuthu et al., 2009; Kumar et al., 2012). Lower fertilization rates at the higher hormonal doses may be associated with excessive hormonal stimulation and altered timing of gamete release. Earlier studies have also suggested that inappropriate hormone doses can result in early milting or inadequate synchronization between male and female gametes (Mahadevi et al., 2020; Das et al., 2016; Bagra et al., 2024).
 
Hatching rate
 
Hatching percentage (Fig 8) showed highly significant differences among treatments (p<0.001). The maximum hatching rate was recorded in T5 (85.83±1.47%), followed by T2 (79.83±2.30%). Lower hatching rates were observed in T6 (48.83±1.64%), T3 (47.83±2.63%), T4 (45.33±1.20%) and T1 (43.25 ± 4.23%). The control group showed no hatching due to absence of induced spawning. The results indicate that WOVA-FH 0.4 ml kg^-1 produced superior egg quality and hatchability compared to other hormonal treatments.


       
The fertilized eggs were free-floating, golden yellow in colour and were usually deposited among submerged vegetation (Fig 6). Egg and embryonic development duration and developmental features were uniform across treatments. Fertilized eggs hatched within 24-26 h after spawning. Yolk sac absorption was completed approximately 72 h post-hatching and larvae exhibited free-swimming behaviour from the fourth day post-hatch (4 DPH). The larvae were fed graded levels of live feed until 30 DPH as per the feeding schedule provided in Table 3.



Larval survival rate (at 30 DPH)
 
Larval survival (Fig 9) at 30 days post-hatch (DPH) differed significantly among treatments (p<0.001). The highest survival rate was observed in T5 (54.17±1.08%), followed by T2 (47.67±1.76%). Moderate survival was recorded in T6 (44.50±0.99%) and T4 (43.33±0.88%), while comparatively lower survival was observed in T3 (37.33± 3.02%) and T1 (32.75±2.06%). These findings suggest that larvae produced under WOVA-FH 0.4 ml kg^-1 treatment possessed better viability and post-hatch survival.


       
The higher hatchability and larval survival observed in T5 further indicate the importance of egg quality and reproductive synchronization. Egg quality is a major determinant of embryonic development and subsequent larval performance (Bromage et al., 1992). The higher larval survival obtained from T5 may therefore be related to the production of better-quality eggs and viable larvae under the optimum hormonal stimulation.
       
The superior overall performance of WOVA-FH, particularly at 0.4 ml kg^-1, compared with PGE treatments may be attributed to its standardized hormonal composition and more consistent endocrine stimulation. WOVA-FH contains synthetic hormonal components that stimulate endogenous gonadotropin secretion and facilitate synchronized final oocyte maturation and ovulation. In contrast, PGE is a crude biological preparation in which gonadotropin potency and concentration may vary depending on the source and preparation of donor pituitaries. Such variability can result in less predictable reproductive responses. Synthetic inducing agents have therefore been reported to provide greater consistency and control over induced spawning compared with crude pituitary preparations (Peter et al., 1988).
       
Nevertheless, PGE at 10+100 mg kg^-1 (T2) produced relatively high egg production, fertilization, hatching and larval survival compared with the other PGE treatments. This indicates that PGE remains a viable and potentially economical option for induced breeding where commercial synthetic hormonal formulations are unavailable or less accessible.
       
Overall, the present findings demonstrate that hormonal dose strongly influences the reproductive performance of striped murrel. Among the treatments evaluated, WOVA-FH at 0.4 ml kg^-1 provided the most favourable overall reproductive performance, based on spawned egg production, fertilization, hatching and larval survival. The findings suggest that optimization of hormone dosage is more important than simply increasing the hormonal dose for achieving efficient seed production of C. striata.

The present study demonstrated that hormonal induction significantly influenced the breeding performance of striped murrel, Channa striata. Among the treatments tested, WOVA-FH at 0.4 ml kg^-1 produced the best results with highest egg production, fertilization, hatching and larval survival rates. PGE 10+100 mg kg^-1 also showed comparatively good performance. Higher hormone dosages reduced latency period but did not improve overall breeding efficiency. Therefore, WOVA-FH 0.4 ml kg^-1 can be recommended as the most effective hormonal treatment for induced breeding and seed production of striped murrel under captive conditions.

The authors are thankful to Tamil Nadu Dr. J. Jayalalithaa Fisheries University, Nagapattinam, for providing the infrastructure and administrative support required for conducting this study. The authors further acknowledge the financial support received from the Tamil Nadu State Land Use Research Board (TNSLURB), which facilitated the execution of a part of this research work.
 
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The authors declare that there are no conflicts of interest regarding the publication of this article.