Boletim do Laboratório de Hidrobiologia

LACISTEMATACEAE DA ILHA DE SÃO LUÍS, MARANHÃO, BRASIL

Lucas Cardoso Marinho — 2024-02-21

As part of the Flora of São Luís Island, Maranhão project, we present the taxonomic treatment of the family Lacistemataceae to the island. To achieve this goal, we consulted the SLUI and MAR herbaria, on São Luís Island, as well as other collections available online. Field expeditions were also carried out in various areas of the island. All known specimens from the region belong to Lacistema pubescens Mart, which was collected during a field expedition to the Sítio do Físico region, in Bacanga State Park.

FLORA OF THE LENÇÓIS MARANHENSES NATIONAL PARK: POLYGALACEAE

Ubirajara Santos de Carvalho — 2024-02-21

The Lençóis Maranhenses National Park is home to important species native and endemic to Brazil, including the Polygalaceae. In this context, the present study proposed to survey the taxonomic diversity of Polygalaceae species occurring in the Lençóis Maranhenses National Park, in the Atins section. Exploratory walks were carried out in the study area, where Polygalaceae with flower and/or fruit were collected. The samples were herborized and identified at the Botanical Studies Laboratory with the aid of dichotomous keys and specialized literature. The photographic plates were assembled from the photos recorded in the laboratory. Six species of Polygalaceae were identified, a number similar to that found in studies in the restingas of Maranhão; Senega Spach being the most diverse genus, with 3 ssp., followed by Asemeia Raf. emend. Small (2 ssp.) and Caamembeca J.F.B.Pastore (1 sp.). This result is consistent with the study carried out in the restinga of Pará, where Senega was also the most abundant. It was observed that the Polygalaceae species found in Atins can be differentiated from the phyllotaxy, morphology of the leaves, sepals and mainly by the carina and seeds. In addition, the species found are well distributed in the Brazilian phytogeographic domains. In this way, the park presented a rich diversity of Polygalaceae, emphasizing the importance of the study for conservation. The need to expand the study to other areas and botanical families is also evident, in order to better understand the park's flora.

PHYTOPLANKTONIC COMMUNITY IN ANTHROPITED AREA IN THE ANIL RIVER ESTUARY, SÃO LUÍS - MA

Maria Clara Cabral Corrêa — 2024-02-21

Estuaries, as they are connecting areas between rivers and seas, favor the development of urban agglomerations and, as a result, enable activities with great socioeconomic impact, in addition to supporting intense biological activity, being authentic nurseries and maternity hospitals. To carry out this work, two sampling campaigns were carried out, corresponding to the rainy season – PC (Apr/2022) and the dry season – PE (Sep/2022), in spring tides,
during the ebb tide. Collections took place at two sampling points, located upstream of the river, therefore, with greater limnetic input. The studied area corresponds to the Anil River estuary – ERA, currently the most urbanized estuary on the island of São Luís, MA. The physical-chemical data and nutrients of the seawater and the qualitative analysis of the phytoplankton were evaluated, packaged in bottles and transported to the Laboratory of Plant and Marine Biology (LBVM/UEMA) and kept in a freezer. Then, the phytoplankton species were identified to the lowest possible taxonomic level with the aid of an optical microscope and identification keys. For the relevant results, the reduction in water
transparency and salinity values during the rainy season occurred due to a greater supply of water received by estuaries and high rainfall. For nutrients, ammonium ion showed high concentrations at both sampling points, which may be a result of the continuous release of sewage in the study area. In ERA, 156 phytoplankton taxa were recorded, there
was a predominance of diatoms, which were the group with the largest number of families and species throughout the study, they are considered the most important and common phytoplankton group in coastal and estuarine areas.

