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Climate change is expected to have major negative effects on marine life across phylogenetic groups. Cephalopods, however, have life history characteristics that suggest they may benefit from certain climate change scenarios. Of all cephalopods, squids reach the greatest biomasses; as a result, they are of substantial importance for human and predator consumption. To test the hypothesis that the effects of climate change are beneficial for commercial squid, we used species distribution models on climate scenarios for the period between 2000 and 2014, as well as the years 2050 and 2100 (RCP [representative concentration pathway] 2.6, 4.5, 6.0, and 8.5; CMIP5). Our results suggest that consequences of climate change scenarios are species specific. In the North Pacific and Northwest Atlantic, squid’s habitat suitability may increase (from + 0.83% [Doryteuthis pealeii] to + 8.77% increase [Illex illecebrosus]), while it is predicted to decrease in other regions (from − 1.03% [Doryteuthis opalescens] to − 15.04% decrease [Loligo reynaudii]). Increases in habitat suitability occurred mostly at higher latitudes (north of 50° N), while suitable habitat decrease was predicted for the tropical regions. These shifts in future habitat suitability were stronger under harsher emission scenarios. Starting in 2050 (with RCP scenarios 4.6, 6.0 and 8.5), as a result of warming of the Arctic, squid habitat may increase along both coasts of North America. In the Southern Hemisphere, squids may lose habitat with no poleward habitat alternatives to move into. Contrary to our hypothesis, these commercial squid do not stand to benefit from climate change. Since these squid are an important food source for marine megafauna and humans, it is imperative that climate change biogeographic impacts are considered for a sustainable management of this important group of molluscs.

Introduction: Historically considered to be a single cosmopolitan species, the so called Octopus vulgaris species complex (OVSC) is now recognized to be a group of (at least) six cryptic species: O. americanus (in the west Atlantic), O. vulgaris (in the northeast Atlantic and Mediterranean Sea), O. aff. vulgaris (in the region of South Africa), O. tetricus (southeastern Oceania), O. sinensis (northwestern Pacific), and O. djinda (western Australia). The potentially different environmental preferences of this highly cryptic species complex may result in distinct consequences under future environmental conditions. Methods: The present study employed species distribution models (SDM) using MaxEnt to investigate potential changes in habitat suitability and geographical distribution of the OVSC in the future (i.e., 2050, and 2100), across four representative concentration pathway scenarios (RCP-2.6, 4.5, 6.0, and 8.5, CMIP5). Results: Differential responses were observed in the OVSC species analyzed. Specifically, O. vulgaris and O. tetricus exhibited a severe loss in distribution across their predicted range; O. americanus exhibited projected extirpation close to the equator, with limited expansion towards the poles; O. aff. vulgaris was projected to lose half of its current distribution; O. sinensis exhibited moderate losses, with projected increases in northern areas; and finally, O. djinda exhibited limited losses to its distribution. Except for O. sinensis, increasing RCP severity exacerbated changes in mean habitat suitability and projected distribution gains and losses. Discussion: Ultimately, this study provides information on the potential biogeographical effects of marine climate change on a key worldwide ecological and economic resource to further disentangle the effects over each OVSC species, with the goal of assisting toward the sustainable management of octopus species at the global scale.

Introduction: Historically considered to be a single cosmopolitan species, the so called Octopus vulgaris species complex (OVSC) is now recognized to be a group of (at least) six cryptic species: O. americanus (in the west Atlantic), O. vulgaris (in the northeast Atlantic and Mediterranean Sea), O. aff. vulgaris (in the region of South Africa), O. tetricus (southeastern Oceania), O. sinensis (northwestern Pacific), and O. djinda (western Australia). The potentially different environmental preferences of this highly cryptic species complex may result in distinct consequences under future environmental conditions. Methods: The present study employed species distribution models (SDM) using MaxEnt to investigate potential changes in habitat suitability and geographical distribution of the OVSC in the future (i.e., 2050, and 2100), across four representative concentration pathway scenarios (RCP-2.6, 4.5, 6.0, and 8.5, CMIP5). Results: Differential responses were observed in the OVSC species analyzed. Specifically, O. vulgaris and O. tetricus exhibited a severe loss in distribution across their predicted range; O. americanus exhibited projected extirpation close to the equator, with limited expansion towards the poles; O. aff. vulgaris was projected to lose half of its current distribution; O. sinensis exhibited moderate losses, with projected increases in northern areas; and finally, O. djinda exhibited limited losses to its distribution. Except for O. sinensis, increasing RCP severity exacerbated changes in mean habitat suitability and projected distribution gains and losses. Discussion: Ultimately, this study provides information on the potential biogeographical effects of marine climate change on a key worldwide ecological and economic resource to further disentangle the effects over each OVSC species, with the goal of assisting toward the sustainable management of octopus species at the global scale.

