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The inadequate supply of food during a fish’s larval stage, in addition to impairing growth and survival, may lead to the emergence of skeletal anomalies, since essential nutrients are involved in the osteogenic process. The aim of this study was to evaluate the effects of two weaning periods on growth, survival and incidence of skeletal anomalies in pacu larvae (Piaractus mesopotamicus) during its initial development. The larvae (5 dph) were placed in 100L tanks at a density of 12 larvae L-1, during 42 days. The experiment was conducted in a completely randomized design with four feeding treatments: (A) larvae fed only Artemia nauplii; (D) larvae fed only formulated diet; and two treatments with different weaning periods, early at six (W6) and late, at twelve days of feeding (W12). Higher growth indexes and survival rates were observed in A and W12, in comparison to W6 and D. At the end of the experiment, larvae fed Artemia nauplii and subjected to late weaning (W12) presented higher mass gain and survival, in comparison to W6 and D, however the incidence of skeletal anomalies was similar among treatments. It was concluded that the emergence of skeletal anomalies in P. mesopotamicus larvae was not associated to the weaning protocols used in this study and late weaning, at 12 days of feeding, did not impair growth and survival of these larvae.

EnglishTo know the non-toxic cryoprotectants to fish oocytes is of extreme importance for tests that aim to increase oocyte resistance to cold, thus allowing more advanced studies in cryopreservation. Therefore, commonly used cryoprotectants such as methanol, dimethyl sulfoxide, ethylene glycol, propylene glycol, sucrose and fructose were studied. Immature oocytes from the initial to vitelogenic (diameter 1.8 mm) stages of Steindachneridion parahybae were evaluated. Four distinct experiments were performed, three using immature oocytes and one using oocytes at the mature stage. For each oocyte stage, the best maintenance solution to be used: Hank or 50% L15 and; viability after baths for 30min (room temperature) at cryoprotectant concentrations ranging from 0.25 to 4M were evaluated. Different tests were used to evaluate oocyte viability: in vitro maturation followed by observation of germinal vesicle breakdown (only for immature oocytes), Trypan Blue staining (all stages) and fertilization and hatching rates (mature stage only). Results showed that the toxic effect of cryoprotectants on oocytes generally increases with increasing concentrations. Sensitivity of oocytes to cryoprotectants increases according to the stage of development, with mature oocytes being more sensitive. Sucrose, fructose, methanol, propylene glycol and dimethyl sulfoxide can be used as cryoprotectants for S. parahybae oocytes. Key words: fish reproduction; fish oocytes; toxicity; concentrations of cryoprotecntants; Steindachneridion parahybae portuguesConhecer os crioprotetores nao toxicos aos oocitos de peixes e de extrema importância para testes que visam aumentar a resistencia dos oocitos ao frio, permitindo, assim, estudos mais avancados em criopreservacao. Desta forma, crioprotetores comumente utilizados como o metanol, dimetil sulfoxido, etilenoglicol, propilenoglicol, sacarose e frutose foram estudados. Os oocitos imaturos, nos estagios inicial ate vitelogenico (diâmetro 1,8mm) de Steindachneridion parahybae foram avaliados. Quatro experimentos distintos foram realizados, sendo tres destes utilizando oocitos imaturos, e um usando oocitos no estagio maduro. Para cada estagio oocitarios foram avaliados, considerando qual a melhor solucao de manutencao a ser utilizada: Hank ou 50% L15 e; viabilidade apos banhos por 30min (temperatura ambiente) em concentracoes de crioprotetores, variando de 0,25 a 4M. Diferentes testes foram utilizados para avaliar a viabilidade dos oocitos: maturacao in vitro seguido por observacao da quebra da vesicula germinativa (somente para oocitos imaturos), coloracao por Azul de Tripan (todos os estagios) e taxas de fertilizacao e eclosao (somente no estagio maduro). Os resultados mostraram que o efeito toxico dos crioprotetores em oocitos geralmente crescem com o aumento das concentracoes. A sensibilidade dos oocitos a crioprotetores aumentam de acordo com o estagio de desenvolvimento, com oocitos maduros sendo mais sensiveis. Sacarose, frutose, metanol, propileno glicol e dimetil sulfoxido podem ser usados como crioprotetores para oocitos de S. parahybae. Palavras-chave: reproducao de peixe; oocitos de peixes; toxicidade; concentracoes de crioprotetores; Steindachneridion parahybae

