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Biologia reprodutiva e ecologia trófica de Conodon nobilis (linnaeus, 1758) e Bagre bagre (linnaeus, 1766) capturados no golfão maranhense – Brasil

2024-06-16T00:00:00Z

Título: Biologia reprodutiva e ecologia trófica de Conodon nobilis (linnaeus, 1758) e Bagre bagre (linnaeus, 1766) capturados no golfão maranhense – Brasil Abstact: Knowledge of fish biology provides data for the correct management of fishing resources, enabling the formulation of conservation measures and fishing management. Considering existing gaps in the explored ichthyofauna, this research aimed to analyze the reproductive biology and trophic ecology of Conodon nobilis (Linnaeus, 1758) and Bagre bagre (Linnaeus, 1766) from artisanal fishing captured in the fishing community of Raposa, located in the Gulf Maranhão. 360 specimens were acquired for each species, between January and December 2021. In the laboratory, the biometric data of each specimen were recorded and then they were sectioned to remove the tissues, stomach and gonad. The gonadosomatic index (IGS), condition factor (K), sex ratio, type of spawning and spawning season were evaluated. Stomach contents were conditioned and preserved in 10% formaldehyde for analysis, identification and classification of food items at the lowest possible taxonomic level. The degree of repellency and feeding strategies of each species were analyzed. For C. nobilis the length ranged from 11 to 31.8 cm. The sex ratio was 1 Male:1.51 Female and negative allometric growth (b<3). Five stages of gonadal maturation were confirmed throughout the sampling period, for both species, namely: Immature phase (IM); Development phase (DP); Spawning capacity phase (SP); Regression phase (RP); Regeneration phase (RGP). The length of first sexual maturity (L50) for males was 18.94cm, for females it was 18.91cm and for the grouped sexes it was 18.92cm and according to the gonadosomatic indices, individuals in spawning capacity were found in the months of January, April, May, July, September and December, indicating which species has split spawning. This species adopts a generalist feeding strategy, with greater consumption of fish and crustaceans. However, due to the predominance of fish in the diet, C. nobilis can be characterized as a species with a carnivorous eating habit and a piscivorous tendency. For the Bagre bagre species, the length varied between 22.08 and 57.6 cm. The sex ratio found was 1 Male:1.29 Females and negative allometric growth (b<3). The length of first sexual maturity (L50) for males was 33.51cm, for females it was 29.40cm and for the grouped sexes it was 31.21cm and the highest gonadosomatic peaks in females were recorded in the months of January and August to December, while for males these peaks varied in the months of January, May, August and December, indicating split spawning. B. catfish demonstrates a generalist, predominantly carnivorous feeding strategy, with a preference for fish. Given this information, it is possible to define closed periods, minimum catch size, in addition to evaluating the impact of fishing on food chains with a view to proposing measures that minimize disturbances in ecosystems and help preserve fish populations at sustainable levels.

Detecção molecular e análise filogenética de filarídeos em primatas Sapajus apella da região geográfica imediatada de Bacabal, Maranhão

2026-03-04T00:00:00Z

Título: Detecção molecular e análise filogenética de filarídeos em primatas Sapajus apella da região geográfica imediatada de Bacabal, Maranhão Abstact: Filarids are nematodes belonging to the superfamily Filarioidea, recognized for infecting various groups of vertebrates, including Neotropical primates. In Brazil, despite the wide distribution and diversity of species of the genus Sapajus, studies aimed at detecting these parasites in wild populations are still scarce. In Maranhão, particularly in the Immediate Region of Bacabal, an ecological transition area between biomes, with high biodiversity and interaction between wildlife and anthropogenic environments, no studies have yet been carried out on filarids in free-ranging Neotropical primates. In this context, the present study aimed to perform the molecular detection and phylogenetic characterization of filarids detected in Sapajus apella from the region. Between September 2024 and January 2025, individuals of the species S. apella were captured using Tomahawk traps. After restraint, blood samples were collected by puncture of the jugular or femoral vein. Part of the samples was used for the preparation of blood smears, stained by the panoptic method, while another fraction was used for genomic DNA extraction using the QIAamp DNA Mini Kit (QIAGEN®, Germany). The extracted DNA was amplified by Polymerase Chain Reaction (PCR) targeting the cox1, 18S, and 12S genes, followed by Sanger sequencing. The sequences obtained for the cox1 gene were analyzed by BLAST and used for phylogenetic inference by the Maximum Likelihood method. Drops of blood were added to LIT medium for Trypanosoma culture for a parallel project. Of the 14 individuals of S. apella analyzed, three (21.43%) individuals were positive with the presence of parasitic forms in blood smears. Regarding PCR, six (42.85%) samples were positive for the cox1, 18S, and 12S genes. All amplified samples were submitted to sequencing; however, for the cox1 gene, four of them (66.7%) presented adequate quality for analysis and were used in the construction of the phylogenetic tree. The sequences obtained showed identity between 96% and 99% with Dipetalonema gracile according to BLAST, clustering exclusively within the clade of the genus Dipetalonema. The results confirm the occurrence of filarids of the genus Dipetalonema in S. apella in Maranhão. This study represents the first record of the presence of this parasite in primates of this species in the state, expanding knowledge about the distribution of filarids in Neotropical primates in Brazil.

