Animal performance and welfare of giant freshwater prawn (Macrobrachium rosenbergii) subjected to feed restriction

Behavior activities of giant freshwater prawn Macrobrachium rosenbergii juvenile, their performance, and acquired lesions when under temporary feed restrictions were analyzed. Five animals/experimental units (10 prawns/m2 ) were employed for treatments DFL ­ daily feed supply in the light phase; DFD ­ daily feed supply in the dark phase; AFL ­ alternating feed supply in the light phase; and AFD ­ alternating feed supply in the dark phase, for a 24-hour period, with four replications each. Prawns were fed a pellet diet, twice a day, with 10% of their biomass/day. Specimens were monitored during 60 consecutive days, with behavior recording daily and weighed every 10 days, with assessment of lesions and/or amputated limbs at the end of the experimental period. Types of behavior comprised exploring, grooming, inactivity, crawling, swimming, excavation, burrowing, agonism, and feed ingestion by scan sampling, with instantaneous registration every 60 s, in 15-min windows, before and after feed, in light and dark phases. Feed restricted in alternate days during light and dark phases did not interfere in growth or survival of the specimens, with increase in apparent feed intake and less feed conversion ratio and specific growth rate. Agonistic behavior was higher in specimens with feed restrictions, with an increase in the number of lesions and amputations. The above demonstrates welfare decrease in farmed M. rosenbergii and depreciation in the quality of the final product.(AU)

Behavior activities of Macrobrachium rosenbergii (De Man, 1879) in monosex and mixed populations, in the laboratory

Monosex all-male populations for the commercial breeding of the freshwater prawn Macrobrachium rosenbergii have been used to lessen the specimens´ aggressiveness and size heterogeneousness. The species´s behavioral variation in mixed, monosex all-male and monosex all-female populations, during the 24-h light-dark period, is assessed. The focal method, with instantaneous report, was employed, featuring a 15-m window for each aquarium, distributed in 12 time shifts throughout the light-dark phase. Eight aquariums contained four prawns each (10 prawns/m2), totaling 96 prawns, monitored for 160 h, during 30 days. Exploring, burrowing, covering with earth, feeding, cleaning, inactivity, crawling, swimming, change and agonistic activity were analyzed. The animals showed a high rate of autogrooming and exploitation during the light and dark phases in three culture modalities, whereas burrowing occurred more frequently during the light period. Agonism was more frequent during the dark phase in all populations, although rates of monosex all-female culture were higher during the light and dark phases when compared to mixed and monosex all-male cultures. The authors recommend shelters and substrates for protection and improvement of the animals´ welfare, especially during the dark shift. Since agonism was more frequent for monosex all-female culture when compared to that in mixed or monosex all-male culture, such population composition is not recommended.(AU)

Behavior activities of Macrobrachium rosenbergii (De Man, 1879) in monosex and mixed populations, in the laboratory

Monosex all-male populations for the commercial breeding of the freshwater prawn Macrobrachium rosenbergii have been used to lessen the specimens´ aggressiveness and size heterogeneousness. The species´s behavioral variation in mixed, monosex all-male and monosex all-female populations, during the 24-h light-dark period, is assessed. The focal method, with instantaneous report, was employed, featuring a 15-m window for each aquarium, distributed in 12 time shifts throughout the light-dark phase. Eight aquariums contained four prawns each (10 prawns/m2), totaling 96 prawns, monitored for 160 h, during 30 days. Exploring, burrowing, covering with earth, feeding, cleaning, inactivity, crawling, swimming, change and agonistic activity were analyzed. The animals showed a high rate of autogrooming and exploitation during the light and dark phases in three culture modalities, whereas burrowing occurred more frequently during the light period. Agonism was more frequent during the dark phase in all populations, although rates of monosex all-female culture were higher during the light and dark phases when compared to mixed and monosex all-male cultures. The authors recommend shelters and substrates for protection and improvement of the animals´ welfare, especially during the dark shift. Since agonism was more frequent for monosex all-female culture when compared to that in mixed or monosex all-male culture, such population composition is not recommended.