EFFECTS OF MANGANESE ON THE MORPHOLOGY OF Lemna minor L. (Araceae)

Samarah Christina Cantanhede Ferreira — 2024-02-21

The present work aimed to compare the physiological responses of the species Lemna minor
L. to increased concentrations of the metal manganese (Mn) in nutrient solution, and whether these plants are capable of phytoremediating environments with high concentrations of this heavy metal. The plants were collected in artificial lakes, without apparent manganese contamination, located at Viveiro Tracoá in the region of São José de Ribamar - MA. The experiment was carried out in petri dishes, where 350 ml of Hoagland’s nutrient solution were added plus increasing doses of Mn (0; 0.2; 0.5 and 0.7mM)) in the form of MnCl2, with 1 ⁄ 4 of ionic strength. The experiment was conducted in a completely randomized design, with five replications, with the experimental unit consisting of 30 plants. Morphological characteristics of the species subjected to increasing concentrations of Mn were evaluated. Individuals from all treatments, except the control treatment, showed visual symptoms of toxicity, including chlorosis, wrinkling and curling of the leaf blade and necrosis. Despite this, there was no death of any L. minor plant, which suggests that it is a species that has the capacity to accumulate this element without major damage to the plants. Therefore, it is concluded that the L.minor species has the potential to be used in phytoremediation and
offers a new resource to explore and discover the mechanisms of Mn accumulation in plants,
in addition to helping to clean contaminated water.

STRUCTURAL ORGANIZATION OF WOODY VEGETATION OF THE DUNES OF PRAIA DO CAOLHO, SÃO LUÍS, MARANHÃO STATE

Ariade Nazaré Fontes da Silva — 2024-02-21

The objective of this study was to analyze the structure and woody composition of the urban dune vegetation in Caolho beach, São Luís, Maranhão. The structural analysis of woody vegetation was carried out using the quadrant point method, totaling 50 points. Plants with a diameter at ground height ≥ 3cm were measured. The plants were collected, identified, herbalized and inserted into the MAR and PEUFR Herbarium. The structural parameters, the Shannon Index and Pielou Equability were analyzed. The structural analysis resulted in 35 species, 31 genera and 20 families. The families with the greatest richness were Fabaceae, Myrtaceae and Rubiaceae, with four species each. The highest importance value was found in Attalea speciosa, Byrsonima crassifolia and Astrocaryum vulgare. The Shannon index was 2.36 nat.ind^-1 and the equability was 0.66. The woody vegetation on Caolho beach is sparse, with low plants and thick stems. However, in dune areas, large diameters are related to tillered individuals due to the sum of their branches. Given the data presented, the importance of restoration and protection measures for urban dunes is emphasized so that the resilience process can guarantee the continuity of the area's ecological standards.

MARINE MACROALGAE FROM PANAQUATIRA BEACH, COASTAL AREA OF SÃO JOSÉ DE RIBAMAR, COAST OF MARANHÃO

Andrea Christina Gomes Azevedo Cutrim — 2024-02-22

Coastal areas play an important role of connection and energy exchange between marine and terrestrial ecosystems, because they are transition regions and it is in these marine and coastal environments that it is possible to observe the occurrence of marine macroalgae. The samples were collected in the months Nov/17, in the dry season (PE), Feb/18 transition period (PT) and Apr/18 in the rainy season (CP). The study was conducted on the beach of Panaquatira, in the Estuarine Complex of São José (CESJ) – MA. The physicochemical data and nutrients of the seawater and the macroalgae collected in the rocky outcrops of Panaquatira beach, packed in jars and transported to the Laboratório de Biologia Vegetal e Marinha (LBVM/UEMA) and kept in freezer. Subsequently, screening was performed in order to isolate genera and species and taxonomic identification was performed with the aid of specialized literature. Similarity analysis, Jaccard similarity and analysis of variance were performed as statistical treatment. Salinity is one of the physicochemical variables that most influence the functional responses of organisms, being higher in drought. There were significant differences in salinity, pH, water transparency, turbidity and water temperature (p<0.05). For the nutrients, ammonia, nitrate, total nitrogen, total phosphorus, phosphate and silicate samples were significantly different. A total of 23 macroalgal taxa were identified on Panaquatira beach, with the Phylum Rhodophyta (76%) being the most representative. As for the similarity, there was an association between the sampling points, with greater similarity to drought and transition (82%). Most algae identified with red algae that are indicators of clean water in protected environments and without impacts.