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1.
The effect of [d-Lys6] salmon gonadotropin-releasing hormone alone (sGnRH) and in combination with domperidone, a dopamine antagonist, on the spawning of common carp, Cyprinus carpio, was investigated during the late spawning season (when mature fish stop spawning under natural conditions when males and females are put together). Fish were induced to spawn by [d-Lys6]-sGnRH salmon gonadotropin-releasing hormone analogue (sGnRH-X) only when injected in combination with domperidone at doses of 10 g kg-1 and 20 mg kg-1 body weight respectively. [d-Lys6]-sGnRH-X alone did not induce spawning at a dose as high as 100 g kg-1 body weight. Fish injected with domperidone alone did not spawn either. These results demonstrate that [d-Lys6]-sGnRH-X in combination with a dopamine antagonist is effective in inducing spawning during the late spawning season.  相似文献   

2.
The effects of intraperitoneal injections of [D-Ala6, Pro9-N-ethylaminde]-luteinizing hormone releasing hormone (LHRH-A) and pimozide (PIM), a dopamine receptor antagonist, on ovulation in loach were investigated. LHRH-A and PIM administered separately were ineffective in inducing ovulation. However, injections of PIM and LHRH-A simultaneously or the injection of PIM 2.5–3 h prior to LHRH-A were highly effective means of inducing ovulation. The simultaneous injection of PIM (1.0 μg/g body wt) and LHRH-A (0.05 μg/g body wt) resulted in a greater ovulatory response than injection of carp pituitary extract (1 pituitary/fish).  相似文献   

3.
An experiment was conducted to induce ovulation in Asian catfish, Clarias batrachus, by a single injection of SGnRHa (d ‐Arg6, Trp7, Leu8, Pro9, Net) in combination with domperidone. The effects of latency periods, 11, 14, 17, 20 and 23 h, and doses of inducing agent, 10 μg SGnRHa+5 mg domperidone, 20 μg SGnRHa+10 mg domperidone, 30 μg SGnRHa+15 mg domperidone and 40 μg SGnRHa+20 mg domperidone kg?1 body weight, were studied on the total egg output, stripping response, fertilization, hatching and normal larval production. The highest (P<0.05) number of eggs were stripped at 23 h of post injection of 20 μg SGnRHa+10 mg domperidone kg?1 female body weight. The highest (P<0.05) stripping response was observed when the females were stripped at 20 and 23 h latency, at all dose levels of the inducing agent. The eggs stripped at 11 h latency did not fertilize, and hence did not hatch irrespective of administration of any dose levels of the inducing agent. The fertilization and hatching per cent of eggs had significantly increased (P<0.05) with increase in latency period to 14–23 h at a dose of 20 μg SGnRHa+10 mg domperidone. The latency period of 14–17 h, and dose of 20 μg SGnRHa+10 mg domperidone and 30 μg SGnRHa+15 mg domperidone kg?1 of female, was found to be suitable to obtain best spawning performance, and good‐quality egg and larval production in C. batrachus.  相似文献   

4.
Abstract.— Control of reproduction in cultured fishes has been improved by the use of gonadotropin releasing hormones (GnRH's) and, in many fishes, the use of dopamine (DA) receptor antagonists. However, little successful use of these treatments has been reported for channel catfish Ictalurus punctatus . This study was conducted to investigate the potential of treatment with a gonadotropin hormone releasing hormone (GnRH) and a dopamine (DA) receptor antagonist to improve cage spawning success in channel catfish. Two and 3-yr-old catfish were selected from ponds. All males were injected with des-Gly10, [D-Ala6]-Leuteinizing hormone releasing hormone ethylamide (LHRHa, 50 μg/kg body weight). Females were randomly assigned to the various injection treatments, control (vehicle injected, C), LHRHa only (L), DA receptor antagonist (pimozide) only (P), and LHRHa and pimozide (LP). After injections, one male and one female were paired and placed into 1 m wide × 1.5 m long × 1.2 m deep spawning cages with a metal spawning can. Spawning cans were checked from 1 to 10 d after injection and successful spawning events were recorded. Five trials were conducted between 13 May and 5 June 1998. The LP treatment yielded significantly more spawns than any other treatment (LP, N = 24, 83% > L, N = 25, 44% > C, N = 23, 43 % > P, N = 11, 36%). The greatest promotion of spawning with LP treatment was in the first two induction trials. In the subsequent three trials, differences between treatments were not significant, although LP tre.ated females tended to spawn more frequently. Percent hatch (60.5 ± 3.4%) did not differ between treatments. Treatment of females with LHRHa + pimozide is a potentially useful method for increasing spawning success, particularly early in the spawning season.  相似文献   

