Preliminary identification and quantification of the age-pigment lipofuscin in the brain of Farfantepenaeus paulensis (Crustacea: Decapoda)

A preliminary study was done on the age-pigment lipofuscin content in the brains of captive Farfantepenaeus paulensis juveniles (5 months old) and wild adults (estimated age of 12-15 months). Random samples of 6 individuals were obtained from each group (juvenile and adult) for histological analysis. Serial sections (6 mum) of the brains were mounted without staining and observed in an epifluorescent microscope. The fluorescent images of the five most central sections of the olfactory lobe cell mass (OLCM) of each individual were digitized for image analysis. The lipofuscin granule mean diameter was similar in both groups (p > 0.05), however the lipofuscin area fraction (percentage of the OLCM occupied by pigment granules) was significantly higher (p < 0.05) in the adult shrimp. The detection of lipofuscin granules in 5 month old F. paulensis indicates that lipofuscin deposition probably takes place even earlier in the juvenile phase. Our results suggested that the amount of granules in the F. paulensis OLCM is related to age, but further studies are necessary to evaluate the relationship between lipofuscin content and the age of captive F. paulensis

Preliminary identification and quantification of the age-pigment lipofuscin in the brain of Farfantepenaeus paulensis (Crustacea: Decapoda)

A preliminary study was done on the age-pigment lipofuscin content in the brains of captive Farfantepenaeus paulensis juveniles (5 months old) and wild adults (estimated age of 12-15 months). Random samples of 6 individuals were obtained from each group (juvenile and adult) for histological analysis. Serial sections (6 mum) of the brains were mounted without staining and observed in an epifluorescent microscope. The fluorescent images of the five most central sections of the olfactory lobe cell mass (OLCM) of each individual were digitized for image analysis. The lipofuscin granule mean diameter was similar in both groups (p > 0.05), however the lipofuscin area fraction (percentage of the OLCM occupied by pigment granules) was significantly higher (p 0.05) in the adult shrimp. The detection of lipofuscin granules in 5 month old F. paulensis indicates that lipofuscin deposition probably takes place even earlier in the juvenile phase. Our results suggested that the amount of granules in the F. paulensis OLCM is related to age, but further studies are necessary to evaluate the relationship between lipofuscin content and the age of captive F. paulensis.

Foi realizada análise preliminar do conteúdo de lipofuscina em cérebros de juvenis de Farfantepenaeus paulensis oriundos de cativeiro (5 meses de idade) e de adultos selvagens (idade estimada de 12-15 meses). Foram coletadas amostras aleatórias de 6 indivíduos de cada grupo (juvenis e adultos) para análises histológicas. Cortes frontais (6 mim) dos cérebros foram montados em lâminas, sem serem corados, e observados em microscópio de epifluorescência. As imagens fluorescentes dos 5 cortes mais centrais da massa de células do lóbulo olfatório (MCLO) de cada indivíduo foram digitalizadas para posterior análise de imagens. O diâmetro médio dos grânulos de lipofuscina foram similares entre os dois grupos (p > 0,05), entretanto, a porcentagem da área de MCLO ocupada por grânulos foi significativamente maior (p 0,05) nos camarões adultos. A detecção de grânulos de lipofuscina em F. paulensis com 5 meses de idade indica a possibilidade de o início de deposição ocorrer anteriormente em juvenis. Os resultados sugerem que a quantidade de grânulos na MCLO de F. paulensis está relacionada à idade, contudo, futuros estudos são necessários para avaliar a relação entre a quantidade de lipofuscina e a idade de F. paulensis mantidos em cativeiro.