Behavioral responses of freshwater prawn according to feeding management in mixed and monosex populations / Respostas comportamentais do camarão de água doce de acordo com o manejo alimentar em populações mistas e monossexo

The effects of two feeding management methods (substrate spreading and feeding tray) were tested for Macrobrachium rosenbergii, evaluating their influence on behavior in mixed (Mi), monosex all-male (Mm) and monosex all-female (Mf) populations. Twelve experimental conditions, totaling 192 animals, with four repetitions each, were performed. Experimental units comprised eight 250-L aquariums (50 x 50 x 100 cm) with soft sand substrate. Behavioral data were collected by focal instantaneous sampling method. Substrate spreading triggered the most extensive behavioral level in all populations under analysis, featuring exploring, autogrooming, crawling, inactivity, burrowing, agonism, swimming and feed ingestion, and revealed that the animals expressed better their behavior when feed was spread. Exceptionally, burrowing in Mm and agonism in Mf had similar level rates for the two feeding managements. Mf had the highest agonistic level when compared to that in Mm and Mi. Data in current analysis indicate that the spread feeding strategy favors animal welfare in all types of population compositions, except in Mf culture, with high agonistic levels in both forms of feeding management.(AU)

Foram avaliados os efeitos de dois métodos de alimentação (a lanço e em comedouros) e sua influência no comportamento de populações mistas (Mi), monossexo fêmea (Mf) e monossexo macho (Mm) de Macrobrachium rosenbergii, nas fases clara e escura do dia. Foram analisadas 12 condições experimentais, com quarto repetições cada, totalizando 192 animais observados. As unidades experimentais consistiram em 8 aquarios (250 L; 50 x 50 x 100 cm) com substrato de areia fina. Dados comportamentais foram coletados usando método de amostragem focal instantâneo. A oferta a lanço, em todas as composições populacionais, induziu a maiores níveis dos comportamentos de exploração, limpeza, enterramento, inatividade, entocamento, agonismo, natação e ingestão do alimento, indicando que os animais encontraram mais oportunidades para expressão de seus comportamentos com o espalhamento da ração. Como exceção, o comportamento de entocamento em Mm e agonismo em Mf foram semelhantes para ambos tipos de manejo alimentar. O cultivo Mf apresentou maiores níveis de agonismo que Mm e Mi. Nesse estudo, os resultados indicam que, em todos os tipos de composição populacional, a alimentação a lanço favoreceu o bem-estar estar animal, exceto para o cultivo Mf, o qual apresentou altos níveis de agonismo em ambas as formas da estratégia alimentar. (AU)

Behavioral responses of freshwater prawn according to feeding management in mixed and monosex populations / Respostas comportamentais do camarão de água doce de acordo com o manejo alimentar em populações mistas e monossexo

The effects of two feeding management methods (substrate spreading and feeding tray) were tested for Macrobrachium rosenbergii, evaluating their influence on behavior in mixed (Mi), monosex all-male (Mm) and monosex all-female (Mf) populations. Twelve experimental conditions, totaling 192 animals, with four repetitions each, were performed. Experimental units comprised eight 250-L aquariums (50 x 50 x 100 cm) with soft sand substrate. Behavioral data were collected by focal instantaneous sampling method. Substrate spreading triggered the most extensive behavioral level in all populations under analysis, featuring exploring, autogrooming, crawling, inactivity, burrowing, agonism, swimming and feed ingestion, and revealed that the animals expressed better their behavior when feed was spread. Exceptionally, burrowing in Mm and agonism in Mf had similar level rates for the two feeding managements. Mf had the highest agonistic level when compared to that in Mm and Mi. Data in current analysis indicate that the spread feeding strategy favors animal welfare in all types of population compositions, except in Mf culture, with high agonistic levels in both forms of feeding management.

Foram avaliados os efeitos de dois métodos de alimentação (a lanço e em comedouros) e sua influência no comportamento de populações mistas (Mi), monossexo fêmea (Mf) e monossexo macho (Mm) de Macrobrachium rosenbergii, nas fases clara e escura do dia. Foram analisadas 12 condições experimentais, com quarto repetições cada, totalizando 192 animais observados. As unidades experimentais consistiram em 8 aquarios (250 L; 50 x 50 x 100 cm) com substrato de areia fina. Dados comportamentais foram coletados usando método de amostragem focal instantâneo. A oferta a lanço, em todas as composições populacionais, induziu a maiores níveis dos comportamentos de exploração, limpeza, enterramento, inatividade, entocamento, agonismo, natação e ingestão do alimento, indicando que os animais encontraram mais oportunidades para expressão de seus comportamentos com o espalhamento da ração. Como exceção, o comportamento de entocamento em Mm e agonismo em Mf foram semelhantes para ambos tipos de manejo alimentar. O cultivo Mf apresentou maiores níveis de agonismo que Mm e Mi. Nesse estudo, os resultados indicam que, em todos os tipos de composição populacional, a alimentação a lanço favoreceu o bem-estar estar animal, exceto para o cultivo Mf, o qual apresentou altos níveis de agonismo em ambas as formas da estratégia alimentar.