5.
The results of reproduction of females from Lithuanian strain B carp after ovulation stimulation with carp pituitary homogenate (CPH; 0.3+2.7 mg kg?1; group I), Ovopel (1/5+1 pellet kg?1; group II) or [d ‐Tle6, ProNHEt9] GnRH‐a (Lecirelin) with metoclopramide (15 μg kg?1+10 mg kg?1 respectively; group III) were investigated. The lowest percentage of spawning females (71%) was recorded in the group treated with CPH. In case of Ovopel or Lecirelin induced ovulation, 86% of females spawned. No statistically significant effect of the ovulation stimulator (group) on the weight of eggs was found; however, the highest mean weight of eggs (expressed both in grams and in the percentage of female body weight) was recorded for the group treated with Ovopel (1400 g and 13%). After the treatment with CPH or Lecirelin, the weight of eggs was 1140 g (11%) and 1100 g (10%) respectively. The ovulation stimulator significantly affected the percentage of live embryos after 36 and 48 h incubation of eggs (P≤0.05; P≤0.01). After treatment with [d ‐Tle6, ProNHEt9] GnRH‐a, eggs of the best quality were obtained and after 36 and 48 h incubation the mean percentages of live embryos were significantly higher than the means calculated for the remaining two groups. No statistically significant differences were found between the percentage of living embryos after 36 and 48 h incubation of groups I and II.  相似文献   

6.
Wild female catfish Silurus asotus (Linnaeus, 1758) were injected with domperidone (DOM) alone, [d ‐Ala6, Pro9 Net]‐luteinizing hormone‐releasing hormone (LHRH‐A) alone once or twice, LHRH‐A plus DOM once or twice simultaneously at 6‐h intervals, LHRH‐A plus carp pituitary extract (CPE) twice simultaneously at 6‐h intervals and LHRH‐A plus human chorionic gonadotropin (HCG) twice simultaneously 6 h apart respectively. The results indicated that injection of LHRH‐A at a dosage of 0.01–0.02 μg g?1 body weight (BWt) alone induced a low but significant increase in serum gonadotropin (GtH) (P<0.05) and resulted in a very low ovulation rate, while DOM at a dosage of 5 μg g?1 BWt alone did not induce an increase in the serum GtH levels and ovulation; in contrast, LHRH‐A at a dosage of 0.01 μg g?1 BWt plus DOM at a dosage of 5 μg g?1 BWt (termed the Linpe technique) increased the serum GtH (P<0.05) significantly and induced an ovulatory rate of 100%, while LHRH‐A plus CPE or HCG resulted in an increase in the serum GtH (P<0.05) and high ovulatory rate, although the latency period was longer when fish were given LHRH‐A plus HCG or CPE.  相似文献   

7.
Nandus nandus is a threatened fish species that plays a significant role in the nutrition of India, especially in the Northeastern states. In the present study, induced spawning of a threatened freshwater fish Nandus nandus (Hamilton-Buchanan) was conducted using three commercially available synthetic GnRH preparations viz., wova- FH, ovaprim, and ovatide in different intensities. The brooder females were injected one time and left to spawn in the spawning hapa. It was found that at different dosages (0.1 ml, 0.2, and 0.3 ml/kg of body weight) hormone wova-FH and ovaprim could induce the fishes to spawn. No spawning was observed by females treated with ovatide and in control set. The spawning time, fertilization rate, hatching rate, and survival rate were quantified in each set of experiment. The egg output/gm female was higher with the dosage of 0.3 ml in comparison to 0.1 ml/kg and 0.2 ml/kg of body weight of ovaprim and wova-FH. The statistical analysis showed significant effect (P < 0.05) between hormonal doses with latency period, fertilization rate, incubation period, hatching percentage, and egg output. The present study suggests that wova –FH and ovaprim at 0.3 ml/kg body weight of fish are more effective in induction of spawning of N. nandus.  相似文献   

