Ocimum basilicum essential oil in pacu Piaractus mesopotamicus: anesthetic efficacy, distribution, and depletion in different tissues.

This study aimed to evaluate the anesthetic activity of Ocimum basilicum essential oil and the distribution and depletion of its major compounds in different tissues of the pacu, Piaractus mesopotamicus. Juveniles (319.08 ± 9.14 g) were individually anesthetized with six concentrations of essential oil from O. basilicum (150, 180, 210, 240, 270, and 300 mg L-1), while in a second experiment, fish (492.39 ± 51.51 g) were subjected to a 10 min immersion bath with essential oil from O. basilicum (300 mg L-1). After anesthetic recovery, blood and tissue samples of the brain, gills, liver, spleen, and white muscle were collected at 0, 0.5, 1.0, 3.0, 6.0, 12.0, and 24 h. A 300 mg L-1 concentration induced anesthesia in the shortest time (193.11 ± 9.31), while at 270 and 300 mg L-1 concentrations, the anesthetic recovery period was the longest (244.33 ± 12.44) Methyl chavicol and linalool were quantified in all tissue samples. The plasma concentrations of methyl chavicol differed (p < 0.05) at all evaluated times. Linalool decreased (p < 0.05) from 0 to 1 h and decreased again only after 12 h. Reduction percentages in 24 h were 92.9% for methyl chavicol, and 97.2% for linalool. Elimination of the compounds methyl chavicol and linalool is slower in the gills, where lower elimination constants (0.03 and 0.15 per h) and longer half-lives (25.84 and 4.53 h), respectively, are noted. In general, essential oil from O. basilicum compounds was readily eliminated, showing promising potential for use as an anesthetic in aquaculture.

Intestinal morphometry and cell density features in tropical farmed fish: A methodological approach.

The digestive tract of fish has many morphological adaptations related to habitat and nutrition. Intestinal biometry may reflect these adaptations. Here, we aimed to describe histometric patterns in farmed fish and their relationship with feeding by using a standardized protocol considering cell density by tissue area. Five juvenile specimens of each species (Pseudoplatystoma corruscans, Piaractus mesopotamicus, and Oreochromis niloticus) were used. O. niloticus possessed higher intestinal weight and length besides higher intestinal quotient and intestinal somatic index than the other species. The general histological composition was similar between species. However, P. corruscans showed differences in thickness between the anterior and posterior segments. O. niloticus had thinner serosa and muscularis layers than the other species. The cell density was distinct in both species and segments. Comparing the intestinal segments, O. niloticus displayed the lowest count of granulocytes. Goblet cell density was lower in P. mesopotamicus in all segments. However, the volume of these cells was higher in the anterior and middle anterior segments. Our data demonstrated that intestinal structural plasticity is associated with the difference in feeding habits. Here, we used quantitative standardized histometric criteria to understand the morphophysiological diversity of the fish digestive tract, and this technique can be applied in future studies to evaluate changes in the digestive tracts of vertebrates.

Evaluation of a panel of microsatellite markers to study their applications in Serrapinnus notomelas and to reveal the genetic diversity in Hyphessobrycon eques.

Jewel tetra (Hyphessobrycon eques) is a freshwater fish found in several rivers and basins in South America. The present study is the first study to create a panel of microsatellite markers for detecting genetic diversity in H. eques and evaluating the application of these markers in Serrapinnus notomelas. In total, 44 individuals were genotyped from the natural (WIL, n = 20) and stock in captivity (CAP, n = 24) population. Moreover, 19 microsatellite markers were obtained, of which only 8 loci presented a high degree polymorphism. In total, 45 alleles were detected, ranging from 126 bp (Hype2G2) to 420 bp (Hype2E2). The Hardy-Weinberg equilibrium (p < 0.05) revealed significant difference in one locus in WIL (Hype1G4) and three loci in CAP (Hype1F4, Hype2C3, and Hype2G2). Null alleles (p < 0.05) were present in only one locus (Hype1G4). The WIL and CAP populations revealed high genetic diversity during FST analysis. The cross-amplification test for S. notomelas revealed that only two loci (Hype2C3 and Hype2G2B) presented satisfactory transferability results. The developed microsatellite primers will be useful in studying the genetic diversity and population structure of H. eques in wild populations and fish farms in the Brazilian and other South American basins.

