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Estudos dos aspectos alimentares e reprodutivos do ariacó Lutjanus synagris (Linnaeus, 1758) (Perciformes: Lutjanidae) capturado na costa amazônica do Maranhão, Brasil

2020-01-01T00:00:00Z

Título: Estudos dos aspectos alimentares e reprodutivos do ariacó Lutjanus synagris (Linnaeus, 1758) (Perciformes: Lutjanidae) capturado na costa amazônica do Maranhão, Brasil Abstact: The feeding habit and aspects of the reproductive cycle of Lutjanus synagris were analyzed for one year (June 2018 to May 2019) based on 359 organisms acquired monthly through artisanal fishing, in a fishing area on the Amazon coast of Maranhenses, Brazil. The specimens were captured with a standard set of longline and gillnet type of sawmill type, stored in isothermal boxes and transported to the Laboratory of Fishery Biology - Biopesq, of the State University of Maranhão. Biometric data such as total length (LT), furcal length (FL) and standard length (SL), total weight (WT), gutted weight (GW), gonad mass (MG) were obtained. For the study of biological aspects, processing of the gonads was carried out and for the study of dietary aspects, an assessment and identification of stomach contents was made, classifying them at the lowest possible taxonomic level. Numerical and gravimetric methods were used to obtain the feed data. For the processing of the gonads, the samples went through specific protocols. The sexual proportion, the weight-length ratio, gonadosomatic index and condition factor, length of first maturation and temporal variations in the gonadal development of females and males were evaluated monthly and established. The environmental data - temperature and precipitation, were obtained through INMET - National Institute of Meteorology and NUGEO - Geoenvironmental Nucleus of the State University of Maranhão and related to feeding and reproduction regarding seasonality in the sample period. Throughout the sample period, fully filled stomachs were the least representative compared to the other replenishment classifications. In the quantification of stomachs 54 were empty due to regurgitation. The values of the degree of repletion were influenced by the sampled months (ANOVA, p<0.05). The diet presented a cumulative curve of 272 items, classified in 9 categories: crustaceans, mollusks, porifers, vegetables, vertebrates, annelids, fragments of fish and shrimp, unidentified organic matter (OMNI) and polymers. The identification of the items showed that decapod crustaceans were the most significant prey observed in the stomachs of L. synagris. The main food items were Brachyura and Carídeos. Reproductive results revealed a sex ratio of 1.40F:1M, with a favorable proportion for females in June and December. Females were predominant in the length class of 36.0 to 40.0 cm of LT and males of 32.0 to 36.0 cm of LT. The LWR presented an allometry coefficient less than three (b <3). The maturational aspects indicated five reproductive stages for males and females: immature, in development, capable of spawning, regression and regeneration. The species showed reproductive activity throughout the year and two reproductive peaks, one during the dry season, the other during the rainy season. The estimate of the average length of the first sexual maturity (L50) for grouped sexes was 26.16 cm 11 LT and can be considered a good indicator of a stock not yet explored, however, the knowledge of the reproductive characteristics of the species L. synagris can be used to define appropriate management and management policies for the species.

Avaliação da sanidade em cultivos de tilápia (Oreochromissp.): qualidade da água, alterações branquiais e identificação de espécies fúngicas

2019-01-01T00:00:00Z

Título: Avaliação da sanidade em cultivos de tilápia (Oreochromissp.): qualidade da água, alterações branquiais e identificação de espécies fúngicas Abstact: The objective of this work was to evaluate the health of tilapia (Oreochromis sp.) crops through water quality, gill alterations and identification of fungal species. The collections were carried out in the metropolitan areas of São José de Ribamar and Paço do Lumiar, in the city of São Luís, state of Maranhão, Brazil, Water and thirty fish were collected to analyze the gills in six fish farms, three in São José de Ribamar (P1, P2 and P3) and three in Paço do Lumiar (P4, P5 and P6). The producers were interviewed from a semi-structured questionnaire to investigate, in particular, the management and sanity of the fish. The parameters were: hydrogenation potential (pH), temperature, salinity, dissolved oxygen (O.D.), ammonia and nitrite in situ in fish farms. Microbiological analyzes for determination of the Most Likely Number (MPN) of total coliforms and Escherichia coli were performed using the Colilert method. The gills and fish skin samples were removed for analysis of histological lesions and fungal isolation. The gills were removed and fixed in 10% formalin for 48 hours and for the preparation of the slides, the samples passed through histological processing. Isolation of the fungi from fish gills and skins samples was done in agaroud dextrose agar medium plus clorafenicol. Histological changes were assessed by calculating the Histological Alteration Index (AHI). The AHI data were analyzed by Student's t-test. The values of temperature. O. D., salinity and nitrite obtained were considered within the recommended standards. The pH verified in P6 is considered potentially stressful to fish and, therefore, predisposing to pathologies. The ammonia in P2 is within the standard considered sublethal. In all fish farms evaluated, the presence of total coliforms with high values for the fish farms of São José de Ribamar was verified. The presence of E. colibacteria was verified in P1 indicating fecal contamination of nursery water by the flow of some source of domestic effluent directly into the nursery or the artesian well that supplies the fish culture. Histopathological analyzes performed on the gills indicated morphological alterations in all tissues analyzed. The lesions were: respiratory epithelial lining, lamellar epithelium hyperplasia, blood vessel congestion, lamellar fusion, dilation of the sinus and lamellar aneurysm. The AHI values indicated statistically significant differences between the lesions found in P3 and P4, P3 and P6. Isolation of fungi samples showed the growth of fungi of the genus Penicillium sp., Aspergillus sp. and Fusarium sp. fungi producing mycotoxins. These species are associated with inadequate processing and storage of feed. The occurrence of these fungi may be environmental or may be related to the use of contaminated feed in the farms. The presence of mycotoxins in food has been associated with several fish pathologies. It is worth mentioning that there must be high fungal counts in the diet to indicate the presence ofmycotoxins