Knowledge on the nutritional value of feed ingredient is an important step in the formulation of diets in order to maximize animal productivity. Thus a study was conducted to determine the apparent digestibility coefficients (ADC) of dry matter (ADCDM), crude protein (ADCCP), gross energy (ADCGE) and amino acids (ADCAA) of conventional feed ingredients for juvenile silver mojarra (13.0 ± 3.23 g). The study was conducted in the laboratory for nutrition and feeding of fish (AQUANUT), using 80 silver mojarra collected in nature, which were kept in digestibility aquaria for a period of 21 days. The following ingredients were evaluated: fish meal, soybean meal, corn meal, corn gluten meal, rice bran, wheat bran and starch, which substituted 30% of a reference pelletized diet with 325.00 g kg-1 crude protein and 3,692 Kcal kg-1 gross energy. Additionally 1.0 g kg-1 chrome oxide was added to each diet as a marker. The excreta were obtained using three repetitions for each tested ingredient, which were dried for further analyses. The soybean meal showed the best ADCDM value (67.45%), followed by the other ingredients. There was no significant difference between the soybean meal (95.16%), fish meal (92.97%) and the corn meal (91.90%) for the best ADCCP coefficients. The ADCGE for soybean meal and maize meal were 65.23% and 60.31%, respectively, followed by fish meal (51.85%). The results demonstrate that silver mojarra can digest animal protein as well as that of vegetal origin. Silver mojarra can also efficiently digest and absorb some of the main amino acids of fish, such as lysine, methionine and threonine, from the same studied ingredients., O conhecimento do valor nutritivo de alimentos é um passo importante na formulação de dietas para maximizar a produtividade animal. Foi realizado um estudo para determinar os coeficientes de digestibilidade aparente (CDA) da matéria seca (CDAMS), da proteína bruta (CDAPB), da energia bruta (CDAEB) e dos aminoácidos (CDAAA) de ingredientes convencionais para juvenis de carapeba (13 ± 3,23 g). O estudo foi realizado no Laboratório de Nutrição e Alimentação de Peixes (AQUANUT), utilizando 80 exemplares de carapeba, coletados na natureza, que foram mantidos em aquários de digestibilidade no período de 21 dias. Foram avaliados os seguintes ingredientes: farinha de peixe, farelo de soja, fubá de milho, farelo de glúten de milho, farelo de arroz, farelo de trigo e amido, que substituíram 30% de uma dieta referência peletizada com 325,00 g kg-1 de proteína bruta e 3692 Kcal kg-1 de energia bruta, utilizando 1,0 g kg-1 óxido de cromo como marcador. As excretas foram obtidas utilizando três repetições para cada ingrediente testado, e após a secagem foram realizadas as análises laboratoriais. O farelo de soja apresentou o melhor resultado para o CDAMS (67,45%) seguido pelos demais ingredientes. Para o CDAPB não houve diferença significativa entre o farelo de soja (95,16%), a farinha de peixe (92,97%) e o fubá de milho (91,90%) que apresentaram os melhores coeficientes de digestibilidade. Em relação ao CDAEB os resultados do farelo de soja e fubá de milho foram 65,23 e 60,31%, respectivamente, seguidos pela farinha de peixe (51,85%). A carapeba aproveita alimentos tanto de origem animal quanto de origem vegetal, evidenciando também eficiência em absorver aminoácidos como a lisina, metionina e treonina, para os mesmos ingredientes estudados.

