Doses Of Carp Pituitary Extract Research Articles

Dimethyl acetamide and dimethyl sulfoxide associated at glucose and egg yolk for cryopreservation of Pseudoplatystoma corruscans semen

Abstract This study aimed to develop a protocol for the cryopreservation of Pseudoplatystoma corruscans semen. For this, mature males were hormonally induced with a single dose of carp pituitary extract (5 mg/kg body weight). Semen was collected and evaluated. Two cryoprotectants were tested to compose the diluents: dimethyl acetamide (DMA) and dimethyl sulfoxide (Me2SO), in two concentrations (8% and 10%), + 5.0% glucose + 10% egg yolk. The semen was diluted in a 1: 4 ratio (semen: extender), packed in 0.5 mL straws and frozen in a dry shipper container in liquid nitrogen vapors. After thawing, sperm kinetics, sperm morphology and DNA integrity of cryopreserved sperm were evaluated. Pseudoplatystoma corruscans males produced semen with sperm motility > 80%. After thawing, all treatments provided semen with total sperm motility > 40%, with no significant difference (P < 0.05) between them, as well as between the other sperm kinetic parameters evaluated. The treatments with DMA provided a smaller fragmentation of the DNA of the gametes. Sperm malformations were identified in both fresh and cryopreserved semen, with a slight increase in these malformations being identified in sperm from thawed P. corruscans semen samples.

Determinação da concentração espermática de tambaqui (Colossoma macropomum) por espectrofotometria

Abstract To assist the reproductive management of tambaqui (Colossoma macropomum) males in laboratory and commercial fish farming, a linear regression model was obtained from concentration curves using the spectrophotometric method. Twenty-two tambaqui males with an average age of three years old were selected and divided into two groups containing 11 animals each. Both groups alternately received a single dose of carp pituitary extract (CPE; 2.0 mg/kg body weight, intracoelomic). Sperm was collected 14 h after hormonal treatment and diluted (1:4000; sperm:formaldehyde saline). The concentration was estimated by counting spermatozoa in a Neubauer chamber and by using a spectrophotometer (λ=540 nm). Individual sperm concentration ranged from 11.40 to 71.13 × 109 sperm/mL. The degree of transmittance ranged from 62.1% to 95.0%. There was a significant correlation (r2 = 0.966; p < 0.0001) between sperm concentration analyzed in a Neubauer chamber and transmittance at 540 nm. Analysis by spectrophotometry and the prediction provided by the equation Y=100.293 - 0.509X proved to be an efficient and fast method for estimating sperm concentration in tambaqui and can be used in routine procedures in artificial fish reproduction laboratories.

Tambaqui females (Colossoma macropomum) spawn after hormonal induction with buserelin acetate

The aim of this study was to evaluate induced reproduction in tambaqui females using buserelin acetate as compared with the traditional treatment regimen with carp pituitary extract (CPE). Reproductive traits of females with a body weight (BW) of 8.47 ± 1.52 kg were evaluated in ten females treated with buserelin acetate at the dose of 0.5 mL/kg BW, in a single application, and in ten females treated with CPE at the dose of 5.5 mg/kg BW, in two applications (10 % and 90 %, with a 12-h interval between applications). Spawning rate did not differ between the females treated with buserelin acetate (40 %) and CPE (40 %). Weight, fertilization rate and hatching rate did not differ between the two treatment groups. Degree-hours (determined as the average temperature multiplied by time, in hours, for spawning after the treatment with the second dose of CPE and after the single treatment with buserelin acetate) for spawning and number of oocytes per gram of gametes collected were greater (P < 0.05) in the females treated with buserelin acetate than in the females treated with CPE. Production index, absolute fecundity and relative fecundity were greater (P < 0.05) in the females treated with CPE. The hormone buserelin acetate promotes reproduction in tambaqui females with there being a similar spawning rate and oocyte quality, however, lesser production indices and fecundity than when there is the conventional treatment regimen imposed with carp pituitary extract.

