A larvicultura é uma das etapas mais críticas do desenvolvimento dos peixes e o seu sucesso está diretamente relacionado ao manejo alimentar, que pode proporcionar maiores sobrevivência e crescimento. Objetivou-se avaliar o tempo de transição alimentar e de fornecimento de meta-náuplios de Artemia spp. (MNA) na larvicultura do acará-bandeira. Dois experimentos foram conduzidos em delineamento inteiramente casualizado com cinco tratamentos e quatro repetições. Em cada experimento foram utilizados 540 peixes distribuídos em 20 aquários com 2 L. No primeiro experimento, avaliaram-se os períodos de transição alimentar (MNA + ração) por 1, 2, 3, 4 e 5 dias. No segundo experimento, avaliou-se o período de fornecimento de MNA por 5, 10, 15, 20 e 25 dias. Foram avaliados: ganho de peso, taxas de crescimento e desenvolvimento específico, sobrevivência e uniformidade do lote (apenas no experimento para avaliar o tempo de fornecimento de MNA). Não houve efeito significativo dos diferentes períodos de transição alimentar sobre as variáveis de crescimento (p>0,05), porém a sobrevivência foi maior (p<0,05) nos tratamentos compostos por 3, 4 e 5 dias de alimentação conjunta. Em relação ao tempo de fornecimento de MNA, foram observados piores resultados (p<0,05) quando o tempo de fornecimento do alimento vivo foi menor (5, 10 e 15 dias). Os animais que foram alimentados com MNA antes da transição alimentar, por mais tempo (20 e 25 dias), apresentaram os melhores resultados de crescimento (p<0,05). Portanto, recomenda-se uma transição alimentar de três dias e um fornecimento de MNA por 20 dias para realizar a substituição total do alimento vivo pela ração. PALAVRAS-CHAVE: Alimentação, peixe ornamental, ração, sobrevivência. Different feeding strategies on larval rearing of angelfish (Peterolophyllum scalare, Cichlidae) ABSTRACTThe hatchery is one of the most critical stages of the development of fish and their success is directly related to food handling that can provide greater survival and growth. The aim of this study was to evaluate the time of dietary transition and providing meta-nauplii of Artemia spp. (MNA) for the angelfish larvae. Two experiments were conducted in a completely randomized design with five treatments and four repetitions. On each experiment there were used 540 fishes, distributed in 20 tanks with 2 liters each. In the first experiment, there were evaluated the dietary transition periods (MNA + Diet) for 1, 2, 3, 4 and 5 days. In the second experiment, there were evaluated the supply of MNA for 5, 10, 15, 20 and 25 days. There were evaluated: weight gain, growth rate and specific development, survival and batch uniformity (only in the experiment to evaluate the time of fish feed with MNA). There was no significant effect of different periods of dietary transition on the growth variables (p>0.05), but survival was higher (p<0.05) in the treatments composed of 3, 4 and 5 days of joint feed. In relation to the time of supply of MNA worse results were observed (p<0.05) when the time of supply of live food was...

The aim of this study was to investigate the tolerance of Hypsolebias radiseriatus larvae to different salinities, and the effects of different prey concentrations and water salinities on the larviculture of this species. Salinity tolerance was tested by subjecting newly-hatched larvae to 96 hours of osmotic shock testing (experiment I) and gradual acclimatization (experiment II) of the following salinities: freshwater (control), 2, 4, 6 and 8 g of salt L-1. A third experiment (experiment III) evaluated three water salinities (S0 - freshwater, S2 - 2 g of salt L-1 and S4 – 4 g of salt L-1) and three initial daily prey concentrations (100, 300 and 500 artemia nauplii larva-1). In experiments I and II, survival was only influenced by the salinity of 8 g of salt L-1 (p < 0.01). After 35 days, weight was only influenced by prey concentration (p < 0.05), with the highest value being with 500 artemia nauplii larva-1. The lowest survival was for 4 g of salt L-1 and for 100 artemia nauplii larva-1. H. radiseriatus larviculture can be carried out in salinity of up to 2 g of salt L-1 and initial daily prey concentrations with 500 artemia nauplii larva-1.