8.
The effects of an intraperitoneal hormone injection of gonadotropin‐releasing hormone agonist (D‐Ala6, Pro9‐NEt GnRHa) alone or in combination with a dopamine antagonist, domperidone (DOM), on ovulation induction in yellow catfish Pelteobagrus fulvidraco were tested. The hormone treatments were as follows: 6 mg kg−1 body weight (BW) of carp pituitary extract as a positive control, GnRHa 10, 20, 40 and 80 μg kg−1 BW and a combination of GnRHa and DOM as follows: 10 μg+5 mg, 20 μg+10 mg, 40 μg+20 mg and 80 μg+40 mg kg−1 BW. Physiological saline (0.7% NaCl) was used as a negative control. Significant differences in the ovulation ratio, latency period and ovulation index (OI) were observed among treatments (P<0.05). The combination of GnRHa and DOM at doses of 40 μg+20 mg kg−1 BW had higher values of the ovulation ratio and OI, and a shorter latency period compared with other treatments. The highest OI in GnRHa treatments was only 56.67%, suggesting a dopaminergic tone on gonadotropin secretion in this fish at the pre‐ovulatory stage. Therefore, ovulation can be successfully induced in yellow catfish with 40 μg kg−1 GnRHa+20 mg kg−1 DOM without affecting the egg quality.  相似文献   

9.
A reliable breeding technique was developed for the mangrove red snapper, Lutjanus argentimaculatus (Forsskal 1775), to help sustain the aquaculture of this immensely popular species in Southeast Asia. Using standardized indices of female maturity (based on mean oocyte diameter of ≥0.40 mm), time of injection (1000–1130) and sex ratio (one female to two males), a single injection of 100 μg kg?1 luteinizing hormone‐releasing hormone analogue (LHRHa) (n=16 fish), but not 50 μg kg?1 (n=five fish), successfully induced egg (62.5% success rate) and larval (43.8%) production. Human chorionic gonadotropin (hCG) at 500 IU kg?1 (n=five fish) also failed to induce spawning, but doses of 1000 (n=22 fish) and 1500 IU kg?1 (n=15 fish) gave spawning (77.3% and 80.0% respectively) and hatching success rates (72.7% and 60.0% respectively) that were not significantly different from those of 100 μg kg?1 LHRHa. No spawning was observed in saline‐injected controls (n=seven fish). While mean spawning latency, egg diameter, egg production per spawn, percent egg viability, hatching rate, percent of normal larvae and cumulative survival of eggs to normal larvae did not differ significantly among the effective hormones and doses, 1000 IU kg?1 hCG had a higher percentage (76.5%) of total spawns with egg production per spawn in excess of one million than those of 1500 IU kg?1 hCG (50.0%) and 100 μg kg?1 LHRHa (40.0%). Mangrove red snapper spontaneously spawned from March–April to November–December with a peak of egg collection and spawning in May–June. Egg collection per spawn ranged from 0.05 to 6.35 million. Spontaneous spawning of mangrove red snapper exhibited lunar periodicity with spawns mostly occurring 3 days before or after the last quarter and new moon phases and occurred consistently between 02:00 and 04:00 hours. High fecundity and good egg quality, coupled with the ability to respond to induce spawning or natural spawning in captivity, provide a sound basis for improving the sustainability of red snapper aquaculture in Southeast Asia.  相似文献   

10.
Forty-six white sturgeon females captured prior to their spawning migration in the San Francisco Bay and during their spawning run in the Sacramento River were induced to ovulate with three different hormonal substances: white sturgeon and common carp crude pituitary extracts, and [D-Ala6] GnRH analogue. All three inducing agents were potent at the respective doses of 2.5 mg, 4.0 mg and 0.1 mg dry matter per kilogram of female body weight. The best ovulatory responses and egg fertilities were observed in fish administered hormonal treatment during the months of March and April. Fish captured prior to and during their spawning migration exhibited similar spawning success.  相似文献   