Successive seminal collections from Leiarius marmoratus during the reproductive period.

This study aim was to verify whether milt quality of male Leiarius marmoratus is maintained among successive samples collected during the same reproductive period. Ten reproductively mature males were used to evaluate four successive sperm samples collected at 10-day intervals. For these collections, seven males were injected with carp pituitary homogenate (CPH) at a dosage of 3.0 mg/kg body weight, in two applications (30% and 70%), at an interval of 10 h. The other three males were administered only saline (control). Injection with CPH or saline occurred prior to each of the four collections. Only one male from the control group released a small volume of milt (0.33 mL), and only during the first collection period. Of the seven males treated with CPH, five released milt during all four collections. Milt volume of the first sample collected (0.63 mL) did not differ from that of other samples (0.59-1.38 mL; P > 0.05). Sperm concentration was greater in the first samples collected (1.98 × 109 spermatozoa/mL) compared to the other samples (0.35 × 109 at 0.92 × 109 spermatozoa/mL; P < 0.05). Sperm motility, curvilinear velocity, straightness, and morphological normality did not differ among the consecutive samples (P > 0.05). Average path velocity, straight-line velocity, oscillation, linearity, progression, and membrane integrity decreased slightly in the samples collected subsequent to the first sample (P > 0.05). In conclusion, milt quality decreased among successive collections; however, quality of all samples from all collections was sufficient for use for fertilization of oocytes.

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 ±â€¯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.

Transferability of heterologous primers in Brycon falcatus

The genus Bryconcomprises fish species of significant socioeconomic and biological importance in Brazil. Despite that, the genetic knowledge about these species is scarce, especially regardingBrycon falcatus. Thus, the objective of this study was to evaluate the transferability of heterologous microsatellite primers inB. falcatus for the first time. Heterologous primers obtained from B. opalinus, B. hilarii, B. insignis, B. orbignyanus, B. amazonicus, Prochilodus argenteus, Prochilodus lineatus, Piaractus mesopotamicus, and Colossoma macropomum were evaluated. The primers that showed the best amplification patterns were applied to a sample of 22 individuals and the genetic parameters were calculated. Nine primers displayed satisfactory cross-amplification withB. falcatus: BoM5 (Brycon opalinus); Bh8, Bh13 and Bh16 (B. hilarii); Borg59 (B. orbignyanus); Bag22 (B. amazonicus); Par12 and Par80 (P. argenteus), and Cm1A8 (C. macropomum). The genetic parameters (number of alleles, effective alleles, allele richness, and expected and observed heterozygosity) and the polymorphic information content (PIC) confirmed the viability of these primers for population genetics analyses. Our study demonstrates the potential of transferability of microsatellite markers from related species and even different genera to B. falcatus, providing usefull tools for future population genetic studies in this species. (AU)

Performance and economic viability of tambaqui, Colossoma macropomum, selectively bred for weight gain

Tambaqui, Colossoma macropomum, is one of the most produced species in Brazilian fish farming, which has boosted the development of new technologies to increase its productivity. The aim of this study was to evaluate production performance in two second-generation tambaqui stocks selectively bred for weight gain in a semi-intensive rearing system and assess its influence on total production cost. We analyzed 300 fish (initial mean weight and standard length of 160 g and 17 cm, respectively) of two families (A and B, 150 fish each). The fish were individually marked with microchips and stocked in an 800-m2 excavated pond. For economic analysis, the obtained performance data were extrapolated for a fish farm with a 10-ha pond, adopting the Total Production Cost methodology. After 270 days of farming, the fish from family B were significantly superior (p < 0.05) for all analyzed performance parameters (final weight = 1965.0 g; weight gain = 1786.7 g; biomass gain = 255.2 kg) and morphometric growth in relation to the fish from family A (final weight = 1881.0 g; weight gain = 1737.5 g; biomass gain: 217.7 kg). The total production cost estimations indicated that fish from family B would allow for a 4% reduction in the average fixed cost and a 1% decrease in the total average production cost. (AU)

Colossoma macropomum females can reproduce more than once in the same reproductive period.