Induced spermiation ofPimelodus britskii(Teleostei: Pimelodidae) during the reproductive period

For the first time was characterized the semen of Pimelodus britskii, hormonally induced and non-induced induced, during the reproductive period. The experiment 1 was conducted with 12 fish per month, divided into: (i) induced with Carp Pituitary Extract (CPE), and (ii) without hormonal induction (testes macerated). The experiment 2 was conducted, with 30 fish, divided into groups for comparison of different doses of CPE and human Chorionic Gonadotrophin (hCG; T1: control; T2: 3.0 mg kg−1 CPE; T3: 0.5 mg kg + 3.0 mg kg−1 CPE; T4: 0.5 mg kg−1 + 7.0 mg kg−1 CPE; T5: 200 UI kg−1 hCG), the same fish were used every month, and the semen was collected by abdominal massage. In both, experiments were assessed the sperm motility and velocity by means of the CASA software. In experiment 1, the concentration of spermatozoids was significantly increase by application of CPE compared untreated males. The volume and motility decreased gradually until the end of the experiment, the highest values were recorded for treatment induced (0.49 ± 0.25 mL and 62.18, respectively). The same occurred to Gonadosomatic Index, showing the smallest value at the end of the reproductive period. The fish from experiment 2 released reduced volume of watery semen (0.1 mL). The values of sperm concentration, motility velocity decreased gradually throughout the months. For P. britskii, the reproductive period influenced the production and sperm quality. Despite small seminal volume released the dose of 7.5 mg kg−1 of CPE proved effective.

Histochemical and morphological features of biopsied and stripped oocytes from the Brazilian endangered teleost pirapitinga, Brycon nattereri (Characiformes)

The aim of the present study was to characterize biopsied and stripped oocytes from the Brazilian endangered teleost pirapitinga (Brycon nattereri) using histochemical and morphological analyses. Biopsied oocytes had a mean diameter of 2.225 mm (modal diameter: 2.312 mm), complete vitellogenesis and a central or slightly eccentric nucleus. Neutral polysaccharides were detected in the follicular cells, zona radiata and yolk globules, while acidic polysaccharides were detected in the follicular cells and cortical alveoli. Ten out of the 19 females treated with two doses of carp pituitary extract (cPE) released oocytes, which were also analysed. Stripping occurred 292 ± 39 degree-hours after the second dose of cPE and led to a mean spawning weight of 36.2 g, 10% spawning index, 241 oocytes/g of ova, 8222 oocytes/female and 23 oocytes/g of body weight. Stripped oocytes had a mean diameter of 2.33 mm and a mode at 2.375 mm, were weakly adhesive and coloration ranged from wine to brown. Under scanning electron microscopy, stripped oocytes exhibited a single funnel-shaped micropyle located at the animal pole and a zona radiata that measured 7.7 μm in thickness with eight pore canals/μm2. Oocyte morphology in Brycon nattereri is similar to that found in other species of the genus, except for the larger size and weaker adhesiveness. These findings provide essential information for a better understanding of the reproductive biology of B. nattereri and the establishment of conservation measures for this threatened species.

A closed recirculating aquaculture system for artificial seed production of the European eel (Anguilla anguilla): Technology development for spontaneous spawning and eggs incubation

The objective of the present study was to obtain spontaneous reproduction in captivity of the European eel (Anguilla anguilla) by using a new closed recirculating aquaculture system provided with spawning and incubation chambers. The influence of two levels of water-flow rates (Low-Flow: 0.8±0.05L/s and High-Flow: 2.4±0.05L/s) on the spawning, fecundity and egg quality was also investigated. For this purpose 12 silver eel females were induced with increasing doses of carp pituitary extract (10, 20, 30 and 40mg CPE/kg BW). Twenty-four hours after the last CPE injection, each female ovulation was induced by injecting a DHP-solution and then transferring them to a new closed recirculating aquaculture system, where they were maintained for 16h with spermiating males (sex ratio 4/1) in order to obtain spontaneous reproduction. The reproduction was tested with 6 females in Low-Flow rate conditions and 6 females in High-Flow rate conditions.The results showed that the designed closed-loop system made it possible to carry out a more spontaneous reproduction for more than 80% of the females that underwent standardized gonadotropic treatment and favored the automatic and complete transfer of the eggs to the hatchery. The results also point out that high or low water current conditions in the tank do not hinder the mating and the emission of gametes by the breeders, but the High-Flow rate in the two incubation chambers showed unsuitable hydrodynamic conditions for embryonic development resulting in a constant loss of viable eggs which reached a mortality of 100% among females with the highest incubation density.

Artificial reproduction of neotropical fish: Extrusion or natural spawning?

