ABSTRACT
Aims@#This study aims to assess the impact of anthropogenic activities on shrimp microbiome in a biodiverse mangrove forest ecosystem, along the Merbok River, Kedah, Malaysia.@*Methodology and results@#To assess the impacts, a microbiome study of wild post larvae shrimps along the river was conducted as a health indicator of the shrimp hosts which in turn would reflect the river conditions. A 16S rRNA gene amplicon sequencing of the wild post larvae shrimp microbiomes sampled across areas of varying human activities was conducted. Samples were obtained from four sites ranging from upstream river habitat to downstream brackish water towards the marine coast. Individuals detected from the sequence were then counted and their relative abundance of bacterial diversity were compared. All abundances are up to 100% and the diversity indices were calculated using proportions of each species. The Operational Taxonomy Unit (OTUs) were obtained by using USEARCH and UPARSE software. Twenty-eight bacterium phyla were detected, dominated by phyla Proteobacteria, Actinobacteria, Firmicutes and Bacteroidetes at each site. Eighteen families were dominant at each site with Streptomycetaceae being the major abundant. At the genus level, the most abundant genera were Streptomyces sp., Mesorhizobium sp., Rhizobium sp., Bacillus sp. and Pseudomonas sp.@*Conclusion, significance and impact of study@#In general, the diversity of opportunistic and coliform bacteria was low. Thus, despite being exposed to various levels of human activities, the Merbok River and its mangrove surroundings still serve as a good spawning and nursery sites of shrimps and presumably other inhabitants.
Subject(s)
Biodiversity , Decapoda , WetlandsABSTRACT
The main challenges facing fish farming include the optimization of Silurid fingerling production through efficient larval rearing and nursery management. This study evaluated growth performance of catfish (Pseudoplatystoma sp) and yaque (Leiarius marmoratus) post-larvae during adaptation to commercial diet containing 40% crude protein of animal origin (e.g., bovine liver and heart). A total of 240 L. marmoratus and Pseudoplatystoma sp. post-larvae were selected at 16 days of age. Postlarvae average weight and lengh were 57.2 ± 4.8 mg and 17.1 ± 1.4 mm for L. marmoratus, and 55.9 ± 6.6 mg and 13.5 ± 2.7 mm for Pseudoplatystoma sp, respectively. Housing density was 4 larvae / L. Four treatments (T) were evaluated, with five replicates each, as follows: T1: commercial feed (C), T2:C + bovine heart (CO), T3: C + liver (HI), and T4: C + liver + fish oil (HI + AP). The best weight gain for larvae of L. marmoratus was observed in T4 (3213 ± 278 mg). For Pseudoplatystoma sp., no significant differences were observed between treatments, although T2 was numerically better (695 ± 149 mg). In conclusion, conditioning to a dry diet was more effective for L. marmoratus post-larvae compared to Pseudoplatystoma sp. This is mainly due to the attractiveness and digestibility of the feed, as well as certain post-larvae characteristics (e.g., development of the digestive tract). It is necessary to conduct specific studies related to the ontogenetic development of the digestive tract to uncover the nutritional needs of each species during growth to match allowances with specific dietary requirements.
El principal desafío de la piscicultura con silúridos consiste en optimizar la producción de alevinos mediante prácticas eficientes de larvicultura y alevinaje. El presente estudio evaluó el desempeño productivo de post-larvas de bagre rayado (Pseudoplatystoma sp) y de yaque (Leiarius marmoratus) durante su acostumbramiento a una dieta comercial del 40% de proteína bruta de origen animal (ej: hígado y corazón de bovino). Fueron seleccionadas 240 post-larvas de L. marmoratus y de Pseudoplatystoma sp de 16 días de edad, con peso y talla promedio de 57.2 ± 4.8 mg y 17.1 ± 1.4 mm para L. marmoratus, y de 55.9 ± 6.6 mg y 13.5 ± 2.7 mm para Pseudoplatystoma sp, respectivamente. La densidad de alojamiento fue de 4 larvas/L. Fueron evaluados 4 tratamientos (T) con cinco réplicas cada uno, así: T1: alimento balanceado comercial (C); T2: C + corazón de bovino (CO); T3: C + hígado (HI) y; T4: C + hígado + aceite de pescado (HI+AP). La mejor ganancia de peso para larvas de L. marmoratus se observó en el T4 (3213 ± 278 mg). Para Pseudoplatystoma sp no se observaron diferencias significativas entre tratamientos, aunque el mejor resultado numérico fue para el T2 (695 ± 149 mg). En conclusión, el acondicionamiento a dieta seca fue más eficiente en post-larvas de L. marmoratus que en Pseudoplatystoma sp, debido principalmente a la atractabilidad y digestibilidad del alimento, así como a características de las post-larvas (desarrollo del tracto digestivo). Se hace necesario realizar estudios específicos de desarrollo ontogénico relacionados con las características del tracto digestivo que permitan evidenciar las necesidades nutricionales de cada especie durante su crecimiento, para formular dietas acordes con los requerimientos específicos.