The aim of the present study was to evaluate induced reproduction in Colossoma macropomum females at the beginning of the reproductive period and 75 days after the first spawning in which reproduction was induced. The experiment was conducted in Nova Mutum, MT, Brazil. Eight 4-year-old C. macropomum females with an average body weight of 6.7 ± 2.4 kg were used. Hormonal induction was performed at the beginning of the reproductive period and repeated 75 days after the first spawning. The following variables were then evaluated: weight of released oocytes, production index, absolute fecundity, oocyte diameter, fertilization rate, and hatching rate. Of the eight females that spawned during the first hormonal induction, three (37.5%) spawned again 75 days after the first spawning. Two females died after the first induced spawning. None of the means of the evaluated variables differed between the two induced spawnings, except for fertilization rate, which was greater (P < 0.05) with the first spawning (88.8 ± 6.1%) than in the second (74.1 ± 10.4%). The results of the present study indicate that C. macropomum females can reproduce again 75 days after a first induced spawning.

Ovopel® and carp pituitary extract for induction of reproduction in Colossoma macropomum females.

The aim of this study was to evaluate the efficiency of the hormonal inducers Ovopel® and carp pituitary extract (CPE) for induction of reproduction in Colossoma macropomum females. The treatments were CPE at the dose of 5.5 mg/kg divided into two applications (10%; and 90% after 12 h) and Ovopel® at doses of 0.2 and 0.4 pellet/kg body weight in a single application. Eight replicates were used in each of the three treatments, totaling 24 experimental units. The females spawned when treated with the 0.2 pellet of Ovopel® (100.0%), 0.4 pellet of Ovopel® (62.5%), and CPE (87.5%), but there were no significant differences among the treatment groups in spawning rate. When there was treatment with Ovopel® spawning occurred with greater (P < 0.05) degree-hours (average water temperature × number of hours until spawning; 0.2 pellet: 417.7; 0.4 pellet: 412.3) in relation to the CPE treatment (268.9). The total oocyte weight was similar when there was treatment with Ovopel® (0.2 pellet: 832.3 g; 0.4 pellet: 798.9 g) and CPE (688.3 g). By contrast, the production index was greater (P < 0.05) with the Ovopel® treatments (0.2 pellet: 8.8%; 0.4 pellet: 9.0%) as compared with CPE (6.7%). Fertility and hatching rates were similar among the treatment groups. Ovopel® and CPE are efficient in induction of reproduction in C. macropomum females. Of the two Ovopel® treatments assessed in this study, the dose of 0.2 pellet/kg body weight is sufficient for effective induction of reproductive processes.

Ovopel and carp pituitary extract for the reproductive induction of Colossoma macropomum males.

The objective of this study was to evaluate Ovopel and carp pituitary extract (CPE) in the reproductive induction of Colossoma macropomum males. Nine treatments were tested in triplicate, totaling 27 experimental units. C. macropomum breeders were subjected to the following treatments: 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, and 0.7 Ovopel pellet/kg; 2.5 mg CPE/kg (traditional protocol); and a control treatment (no hormone). Breeders under hormone treatment produced a larger (P < 0.05) semen volume (2.4 ± 0.7 to 4.2 ± 0.3 mL) compared with the control (0.9 ± 0.4 mL). Sperm concentration did not differ significantly among treatments (7.2 × 109 ± 1.7 to 10.8 × 109 ± 2.6 spermatozoa/mL). Total sperm count was higher (P < 0.05) after treatment with 0.3, 0.4, and 0.6 Ovopel pellet/kg (41.6 ± 9.3 to 42.3 ± 10.5 × 109 spermatozoa) than the other Ovopel treatments (20.0 ± 2.4 to 26.9 ± 8.2 × 109 spermatozoa) and control (6.6 ± 1.1 × 109 spermatozoa), but did not differ significantly from CPE (33.7 ± 3.2 × 109 spermatozoa). Sperm motility was higher (P < 0.05) in the CPE treated, and 0.2, 0.3, and 0.7 Ovopel pellet/kg (88.3 ± 2.9 to 90.0 ± 5.0) breeders when compared with the other treatments (70.0 ± 10.0 to 78.3 ± 5.8), except for the 0.4 pellet/kg (81.7 ± 2.9) treatment, which did not differ significantly from any of the treatments. The motility period of the spermatozoa did not differ significantly among treatments (93.5 ± 15.7 to 120.0 ± 7.6 s). For the sperm morphological analysis, occurrence of normal spermatozoa was similar across the treatments, with three sperm abnormalities (short tail, bent tail, and detached head) differing (P < 0.05) among the treatments. Ovopel efficiently induced reproduction of C. macropomum breeders, with treatment using 0.3 and 0.4 Ovopel pellet/kg and CPE providing the best semen characteristics.