Activity patterns and use of microhabitat in lizards of the genus Tropidurus in a urbanized area of Natal, Brazil / Padrões de atividade e utilização de micro-habitat em lagartos do gênero Tropidurus em espaço urbanizado de Natal, Brasil

This study analyzed sun exposure, substrate type selected, and various behaviors exhibited by the lizard Tropidurus during thermoregulation. Observation entailed thirty days in an urbanized area of Centro de Biociências/ Universidade Federal do Rio Grande do Norte. Their behavior was recorded using a scan sampling route and an instantaneous record method at three different time intervals (9am to 10am, 12am to 1pm, and 3pm to 4pm). Significant differences were seen with sun exposure (p = 0.027), with most lizards remaining in shadowed areas, where the animals preferentially remained standing (p 0.001). We were also able to observe more lizards in the following substrates: tile, wall, rocks, and bricks (p 0.001). In addition, the animals were in these substrates more frequently from 12am to 1pm (p = 0.004). (AU)

Analisamos a exposição solar, o tipo de substrato e os comportamentos exibidos por lagartos Tropidurus durante a termorregulação. Foram realizados 30 dias de observações nos horários 9h-10h, 12h-13h e 15-16h, através de amostragem por escaneamento, com registro instantâneo a cada um minuto, em um espaço urbanizado do Centro de Biociências/Universidade Federal do Rio Grande do Norte. Observamos diferença significativa quanto à exposição solar (P = 0,027), com a maior ocorrência de lagartos em áreas sombreadas, onde os animais preferencialmente permaneceram parados (P < 0,001). Observou-se maior frequência de lagartos em substratos compostos por telhas, paredes, rochas e tijolos (P < 0,001). Os animais tiveram maior ocorrência nesses substratos no horário 12h-13h (P < 0,05).(AU)

Activity patterns and use of microhabitat in lizards of the genus Tropidurus in a urbanized area of Natal, Brazil / Padrões de atividade e utilização de micro-habitat em lagartos do gênero Tropidurus em espaço urbanizado de Natal, Brasil

This study analyzed sun exposure, substrate type selected, and various behaviors exhibited by the lizard Tropidurus during thermoregulation. Observation entailed thirty days in an urbanized area of Centro de Biociências/ Universidade Federal do Rio Grande do Norte. Their behavior was recorded using a scan sampling route and an instantaneous record method at three different time intervals (9am to 10am, 12am to 1pm, and 3pm to 4pm). Significant differences were seen with sun exposure (p = 0.027), with most lizards remaining in shadowed areas, where the animals preferentially remained standing (p 0.001). We were also able to observe more lizards in the following substrates: tile, wall, rocks, and bricks (p 0.001). In addition, the animals were in these substrates more frequently from 12am to 1pm (p = 0.004).

Analisamos a exposição solar, o tipo de substrato e os comportamentos exibidos por lagartos Tropidurus durante a termorregulação. Foram realizados 30 dias de observações nos horários 9h-10h, 12h-13h e 15-16h, através de amostragem por escaneamento, com registro instantâneo a cada um minuto, em um espaço urbanizado do Centro de Biociências/Universidade Federal do Rio Grande do Norte. Observamos diferença significativa quanto à exposição solar (P = 0,027), com a maior ocorrência de lagartos em áreas sombreadas, onde os animais preferencialmente permaneceram parados (P < 0,001). Observou-se maior frequência de lagartos em substratos compostos por telhas, paredes, rochas e tijolos (P < 0,001). Os animais tiveram maior ocorrência nesses substratos no horário 12h-13h (P < 0,05).