Poecilia velifera is a popular fish in freshwater aquarism that naturally inhabits aquatic habitats with a wide range of salinities. Nonetheless, the effects of different salinities on the reproductive success and sex ratio of the species remain unknown. Male sex characters, sex ratio and reproductive success of P. velifera were evaluated by maintaining 160 juveniles (0.078 ± 0.011 g) in four different salinities (0; 12; 24; 36 g/L), with four replicates. The only modification observed in males was the formation of a copulatory organ from the anal fin, which was used to distinguish them from females. Timing of the formation of the male copulatory organ, and the weight and total length of males when it occurred, were recorded. Twenty‐eight fish from each treatment were euthanized after 150 day to examine the gonads and confirm sex. Eight females and four males from each treatment were then kept in their respective salinity treatments for 65 days to examine the effects of salinity on reproduction. Males were kept with females in the different treatments for 15 days, at which point they were removed. Salinity was negatively correlated with male weight and length. Salinity also affected the sex ratio, with the percentages of males and females being 32.5 and 67.5%, and 27.5 and 72.5% in the salinities of 24 and 36 g of salt/L, respectively. Fifty percent of the females kept in freshwater reproduced, while there was no reproduction in the other treatments. The maintenance of P. velifera in freshwater promoted greater reproductive success and precocity, as well as larger males.

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A mitilicultura é uma forma alternativa de várias famílias trabalharem reduzindo o extrativismo e pressão sobre  as populações naturais de mexilhão. O objetivo dessa investigação foi caracterizar a distribuição dos diferentes tamanhos  de sementes do mexilhão  Perna perna em um costão rochoso de Piúma, Espírito Santo, e avaliar sua exploração para  utilizá-las em projetos de cultivo. O trabalho foi realizado no Instituto Federal do Espírito Santo–Campus de Piúma, onde  foram analisadas 16 amostras em quatro tratamentos: T1 - início das sementes no costão; T2 - 1 metro abaixo do inicial;  T3 - 2 metros abaixo; T4 - 3 metros abaixo, cada um com quatro repetições em delineamento inteiramente casualizado.  Foram observadas, pelo teste de Shannon-Wiener, heterogeneidade na quantidade de sementes na faixa de 1,5 - 2,4 cm na  distribuição vertical; também nas de 1,5 - 2,4 cm e 3,6 - 4,5 cm na distribuição vertical por peso. A fauna acompanhante  também apresentou heterogeneidade.

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Killifish is the name given to a group of fish, usually measuring between 3 and 7 cm, that belong to the order Cyprinodontiformes and which present a great diversity of colours and shapes, a fact that has aroused interest in the ornamental sector. Currently, there are fish houses around the world that specialize exclusively in the breeding and reproduction of these species. In addition, killifish have been of scientific interest for several reasons, including their diversity and particular biological characteristics (Costa, 2003).According to studies by Instituto Chico Mendes de Conservação da Biodiversidade (ICMBio, 2013), more than 320 species of killifish have been catalogued in South America alone between Mexico and Argentina. However, some of these species have been suffering from anthropic actions, such as disordered urban expansion, implementation of enterprises and agrosilvopastoral activities. Indeed, according to normative instruction No. 5 of the Ministério do Meio Ambiente, 21 May 2004, 52 species of rivulids are already threatened with extinction in Brazil, which has led authorities to put together an action plan to preserve killifish species.

The objective of this work was to evaluate the effects of ultraviolet radiation (UV) and water salinity on nitrification, water quality, bacterial load, and juvenile tilapia growth in recirculating aquaculture systems (RASs). The experimental period was divided into two phases. The first one lasted 20 days and evaluated the effects of salinity (0 and 2 g L-1) and UV (with or without) on water quality during the period of substrate colonization by nitrifying bacteria. In the second phase, after the storage of juvenile tilapia, the effects of the same experimental factors were evaluated on water quality, bacterial load, and fish growth performance. The RASs employed were efficient for ammonia removal, regardless of the treatments used. During the experimental period, the nitrite concentrations increased linearly, with a more pronounced increase after fish storage until 30 days of the experiment. There were no significant effects of UV, salinity, or the interaction of both on total ammonia, nitrite, and alkalinity. The low levels of salinity (2 g L-1) and UV did not affect the nitrification process and fish performance. The use of UV is efficient to reduce the bacterial load of recirculating aquaculture systems.