Genetic Variability of Brycon hilarii in a Repopulation Program

ABSTRACT Brycon hilarii, popularly called piraputanga in Brazil, is a species distributed throughout the whole basin of the river Paraguay. In recent years, the species has been on a repopulation program due to its remarkable decline as a wild species in the region. Assessment of the genetic diversity of broodstock and fingerling stocks in repopulation programs is basic to avoid genetic impacts on wild populations. The genetic variability of the wild population and of the broodstock and fingerling stocks of B. hilarii in a repopulation program in the river Itiquira MT Brazil will be determined. Seven microsatellite loci produced 52 polymorphic alleles and heterozygosity revealed rates between 0.5794 and 0.7204. FIS did not register any endogamy in the broodstock but it was present in fingerlings and wild populations. Intra- and inter-specific genetic variability rates were higher within each combination but not between groups. Grouping in fingerling groups had a lower density when compared to the others. There is a higher genetic proximity between the natural population and broodstock (0.0237) when the distance between populations was analyzed, even though the two were greatly distant from the fingerling group (0.2622 - 0.2617). Results show that the wild population and the broodstock had high genetic variability and low genetic divergence; contrastingly, fingerlings showed mild genetic variability and great divergence when compared to other groups, indicating that they were not adequately constituted.

Seminal characteristics of piabanha before and after induction with different hormones / Características seminais de piabanha antes e após a indução com diferentes hormônios

The migratory species piabanha does not reproduce in lentic environments since it requires environmental stimuli for the maturation and extrusion of gametes, and therefore hormonal induction is mandatory. Current study compares the seminal characteristics of Brycon insignis without any hormonal induction (Control - Ctrl) and with two types of hormonal inductors, or rather, carp pituitary extract (T1 - 2.5 mg kg-1 body weight) and GnRH analogues, the latter applied in two different concentrations (T2 - 0.7 mg kg-1 body weight and T3 - 1.4 mg kg-1 body weight). Post-induction analyses showed that the hormones increased the motility rate - Ctrl (95%), T1 (100%), T2 (100%) and T3 (98%), although sperm concentration - Ctrl (11.52 x 109); T1 (4.37 x 109); T2 (4.34 x 109); T3 (4.01 x 109) decreased. Assessments for sperm vigor, motility time and spermatic morphology did not vary with hormonal induction. Hormonal inducer does not alter negatively the seminal characteristics of the piabanha, and the choice for the proper hormone depends on the preference of the dispenser.

A espécie migradora piabanha não possui a capacidade de reproduzir em ambientes lênticos devido à necessidade de estímulos ambientais para a maturação e extrusão dos gametas, por isso a necessidade da indução hormonal. No presente estudo, as características seminais do Brycon insignis foram comparadas sem indução hormonal (Ctrl) e utilizando dois tipos de indutores hormonais - Extrato de Hipófise de Carpa (T1 - 2,5 mg kg-1 de peso vivo) e Análogos de GnRH, sendo este último aplicado em duas concentrações distintas (T2 - 0,7 mg kg -1 de peso vivo e T3 - 1,4 mg kg-1 de peso vivo). As análises realizadas após a indução mostraram que os hormônios utilizados produziram um aumento da taxa de motilidade - Ctrl (95%), T1 (100%), T2 (100%) e T3 (98%), porém houve uma diminuição na concentração espermática - Ctrl (11,52 x 109), T1 (4,37 x 109), T2 (4,34 x 109) e T3 (4,01 x 109). Os restantes das avaliações, vigor espermático, tempo de motilidade e morfologia espermática não apresentaram variações com a indução hormonal. Portanto, a utilização do indutor hormonal não altera negativamente as características seminais de piabanha, e a escolha do mesmo se deve à preferência do manipulador.