O principal desafio da aquicultura com silúridas é optimizar a produção de alevines mediante práticas eficientes de larvicultura e alevinagem. O presente estudo avaliou o desempenho produtivo de pós-larvas de pintado (Pseudoplatystoma sp) e Yaque (Leiarius marmoratus) durante o período de adaptação a uma dieta comercial com 40% de proteína bruta de origem animal (por exemplo, fígado e coração de bovino). Foram seleccionados 240 pós-larvas de L. marmoratus e Pseudoplatystoma sp 16 dias de idade, peso e comprimento médio de 57.2 ± 4.8 mg e 17.1 ± 1.4 mm para L. marmoratus, e 55.9 ± 6.6 mg e 13.5 ± 2.7 mm para Pseudoplatystoma sp, respectivamente. A densidade de alojamento foi de 4 larvas/L. Foram avaliados quatro tratamentos (T), com cinco repetições, conforme segue: T1: ração comercial (C), T2: C + coração (CO), T3: C + fígado (HI) e T4: C + fígado + óleo de peixe (HI + AP). O melhor ganho de peso para as larvas de L. marmoratus foi observado no T4 (3213 mg ± 278). Para Pseudoplatystoma sp não houve diferenças significativas entre os tratamentos, embora o resultado numérico foi melhor para o T2 (695 mg ± 149). Em conclusão, condicionado à dieta seca foi mais eficaz no pós-larvas de L. marmoratus que no Pseudoplatystoma sp, principalmente devido à atractividade e digestibilidade de alimentos para animais,bem como características de pós-larvas (desenvolvimento do trato digestivo). É necessário realizar estudos específicos relacionados com o desenvolvimento ontogênico das características do aparelho digestivo que revelam as necessidades nutricionais de cada espécie durante o seu crescimento para fazer concessões em conformidade com os requisitos específicos.
ABSTRACT
The aim of this study was to evaluate the survival and growth of pintado, Pseudoplatystoma corruscans, post-larvae (PL) submitted to seven salinities: S1: 0; S2: 1.7; S3: 3.3; S4: 5; S5: 6.7; S6: 8.3 and S7: 10 distributed in a complete randomized design with three replicates. PL were stocked in 5-l round plastic containers at a density of 15 PL/liter and maintained in the dark. The water was salinized with iodine-free sodium chloride (NaCl). PL were fed six times a day with 500 Artemia sp. nauplii/PL. Survival was high up to salinity 1.7, both on the fifth and on the tenth day of experiment, but decreased quickly in salinities above 5. Better growth rates were observed in salinities 0 and 1.7, however, high growth observed in freshwater was due to cannibalism. Results showed that pintado larviculture would be suitable in 1.7 salinity water.
O objetivo deste estudo foi avaliar a sobrevivência e o crescimento de pós-larvas (PL) de pintado, Pseudoplatystoma corruscans, submetidas a sete salinidades: S1: 0; S2: 1,7; S3: 3,3; S4: 5; S5: 6,7; S6: 8,3 e S7: 10, distribuídas num delineamento inteiramente ao acaso, com três repetições. As pós-larvas foram estocadas em recipientes plásticos circulares com volume de 5 litros, numa densidade de 15 pós-larvas/litro e mantidas em fotoperíodo escuro. A água de cultivo foi salinizada com cloreto de sódio (NaCl) não-iodado. As pós-larvas foram alimentadas seis vezes ao dia na proporção de 500 náuplios de Artemia sp/PL/dia. A sobrevivência apresentou crescimento mais acentuado até a salinidade de 1,7, tanto no quinto como no décimo dia de experimento, decrescendo bruscamente em salinidades superiores a 5. Os maiores valores de crescimento foram observados nas salinidades de 0 e 1,7, porém, o elevado crescimento observado em água doce foi decorrente do canibalismo. Pelos resultados obtidos, recomenda-se o cultivo de pós-larvas de pintado em água salinizada a 1,7.