In this study, the gross morphology of the mouthparts and foregut of the ghost shrimp Lepidophthalmus siriboia were investigated from larvae and postlarvae reared in the laboratory. The mouthparts (maxillae and maxillipeds) of the zoeae have a reduced number of setae and spines (or is absent in some individuals), and the foregut, under developed, have few minute setae in the cardiac and pyloric chambers. In contrast, after the metamorphosis into megalopa stage, all feeding appendages have many setae and, the foregut shows a well-developed gastric mill with strong lateral teeth. In the juvenile stage occurs an increase of setae and spines in the mouthparts and the foregut becomes more specialized. These observations strongly suggest that a lecithotrophic development occurs during all zoeal stages but the megalopa and juvenile stages are feeding animals. The functional morphology of the feeding structures of L. siriboia and other decapods will be briefly discussed. KEYWORDSCallianassidae, Lepidophthalmus siriboia, mouthparts, foregut, morphology. Morfologia funcional dos apêndices bucais e do estômago de larvas e pós-larvas de Lepidophthalmus siriboia

This study provides morphological and molecular data of a new parasite species found in the muscle layer of the intestinal tract of the South American silver catfish, Rhamdia quelen from Marajó Island region (Pará State, Brazil), an important fishery resource with recognized potential for fish farming. The morphology of these parasites was reanalyzed and phylogenetic analyses were run on their 18S rDNA gene sequences. The spores were morphologically distinct from those of other Myxobolus species described previously. The obtained partial sequence of the 18S rDNA gene sequences of the new species were compared to those of 24 other Myxobolus and Henneguya species available in GenBank. The results of morphological and molecular analyses indicated clearly the existence of a new species, Myxobolus marajoensis sp. n.

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The present study investigated

The early stages of the Panulirus echinatus were hatched and reared in the laboratory. Ovigerous females were captured in their habitat and carefully transported to the laboratory. Larvae were transferred in a recirculation water tank at a density of 10 larvae.L -1. The larvae were fed on Artemia and gonads of mussel Brachydonts sp. Microalgae Dunaliella viridis was added at a concentration of 150 x 10 4 cell.mL -1 . Larvae and exuviae of each zoeal stage were preserved in an alcohol 70% + glycerin (1:1) solution. The phyllosomas moulted eight times; the intermoulting period of each instar averaged about 7 to 10 days. The main morphological changes of each appendage were described in detail, illustrated and compared with previous reports.Keywords: spiny lobster, phyllosoma, larval development, morphology. Os primeiros estágios de filosoma da lagosta Panulirus echinatus (Decapoda: Palinuridae) cultivados em laboratório ResumoOs estágios iniciais de lagosta tropical Panulirus echinatus eclodiram e foram cultivados em laboratório. Fêmeas ovígeras foram capturadas em seu habitat e cuidadosamente transportadas para o laboratório. As larvas foram cultivadas em tanques de recirculação de água e alimentadas com náuplios de Artemia e gônadas mexilhão Brachydonts sp. Microalga Dunaliella viridis foi adicionada em cada tanque de cultivo na concentração de 150 x 10 4 cel.mL -1 . Os filosomas mudaram oito vezes e o período de intermuda de cada instar foi de cerca de 7 a 10 dias. As principais mudanças morfológicas de cada apêndice foram descritas, ilustradas e comparadas com trabalhos anteriores.Palavras-chave: lagosta, filosoma, desenvolvimento larval, morfologia.

The myxosporidians of the genus Kudoa cause post mortem myoliquefaction in fishery products and may potentially transmit zoonoses. The present study describes the infection of the skeletal musculature by Kudoa sp. in two sea catfish species, Cathorops spixii (Agassiz, 1829) and Cathorops agassizii (Eigenmann & Eigenmann, 1888), captured monthly in an estuary of the municipality of Vigia de Nazaré, in Pará, northern Brazil between March, 2015, and August, 2016. The morphological features of the spores are described, and the influence of the seasonal variation on the occurrence of the parasite is discussed. The specimens were taken to the laboratory for analysis using a hand lens and light microscopy. When parasites were identified in the musculature, small fragments of the tissue were removed for histological processing and staining by the Hematoxylin-Eosin, Ziehl-Neelsen, May Grunwald-Giemsa, and Gomori techniques. The pseudocysts were found in the muscle fibers, and the spores were star-shaped with elongated extremities and 4 piriform/rounded polar capsules of equal size. No infections were observed in the fish specimens collected during the rainy season, whereas all (100%) of the Cathorops specimens examined during the dry season were infected. This indicates that the ecology and infection patterns of the parasite (identified as a species of the genus Kudoa, on the basis of its morphological features) is influenced by salinity levels.

A new myxozoan was found parasitizing the freshwater catfish, Rhamdia quelen (Quoy & Gaimard), in the Marajó island, Amazon region, Brazil. The new species is described based on the results of morphological and molecular analyses. The parasite is approximately 1.5 mm in diameter and develops in the musculature of the host in the form of spherical, whitish cysts, which are visible macroscopically between the epaxial and hypaxial layers. When ruptured, these cysts produced ellipsoidal spores with a mean length of 11.4 μm (10.7–12.6) and width of 7.2 μm (6.4–7.9). Anomalous spores with a caudal elongation, vesicles in the peripheral portion of the spore and ornamentation of the valves were also observed. The results of the phylogenetic analysis of sequences of the 18S rDNA gene using Bayesian Inference indicated clear differences among the Myxobolus species that reinforced the taxonomic position of the parasite, confirming its status as a new species, denominated Myxobolus arariensis n. sp.