Functional integrity of Colossoma macropomum (Cuvier, 1816) sperm cryopreserved with enriched extender solutions

Cryoprotectant solutions are used to protect the sperm from alterations caused by the low temperature in the cryopreservation process. We evaluated the quality of Colossoma macropomum semen after freezing, using dimethyl sulfoxide (DMSO) as a cryoprotectant, combined with two extender solutions (T1 - Solution 1: Glucose 90.0 g/L, Sodium Citrate 6.0 g/L, EDTA 1.5 g/L, Sodium Bicarbonate 1.5 g/L, Potassium Chloride 0.8 g/L, Gentamycin Sulphate 0.2 g/L, and T2 - Solution 2: Glucose 90.0 g/L, ACP(r)-104 10.0 g/L). Motility rate and motility time did not differ between T1 and T2 and were lower than fresh semen. The number of normal sperm was significantly different in treatments T1 (15.1%) and T2 (21.9%), and both showed a reduction in the percentage of normal sperm compared to fresh semen (57.4%). The values found for the rates of fertilization and hatching, mitochondrial functionality and sperm DNA, did not differ between the treatments (T1 and T2). Regarding membrane integrity, there was a higher percentage of spermatozoa with intact membranes in T1 (53.4%) than T2 (43.7%). The extender solutions, combined with 10% DMSO, maintained the sperm DNA intact in almost all the C. macropomumsperm cells, however there was a loss in their functionality.

As soluções crioprotetoras são utilizadas para proteger os espermatozoides das alterações causadas por baixas temperaturas durante o processo de criopreservação. Avaliamos a qualidade do sêmen de Colossoma macropomumapós o congelamento, utilizando dimetilsulfóxido (DMSO) como crioprotetor, combinado com duas soluções diluidoras (T1 - Solução 1: Glicose 90,0 g/L, Citrato de Sódio 6,0 g/L, EDTA 1,5 g/L, Bicarbonato de Sódio 1,5 g/L, Cloreto de Potássio 0,8 g/L, Sulfato de Gentamicina 0,2 g/L, e T2 - Solução 2: Glicose 90,0 g/L, ACP(r)-104 10,0 g/L). A taxa de motilidade (%) e o tempo de motilidade (s) não diferiram entre T1 e T2, porém foram mais baixos do que no sêmen fresco. O número de espermatozoides normais foi significativamente diferente nos tratamentos T1 (15,1%) e T2 (21,9%), e ambos mostraram uma redução na porcentagem de espermatozoides normais, comparado ao sêmen fresco (57,4%). Os valores encontrados para as taxas de fertilização e eclosão, funcionalidade mitocondrial e DNA do esperma, não diferiram entre os tratamentos (T1 e T2). Para a integridade da membrana, houve uma porcentagem mais elevada de espermatozóides com a membrana intacta em T1 (53,4%) do que T2 (43,7%). As soluções diluentes combinadas com DMSO a 10% preservaram o DNA espermático intacto em quase todas as células do sêmen de C. macropomum, mas houve perda na funcionalidade dos mesmos.

Ovopel and Carp Pituitary Extract as Spawning Inducers in Males of the Amazon Catfish Leiarius marmoratus (Gill, 1970)

The objective of this study was to evaluate Ovopel and carp pituitary extract as spawning inducers in the males of the Amazon catfish L. marmoratus. The following treatments, applied in a single dose, were studied: 0.2, 0.4 and 0.6 Ovopel pellet/kg live weight, and 2.5 mg carp pituitary extract/kg live weight. Each treatment was repeated four times. No significant difference in sperm volume, motility and vigor, time of motility, sperm count, or percentage of normal and abnormal spermatozoa was observed between the treatments. There was also no significant difference in terms of primary or secondary sperm defects, except for the secondary defect of loose heads, which was less frequent in the treatments using 0.4 and 0.6 Ovopel pellet/kg live weight. It was concluded that Ovopel could replace carp pituitary extract for induction spawning in the males of the Amazon catfish L. marmoratus.

Physiological responses of pacu (Piaractus mesopotamicus) treated with homeopathic product and submitted to transport stress.