Caracterização clínica, cito-histomorfológica e molecular da esporotricose felina na Ilha de São Luís-MA

2024-06-17T00:00:00Z

Título: Caracterização clínica, cito-histomorfológica e molecular da esporotricose felina na Ilha de São Luís-MA Abstact: Sporotrichosis is a zoonotic cutaneous mycosis caused by saprophytic fungi of the genus Sporothrix spp. which affects cats, armadillos, horses, dogs and humans. In urban areas, cats are the main transmitters of the disease to humans, through bites and scratches. The clinical forms of the disease are: fixed cutaneous, disseminated cutaneous, extracutaneous and lymphocutaneous. The aim of this study was to carry out the clinical, phenotypic and molecular characterization of sporotrichosis in cats living on the island of São Luís, in the state of Maranhão. From October 2022 to July 2023, clinical assessments and cytological examinations were carried out on cats suspected of having sporotrichosis seen at the Francisco Edilberto Uchôa Lopes Veterinary Hospital of the State University of Maranhão. Felines with lesions suggestive of sporotrichosis were selected, without criteria of breed, sex, age or reproductive status. Exudate from the lesions was collected for fungal culture and cytological examination. The positive samples were isolated and sent for phenotypic and molecular identification of the fungal genus. A total of 46 animals were selected: 33 males and 13 females. The disseminated cutaneous clinical form was observed in 70% of the cats evaluated. The regions of the body with the most lesions were the face, ears, back of the thoracic region and limbs. In the fungal culture, white colonies were observed, which progressively became blackish and had a leathery texture compatible with the species Sporothrix spp. The micromorphological analysis showed hyaline hyphae with round conidia and daisy-like conidiophores. The samples that tested positive in the micromorphological evaluation were sent for molecular analysis. PCR was carried out using primers specific to the S. brasiliensis species. All 46 samples successfully amplified the CAL gene. Five samples were selected for phylogenetic analysis. The BLASTn analysis found isolates with percentages of genetic identity ranging from 90 to 100% with sequences of S. brasiliensis (cal gene), previously deposited in the genbank of isolates from different hosts and locations, such as felines, dogs and humans. S. brasiliensis is responsible for causing disease in felines living on the island of São Luís - MA.

Epidemiologia molecular e caracterização de Leucocytozoon spp. em frangos caipiras na ilha de São Luís - MA

2026-10-14T00:00:00Z

Título: Epidemiologia molecular e caracterização de Leucocytozoon spp. em frangos caipiras na ilha de São Luís - MA Abstact: Subsistence poultry farming is an activity present in the life of rural communities in the state of Maranhão, having an important cultural and economic role. In domestic poultry breeding sites, it is common to witness the interaction and breeding of these animals with wild and migratory bird species. These aspects can favor the dispersion and occurrence of several infectious and parasitic agents, since these animals can act as potential biological carriers or mechanical transporters, allowing them to colonize new areas and parasitize susceptible hosts. Avian leukocytozoonosis is caused by protozoa of the genus Leucocytozoon spp. Its transmission occurs through the bite of dipteran insects, belonging to the Simuliidae and Ceratopogonidae families. Given the above, the objective of this work was to verify the occurrence of Leucocytozoon spp. in free-range chickens that live with migratory birds on the island of São Luís, Maranhão. 100 blood samples were collected from free-range chickens from the four municipalities that are part of the island of São Luís - MA. To identify the parasite, the Nested PCR technique was performed. However, of all the samples analyzed, none showed a positive result for Leucocytozoon spp. Although the presence of Leucocytozoon spp. has not been identified, future studies are needed to help determine the geographic distribution of the parasite, since the island of São Luís is part of the migratory route of coastal birds that can carry several pathogens, in order to avoid the occurrence of hemosporidian in subsistence poultry farms