In captive conditions, most neotropical migratory species do not have the necessary incentive to complete gonadal maturation and spawning, which require induction techniques, usually with the use of hormones. Numerous studies have therefore focused on finding an effective hormonal treatment to induce reproduction for each species. A standard treatment was successfully developed for most of these species, which consists of two doses of Carp Pituitary Extract (CPE), totaling 5.5 mgCPE/kg of fish. However, the best strategy for the subsequent fertilization of gametes is still unclear. This study was conducted with five species of commercial interest that do not reproduce naturally in captivity: pacu Piaractus mesopotamicus, piracanjuba Brycon orbignyanus, curimbatá Prochilodus lineatus, dourado Salminus brasiliensis and piau?u Leporinus macrocephalus. Ninety-nine broodstocks were used, consisting of males and females of the five species to compare two techniques for spawning and fertilization: extrusion followed by the dry method and natural spawning. All fish were induced with two hormone doses, i.e., 0.5 and 5.0 mgCPE/kg, and were subjected to one of the two types of fertilization. The results were compared using the fertilization rate, number of oocytes produced, relative fecundity and the broodstocks' survival rate on days following spawning. All species responded positively to spawning for extrusion, and only S. brasiliensis did not spawn through the natural spawning method. The natural spawning technique provided a higher fertilization rate of eggs and a greater broodstock survival rate (P S. brasiliensis. It was concluded that the natural spawning technique can increase the production of viable eggs and reduce the mortality of species during breeding, except for S. brasiliensis.

Spermatozoa motility, cryoresistance, and fertilizing ability in sterlet Acipenser ruthenus during sequential stripping

We describe spermatozoa characteristics from sequential collections in sterlet, Acipenser ruthenus, following a single dose of carp pituitary extract (CPE). Sperm production and spermatozoa fertilizing ability, percent motility, and curvilinear velocity (VCL) were investigated in fresh and frozen/thawed sperm. Sperm was collected by two procedures: (A) stripping 3 times per 24h at 3h intervals on 3 consecutive days beginning 12h after CPE treatment, and (B) stripping 3 times over 6h beginning 36h after CPE treatment. Spermatozoa motility and VCL were evaluated by video microscopy, and sperm production was measured as volume and concentration. Sperm samples were frozen by a conventional freezing procedure in a cryoprotective medium containing 10% methanol. Fertilization was conducted using a ratio of 105 spermatozoa/egg. Both sequential stripping procedures yielded larger volumes of viable spermatozoa than did a single collection. Sperm parameters such as density and volume varied widely depending on collection time. The highest numbers of spermatozoa per individual were collected 15–42h post-CPE treatment in (A) and at 42h post-CPE treatment in (B) (85±4% and 64±5% of total spermatozoa count, respectively). Median percent motility in spermatozoa before cryopreservation was 26–100% and 5–67% post-thaw. Fertilization rates obtained with frozen/thawed spermatozoa were 13–76% (median value). A significant increase in spermatozoa motility parameters and fertilizing ability at the second collection on each day was observed. Sequential stripping and spermatozoa cryopreservation in combination could improve the efficiency of sturgeon aquaculture.

Induction of Sexual Maturation in Wild Female European Eels (Anguilla anguilla) in Darkness and Light

Sexual maturity was induced in wild silver eel females of the European eel (Anguilla anguilla) using a protocol similar to that successfully used for Anguilla japonica. Eels were injected for sixteen weeks with increasing doses of carp pituitary extract (10, 20, 30, and 40 mg CPE/kg body wt) and kept in natural light or completely dark conditions. In both groups, final oocyte maturation and ovulation were induced by injection of 17,20 h-dihydroxy-4-pregnen-3-one (DHP) at 2 mg/g body wt. All sixty eels turned out to be silver and actively migrant (58 in stage V and two in stage IV), showing a particularly high eye index (15.75±1.40), and distributed within three age classes (7-9 years). In the group kept in darkness, one of the four females ovulated 12 h after DHP injection in the thirteenth week. The remaining three females received the final (16th) CPE injection and ovulated 12-36 h after the DHP injection. In the group kept in light, two of the four females received the 16th CPE injection and ovulated 12-36 h after the DHP injection; the remaining two did not ovulate within 36 h post DHP injection. The total number of eggs released by the group kept in darkness (1,485,600) was significantly higher than that of the group kept in light (274,000). There was no mortality during the experiment.

Effects of Latency Periods and Injection Doses with Carp Pituitary Extract on Spawning Performance and Egg Quality of Asian Catfish, Clarias batrachus (Linn.)

ABSTRACT An experiment was conducted to evaluate the spawning performance and egg quality of Clarias batrachus at variable latency periods (11, 14, 17, 20, and 23 h) and doses of carp pituitary extract (10, 20, 30, 40, and 50 mg/kg). The fish could not be stripped at 11 h latency with 10 or 20 mg carp pituitary extract (CPE). The highest quantity of eggs was obtained at 14 to 23 h latency with 30–40 mg CPE or 50 mg CPE with 14 to 17 h latency, which did not vary significantly (P < 0.05) at a water temperature of 27°C–28.5°C. The eggs did not fertilize and hatch when stripped at 11-h latency period. Over 80% of total eggs stripped from females injected with 30 and 40–50 mg CPE per kg body weight, and stripped at 14 to 23 h and 14- to 17-h latency, respectively, were fertilized. However, the highest (P < 0.05) number of larvae was obtained from females injected with 40 mg CPE and stripped at 14 or 17 h latency periods. Therefore, this CPE dose and 17 h latency period combination was regarded as the best for obtaining the highest number of larvae during induced spawning of C. batrachus.