BACKGROUND: Pacu (Piaractus mesopotamicus) is a species with great potential for Brazilian fish farming and losses through mortality are common after transport as a direct or indirect result of stress. The use of homeopathic complex is a further option to minimize the various stress factors that can interfere negatively in production. METHODS: After feeding for 10 consecutive days with commercial diet; or diet supplemented with sucrose; or commercial diet supplemented with homeopathic complex, juvenile pacu were placed in a polyethylene bags and transported for four hours with the following treatments: commercial diet (control); commercial diet and homeopathic complex dissolved in the transport water (W + HP); commercial diet supplemented with sucrose (D + SU) and commercial diet supplemented with homeopathic complex (D + HP). Blood was collected before transport (basal), after transport (arrival), 24 and 72 h after transport. The physiological indicators of the stress were blood glucose, cortisol and chloride levels, hematocrit, hemoglobin and total protein. Condition factor and mortality were also determined. RESULTS: Blood glucose increased significantly on arrival, returning to the basal values 24 h after, similarly in all treatments. Plasma cortisol levels were elevated on arrival but not significantly compared to the basal values for fish from W + HP and D + SU groups. Increase in hematocrit and hemoglobin and low plasma chloride levels were observed after transport in all treatments. CONCLUSION: Transport resulted in stress responses in juvenile pacu and the homeopathic complex, administered in the water or diet, did not minimize these responses. Sucrose supplementation altered the cortisol and blood glucose levels, suggesting a moderating effect on these stress indicators.

Microsatellite analysis of the parental contribution of Piaractus mesopotamicus to the production of offspring in the semi-natural system of reproduction

The objective of this study was to evaluate the genetic diversity and the parental contribution of Piaractus mesopotamicus in the production of offspring in the semi-natural system of reproduction. Twenty parental fishes (eleven males and nine females) and the total of 100 larvae were evaluated by microsatellite marker. The parents and offspring had thirty-one alleles and heterozygosity of 0.550 and 0.563, respectively. The females were fertilised by two up to six males while the males fertilised three up to five females. The contribution of the females and males to the offspring were 66.6 and 58 percent, respectively. Such results indicated no loss in the genetic variability in the offspring, and the parents had multiple paternity and reasonable contribution to the offspring production.

O objetivo deste trabalho foi avaliar a diversidade genética e a contribuição parental de Piaractus mesopotamicus na produção de descendência no sistema seminatural de reprodução. Vinte peixes parentais (onze machos e nove fêmeas) e o total de 100 larvas foram avaliados por meio do marcador microssátelite. Os parentais e a progênie tiveram trinta e um alelos e heterozigosidade de 0,550 e 0,563, respectivamente. As fêmeas foram fertilizadas por dois até seis machos enquanto machos fertilizaram três até cinco fêmeas. A contribuição de fêmeas e machos para a descendência seja 66,6 e 58,0 por cento, respectivamente. Tais resultados não indicam diminuição da variabilidade genética na progênie e os parentais apresentaram paternidade múltipla e razoável contribuição à produção de descendência.

Diversidade genética de quatro linhagens de Oreochromis miloticus utilizando o marcador RAPD / Genetic diversity of four Oreochromis niloticus strains using the RAPD marker

O objetivo do presente estudo foi analisar a diversidade genética de quatro linhagens de tilápia do Nilo (Oreochromis niloticus), utilizando o marcador RAPD. Foram coletadas amostras de nadadeira de estoques de juvenis das linhagens GIFT (G), Chitralada (C), Supreme (S) e Bouaké (B). Os 11 primers utilizados produziram 81 fragmentos dos quais 41,98% foram polimórficos. A porcentagem de fragmentos polimórficos (G: 18,52%; C: 19,75%; S: 20,99% e B: 24,79%) e os resultados do Gst confirmaram que houve alta (BxG: 0,231; BxC: 0,224; GxC: 0,194 e SxC: 0,208) e elevada (BxS: 0,315 e GxS: 0,270) diferenciação genética entre as linhagens. O fluxo gênico (Nm) foi maior entre as linhagens GxC (2,082). Os valores de distância e identidade genética (0,044 e 0,957 respectivamente) e o dendrograma indicam que as linhagens GxC são os mais semelhantes geneticamente. A similaridade genética foi alta dentro das linhagens (G: 0,932; C: 0,903; S: 0,891 e B: 0.900). Os resultados deste estudo possibilitarão o correto manejo reprodutivo e genético das linhagens.