Estruturação e aspectos reprodutivos da assembleia de peixes de importância econômica na bacia do rio pindaré

2019-11-01T00:00:00Z

Título: Estruturação e aspectos reprodutivos da assembleia de peixes de importância econômica na bacia do rio pindaré Abstact: The hydrographic basin region of the Pindaré River is represented by its relevance in fishing, since they present great diversity of species that constitute food resources for most of the traditional populations, besides supplying several municipalities of the state of Maranhão. Thirteen species of fish from the Pindaré River and eight species of Lake Viana were evaluated for richness, diversity, trophic structure and weight - length ratio of five species commercially exploited at these two sites. The samples were collected through local trade between January 2015 and June 2016. A total of 2308 specimens (1859 from Pindaré River and 449 from Lake Viana) were collected from 4 orders (Characiformes, Siluriformes, Cichliformes and Perciformes) and 9 families (Anostomidae, Serrasalmidae, Curimatidae, Erythrinidae, Cichlidae, Prochilodontidae, Auchenipteridae, Doradidae and Scianidae). The most representative families in the number of individuals collected in the Pindaré River were Auchenipteridae, Doradidae, followed by Curimatidae, Anostomidae, Scianidae, Serrassalmidae, Prochilodontidae, Erythrinidae and Cichlidae. Four food groups (carnivorous, detritusive, piscivorous and omnivorous) were estimated. The biological diversity indexes show that higher values of richness (S) and diversity of species were observed in the Pindaré River, while lower values were observed in the Viana Lake. The results referring to the macroscopic stages of gonadal maturation, recorded occurrence of individuals in the following maturational stages: A = immature; B = maturing; C = spawning capable and; D = regressing. Regarding the growth pattern, all individuals from the Pindaré River presented negative allometry, while two species collected in the Viana Lake presented positive allometry indicating a discrete variation in this environment. The results obtained show that, despite being two environments with different characteristics, they present similarities regarding the composition of fish assemblages, trophic guilds and reproductive aspects

Identificação molecular dos bivalves da Família Veneridae, Rafinesque, 1815 (Mollusca, Bivalvia) na Zona Costeira Amazônica (Ilha de Upaon-Açu, Maranhão, Brasil)

2021-01-01T00:00:00Z

Título: Identificação molecular dos bivalves da Família Veneridae, Rafinesque, 1815 (Mollusca, Bivalvia) na Zona Costeira Amazônica (Ilha de Upaon-Açu, Maranhão, Brasil) Abstact: In Brazil, 40 species of the Veneridae family are popularly known as seafood, bergigão, congole, maçinim, chumbinho and sarnambi. The identification of these taxa based only on morphological characters has generated taxonomic uncertainties. In this sense, the present work aimed to molecularly identify the species of sarnambi found in the coastal zone of the Amazon. The DNA Barcoding methodology was applied, in which a fragment of the Citrochrome Oxidase Subunit I (COI) gene is used. The samples were obtained during the period 2018-2019 in areas of beach and mangrove in the four municipalities of the Island of Upaon-Açu, Maranhão, being registered and identified morphologically. DNA was isolated using Promega's Wizard Genomic DNA Purification protocol kit. The isolation and amplification of the gene were performed through PCR using universal primers. The PCR products were sequenced and data analysis was performed using specific software. In the sequencing of 48 samples, fragments of the COI gene were obtained for Anomalocardia flexuosa with 656 bp, Tivela sp with 647 bp and 653 bp for Leukoma sp. The means of intraspecific genetic divergences showed values of 0.63% for A. flexuosa, 0.65% for Tivela sp. and 0.16% for Leukoma sp. The phylogenetic tree grouped the three species in different clades and strongly supported with 100% bootstrap. The divergence percentages showed high values and similarity below 96% in the comparison between Tivela sp. and Tivela mactroides, the closest species available in BOLDSYSTEMS and although they belong to the same clade, they show a differentiation greater than 4.5%, indicating the existence of a new species, for presenting morphological differences and genetic distance of the species T. mactroides. DNA barcoding confirmed the identification of the A. flexuosa sarnambi in synonymy with Anomalocardia brasiliana. The species Leukoma sp was identified molecularly down to the genus level, due to the lack of data for this taxon on the platform. However, its morphological characteristics point to Leukoma pectorina. The sequence of the COI gene of this species has not yet been included in the BOLDSYSTEMS platform, and this study is a pioneer in the molecular characterization of this taxon. Therefore, our approach with DNA barcoding proved to be efficient and showed the occurrence of a new species for the genus Tivela