In recent years, a number of South American freshwater fish have gained increasing attention for their potential in aquaculture, not only because of their excellent performance in farming systems but also to meet the high consumer demand for these species due to declining fishery resources. Many South American freshwater species are migratory and produce altricial larvae, with a small amount of yolk reserves. Unlike precocial freshwater species and altricial coldwater marine fish, these freshwater fish investigated have rapid yolk depletion and metamorphosis. Specific studies on the initial development of South American fish are scarce and fragmented. One of the most widely studied species is the pacu (Piaractus mesopotamicus), farmed in warm continental waters. In the present review we compile new and published data on the initial development of pacu, including morphogenesis of the skeletal, muscle, digestive and sensory systems; compare it to other Neotropical species; and discuss the importance of this information to develop larviculture protocols. When pacu larvae exhaust yolk reserves, they initiate a new form of interaction with the environment, becoming exclusively exotrophic. This type of interaction is made possible by the rapid development of sensory, skeletal, locomotor and digestive structures. In addition to understanding fish ontogeny, studies on larval development are necessary to improve farming systems and larviculture techniques aimed at producing high-quality juveniles in aquaculture.

Skeletal anomalies in fish are frequent, representing a major problem for the aquaculture industry. The anomalies usually arise in the larval phase and worsen, persist, or recover over the ensuing stages of development. In addition to impairing larval quality, they compromise the growth, health, and food conversion of fish, lowering their economic value. This study evaluated the occurrence of skeletal anomalies in pacu larvae during the first 30 d of development. The newly hatched larvae of six breeding pairs taken from the Paranapanema River (offspring A, B, C, D, E, and F) and subjected to induced spawning were reared separately for 30 d, feeding on live prey (Artemia nauplii). Nearly 20 larvae from each breeding pair were killed and stored 1, 2, 4, 6, 8, 10, 13, 16, 19, 22, 25, and 30 days post-hatching. The larvae were stained to differentiate cartilage and bones and examined under a stereo microscope. A total of 1310 larvae were checked for the presence (1) or absence (0) of anomalies in the head, vertebral column, and fins. Associations between growth parameters (total length [TL] vs. standard length [SL]; SL vs. vertebral column length [VL]) were obtained by regression. Correspondence analysis was used to correlate data on the different parameters evaluated. On completion of observation, larvae from pair E had the highest SL, whereas offspring F were the shortest. All types of skeletal anomalies were detected in the larvae irrespective of the offspring, affecting the normal growth of pacu larvae obtained from wild-caught breeders.

SummaryThe present study investigates the effect of different slow chilling curves on the storage of pacu (Piaractus mesopotamicus) embryos submitted to chilling at −8°C. Embryos at the blastopore closure stage were divided into two groups: G1 – embryos exposed to cryoprotectant solution containing methanol (10%) and sucrose (0.5 M), treated as follows: (T1) taken directly from room temperature to the refrigerator without being submitted to the curve; (T2) chilling curve of 0.5°C/min; and (T3) chilling curve of 1°C/min; and G2 – the cryoprotectant solution alone was submitted to these same temperatures, receiving the embryos only after temperature had decreased, corresponding to treatments T4, T5 and T6, respectively. Treatments were kept at −8°C for a period of 6 h. Embryo development was evaluated for each treatment, with six replicates in an entirely randomized design. Survival among embryos not submitted to refrigeration was 94.3 ± 8.05%. Percentage of total larvae (TL) and addled eggs (AE) did not differ statistically between the groups, although percentage of swimming larvae (SL) exhibited higher values in G1 for the 1°C/min curve. Furthermore, when comparing the three chilling curves, a decrease of 1°C/min resulted in the highest TL percentage (90.85%), followed by the 0.5°C/min curve (78.52%). Thus, the use of 1°C/min chilling curves is recommended for P. mesopotamicus embryos stored for 6 h at −8°C.