Growth, Maturation, Induced Spawning, and Production of the First Generation of South American Catfish, Pseudoplatystoma sp., in North America

Abstract Growth, plasma steroids, and the appearance of gonads (histology and gonadosomatic index) were followed in South American catfish (surubim, Pseudoplatystoma sp.) raised in captivity in the aquaculture facility at The Ohio State University, Columbus, Ohio, USA, from 2003 until 2006. Broodstock growth showed a great individual variation and it did not seem sex dependent. The levels of 11‐ketotestosterone were high in males during the reproductive season. Three out of six females spawned after receiving two doses of carp pituitary extract (0.5 and 5 mg/kg) at 11‐h intervals. Fertilization was performed in only one female in February 2006. Egg size was 0.73 ± 0.06 mm in diameter at stripping. Two males released sperm, and it was used for fertilization. Sperm concentrations were 24 × 109 and 15.5 × 109 spermatozoa/mL in Male 1 and Male 2, respectively, and viability was confirmed after activation in 0.3% NaCl. Embryo survival at 9 h after fertilization was 44 and 23% for Male 1 and Male 2, respectively. Embryos hatched 15 h after fertilization. Larvae were 3.53 ± 0.09 mm in length at hatching and were successfully raised (72% survival after 2 wks) using live brine shrimp nauplii.

Spawning induction in the Mediterranean grey mullet Mugil cephalus and larval developmental stages

Spawning induction in the present study was carried out in two steps. The first treatment consisted of a priming dose of carp pituitary extract with 20 to 70 mg, or 10000 IU of human chorionic gonadotropin (HCG) per fish, while the second dose given 24 h later was the resolving dose of 200 µg/Kg luetenizing and releasing hormone (LHRH-a). After the resolving dose the females were maintained together with males and spawning occurred after 17 to 24 h on average. Running ripe males rated (+2) were used in 3:1 male to female sex ratio, in all spawning trials to optimize fertilization rates. The fecundity varied between 1 - 2.70 million eggs/spawn which represents 1395.3 ± 190 eggs/g bw. The ripe unfertile eggs ofM.cephalus were rounded, colorless and transparent with one oil globule. The surface of the fertilized egg shell is smooth, however; the yolk was unsegmented. After 20 min from fertilization the egg membrane swells up and separated from the previtelline space. The embryo began to be noticed after 13 ± 1 h post fertilization. The egg diameter was 870 ± 30 µm and oil globule was 350 µm. After about 26 ± 4 h post fertilization hatching was started at 25 ± 1°C and water salinity of 34 ppt. The percent of fertilization varied between 75 to 80% and hatching rate was about 90%. The newly hatched M. cephalus larvae was about 1.97 ± 0.23 mm in total length; larvae began feeding 3–5 days after hatching. The time of eye completion is nearly that of mouth opening and body axis becomes straight, which helps the larvae to identify their food as internal-external feeding starts. Key words: Mugil cephalus, carp pituitary extract (CPE), human chorionic gonadotropin (HCG), luetenizing and releasing hormone (LHRH-a), embryonic and larval stages.

Dose inseminante para fertilização artificial de ovócitos de jundiá cinza, Rhamdia quelen (Quoy &amp; Gaimardm, 1824)

Para determinação da dose inseminante ideal na fertilização artificial de ovócitos de jundiá cinza (Rhamdia quelen), foram selecionadas duas fêmeas com papila urogenital avermelhada, abdômen arredondado e liberação de ovócitos de cor e tamanho uniforme e quatro machos que apresentavam liberação de sêmen sob pressão da papila genital. As fêmeas e os machos receberam duas doses de extrato de hipófise de carpa (doses inicial e final de 0,5 e 0,25 mg.kg-1 e de 5,0 e 2,5 mg.kg-1, para fêmeas e machos, respectivamente). As duas fêmeas produziram 169 g de ovos contendo 1.141 ovócitos.g de ovócitos-1 e os machos, um total de 23,6 mL de sêmen. Do sêmen dos quatro machos foi realizado um pool e analisadas as seguintes características: concentração espermática (1,97x10(10) espermatozóides.mL-1), índice de sobrevivência espermática (96%) e morfologia espermática (66,9% de espermatozóides normais). No ensaio de fertilização, utilizou-se delineamento experimental inteiramente casualisado, composto de cinco tratamentos (6x10³, 6x10(4), 6x10(5), 6x10(6), 2x10(7) espermatozóides.ovócito-1) e quatro repetições. Após 8 horas de incubação, foram analisadas as taxas de fertilização para cada tratamento. A melhor relação espermatozóide.ovócito-1 foi de 89.497 espermatozóide.ovócito-1, o que provocou taxa de fertilização máxima teórica de 86,68%.

