Although the tambaqui (Colossoma macropomum) is the most cultivated native fish species in Brazil, estimated breeding values for growth traits are rarely used for selection of superior individuals in commercial fingerling production. This study aimed to estimate the (co)variance components of growth traits. Body weight, length and width of 2500 tambaqui were determined at tagging and at 6 and 12 months after tagging in a commercial breeding programme in Brazil. Heritability estimates were low for traits measured at tagging (0.10 to 0.19) and moderate to high for traits measured at 6 and 12 months (0.23 to 0.81). Common full-sib effects were high at tagging (>73%), low at 6 months and negligible at 12 months. Positive genetic correlations were found among growth traits at 12 months (0.84 to 0.99) and between growth traits at 6 and 12 months (0.80 to 0.92). These results show that animal selection can be performed at 6 months after tagging. Expected genetic gains for growth traits ranged from 8% to 31%. A simulation of the sex ratio was performed, as individuals did not reach sexual maturity during the experimental period. Because of the sexual dimorphism, more accurate heritability estimates were obtained when considering the female proportion to be 90% in the high-weight group. The findings indicate that it is possible to obtain considerable genetic gains in growth by selecting for growth traits. The development of a tool to determine the sex of animals at early stages can improve the response to selection in tambaqui.

Digital image analysis is a practical, non‐invasive, and relatively low‐cost tool that may assist in the evaluation of body traits in Nile tilapia, being particularly useful for assessing difficult‐to‐measure variables, such as body areas. In this study, we aimed to estimate variance components and genetic parameters for body areas of Nile tilapia obtained by digital images. The data set comprised body weight (BW) records of 1,917 pond‐reared fish at 366 days of age. Of this total, 656 animals were photographed and subjected to image analysis of trunk area (TA), head area (HA), caudal fin area (CFA) and fillet area (FA). Heritabilities and genetic correlations were estimated through multiple‐trait models based on Bayesian inference. Heritability estimates for BW, TA, HA, CFA and FA were 0.25, 0.23, 0.26, 0.21 and 0.25, respectively. Genetic correlations between the traits were high and positive, ranging from 0.70 to 0.98. We highlight the genetic correlation between BW and TA (rG = 0.98) and FA (rG = 0.97). In view of the observed results, it can be concluded that trunk and fillet areas obtained by digital image analysis can lead to indirect genetic gains in weight and other body areas. In addition, the areas studied have potential as a selection criterion and may assist in studies on changes in the body shape in Nile tilapia.

Com a crescente preocupação em se obter alimentos de qualidade, aliada ao setor da aquicultura, que cada vez mais vem se destacando em relação à tecnologia, o bemestar animal voltado ao pescado é um ponto que precisa ser ligeiramente integrado e discutido. O abate possui várias etapas que o precedem, e todas elas influenciam na qualidade final do produto. Estas etapas são, despesca, jejum, transporte e insensibilização, que pode ocorrer por diferentes métodos, os quais afetam de maneira positiva ou negativa. Dentre as práticas que são utilizadas para o abate, se inclui aqueles que causam menor sofrimento e melhor qualidade da carne, quando realizados de modo correto, sendo, por choque elétrico, golpe letal na cabeça (com insensibilização) e secção de medula, e, os que geram sofrimento nos peixes, que são por asfixia (em ar ou no gelo) e choque térmico, os quais são os métodos mais tradicionais. Portanto, é preciso que haja a inclusão de legislação voltada ao bem-estar no abate do pescado, pois, assim como os outros animais, o peixe é um animal que possui consciência das sensações. O objetivo desta revisão é ressaltar a importância do bem-estar no manejo pré-abate e abate de pescado.Palavras chave: bem-estar, manejo, peixes, qualidade Good practices in pre-slaughter and slaughter of fishABSTRACT. With the growing concern to obtain quality food, allied to the aquaculture sector, which has been increasingly important in relation to technology, animal welfare focused on fish is a point that needs to be linked and integrated. The slaughter has several steps that precede, and all of them influence the final quality of the product. These steps are harvest, fasting, transportation and stunning, which can occur by different methods, which affect positively or negatively. Among the practices that are used for slaughter, it includes those that cause less suffering and better quality of meat, being, by electric shock, lethal blow to the head (with insensibiling) and bone marrow section, and those that generate suffering in fish, which are by asphyxiation (in air or ice) and thermal shock, which are the most traditional methods. Therefore, it is necessary to include welfare legislation in the slaughtering of fish, since, like other animals, fish is an animal that is aware of sensations. The objective of this review is to emphasize the importance of welfare in pre-slaughter and fish slaughtering.

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The homeopathy has been practiced for many years, mainly using rodent as a research model. Zebrafish have been used as an animal model in different scientific areas and may represent an important model in studies with this therapy. This paper aimed to evaluate the action of Homeopatila 100 ® on the growth, the action on the liver and reproduction of zebrafish. The study was carried out with 192 six months old animals. The experimental period was three months, being evaluated the growth, the hepatosomatic and viscerosomatic indexes, the number of hepatocytes per area and the percentage of glycogen in these cells, performing the hepatic histology of males and females. It was evaluated the reproduction of the animals, checking the production and probability of hatching of the eggs. It was found that homeopathy increases the number of hepatocytes and glycogen in females, as well as improved the reproductive indices evaluated.