Cytotaxonomy in distinct populations of Hoplias aff. malabaricus (Characiformes, Erythrinidae) from lower Paranapanema River basin.

Cytogenetic and morphometric analyses were carried out in Hoplias aff. malabaricus specimens from six distinct populations from the lower Paranapanema River basin, located between the states of Paraná and São Paulo, Brazil. Measurements were also taken from a specimen collected in Surinam. In a population from a fish farm station at Universidade do Norte do Parana (EPUNOPAR), two sympatric cytotypes (2n = 40 and 2n = 42 chromosomes) are found. A population from a fish farm station at Universidade Estadual de Londrina (EPUEL) shows 2n = 42 meta-submetacentric chromosomes for males and females with a simple sex chromosome system of XX/XY type. Populations from the Vermelho and Rancho Alegre Rivers, Três Bocas Stream and Paranapanema River have 2n = 39 chromosomes in males and 2n = 40 chromosomes in females, showing a multiple sex chromosome system of X(1)X(1)X(2)X(2)/X(1)X(2)Y type. Twenty morphological variables were studied. These measurements were used for an analysis of the canonical variables and standard analysis of proportional measurements. The most variable measurements among the specimens are the maxilla length (MXL) and the pre-dorsal distance (PDD). Analysis of canonical variables indicates three distinct groups in the first canonical axis formed by: (1) Três Bocas Stream, (2) Rancho Alegre + Vermelho River + EPUNOPAR and (3) EPUEL + Paranapanema River. This axis retained 79.4% of information from the original matrix. Analysis of morphometrics reveals differences among populations from the Paranapanema River basin and between these and the specimen from Surinam. The morphometric and cytogenetic differences among the studied populations suggest a species complex.

Taguchi's loss function applied in the breeding of Tilapia, Oreochromis niloticus fed with different levels of proteins of yeast in tank-nets / Função perda de taguchi aplicada na criação de tilápia, oreochromis niloticus alimentadas com diferentes níveis de proteínas de levedura em tanques-rede / Función pérdida de taguchi aplicada en la creación de tilapia, oreochromis niloticus alimentadas con diferentes niveles de proteínas de levadura en estanques-red

The experiment was based on observations of 120 juveniles of tilapias of Nile, Oreochromis niloticus, sexually reverted, with an initial medium weight of 116.65 0.85 g, distributed in a completely randomized design for 168 days. The objective of this work was to evaluate the effect of introducing tank-nets on the function Taguchi's loss fed with 0% (control), 20%, 40% and 60% (tests) of yeast distillery protein in substitution of traditional source of protein. The test of Tukey was accomplished showing that there were not statistical differences (p > 0.05) among the effi ciency, the length and the weight of the fi sh. With relationship to the survival, it was observed that the treatments (T2, T3, T4) were statistically superior (p < 0.01) to the treatment T1. Taguchi's loss for the cost of production and for the dead fi shes in tank-nets in the treatment T2 = 20%, T3 = 40% and T4 = 60% (tests) were lower the group control (T1 = 0%). This result confi rm the direction of yeast distillery protein in substitution of traditional source of protein.

Foram utilizados 120 juvenis de tilápia do Nilo, Oreochromis niloticus, sexualmente revertidos, com peso médio inicial de 116,65 ± 0,85 g, distribuídos num delineamento inteiramente casualizado, durante 168 dias. O objetivo foi avaliar o efeito da introdução de tanques-rede com cultivo de peixes alimentados com 0% (grupo padrão), 20%, 40% e 60% (grupos testes) de proteína oriunda de levedura de destilaria em substituição à proteína de fontes tradicionais sobre a função perda de Taguchi. O teste de Tukey foi realizado mostrando que não houve diferenças estatísticas (p > 0,05) entre a efi ciência, o comprimento e o peso dos peixes. Com relação à sobrevivência, foi observado que os tratamentos (T2 , T3 , T4 ) foram estatisticamente superiores (p < 0,01) ao tratamento T1 . As perdas de Taguchi para o custo de produção e para os peixes mortos nos tanques para os tratamentos T2 = 20%, T3 = 40% e T4 = 60% , foram inferiores ao grupo controle (T1 = 0%). Este resultado confi rma o direcionamento da proteína oriunda de levedura de destilaria em substituição à proteína de fontes tradicionais.

Fueron utilizados 120 joveniles de tilapia del Nilo (Oreochromis niloticus), sexualmente revertidas con peso mediano inicial de 116,65 mas o menos 0,85g distribuido en un diseno totalmente seleccionado al azar por 168 dias. El objetivo de este trabajo fue evaluar el efecto de la sustitución de 0% (control), 20%, 40% y 60% (grupo teste) de proteína oriunda de levadura de destilería en sustitución a la proteína de fuentes tradicionales sobre la función pérdida de Taguchi. La prueba de Tukey era demonstración lograda que no había diferencias estadísticas (p>0,05) entre la eficacia, la longitud y el peso de los pescados. Con relación a la supervivencia, fue observado que los tratamientos (T2, T3, T4) eran estatisticamente superior (p<0,01) ao T1 del tratamiento. Las pérdidas de Taguchi para el coste de producción y para los peces muertos en los estanques-red para los tratamientos T2 = 20%, T3 = 40% y T4=60%, fueron inferiores al grupo control (T1 = 0%). Este resultado confirma el direccionameiento de la proteína oriunda de la levadura de destilería en sustitución a la proteína de fuentes tradicionales.