Behavioral profile of Macrobrachium rosenbergii in mixed and monosex culture submitted to shelters of different colors

Current research analyzed the behavioral activities of Macrobrachium rosenbergii and its preference for colored shelters in male monosex, female monosex and mixed culture. Ten shrimps m-2 were maintained in eight 250-L aquaria. Three artificial shelters, colored red, black and orange, were placed in each aquarium. Four aquaria were maintained in light/dark photoperiod respectively between 6h00 am and 6h00 pm and between 6h00 pm and 6h00 am, whereas the other four aquaria were submitted to an inverted photoperiod. The animals were observed for 30 days by Focal Animal Method for 15 minutes, with instantaneous recording every 60 seconds, at six different instances within the light and dark phases. Preference for black shelters occurred in male monosex and mixed cultures, whereas red and orange shelters were the preference of female monosex. M. rosenbergii kept in the shelter mostly during the light phase in male monosex and mixed populations. Results suggest that black, red and orange shelters may improve the animals' well-being in the culture since aggressive encounters would decrease, especially during the light phase.

Behavioral profile of Macrobrachium rosenbergii in mixed and monosex culture submitted to shelters of different colors / Perfil comportamental de Macrobrachium rosenbergii submetido a abrigos de diferentes colorações em cultivos mistos e monosexo

Current research analyzed the behavioral activities of Macrobrachium rosenbergii and its preference for colored shelters in male monosex, female monosex and mixed culture. Ten shrimps m-2 were maintained in eight 250-L aquaria. Three artificial shelters, colored red, black and orange, were placed in each aquarium. Four aquaria were maintained in light/dark photoperiod respectively between 6h00 am and 6h00 pm and between 6h00 pm and 6h00 am, whereas the other four aquaria were submitted to an inverted photoperiod. The animals were observed for 30 days by Focal Animal Method for 15 minutes, with instantaneous recording every 60 seconds, at six different instances within the light and dark phases. Preference for black shelters occurred in male monosex and mixed cultures, whereas red and orange shelters were the preference of female monosex. M. rosenbergii kept in the shelter mostly during the light phase in male monosex and mixed populations. Results suggest that black, red and orange shelters may improve the animals' well-being in the culture since aggressive encounters would decrease, especially during the light phase.

Esta pesquisa analisou as atividades comportamentais de Macrobrachium rosenbergii e a preferência pela coloração de abrigos em cultivos monosexo macho, monosexo femea e mistos. Dez camarões m-2 foram mantidos em oito aquários de 250 L. Três abrigos artificiais (vermelho, preto e laranja) foram disponibilizados em cada aquário. Quatro aquários foram submetidos à fase clara de 6h00 ­ 18h00 e à fase escura das 18h00 ­ 6h00, e quatro submetidos a fotoperíodo invertido. Os animais foram observados usando Método Animal Focal por 15 minutos, com registro instantâneo a cada 60 segundos, em seis diferentes momentos na fase clara e na fase escura, por 30 dias de observação. Nos cultivos monosexo macho e misto ocorreu uma forte preferência por abrigos de cor preta. No cultivo monosexo fêmea, os camarões preferiram abrigos vermelhos e laranja. M. rosenbergii entoca-se mais frequentemente na fase clara, em populacões monosexo macho e mistas. Estes resultados sugerem que a colocação de abrigos nas cores preto, vermelho e laranja, poderão contribuir com a melhoria do bem-estar dos animais em cultivo, uma vez que podem reduzir a ocorrência de encontros agressivos, principalmente na fase clara do dia.

Behavioral profile of Macrobrachium rosenbergii in mixed and monosex culture submitted to shelters of different colors / Perfil comportamental de Macrobrachium rosenbergii submetido a abrigos de diferentes colorações em cultivos mistos e monosexo

Current research analyzed the behavioral activities of Macrobrachium rosenbergii and its preference for colored shelters in male monosex, female monosex and mixed culture. Ten shrimps m-2 were maintained in eight 250-L aquaria. Three artificial shelters, colored red, black and orange, were placed in each aquarium. Four aquaria were maintained in light/dark photoperiod respectively between 6h00 am and 6h00 pm and between 6h00 pm and 6h00 am, whereas the other four aquaria were submitted to an inverted photoperiod. The animals were observed for 30 days by Focal Animal Method for 15 minutes, with instantaneous recording every 60 seconds, at six different instances within the light and dark phases. Preference for black shelters occurred in male monosex and mixed cultures, whereas red and orange shelters were the preference of female monosex. M. rosenbergii kept in the shelter mostly during the light phase in male monosex and mixed populations. Results suggest that black, red and orange shelters may improve the animals" well-being in the culture since aggressive encounters would decrease, especially during the light phase.(AU)