Induced spawning of hatchery-raised Brazilian catfish, cachara Pseudoplatystoma fasciatum (Linnaeus, 1766)

In the months of January 2001 and 2002, female cachara Pseudoplatystoma fasciatum were selected during their first and second gonadal maturation (2 years and 7 months old and 3 years and 7 months old, respectively) with an of oocyte diameter of 937.5 μm (82.5% with central nuclei and 17.5% with peripheral nuclei). Nine females in first maturation received two doses of carp pituitary extract (CPE), 0.5 mg/kg and 5.0 mg/kg; seven received two doses of human chorionic gonadotropin (hCG), 5 and 10 IU/g; five received doses of 0.5 CPE mg/kg and 5 hCG IU/g (CPE+hCG); and four received 0.9% saline (saline). Nine females from CPE and seven from hCG presented oocytes with the same diameter at the moment of oocyte release (100% with germinal vesicle breakdown and fertilization rate of 53.44±18.3 and 54.81±11.8%; larvae number of 165,330±94.1 and 158,570±20.6, respectively). The five females from CPE+hCG did not respond to the hormonal treatment. The four females from the saline group did not ovulate. In January 2002, 6 of 15 selected females that were going through the second reproductive cycle received CPE (five received hCG and four received saline), showing oocyte diameters similar to the ones in the first maturation. At stripping, CPE females had an oocyte diameter of 1062.5 μm (the hCG females had oocyte diameters ranging from 937.5 to 1125.0 μm; fertilization rates of 56.08±30.9 and 81.90±17.3%; 364,547±244 and 633,129±190, larvae, respectively). The fertilization rates and larvae number were higher in the second gonad maturation, both for CPE and hCG.

Spawning induction in common carp ( Cyprinus carpio) using pituitary extract or GnRH superactive analogue combined with metoclopramide: analysis of hormone profile, progress of oocyte maturation and dependence on temperature

Spawning experiments under routine hatchery conditions on Israeli farms showed that successful ovulation in the common carp (Dor 70×Yugoslavian lines) can be achieved by a single administration of 10 μg/kg sGnRHa ([D-Arg 6,Pro 9-NEt]-sGnRH) combined with 20 mg/kg of the water-soluble dopamine receptor antagonist, metoclopramide (GnRH + MET). An initial rise in the maturational gonadotropin (cGtH) level occurred 3 h after treatment, gradually increasing thereafter, and reaching a peak of 227±41.8 ng/ml (mean ± s.e.m., n = 10) 14 h after treatment, when full ovulation took place, as reflected by the presence of a few expelled eggs on the bottom of the tank. This rise was associated with increased levels of oestradiol-17 β (E 2; 19.5 ± 3.4 ng/ml) and 17 α,20 β-dihydroxy-4-pregnen-3-one (17,20-P; 23.9±19.7 ng/ml). Ovarian biopsies showed a gradual progress in oocyte maturation with germinal vesicle breakdown (GVBD) occurring during the rise in both steroids. At the time of initial egg release, GtH remained at a high level while the steroids started to decline. In a parallel group, fish were primed with a dose of carp pituitary extract (CPE), calibrated to contain 0.07 mg/kg cGtH, and 11 h later with a resolving dose of CPE (0.34 mg/kg cGtH). Following priming, circulating GtH and E 2 increased moderately, and the germinal vesicle migrated towards the oocytes' periphery. A further increase in cGtH and E 2, and a sharp peak in 17,20-P, occurred concomitantly with GVBD, 6 h after the resolving dose was given. Data compiled from several spawning experiments showed that the interval between hormone administration and initial egg release (latency) was negatively correlated with water temperature over the range of 20–26°C. While latency was always longer in GnRH+MET than in CPE treatment, in each treatment it was nonetheless constant between 22.5°C and 25°C. GnRH+MET given at various hours of the day or evening resulted in identical spawning with the same latency. This fact, together with the predicted latency at a given temperature, may provide the aquaculturist with a protocol to accurately schedule spawning induction in the common carp.