Analisou-se a diversidade genética de estoques de reprodutores de Tambaqui (Colossoma macropomum), mediante o uso de marcador RAPD, utilizando-se 10 primers para analisar 30 amostras do estoques de reprodutores das pisciculturas de Boa Esperança e Vale Verde, localizadas no Estado de Rondônia. A porcentagem de fragmentos polimórficos e o índice de diversidade genética de Shannon foram altos nos dois estoques de reprodutores. O estoque de reprodutores de Boa Esperança apresentou um fragmento exclusivo. A diferenciação genética foi baixa e o número de migrantes por geração foi alto entre os estoques de reprodutores. O dendrograma não separou os indivíduos dos estoques de reprodutores em grupos distintos. Há alta variabilidade genética nos estoques de reprodutores, um pouco inferior no estoque de Vale Verde, e há grande proximidade genética entre os indivíduos dos estoques de reprodutores. The genetic diversity of tambaqui (Colossoma macropomum) broodstocks from two hatchery station in Rondônia State was studied by the RAPD marker. Ten primers were used to analyze 30 broodstocks samples from the hatchery stations of Boa Esperança and Vale Verde. The polymorphic fragments percentage and Shannon genetic diversity index were high in the two broodstocks. The Boa Esperança broodstock presented an exclusive fragment. The genetic differentiation was low and the number of migrants per generation was high among the broodstocks. The dendrogram did not separate the broodstocks individuals in different groups. The results indicate a high genetic variability in the broodstocks, being a little bit lower in the Vale Verde broodstock. Besides, there is a genetic proximity among the broodstocks.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T19:01:16Z No. of bitstreams: 1 S0103-90162011000300006.pdf: 208355 bytes, checksum: 687da7d492b75c11ad314c69258c536b (MD5) Made available in DSpace on 2013-08-22T19:01:16Z (GMT). No. of bitstreams: 1 S0103-90162011000300006.pdf: 208355 bytes, checksum: 687da7d492b75c11ad314c69258c536b (MD5) Previous issue date: 2011-06-01 Made available in DSpace on 2013-09-30T17:42:16Z (GMT). No. of bitstreams: 2 S0103-90162011000300006.pdf: 208355 bytes, checksum: 687da7d492b75c11ad314c69258c536b (MD5) S0103-90162011000300006.pdf.txt: 35429 bytes, checksum: 20f29fbd27d2b5c1335c668461d9f8fd (MD5) Previous issue date: 2011-06-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:12:41Z No. of bitstreams: 2 S0103-90162011000300006.pdf: 208355 bytes, checksum: 687da7d492b75c11ad314c69258c536b (MD5) S0103-90162011000300006.pdf.txt: 35429 bytes, checksum: 20f29fbd27d2b5c1335c668461d9f8fd (MD5) Made available in DSpace on 2014-05-20T13:12:41Z (GMT). No. of bitstreams: 2 S0103-90162011000300006.pdf: 208355 bytes, checksum: 687da7d492b75c11ad314c69258c536b (MD5) S0103-90162011000300006.pdf.txt: 35429 bytes, checksum: 20f29fbd27d2b5c1335c668461d9f8fd (MD5) Previous issue date: 2011-06-01 O monitoramento da diversidade genética é fundamental em um programa de repovoamento. Avaliouse a diversidade genética de pacu Piaractus mesopotamicus (Holmberg, 1887) em duas estações de piscicultura em Andirá -Paraná, Brasil, utilizadas no programa de repovoamento do Rio Paranapanema. Foram amplificados seis loci microssatélite para avaliar 60 amostras de nadadeira. O estoque de reprodutores B apresentou maior número de alelos e heterozigose (alelos: 22 e H O: 0,628) que o estoque de reprodutores A (alelos: 