The productive performance and the variable cost of production were evaluated for different feeding strategies for tilapia during the production cycle. A sample of 2,000 juvenile tilapia was distributed (23.55 ± 2.38 g) into five treatments and with four repetitions as follows: C (feed consumption to apparent satiety), R20 (beginning feed restriction when fish reached an average weight of 20 g), R200 (beginning feed restriction when fish reached an average weight of 200 g), R400 (beginning feed restriction when fish reached an average weight of 400 g) and R600 (beginning feed restriction when fish reached an average weight of 600 g). The fish were given extruded commercial feed containing 34% crude protein until they reached a weight of 200 g, at which time they received feed containing 32% crude protein. Monthly biometrics were performed in order to determine the food restriction starting point, which was one day of restriction followed by six feeding days. The following parameters were evaluated: water quality, productive performance variables, the variable costs of production and excreted nitrogen. The results were subjected to analysis of variance, and the means were compared using Tukey’s test (5% significance). No statistical differences were observed in final weight, weight gain, feed consumption, feed conversion or survival. The fish from the R20 treatment had the lowest variable cost of production (g fish-1) and the lowest nitrogen excretion into the water. This suggests that feed restriction from the early stages of life does not compromise the productive performance and contributes to reducing the variable costs and the quantity of nitrogen excreted into the environment. Thus, a one-day per week feed restriction strategy can be applied from the earliest stages of life without compromising the productive performance or body composition of Nile tilapia. This strategy can also reduce variable costs of production by means of reducing relative labour and feed, Foi avaliado o desempenho produtivo e o custo de produção variável da utilização de diferentes estratégias de alimentação para tilápia durante o ciclo de produção. Foram distribuídos 2000 juvenis (23,55 ± 2,38 g) em cinco tratamentos e quatro repetições: C (consumo até a saciedade aparente), R20 (início da restrição quando peixes atingiam peso médio de 20 g), R200 (início da restrição quando peixes atingiam peso médio de 200 g), R400 (início da restrição quando peixes atingiam peso médio de 400 g) e R600 (início da restrição quando peixes atingiam peso médio de 600 g). Os peixes foram alimentados com ração comercial extrusada com 34% de proteína bruta até atingirem 200 g, quando passaram a receber ração contendo 32% de proteína bruta. Foram realizadas biometrias mensais para determinação do início da restrição alimentar, que foi de um dia de restrição seguido de seis dias de alimentação. Foram avaliados os parâmetros de qualidade da água, variáveis de desempenho produtivo, os custos variáveis de produção e o nitrogênio excretado. Os resultados obtidos foram submetidos à análise de variância e as médias foram comparadas pelo teste Tukey (5%). Não foram verificadas diferenças estatísticas no peso final, ganho de peso, consumo de ração, conversão alimentar e sobrevivência. Os peixes do tratamento R20 apresentaram o menor custo variável de produção (g peixe-1) e a menor excreção de nitrogênio na água, sugerindo que a restrição alimentar desde as primeiras fases de vida não compromete o desempenho produtivo e contribui para a redução nos custos variáveis e na excreção de nitrogênio no ambiente. Assim, a restrição alimentar de um dia na semana pode ser empregada, sem que haja prejuízos no desempenho produtivo e composição corporal dos peixes, além de contribuir para a redução dos custos variáveis de produção, através da redução dos custos relativos à ração e mão-deobra.

Introdução: Avaliou-se no presente estudo a associação entre o uso de exercícios monoarticulares nas séries de musculação de alunos iniciantes e em alunos que praticam desporto, na visão do profissional de Educação Física. Materiais e Métodos: A metodologia adotada foi de cunho descritivo com tipologia PAR-Q simples, com 62 profissionais formados, de diferentes municípios, preenchendo questionário sem divisão no PAR-Q. As descobertas mais importantes para nosso estudo foram: o uso indevido de exercícios monoarticulares tornando-se desnecessários para a série; uso pertinente dos exercícios monoarticulares, porém sem metodologias a seguir, o que deixa às vezes um trabalho sem parâmetros importantes; e falta de conscientização. Resultados: Para análise usou-se 169 respostas de profissionais da área de Educação Física. Discussão: Constatou-se a utilização dos exercícios monoarticulares de maneira devida, mas há necessidade de conscientização para o uso dos mesmos.

Precede ó tít.: El pensamiento de Salazar

Precede ó tít.: El pensamiento de Salazar