Esta pesquisa analisou as atividades comportamentais de Macrobrachium rosenbergii e a preferência pela coloração de abrigos em cultivos monosexo macho, monosexo femea e mistos. Dez camarões m-2 foram mantidos em oito aquários de 250 L. Três abrigos artificiais (vermelho, preto e laranja) foram disponibilizados em cada aquário. Quatro aquários foram submetidos à fase clara de 6h00 18h00 e à fase escura das 18h00 6h00, e quatro submetidos a fotoperíodo invertido. Os animais foram observados usando Método Animal Focal por 15 minutos, com registro instantâneo a cada 60 segundos, em seis diferentes momentos na fase clara e na fase escura, por 30 dias de observação. Nos cultivos monosexo macho e misto ocorreu uma forte preferência por abrigos de cor preta. No cultivo monosexo fêmea, os camarões preferiram abrigos vermelhos e laranja. M. rosenbergii entoca-se mais frequentemente na fase clara, em populacões monosexo macho e mistas. Estes resultados sugerem que a colocação de abrigos nas cores preto, vermelho e laranja, poderão contribuir com a melhoria do bem-estar dos animais em cultivo, uma vez que podem reduzir a ocorrência de encontros agressivos, principalmente na fase clara do dia.(AU)

Efeito do tipo de sedimento na eficiência alimentar, crescimento e sobrevivência de Litopenaeus vannamei (Boone, 1931) / Effect of sediment type on feed efficiency, growth and survival of Litopenaeus vannamei (Boone, 1931)

Este estudo avaliou o desempenho zootécnico do camarão marinho Litopenaeus vannamei em diferentes tipos de substratos não consolidados. Juvenis (0,97 ± 0,27 g) foram aclimatados na densidade de 52 m-2, em 21 caixas de polietileno com biofiltros individuais, em um sistema fechado de filtração contínua, sendo submetidos aos tratamentos: 1) A = 25% silte + 25% argila + 25% areia muito fina + 25% areia fina; 2) B = 50% areia fina + 50% areia muito fina e 3) Controle = sem substrato, em um delineamento experimental completamente casualizado, com três tratamentos e sete repetições cada. Os animais foram alimentados com 12% da biomassa/dia com ração peletizada (35% de proteína bruta), ofertada em bandejas e parcelada em duas ofertas diárias (8 e 16h). O estudo teve duração de 48 dias, sendo avaliados: consumo aparente de ração, eficiência alimentar, taxa de crescimento específico, sobrevivência e ganho de peso. Foram acompanhados diariamente salinidade, pH, amônia e temperatura da água. A análise estatística dos dados se deu por meio dos testes Anova ou Kuskal-Wallis, em função da sua parametricidade. Não foram observadas diferenças significativas com relação aos fatores avaliados nas diferentes granulometrias de sedimento testadas, indicando que estas não exerceram influência sobre o desempenho zootécnico de L. vannamei juvenil.

This study aimed to evaluate the zootechnical performance of Litopenaeus vannamei shrimp at different types of unconsolidated substrate. Juvenile shrimp (0.97 ± 0.27 g) were acclimatized, in a stocking density of 52 m-2, to 21 polyethylene boxes (50 L) connected individually to biofilters in a closed water exchange system. The animals were submitted to the treatments: 1) A = 25% silt + 25% clay + 25% very fine sand + 25% fine sand; 2) B = 50% fine sand + 50% very fine sand and 3) Control = no sediment, with seven replications each. Photoperiod was set on 12L: 12D. Shrimps were fed twice a day (at 08:00 and 16:00h) with 12% total biomass day-1. Food was offered in feeding trays 2 cm from the substrate. The experiment had a duration of 48 days, evaluating: apparent ration intake, food efficiency, specific growth rate, survival and weight gain. During this period, water quality was monitored daily. Data was analyzed by Anova or Kuskal-Wallis test, depending on normality (SigmaStat 3.1, 2004 and STATISTICA 6.0, 2001). There were no differences among groups regarding weight gain, food intake, SGR and survival, indicating that these did not exert influence on the zootechnical performance of L. vannamei juvenil.