Background: is an opportunistic and omnivorous species that primarily feeds on plant material. Recent studies have shown that Endo-β-1,4-glucanase and Endo-β-1,4-mannanase are expressed in the transcriptome of adult specimens, while juveniles are capable of digesting nutrients from purified cellulose in their diet. In organisms that degrade raw plant material, laccase plays a key role in oxidizing phenolic compounds found in lignin, leading to its depolymerization and increasing access to cellulose and hemicellulose microfibrils.
View Article and Find Full Text PDFBackground: Macrobrachium amazonicum is a freshwater prawn widely distributed in South America that is undergoing speciation, so the denomination "M. amazonicum complex" is used for it. The mitochondrial cytochrome c oxidase subunit I (COI) gene has been used to elucidate this speciation, but heteroplasmies and pseudogenes have been recorded, making separation difficult.
View Article and Find Full Text PDFIn the present study, we report for the first time the occurrence of the alpheid shrimps Leptalpheus forceps Williams, 1965 and Leptalpheus marginalis Anker, 2011 in the state of Pará, in northern Brazil. Both Leptalpheus species (males, non-ovigerous females, and females carrying eggs) were collected from the burrows of the callichirid "ghost" shrimp, Lepidophthalmus siriboia Felder Rodrigues, 1993, in a muddy-sandy intertidal zone of the Ajuruteua Peninsula, in the Bragança region. These records update the known geographical distribution of the two species, with L.
View Article and Find Full Text PDFSporadic fluctuations in food availability may affect larval biology and post-metamorphic development in many marine invertebrates. In an experimental study in the laboratory, we investigated whether different regimes (1, 3, and 5 days) of initial starvation or feeding affect the survival and duration of the last planktotrophic larval stage (, megalopa) of the neotropical mangrove fiddler crab . Newly metamorphosed crabs originating from megalopae starved for 1 and 3 days were cultured through the first 5 juvenile stages to further evaluate whether prior nutritional experience affects the post-larval performance of this species.
View Article and Find Full Text PDFThe morphology of the mouthparts and foregut of the larvae and post-larvae of Macrobrachium jelskii was investigated to determine their functional roles in feeding, in order to understand the larval feeding behaviour and the changes that occur during its development. The mouthparts and foregut of the zoea I and II are morphologically similar, rudimentary and non-functional in feeding. Only in the final larval stage, zoea III, do the external mouthparts and foregut become structurally more complex and thus likely to play a potential role in feeding.
View Article and Find Full Text PDFIn the present study, we carried out experiments on the diet of the freshwater prawn Macrobrachium equidens. We tested which type of food and which density of food is suitable for larval development. For the experiment on the type of food, eight treatments were carried out: (I) starvation, (AL) microalgae, (RO) rotifers, (AN) Artemia, (RO + AN) rotifers + Artemia, (AL + RO) microalgae + rotifers, (AL + AN) microalgae + Artemia, (AL + RO + AN) microalgae + rotifers + Artemia.
View Article and Find Full Text PDFThe larval development of Upogebia vasquezi consists of four zoeal stages and a megalopa. In the present study, each larval stage was described and illustrated in detail. The first two stages are re-described in order to provide a detailed comparison with the data available for this species recorded in a previous study.
View Article and Find Full Text PDFThe sodium metabisulphite salt is usually used in shrimp culture to prevent black spot. Unfortunately the toxicological effect of this xenobiotic in decapod crabs is unknown. Thus, the present study aims to investigate the sodium metabisulphite LC(50) - 96 h in the mangrove species Ucides cordatus.
View Article and Find Full Text PDFBull Environ Contam Toxicol
August 2012
Sodium metabisulphite (SMB) is used in marine shrimp aquaculture to prevent the occurrence of black spot. The release SMB into the estuarine environment from shrimp farm pond effluents has been reported. This study evaluated the susceptibility of larvae and post-larvae of land crab, Cardisoma guanhumi to this salt.
View Article and Find Full Text PDFFeeding is an important factor for the successful rearing of larvae of the crab species. Further information on the morphological features of the foregut may to reveal larval feeding behaviour and or/whether there is a lecithotrophy in some or even in all stages of the larval cycle. In the present study, the structural development of the foregut and their digestive functions were examined in larvae of two brachyurans, Uca vocator and Panopeus occidentalis, reared in the laboratory.
View Article and Find Full Text PDFMegalopae of many decapod crab species accelerate their development time to metamorphosis (TTM) when exposed to natural physical and/or chemical cues characteristic of the parental habitat. In the present study, the influence of natural settlement cues on the moulting rates and development TTM in megalopae of the fiddler crab Uca vocator was investigated. The effects of mud from different habitats (including well-preserved and degraded-polluted mangrove habitats) and conspecific adult 'odours' (seawater conditioned with crabs) on the induction of metamorphosis were compared with filtered pure seawater (control).
View Article and Find Full Text PDFFood supply is considered critical for a successful culturing of decapod larvae. However, some species may present yolk reserve sufficient to complete their larval development without external food supply (known as lecithotrophic larval development). In the present study, two experiments were carried out in order to verify whether the callianassid Lepidophthalmus siriboia have lecithotrophic behaviour or, if they need external food for their larval development: Experiment 1, larvae submitted to an initial feeding period and Experiment 2, larvae submitted to an initial starvation period.
View Article and Find Full Text PDFThe present study investigated whether the callianassid Callichirus major shows a lecithotrophic behaviour during larval development. Two experiments were carried out. In the first experiment, larvae were subjected to an initial period of feeding, while in the second they were subjected to an initial period of starvation.
View Article and Find Full Text PDF