11.
The silver perch (Bidyanus bidyanus Mitchell) (Teraponidae), is a native Australian freshwater fish that, due to its high potential for aquaculture, was introduced to Israeli fish farming. The objective of this study was to find an optimal method for inducing spawning of silver perch. The agents tested for this purpose were: human chorionic gonadotropin (hCG; 150 or 200 IU/kg BW); salmon gonadotropin releasing hormone analogue (sGnRHa at 10, 20, 30, or 40 μg/kg BW); mammalian GnRH analogue (mGnRHa at 30 μg/kg) and the combination of sGnRHa at 20 μg/kg and domperidone at 5 mg/kg BW. Based on spawning success and relative fecundity, sGnRHa at the dose of 30 μg/kg was found to be more efficient than hCG, mGnRHa or sGnRHa with domperidone. Since domperidone does not improve the GnRHa effect on final oocyte maturation (FOM) and spawning, it is suggested that the dopaminergic inhibition during the stages of FOM in the silver perch is weak. Therefore, the use of GnRHa alone is sufficient to induce spawning in this fish. Immunoreactive gonadotropin (IR-GtH) and estradiol levels increased after a single injection of sGnRHa, and peaked after 24 h. Plasma levels of 17α,20β-dihydroxy-4-pregnen-3-one (17,20-P) also increased significantly 24 h after the injection of mGnRHa, 12 h before spawning, suggesting that 17,20-P is the maturation-inducing steroid in silver perch. In order to reveal whether the heterologous gonadotropin may elicit an immunological reaction, silver perch was subjected to prolonged treatment with hCG. This treatment resulted in no detectable titer of antibodies against the mammalian gonadotropin. In conclusion, although hCG has no deleterious effects in this fish, and is the more commonly used for spawning induction, sGnRHa at 30 μg/kg is the recommended treatment for spawning induction of female silver perch under the conditions prevailing in Israeli aquaculture.  相似文献   

12.
Four distinct forms of native gonadotropin‐releasing hormone (GnRH) and two newly designed analogues were tested for their in vivo activity to induce ovulation in African catfish. The effects of these peptides on ovulatory parameters were compared with those of carp pituitary and [d ‐Ala6, Pro9‐NEt]‐mammalian GnRH analogue (mGnRHa), two tested ovulation‐inducing agents in African catfish. Assessment of ovulation was carried out by determining the ovulation ratio and the relative quantity of egg produced. From the results of the experiments, the order of potency of the native GnRH peptides is summarized as chicken GnRH‐II (cGnRH‐II) >salmon GnRH (sGnRH) >mammalian GnRH >chicken GnRH‐I (cGnRH‐I). Chicken GnRH‐II was as potent as mGnRHa while cGnRH‐I was totally ineffective. The new d ‐Orn6‐cGnRH‐II and d ‐Orn6‐sGnRH with a substitution at position 6 with d ‐isomer residue were as potent as the most extensively used mGnRHa, indicating that the position 6 modification might be more crucial than the substitution at the C‐terminal. On the basis of our results, the potential use and incorporation of cGnRH‐II and sGnRH for the development of more generic spawning induction therapies are suggested.  相似文献   

13.
The traditional GnRH analogue treatments applying the chemicals in pure form proved to be ineffective in inducing ovulation in northern pike (Esox lucius L). Neither mGnRHa ([D‐Ala6, Pro9NEt]‐mGnRH) nor sGnRHa ([D‐Arg6, Pro9‐Net]‐sGnRH) administered alone or together with pimozide (mGnRHa), metoclopramide (mGnRHa) or domperidone (sGnRHa) induced ovulation in females, whereas in groups receiving a carp pituitary injection most females ovulated. Spawning‐inducing agent Dagin did not induce ovulation, whereas all but one female ovulated in the carp pituitary‐treated group. Treatment with another preparation, Ovaprim, resulted in similar or lower ovulation ratio than treatment with carp pituitary. After the Ovaprim treatment, time to ovulation was not as predictable as after the carp pituitary injection. The mean fertilization rate was relatively low and similar in the groups treated with Ovaprim (54.7 ± 12.3% and 58.7 ± 19.1% for the first and second experiment respectively) and with carp pituitary (53.7 ± 10.5% and 58.9 ± 14.9%). The mean pseudogonadosomatic index (PGSI) was also similar between the Ovaprim‐treated group (14.5 ± 6.1%) and the carp pituitary‐treated one (17.9 ± 4.1%). In the present experiments, treatment with Ovaprim was less effective than that with carp pituitary.  相似文献   

