Desempenho de pós-larvas do camarão-rosa Farfantepenaeus paulensis alimentadas com diferentes frequências durante a fase de berçário = Performance of Farfantepenaeus paulensis shrimp postlarvae fed in different feeding frequencies during nursery rearing

Este estudo avaliou os efeitos da frequência de arraçoamento na sobrevivência e crescimento do camarão-rosa Farfantepenaeus paulensis criado durante a fase de berçário primário. Uma dieta comercial foi oferecida até a saciedade aparente em um, dois, quatro ou seis refeições, e cada tratamento recebia diariamente a mesma quantidade. A sobrevivência não foi significativamente afetada, mas o peso final dos camarões foi superior com o aumento da frequência de arraçoamento. Algumas hipóteses podem explicar a vantagem emdividir o arraçoamento em várias refeições diárias: a diminuição das perdas de nutrientes por lixiviação, a menor atratividade da dieta exposta à água, a incapacidade dos camarões ingerirem maior quantidade de alimento ou a menor desintegração das partículasalimentares, o que dificultaria a manipulação e ingestão da dieta pelos camarões.<br><br>This study assessed the effects of feeding frequency on the survival and growth of the shrimp Farfantepenaeus paulensis reared during the nursery phase. Shrimp from each treatment were fed the same dailyamount of a commercial shrimp diet, which was offered to apparent satiation in 1, 2, 4 or 6 meals. Although survival was not significantly affected, final shrimp weight increased significantly at higher feeding frequencies. The advantage of dividing feeding in more than one daily meal may be explained by one or more of the following factors: lower loss of nutrients by lixiviation; smaller disintegration of food particles (which may hinder manipulation by shrimp and hence ingestion); loss of appeal of the diets after a longexposure to water; and the inability of shrimp to ingest large amounts of feed due to their relatively small digestive system

Desempenho de pós-larvas do camarão-rosa Farfantepenaeus paulensis alimentadas com diferentes frequências durante a fase de berçário

Este estudo avaliou os efeitos da frequência de arraçoamento na sobrevivência e crescimento do camarão-rosa Farfantepenaeus paulensis criado durante a fase de berçário primário. Uma dieta comercial foi oferecida até a saciedade aparente em um, dois, quatro ou seis refeições, e cada tratamento recebia diariamente a mesma quantidade. A sobrevivência não foi significativamente afetada, mas o peso final dos camarões foi superior com o aumento da frequência de arraçoamento. Algumas hipóteses podem explicar a vantagem em dividir o arraçoamento em várias refeições diárias: a diminuição das perdas de nutrientes por lixiviação, a menor atratividade da dieta exposta à água, a incapacidade dos camarões ingerirem maior quantidade de alimento ou a menor desintegração das partículas alimentares, o que dificultaria a manipulação e ingestão da dieta pelos camarões.This study assessed the effectsof feeding frequency on the survival and growth of the shrimp Farfantepenaeus paulensis reared during the nursery phase. Shrimp from each treatment were fed the same daily amount of a commercial shrimp diet, which was offered to apparent satiation in 1, 2, 4 or 6 meals. Although survival was not significantly affected, final shrimp weight increased significantly at higher feeding frequencies. The advantage of dividing feeding in more than one daily meal may be explained by one or more of the following factors: lower loss of nutrients by lixiviation; smaller disintegration of food particles (which may hinder manipulation by shrimp and hence ingestion); loss of appeal of the diets after a long exposure to water; and the inability of shrimp to ingest large amounts of feed due to their relatively small digestive system

Correction: Occurrence of Natural Vertical Transmission of Dengue-2 and Dengue-3 Viruses in Aedes aegypti and Aedes albopictus in Fortaleza, Ceará, Brazil

BACKGROUND: Aedes aegypti and Aedes albopictus perform an important role in the transmission of the dengue virus to human populations, particularly in the tropical and subtropical regions of the world. Despite a lack of understanding in relation to the maintenance of the dengue virus in nature during interepidemic periods, the vertical transmission of the dengue virus in populations of A. aegypti and A. albopictus appears to be of significance in relation to the urban scenario of Fortaleza. METHODS: From March 2007 to July 2009 collections of larvae and pupae of Aedes spp were carried out in 40 neighborhoods of Fortaleza. The collections yielded 3,417 (91%) A. aegypti mosquitoes and 336 (9%) A. albopictus mosquitoes. Only pools containing females, randomly chosen, were submitted to the following tests indirect immunofluorescence (virus isolation), RT-PCR/nested-PCR and nucleotide sequencing at the C-prM junction of the dengue virus genome. RESULTS: The tests on pool 34 (35 A. albopictus mosquitoes) revealed with presence of DENV-3, pool 35 (50 A. aegypti mosquitoes) was found to be infected with DENV-2, while pool 49 (41 A. albopictus mosquitoes) revealed the simultaneous presence of DENV-2 and DENV-3. Based on the results obtained, there was a minimum infection rate of 0.5 for A. aegypti and 9.4 for A. albopictus. The fragments of 192 bp and 152 bp related to DENV-3, obtained from pools 34 and 49, was registered in GenBank with the access codes HM130699 and JF261696, respectively. CONCLUSIONS: This study recorded the first natural evidence of the vertical transmission of the dengue virus in populations of A. aegypti and A. albopictus collected in Fortaleza, Ceará State, Brazil, opening a discuss on the epidemiological significance of this mechanism of viral transmission in the local scenario, particularly with respect to the maintenance of these viruses in nature during interepidemic periods