21 e H O: 0,600). Alelos com baixos níveis de frequência foram observados nos dois estoques. Os coeficientes positivos de endogamia no locus Pme2 (estoque A: F IS = 0,30 e estoque B: F IS = 0,20), Pme5 (estoque B: F IS = 0,15), Pme14 (estoque A: F IS = 0,07) e Pme28 (estoque A: F IS = 0,24 e estoque B: F IS = 0,20), indicaram deficiência de heterozigotos. Foi detectada a presença de um alelo nulo no lócus Pme2. As estimativas negativas nos loci Pme4 (estoque A: F IS = -0,43 e estoque B: F IS= -0,37), Pme5 (estoque A: F IS = - 0,11), Pme14 (estoque B: F IS = - 0,15) e Pme32 (estoque A: F IS = - 0,93 e estoque B: F IS = - 0,60) foram indicativas de excesso de heterozigotos. Foi evidenciado desequilíbrio de ligação e riqueza alélica baixa só no estoque A. A diversidade genética de Nei foi alta nos dois estoques. A distância (0,085) e identidade (0,918) genética mostraram similaridade entre os estoques, o qual reflete uma possível origem comum. 6,05% da variância genética total foi devida a diferenças entre os estoques. Foi observado um recente efeito gargalo nos dois estoques. Os resultados indicaram uma alta diversidade genética nos estoques de reprodutores e baixa diferenciação genética entre eles, o que foi causado pelo manejo reprodutivo das pisciculturas, redução do tamanho populacional e intercâmbio genético entre as pisciculturas. Monitoring the genetic diversity has fundamental importance for fish stocking programs. This experiment aims to evaluate the genetic diversity in two hatchery stations (A and B) with pacu Piaractus mesopotamicus (Holmberg, 1887) in Andirá, state of Paraná, Brazil used in stocking programs of Paranapanema River. Six microsatellite loci were amplified using DNA extracted from 60 fin-clipping samples. The broodstock B had the average number of alleles and the mean heterozygosity (alleles: 3.7 and H O: 0.628) higher than the broodstock A (alleles: 3.5 and H O: 0.600). Alleles with low frequency levels were observed in the both broodstocks. The positive coefficients of endogamy in the locus Pme2 (broodstock A: F IS = 0.30 and broodstock B: F IS = 0.20), Pme5 (broodstock B: F IS = 0.15), Pme14 (broodstock A: F IS = 0.07) and Pme28 (broodstock A: F IS = 0.24 and broodstock B: F IS = 0.20) indicated deficiency of heterozygotes. Presence of null allele in the locus Pme2 was detected. The negative estimates in loci Pme4 (broodstock A: F IS = - 0.43 and broodstock B: F IS = - 0.37), Pme5 (broodstock A: F IS= - 0.11), Pme14 (broodstock B: F IS= - 0.15) and Pme32 (broodstock A: F IS = - 0.93 and broodstock B: F IS = - 0.60) were indicating the excess of heterozygotes. Evidence of linkage disequilibrium and lower allelic richness was found only in the broodstock A. Nei's gene diversity was high in both broodstocks. The genetic distance (0.085) and identity (0.918) showed similarity between broodstocks, which reflects a possible common origin. 6.05% of the total genetic variance was due to differences among broodstocks. Recent bottleneck effect in two broodstocks was observed. The results indicated a higher genetic diversity in the two broodstocks and they presented low genetic difference. This was caused by the reproductive management in both hatchery stations, reduction of population size and genetic exchange between the hatchery stations. UFMT Inst. de Ciências Agrárias e Tecnológicas UEM Centro de Ciências Agrárias Núcleo de Pesquisa PeixeGen UNESP CAUNESP UNESP CAUNESP