14.
Kutum Rutilus frisii kutum (Kamenskii, 1901), Cyprinidae is an endemic fish of the Caspian Sea. Iranian Fisheries Organization (Shilat) produce up to 200 million fry (1–2 g body weight (b.w.)) to restock the Caspian Sea population annually. Some of these fry are produced by spawning induction in broodfish by carp pituitary extract (CPE). The objective of this study was to assay the effectiveness of the gonadotropin releasing hormone analogue (d ‐Ala6, Pro9‐Net GnRH) alone or in combination with metoclopramide (MET), a dopamine antagonist, on the percentage of ovulated females, latency period, ovulation index and fertilization success. The following hormone treatments were tested: single injection of 2 mg kg?1 b.w. of CPE as a positive control, GnRHa alone 20 and 40 μg kg?1 b.w. and combination of GnRHa and MET as follows: 5 μg+2.5 mg, 10 μg+ 5 mg and 20 μg+10 mg kg?1 b.w. Negative control group was injected with 0.7% saline. The percentage of ovulated females, ovulation index and fertilization success were 90%, 71.3±1.24%, 68.4±2.3%, respectively, in the group treated with GnRHa+MET at a dose of 20 μg+10 mg kg?1 b.w. and were significantly higher than those in the positive control (60%, 64.5±0.23%, 69.1±4.5%) (P<0.05). However, the latency period in this group was longer than that in the positive control (P<0.05). Only 20% and 40% fish ovulated in groups that received 20 or 40 μg kg?1 b.w. GnRHa. No fish ovulated in the negative control.  相似文献   

15.
ABSTRACT

An experiment was investigated to evaluate the effects of different doses of a new spawning agent Ovatide on induced spawning of striped snakehead, Channa striatus. Nine matured females with swollen abdomen and 18 male fishes with body weights ranging from 750 to 900 g, were randomly assigned to three treatment groups. Fishes in each group were administered 0.2, 0.4, and 0.6 mL of Ovatide/kg body weight, respectively. Each breeding set consists of two males and one female. Partial spawning response was observed when the fishes were administered with 0.2 mL/kg BW of Ovatide. Complete spawning was noticed in the medium (0.4 mL/kg BW) and higher (0.6 mL/kg BW) dose administered groups. The latency period and number of eggs spawned ranged from 23 to 27 hours and 1,764 to 7,096, respectively. No significant difference (P > 0.05) was noticed in the fertilization and hatching rate between the medium and higher doses of Ovatide tested. Thus, C. striatus could be successfully induced to spawn using a synthetic gonadotropin-releasing hormone with a dopamine antagonist at the dose of 0.4 mL/kg BW under captive conditions at 29 ± 1.5°C.  相似文献   

16.
Banded morwong (Cheilodactylus spectabilis) are of interest for marine finfish aquaculture in temperate southern Australia. To improve their ovulatory response, adult females were implanted during the autumn spawning season with slow‐release pellets containing 0–400 μg luteinizing‐hormone‐releasing hormone analogue (LHRHa)/kg body weight within 24 h of capture from the wild. Compared to the sham control group, animals treated with LHRHa produced significantly more eggs on each day after implantation for the following 7 d (91 ± 39 and 290 ± 38 mL) and a higher proportion ovulated (8/12 and 27/27). Of fish treated with LHRHa, 93% ovulated 2 d after implantation and 79% ovulated three times at 2‐d intervals, whereas control animals showed no cyclicity of ovulation and few ovulated more than once. Egg production was highest at the first ovulation after LHRHa treatment and declined at subsequent ovulations. In a second experiment investigating the range 100–400 μg LHRHa, there was no effect of dose rate on ovulation parameters, which additionally examined implantation either immediately after capture or after a 5‐d delay. Compared to immediate implantation, a delay resulted in a lower proportion of animals that could be stripped after implantation (100 and 50%, respectively) and the volume of eggs was lower (135 ± 15 and 107 ± 10 mL). The egg quality was poor following delayed implantation, resulting in no fertilization after artificial insemination compared with immediate implantation in which fertilization and hatch rates were higher for eggs collected on Day 2 after implantation (79 ± 8% and 58 ± 9%) than on Day 4 (23 ± 7% and 15 ± 6%). Thus, it is important to implant animals as soon as possible after capture to ensure optimum egg quality. Good‐quality eggs were buoyant and spherical and had a diameter of 1050 ± 25 μm with a single pigmented oil droplet of 190 ± 9 μm. When a separate large batch of eggs collected 2 d after implantation with 100 μg LHRHa was inseminated and cultured at 18 C, larvae hatched after 63 ± 2 h at a standard length of 2.6 ± 0.4 mm. Newly hatched larvae were buoyant and transparent with only a few melanophores, eyes were nonpigmented and jaws were nonfunctional. By the fourth day, jaws were functional and eyes were fully pigmented. Utilization of the endogenous yolk and oil was completed by Day 6, and swimming commenced with exogenous feeding. Larvae, initially fed lipid‐enriched rotifers followed by Artemia, reached 8.9 ± 0.7 mm length on Day 55, after which they metamorphosed to the postlarval paperfish stage of development, 22 ± 0.9 mm on Day 100, and 43 ± 1.0 mm at 6 mo of age. The results show that treatment of wild‐caught females with slow‐release pellets containing LHRHa is effective for the production of eggs for hatchery rearing.  相似文献   

