Hermetia illucens (Diptera: Stratiomydae) larvae and prepupae: Biomass production, fatty acid profile and expression of key genes involved in lipid metabolism.

The Black Soldier Fly (BSF) Hermetia illucens provides a promising strategy in the waste valorisation process and a sustainable alternative source of valuable nutrients, including lipids for food and feed. In the present study, the differences in growth performances and nutritional values of BSF V instar larvae and prepupae reared on vegetable waste were analyzed and compared focusing on fat content. V instar larvae showed higher capacity to bioconvert the substrate into biomass than prepupae. The nutritional composition and the fatty acid profiles were dependent on the developmental stage. The expression levels of acetyl-CoA carboxylase (acc), fatty acid synthase (fas), lipase (lip) and acyl-CoA dehydrogenase (acd) genes involved in the lipid metabolism pathway and herein characterized for the first time, were evaluated in order to understand the molecular basis underlying the observed differences in fatty acid profiles. Our results suggest that the different fatty acid profiles of BSF V instar larvae and prepupae may be related to the modulation of the lipid metabolism-related genes expression during larval development. Our study highlights substantial differences between H. illucens V instar larvae and prepupae giving important features regarding the opportunity to modulate the preferable fatty acid profile to meet the industrial requirements.

Pro-inflammatory cytokines in the serum of silver catfish (Rhamdia quelen) naturally infected by Clinostomum complanatum: a preliminary study.

Clinostomum complanatum is a zoonotic parasite of birds, and its larval form (metacercariae) may cause disease in fish. The immune response of fish infected by C. complanatum is unknown, and therefore the objective of this study was to evaluate serum levels of pro-inflammatory cytokines in silver catfish (Rhamdia quelen) infected by this parasite. The analysis showed that fish infected with metacercariae presented significantly (P < 0.05) higher levels of tumor necrosis factor alpha (TNF-α), interleukin 1 (IL-1), and interleukin 6 (IL-6) when compared to those not infected. These data suggest that C. complanatum larvae activate the host immune response.

Hidrolisados cárneos na alimentação do surubim do Iguaçu (Steindachneridion melanodermatum)

O presente estudo objetivou verificar a influência da inclusão de diferentes fontes de hidrolisados cárneos na alimentação do surubim do Iguaçu (Steindachneridion melanodermatum). Para a realização do experimento, foram utilizados 256 juvenis de surubim com peso inicial médio de 23,54±0,83g e comprimento total médio de 13,26±0,22cm. Realizou-se um delineamento em blocos ao acaso com quatro tratamentos e quatro repetições. Foram formuladas 4 dietas isoprotéicas e isoenergéticas. Foram incluídas às dietas, hidrolisados de fígado suíno, carcaça de tilápia e sardinha em uma proporção de 60, 40 e 60 g/kg de ração, respectivamente. Na dieta controle não houve acréscimo de hidrolisado. Ao final do experimento, determinaram-se os parâmetros de desempenho zootécnico, hematológicos e composição química da carcaça. Os dados referentes aos parâmetros avaliados foram submetidos à análise de variância de efeitos principais e posteriormente ao teste de Tukey ao nível de 5% de probabilidade através do programa estatístico Statisttics 7.0.Em relação aos parâmetros zootécnicos, as dietas testadas influenciaram significativamente (P 0,05) os valores de peso final, comprimento final e conversão alimentar aparente. Os parâmetros bioquímicos mensurados e a composição de carcaça não diferiram estatisticamente (P>0,05). A inclusão de hidrolisado de fígado suíno e de sardinha em dietas melhora o

Effect of glyphosate herbicide on acetylcholinesterase activity and metabolic and hematological parameters in piava (Leporinus obtusidens).

In this study, teleostean fish Leporinus obtusidens (piava) were exposed to different concentrations of Roundup, a glyphosate (acid equivalent) herbicide: 0 (control), 3, 6, 10, and 20 mg/L for 96 h (short-term). Acetylcholinesterase (AChE) activity was verified in brain and muscle tissues. Metabolic parameters in the liver and muscle (lactate, glycogen, glucose, protein, and ammonia), as well as some hematological parameters, were determined. Unexposed fish exhibited significantly higher brain AChE activity when compared to that of the muscle (P<0.05) (13.8+/-0.76 and 6.1+/-1.31 micromol/min/g protein, respectively). Results indicated that AChE activity significantly decreased in the brain of fish exposed to all glyphosate concentrations tested, but in the muscle this parameter was not altered. In addition, fish exposed to all glyphosate concentrations showed a significant increase in hepatic glycogen and glucose, but a significant reduction in muscle glycogen and glucose. Lactate and protein of fish exposed to all glyphosate concentrations presented a significant decrease in the liver, but did not change significantly in the muscle. Levels of ammonia in both tissues increase in fish at all glyphosate concentrations. Exposure to this herbicide produced a decrease in all hematological parameters tested. These results indicate that AChE activity as well as metabolic and hematological parameters may be good early indicators of herbicide contamination in L. obtusidens.