The aim of this study was to analyze the genetic diversity of four Nile Tilapia (Oreochromis niloticus) strains using the RAPD marker. Fin samples of GIFT (G), Chitralada (C), Supreme (S) and Bouaké (B) juvenile stocks have been collected. The 11 primers used yielded 81 fragments of which 41.98% were polymorphic. The percentage of polymorphic loci (G: 18.52%; C: 19.75%; S: 20.99% and B: 24.79%) showed that there was a genetic differentiation among the strains, showing the Gst values a high (BxG: 0.231; BxC: 0.224; GxC: 0.194 and SxC: 0.208) and elevated (BxS: 0.315 and GxS: 0.270) differentiation. The highest gene flow (Nm) was among the GxC (2.082) strains. The distance and genetic identity values (0.044 and 0.957 respectively) and the dendrogram indicate that the GxC is the most genetically similar strains. The genetic similarity was high among of the strains (G: 0,932; C: 0,903; S: 0,891 AND B: 0.900). These results will enable a correct reproductive and genetic strains management.

Caracterização genética de estoques de Prochilodus lineatus(Valenciennes, 1836) (Characiformes: Prochilodontidae), utilizados em programas de repovoamento: importância para a conservação da ictiofauna e do ecossistema / Genetic characterization of Prochilodus lineatus (Valenciennes, 1836)

Alterações ambientais provocadas pelas mudanças climáticas e principalmente por ações humanastêm reduzido populações naturais de peixes nos últimos anos. Os programas de repovoamento têm sido utilizados como forma de conservação, porém, sem uma correta orientação científica essas medidas podem gerar distúrbios sobre a diversidade genética da ictiofauna e sobre o ecossistema. O objetivo deste estudo foi analisar a diversidade genética de dois estoques de alevinos de Prochilodus lineatus utilizados em programas de repovoamento, mediante o marcadormolecular RAPD. Foram analisados 60 alevinos (estoque A e B) de uma piscicultura localizada no município de Rolândia, PR (Brasil). Os sete iniciadores selecionados produziram um total de 77 fragmentos, dos quais 81,82% foram polimórficos. Os valores de variabilidade genética estimados pela porcentagem de fragmentos polimórficos (A= 83,12%;B= 81,82%) e pelo índice de diversidade genética de Shannon (A= 0,473; B= 0,463) mostraram que não existe uma alta diferenciação genética entre os dois estoques, possivelmente devido ao efeito fundador e ao manejo reprodutivo. Este resultado foi corroborado com o valor de Gst (0,043), do dendrograma e da distância e identidade genética (0,967 e 0,034)que mostram uma baixa diferenciação genética entre eles. Os resultados deste estudo possibilitarão o correto manejoreprodutivo e genético dos estoques e a orientação objetiva de programas de repovoamento, permitindo a conservação da ictiofauna e dos ecossistemas impactados.

Environmental alterations caused by the climatic changes and mainly for human actions, it hasbeen reducing fish natural populations in the last years. The stocking programs have been used as conservation form,however, without a correct scientific orientation those measured can generate disturbances about the genetic diversity of the ichthyofauna and on the ecosystem. The objective of this study was to analyze the genetic diversity of two juvenile Prochilodus lineatus stocks used in stocking programs, by the RAPD molecular marker. Sixty juvenile (A and B stocks) of a fish farm located in the Rolândia Municipal District, PR (Brazil) were analyzed. The seven primers selected produced a total of 71 fragments, of which 89.44% were polymorphic. The genetic variability values estimated by the percentage ofpolymorphic fragments (A = 83.12%; B = 81.82%) and for the genetic diversity of Shannon index (A = 0.473; B = 0.463) showed that a high genetic differentiation doesn't exist among the two stocks, possibly due to the founder effect and the reproductive management. This result was corroborated with the Gst value (0.043), of the dendrogram and of the distance and genetic identity (0.967 and 0.034) that show a low genetic differentiation among them. The results of this study will make possible the correct reproductive and genetic management stocks and the objective orientation at of stocking programs, allowing the ichthyofauna and the impact ecosystems conservation.

