DSpace Coleção:http://repositorio.ufc.br/handle/riufc/112026-06-09T22:35:03Z2026-06-09T22:35:03ZOptimal levels of methionine and the impact of water leaching in juvenile Penaeus vannamei dietsFaçanha, Felipe N.Masagounder, KarthikNunes, Alberto J.P.http://repositorio.ufc.br/handle/riufc/864262026-05-22T16:33:20Z2025-01-01T00:00:00ZTítulo: Optimal levels of methionine and the impact of water leaching in juvenile Penaeus vannamei diets
Autor(es): Façanha, Felipe N.; Masagounder, Karthik; Nunes, Alberto J.P.
Abstract: An 8-week feeding trial was conducted to determine the optimal levels of dietary methionine
(Met) for juvenile Pacific whiteleg shrimp, Penaeus vannamei, while evaluating the effects of
amino acid (AA) leaching. Six practical diets were formulated to be isonitrogenous and isolipidic,
with total Met levels ranging from 0.51 % to 1.37 % in 0.14–0.21 % increments, and total sulfur
AA (Met + Cysteine) levels from 0.88 % to 1.75 % on a dry matter basis (DM). The total nitrogen
content was balanced across all diets by replacing Met with a non-essential AA mixture. Each diet
was randomly assigned to seven replicate groups of 15 juvenile shrimp with an initial body
weight (BW) of 0.80 ± 0.05 g. Shrimp were fed six times daily until apparent satiation. The effects
of varying dietary Met levels on survival, growth performance, feed utilization, and muscle tissue
composition were evaluated, with Met leaching rates measured at 30 minutes in full-strength
seawater. Results showed consistently high survival rates across all treatments, while final
shrimp BW significantly increased with higher Met levels, particularly between diets containing
0.82 % and 0.99 % Met. Met leaching rates positively correlated with synthetic Met supplementation, significantly increasing as total dietary Met concentration rose. Muscle tissue
composition analysis highlighted Met’s crucial role in protein synthesis and physiological function, revealing significant differences in crude protein and essential AA deposition among dietary
treatments. Higher dietary Met promoted optimal protein and AA muscle content up to 0.82 %,
after which a saturation effect was observed. In conclusion, this study emphasizes the importance
of accounting for nutrient leaching when determining optimal AA levels for juvenile P. vannamei.
Quadratic regression analysis indicated that an optimal dietary Met level of approximately 1.04 %
in the dry diet (2.73 % of dietary protein) was most effective under these experimental conditions.
Considering Met leaching rates to more accurately estimate the amount of Met available to
shrimp after feed exposure to water, it was established that an optimal level of 0.74 % Met in the
dry diet (2.20 % of dietary protein) after 30 minutes of immersion in water optimally supports
growth and feed efficiency. This finding refines the actual optimal dietary Met level for juvenile
Penaeus vannamei, establishing a new benchmark for future nutritional research in shrimp
aquaculture.
Tipo: Artigo de Periódico2025-01-01T00:00:00ZEffects of water temperature on digestive protease activity and apparent nutrient digestibility in Pacific whiteleg shrimp, Litopenaeus vannamei (Boone, 1931)Castro, BenjaminKovac, ZlatkoLeyton, PabloNunes, AlbertoEspinoza, Carloshttp://repositorio.ufc.br/handle/riufc/864252026-05-22T16:20:09Z2026-01-01T00:00:00ZTítulo: Effects of water temperature on digestive protease activity and apparent nutrient digestibility in Pacific whiteleg shrimp, Litopenaeus vannamei (Boone, 1931)
Autor(es): Castro, Benjamin; Kovac, Zlatko; Leyton, Pablo; Nunes, Alberto; Espinoza, Carlos
Abstract: Water temperature strongly influences metabolic rate, digestive physiology, and nutrient utilization in poikilothermic aquatic species such as shrimp. This study evaluated the effects of two culture temperatures (27 and
31 ◦C) on growth performance, apparent nutrient digestibility, hepatopancreatic protease production, and
protease activity in Pacific white shrimp (Litopenaeus vannamei). Adult shrimp (≈16 g) were maintained at the
experimental temperatures for 21 days, following a gradual acclimation period. Growth performance and
apparent digestibility coefficients (AD) of dry matter, protein, methionine, and lysine were not significantly
affected by temperature. However, lipid digestibility was significantly higher at 27 ◦C. Shrimp reared at 27 ◦C
also exhibited a significantly higher hepatosomatic index and greater total quantity of stored protease
throughout the circadian cycle, indicating enhanced digestive enzyme synthesis. Although protease catalytic
activity was higher at 31 ◦C, shrimp maintained digestive efficiency at 27 ◦C through compensatory increases in
enzyme production and lipid utilization. These findings demonstrate that L. vannamei exhibits substantial
digestive plasticity, allowing maintenance of growth and protein utilization at moderately sub-optimal temperatures through coordinated metabolic and enzymatic adjustments.
