Comparación del desarrollo embrionario de piaractus brachypomus (Serrasalmidae) y pseudoplatystoma sp. (Pimelodidae) / Comparison of the embryonic development of piaractus brachypomus (Serrasalmidae) and pseudoplatystoma sp. (Pimelodidae)

Pseudoplatystoma sp y Piaractus brachypomus son dos especies de peces dulceacuícolas endémicas de América del Sur de alto interés comercial como peces de cultivo. El objetivo de este trabajo fue comparar el desarrollo embrionario hasta la eclosión en estas dos especies. Para observar el desarrollo embrionario se incubaron oocitos fertilizados, obtenidos por inducción hormonal, en incubadoras de flujo ascendente tipo Woynarovich bajo condiciones controladas de calidad de agua. Los clivajes, la fase de blástula, gástrula hasta el cierre del blastoporo y eclosión en Pseudoplatystoma sp se observaron entre las 0:30 - 18:00 HPF, mientras que en P. brachypomus fue más rápida, observándose desde las 0:30 hasta las 14:00 HPF, siendo más homogénea que en Pseudoplatystoma sp.

Pseudoplatystoma sp. and Piaractus brachypomus are two species of freshwater fishes endemic to South America as a high commercial crop species. The aim of this study was to compare the embryonic development of these two species until they hatch. To observe embryonic development fertilized oocytes were incubated obtained by hormonal induction in upwelling incubators Woynarovich type under controlled conditions of water quality. The cleavages were observed for Pseudoplatystoma sp. from 0:30 hours post fertilization (HPF) until 2:00 pm (HPF), whereas in P. brachypomus these occurred between 0:30 - 1:30 HPF. The stage of blastula, gastrula until the closure of blastopore Pseudoplatystoma sp. was observed in sp between 2:00 to 12:00 P. HPF while in P. brachypomus between 2:00 to 8:00. The hatching in Pseudoplatystoma sp was observed between 14:00 to 18:00 HPF, whereas P. brachypomus was faster, was observed from 12:00 until 14:00 HPF HPF, and was more homogeneous than Pseudoplatystoma sp.

Heparina e Na2EDTA como anticoagulantes para surubim híbrido (Pseudoplatystoma reticulatum x P. corruscans): eficácia e alterações hematológicas / Heparin and Na2EDTA as anticoagulants for hybrid surubim catfish (Pseudoplatystoma reticulatum x P. corruscans): efficacy and hematological changes

Este estudo avaliou o efeito da heparina 100UI e do Na2EDTA nas concentrações de 3, 5 e 10 por cento sobre a coagulação sanguínea e os parâmetros hematológicos de surubim híbrido. Foram utilizados 10 peixes, com peso médio de 386,7±24,3g e comprimento total médio de 38,7±6,4cm, para colheita das amostras sanguíneas e determinação do percentual do hematócrito, teor de proteínas plasmáticas totais e teste de fragilidade osmótica dos eritrócitos (FOE). Os dados foram submetidos à análise de variância, e as médias foram comparadas pelo teste de Tukey, a 5 por cento de probabilidade. A coagulação foi eficientemente inibida quando utilizado o Na2EDTA; já as amostras com heparina coagularam 10 horas após a coleta. Houve aumento na fragilidade osmótica dos eritrócitos (P<0,01), especialmente quando utilizado o Na2EDTA 10 e 5 por cento, não havendo diferença entre o controle e a heparina. No hematócrito e teor de proteínas plasmáticas totais, não foram verificadas diferenças significativas. O Na2EDTA 3 por cento é seguro e eficiente como anticoagulante para surubim híbrido, prevenindo a coagulação por mais de 10h e ocasionando discreto efeito sobre a fragilidade osmótica dos eritrócitos.

The effect of heparin 100IU and Na2EDTA in concentration of 3 percent, 5 percent and 10 percent on the blood coagulation and hematological parameters of hybrid surubim catfish were evaluated. We used ten fish weighing 386,7±24,3g and average length of 38,7±6,4cm for collection of blood samples and determination of the percentage of hematocrit, plasma total protein content and osmotic fragility erythrocytes test (OFE). Data were submitted to analysis of variance and averages compared by Tukey test at 5 percent probability. Coagulation was efficiently inhibited when used the Na2EDTA, while the samples with heparin coagulate ten hours after collection. There was an increase in osmotic fragility of erythrocytes (P<0.01), especially when using Na2EDTA 10 percent and 5 percent, with no difference between control and heparin. In hematocrit and total plasma protein content were not observed statistical differences. The Na2EDTA 3 percent is safe and effective anticoagulant for hybrid surubim catfish, preventing clotting for more than 10 hours causing slight effect on the osmotic fragility of erythrocytes.