17.
Goldfish,Carassius auratus, spawn several times within a spawning season. A gonadotropin (GtH) surge occurs at the time of ovulation in this cyprinid species. This ovulatory GtH surge mediates the processes of final oocyte maturation and ovulation, and occurs at the end of each spawning cycle. Within a cycle, there is a shift in the predominant plasma steroid from estradiol to testosterone, and finally 17α, 20β-dihydroxy-4-pregnen-3-one at the time of the ovulatory GtH surge. High levels of testosterone were always observed before ovulation. When ovariectomized or sexually regressed female goldfish were implanted with testosterone, they exhibited a GtH surge which was similar to those normally observed at ovulation. These results strongly suggest that elevated plasma testosterone is an important physiological requirement for the occurrence of the GtH surge.  相似文献   

18.
The effects of a single injection of mammalian superactive analogue [d ‐Ser(tBu)6,Pro9‐NEt]‐LHRHa (20 μg/ kg?1) combined with the dopamine antagonist, haloperidol (HAL, 0.5 mg kg?1), for induction of ovulation in the koi carp broodstocks were determined under routine hatchery conditions. The results were compared with classic carp pituitary extract (CPE, double injection) application (water temperature 22 °C). Physiological saline (0.7% NaCl)‐injected fish were used as a control group and no ovulation occurred in this group. The spawning ratio was high in the LHRHa+HAL treatment group and in the CPE treatment group (6/7 and 5/7 respectively). The latency period was 14–16 h in the LHRHa+HAL treatment group and 12–14 h in the CPE treatment group (after the second injection). There was no difference between the two ovulating groups with respect to the spawning index (the weight of eggs as a percentage of female body weight) and fertilization rate of eggs (P>0.05). As a result, ovulation can be induced successfully in koi carp broodstocks with 20 μg kg?1 [d ‐Ser(tBu)6,Pro9‐NEt]‐LHRHa+0.5 mg kg?1 HAL treatment in a single injection without decreasing the egg quality. Application of this combination can be useful for hatchery and broodstock management in koi carp culture.  相似文献   

19.
Two spawning inducing agents—Aquaspawn (a rapidly metabolized synthetic decapeptide gonadotropin-releasing hormone [GnRH]) and Dagin ([D-Arg6, Pro9-NEt]-sGnRH) combined with 20 mg/kg of the water-soluble dopamine receptor antagonist metoclopramide (GnRH + MET)—were tested for their efficacy in stimulating ovulation in Labeo victorianus held in its natural environment and under captive conditions. Successful ovulation, when migratory vesicle oocytes became completely transparent, was obtained with GnRH + MET, while GnRH only caused oocyte clearance up to the highly translucent phase. L. victorianus eggs were non-adhesive, semi-buoyant, and transparent at ovulation. First hatching occurred after 26 h and lasted for 8 h at 24 C. Water temperature was shown to significantly affect spawning latency and incubation time. Thus, L. victorianus could be successfully induced to spawn using a synthetic gonadotropin-releasing hormone coupled with a dopamine antagonist followed by natural fertilization in floating net cages at temperatures between 24 and 27 C.  相似文献   

20.
Induced breeding of climbing perch, Anabas testudineus was conducted by synthetic hormone Wova‐FH in the intensity level of 0.1, 0.2 and 0.3 mL kg?1 of body weight respectively. The brooders were injected one time and left to spawn in the spawning hapa in the sex ratio between male and female as 2:1. It was found that at all the intensity level hormone Wova‐FH could enhance the fishes to breed and lay eggs whereas no breeding was observed in control set. The spawning time, quantity of the brooder spawn, fertilization rate, hatching rate and survival rate were quantified in each set of experiment. The egg output/female was significantly higher in 0.3 mL in comparison with 0.1 and 0.2 mL kg?1 of body weight. The statistical analysis showed significant (P≤0.05) effect between hormone dose on fertilization rate, egg output and hatching rate. The present experiment suggests that Wova‐FH at the dose of 0.3 mL kg?1 body weight of fish is more effective which might be considered for raising captive population.  相似文献   

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