Tipo: Artigo de Periódico2026-01-01T00:00:00ZSpatial and seasonal drivers of fish fauna in estuaries from the Brazilian semiarid coast: Taxonomic and functional perspectivesGurgel-Lourenço, Ronaldo CésarPinto, Leonardo MesquitaRodrigues-Filho, Carlos Alberto de SousaGarcez, Danielle SequeiraSánchez-Botero, Jorge Ivánhttp://repositorio.ufc.br/handle/riufc/861252026-05-05T16:59:20Z2026-01-01T00:00:00ZTítulo: Spatial and seasonal drivers of fish fauna in estuaries from the Brazilian semiarid coast: Taxonomic and functional perspectives
Autor(es): Gurgel-Lourenço, Ronaldo César; Pinto, Leonardo Mesquita; Rodrigues-Filho, Carlos Alberto de Sousa; Garcez, Danielle Sequeira; Sánchez-Botero, Jorge Iván
Abstract: Estuaries are spatiotemporally dynamic environments that structure biological communities in a complex manner. We investigated how the taxonomic and functional structures of the fish fauna in estuaries along the Brazilian semiarid coast (BSC) vary between estuarine zones and seasons. Standardized collection methods sampled fish in five estuaries of the BSC. Each species was categorized by trophic guild and estuarine use guild, and fish–estuary association score (FEAS). Non-metric multidimensional scaling (nMDS) analyzed species and trophic guild compositions according to zone and season. PERMANOVA tested differences among groups. Similarity percentage (SIMPER) analysis and the relative preference index (RPi) identified the species and trophic guilds that contributed most to group distinction (lower zone versus upper zone, and dry season versus rainy season). In total, 113 fish species were recorded. The most representative estuarine use guilds were marine migrants and estuarine. Among the nine trophic guilds, the most representative were detritivores, omnivores, opportunists, macrocarnivores, and zoobenthivores. Taxonomic (species composition) and functional (trophic guilds) approaches revealed both spatial and temporal differences. The functional approach using FEAS detected spatial variation of small magnitude and indicated temporal homogeneity. Thus, there is substantial taxonomic and functional heterogeneity considering approaches from species, estuarine use guilds, and trophic guilds.
Tipo: Artigo de Periódico2026-01-01T00:00:00ZAmbiente, e não só a pesca, determina o futuro das lagostas no Brasil, revela estudo internacional.Cruz, RaulFerreira, Antônio G.Santana, João V. M.Torres, Marina T.Gaeta, Juliana C.Silva, Jessica L. S. daBarreto, Carlos G.Borda, Carlos A.Abreu, Jade O.Viana, Rafael D.Lima, Francisco R. deCintra, Israel H. A.http://repositorio.ufc.br/handle/riufc/860442026-04-27T16:14:30Z2026-01-01T00:00:00ZTítulo: Ambiente, e não só a pesca, determina o futuro das lagostas no Brasil, revela estudo internacional.
Autor(es): Cruz, Raul; Ferreira, Antônio G.; Santana, João V. M.; Torres, Marina T.; Gaeta, Juliana C.; Silva, Jessica L. S. da; Barreto, Carlos G.; Borda, Carlos A.; Abreu, Jade O.; Viana, Rafael D.; Lima, Francisco R. de; Cintra, Israel H. A.
Tipo: Resumo2026-01-01T00:00:00Z