Nowadays it has been verified the decrease and the disappearance of many fish species in several aquatic environments in the Brazil. As form of minimizing that impact, stocking programs come being used with more intensity, meantime, little importance has been given to the genetic variability, fundamental parameter for any conservation practices. The objective of this study was to analyze the genetic diversity of Piaractus mesopotamicus stocks used in stocking programs, through the RAPD molecular marker. Sixty broodstocks of two fish farms stations located in the Sapopema (S) and Cambara (C) cities in the Parana State (Brazil) and 30 larvae of the Sapopema offspring (PS) were analyzed. The 10 selected primers yielded 69 fragments of which 62 (89.85%) were polymorphic. Differences (p

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:56:18Z No. of bitstreams: 1 S0102-09352009000500023.pdf: 221455 bytes, checksum: 1c52e716e36b262d65013ec8d1266f12 (MD5) Made available in DSpace on 2013-08-22T18:56:18Z (GMT). No. of bitstreams: 1 S0102-09352009000500023.pdf: 221455 bytes, checksum: 1c52e716e36b262d65013ec8d1266f12 (MD5) Previous issue date: 2009-10-01 Made available in DSpace on 2013-09-30T19:50:05Z (GMT). No. of bitstreams: 2 S0102-09352009000500023.pdf: 221455 bytes, checksum: 1c52e716e36b262d65013ec8d1266f12 (MD5) S0102-09352009000500023.pdf.txt: 17896 bytes, checksum: 3dab7ef0496570fb7f0ac929eaf660a9 (MD5) Previous issue date: 2009-10-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:12:32Z No. of bitstreams: 2 S0102-09352009000500023.pdf: 221455 bytes, checksum: 1c52e716e36b262d65013ec8d1266f12 (MD5) S0102-09352009000500023.pdf.txt: 17896 bytes, checksum: 3dab7ef0496570fb7f0ac929eaf660a9 (MD5) Made available in DSpace on 2014-05-20T13:12:32Z (GMT). No. of bitstreams: 2 S0102-09352009000500023.pdf: 221455 bytes, checksum: 1c52e716e36b262d65013ec8d1266f12 (MD5) S0102-09352009000500023.pdf.txt: 17896 bytes, checksum: 3dab7ef0496570fb7f0ac929eaf660a9 (MD5) Previous issue date: 2009-10-01 Avaliou-se a variabilidade genética dos estoques de reprodutores e dos peixes jovens de Piaractus mesopotamicus de três pisciculturas do estado do Paraná, utilizadas no programa de aumento de estoque de peixes no rio Paranapanema. Foi utilizado o marcador RAPD para avaliar as amostras do estoque de reprodutores e dos peixes jovens das pisciculturas de Palotina, Cambará e Andirá. A porcentagem de fragmentos polimórficos e o índice de diversidade genética de Shannon dos estoques de reprodutores variaram de 75,0% a 71,4% e de 0,434 a 0,376, respectivamente. Os peixes jovens das pisciculturas apresentaram valores mais elevados para ambos os parâmetros, com exceção da piscicultura de Palotina, na qual o índice de diversidade genética de Shannon foi semelhante. Os estoques de reprodutores apresentaram alta variabilidade genética, e esta foi mantida nos peixes jovens. The genetic variability of broodstocks and juveniles of Piaractus mesopotamicus raised in three hatchery stations in Parana state, that were used in the fish stock enhancement program of the Paranapanema River, was estimated. The RAPD marker was used to evaluate samples taken from broodstocks and juveniles in the hatchery stations of Palotina, Cambará, and Andirá cities. The percentage of polymorphic fragments and the Shannon genetic diversity index of broodstocks ranged from 75.0% to 71.4% and from 0.434 to 0.376, respectively. The juveniles of the hatchery stations presented higher values for both parameters, except in the hatchery station of Palotina in which the Shannon genetic diversity index was similar. The broodstocks presented high genetic variability, and this was maintained in the juveniles. Universidade Federal de Mato Grosso Universidade Estadual de Maringá (UEM) Universidade Federal de São Carlos (UFSCar) UNESP Centro de Aqüicultura UNESP Centro de Aqüicultura

Las poblaciones de peces nativos estan disminuyendo debido a varios factores que impactan en el ambiente. Como forma de abordar este problema, se han realizado varias acciones como por, ejemplo, el repoblamiento. Sin embargo, estas acciones se realizan sin ningun respaldo cientifico. Esto puede, ademas de no ser eficiente, provocar una perdida de la diversidad genetica en las poblaciones, pudiendo ocasionar impactos irreversibles en las proximas generaciones. Por esta razon, el empleo de marcadores moleculares, que permitan monitorear geneticamente las poblaciones parece fundamental para lograr la conservacion de la ictiofauna

O objetivo deste trabalho foi estudar a diversidade genética das amostras de pacu do médio Rio Paranapanema e do estoque de reprodutores utilizado no programa de repovoamento da Estação de Aqüicultura e Hidrologia da usina hidrelétrica Duke Energy, por meio do marcador RAPD. Foram utilizados 14 primers para analisar 30 indivíduos capturados no médio Rio Paranapanema e 29 indivíduos do estoque de reprodutores. O índice de diversidade genética de Shannon e a percentagem de fragmentos polimórficos foram superiores nos indivíduos capturados do Rio Paranapanema. A similaridade genética foi maior nos indivíduos do estoque de reprodutores. A análise da variância molecular mostrou que a maior parte da variação está dentro de cada grupo (84,2%) e não entre os grupos (15,8%). A identidade e distância genética entre os grupos foram 0,9517 e 0,0549, respectivamente. Moderada diferenciação genética (F ST = 0,15) e alto número de migrantes por geração (Nm = 5,33) foram observados entre os dois grupos. Há menor diversidade genética do estoque de reprodutores em relação aos indivíduos capturados do Rio Paranapanema. The objective of this work was to study the genetic diversity of pacu samples from the middle Paranapanema River and from the broodstock used in the stock enhancement program of the Aquaculture and Hydrology Station at the Duke Energy Power Plant, by RAPD marker. Fourteen primers were used to analyze 30 individuals captured in the middle Paranapanema River and 29 individuals from the broodstock. The Shannon genetic diversity index and percentage of polymorphic fragments were higher in individuals captured in the Paranapanema River. Genetic similarity was larger in individuals of the broodstock. Results of analysis of molecular variance showed that the major part of the genetic variation is within the groups (84.2%) and not between them (15.8%). The identity and genetic distance among the groups were 0.9517 and 0.0549, respectively. Moderate genetic differentiation (F ST = 0.15) and high number of migrants per generation (Nm = 5.33) were observed between the two groups. The genetic diversity was lower in the broodstock than in fish captured in the middle Paranapanema River.