Características qualitativas do sêmen de pacu (Piaractus mesopotamicus) após indução hormonal / The semen qualitative characteristics and spermatozoa life time ofo pacu (Piaractus mesopotamicus) after hormonal induction

Parâmetros qualitativos do sêmen de 44 Piaractus mesopotamicus foram analisados com e sem a indução reprodutiva com extrato de hipófise de carpa. Não ocorreu diferença (P>0,05) para a motilidade progressiva e vigor espermático entre os tratamentos, muito embora tenha ocorrido uma tendência de médias maior para o sêmen oriundo de animais induzidos, 79,5 por cento e 3,7 pontos contra 73,5 por cento e 3,5 pontos respectivamente. O tempo de vida dos espermatozóides também não apresentou diferença (P>0,05) para o sêmen analisado com e sem indução hormonal 50,3 e 52,4 segundos, respectivamente. Não houve diferença (P>0,05) no sêmen analisado de pacus induzidos e não induzidos, para porcentagem de espermatozóides normais (58,2 e 62,6) com patologias leves (12,9 e 12,1) e graves (28,9 e 25,3). Os tipos de patologias mais incidentes, tanto no sêmen de animais induzidos e não induzidos, foram cauda quebrada e enrolada, sendo os dois tipos graves. Através dos resultados conclui-se que a indução hormonal com extrato de hipófise de carpa, não causou alterações significativas para os parâmetros qualitativos avaliados. Porém, ficou constatado a incidência elevada de patologias graves no sêmen de pacu, especialmente, cauda enrolada, quebrada e corrugada.

Qualitative parameters of 44 Piaractus mesopotamicus semen were analyzed with and without reproductive induction using hypophysis extract obtained from carp. There was no difference (P>0.05) in what concerns both the progressive motility and the spermatic vigor between the treatments, although there was a tendency of greater medians for the semen of induced animals, 79.5 per cent and 3.7 points against 73.5 per cent and 3.5 points, respectively. The spermatozoa’s life time did not show any difference as well (P>0.05) for the semen analyzed with and without hormonal induction during 50.3 and 52.3 seconds, respectively. There was no difference (P>0.05) in the analyzed semen of either the induced or not induced pacu fish, considering the percentage of normal spermatozoa (58.2 and 62.6) with secondary pathologies (12.9 and 12.1) and with primary pathologies (28.9 and 25.3). The most incident primary types of pathologies in the semen of both the induced and not induced animals were broken and coiled tail. Based on the results it can be concluded that the hormonal induction with hypophysis extract obtained from carp did not cause any significant changes for the qualitative parameters evaluated. However, a high incidence of primary pathologies was observed in the pacu’s semen, mainly crooked, bent and coiled tail.

Comparação do sêmen de Curimbá (Prochilodus lineatus) induzido por extrato de hipófise de frango, coelho ou carpa / Comparison of Curimba semen (Prochilodus lineatus) induced by pituitary extract from chicken, rabbit or carp

Foram selecionados 48 Curimbás (Prochilodus lineatus) e hipofisados com extrato de hipófise de frango (EHF), extrato de hipófise de coelho (EHCo) e o controle com extrato de hipófise de carpa (EHC). Os animais foram induzidos, aleatoriamente, com os tratamentos arranjados em um fatorial de três hormônios e três semanas. Animais tratados com EHF, EHC ou EHCo produziram, em média, 0,65, 0,45 e 0,20 mL de sêmen, respectivamente, havendo diferença (P<0,05) entre os tratamentos com EHF e EHCo, mesmo comportamento verificado para o número médio de espermatozóides totais produzidos. Para os animais tratados com EHCo, houve maior concentração de espermatozóides/mm³ de sêmen quando comparado com os machos induzidos com EHC (P<0,05). Todavia, não houve diferença (P>0,05) quando comparados com os machos induzidos com EHF. Prochilodus lineatus induzidos com EHF mostraram motilidade espermática progressiva superior (P<0,05) aos animais induzidos com EHC, porém, Prochilodus lineatus induzidos com EHCo apresentaram um comportamento semelhante (P>0,05) aos tratados com EHC ou EHF. Quanto ao vigor espermático, os machos responderam de forma semelhante (P>0,05) para os três indutores utilizados, sendo em média, 2,75 pontos. De acordo com os resultados obtidos, conclui-se que o EHF apresentou eficiência semelhante ou melhor do que o tradicional EHC. Entretanto, o EHCo necessita de mais pesquisas, visando testar hipófise de animais mais idosos.