The mussel Perna viridis, commonly known as Green Mussel, is native from the Indo-Pacific region and has been introduced in various countries around the globe. In Brazil, the species has already been recorded in Rio de Janeiro and Ceará states. With the aim of assessing the presence of mussels in the southern region of the country, 14 individuals were collected in the Paranaguá Estuarine Complex, Paraná. The mussels were found attached at a depth of 2 m on the artificial structure of Ponta do Poço Marina. The DNA was extracted using a commercial kit, the COI gene was amplified through PCR using the primers dgL-CO-1490 and dgHCO-2198, sequenced by the Sanger method, and the species was identified through the BOLD Systems. The phylogenetic tree was built on the software MEGA 11 using 28 sequences from three Perna species. Therefore, the present study confirms the occurrence of P. viridis in Brazil through molecular identification for the first time and adds a second Brazilian state where it has been recorded. The Brazilian coastline provides optimal environmental conditions for the establishment and development of P. viridis.

The large pelagic species play an important role in transferring energy in vast distant marine ecoregions. Results obtained report on extraordinary findings of important commercial species in southeast–south Brazilian waters, including the Southern bluefin tuna Thunnus maccoyii and the Pacific bluefin tuna Thunnus orientalis, an endemic species from the Pacific Ocean. These specimens were identified within the genomic description of 10 individuals randomly selected from the catch to evaluate the catch composition of pelagic longline fisheries off Brazilian waters. Most of the records were from T. maccoyii (6), followed by the Bigeye tuna T. obesus (2), Yellowfin tuna T. albacares (1), and T. orientalis (1). Yellowfin and Bigeye tuna are expected to be captured in the vicinity of the longline fishing areas. However, the unlikely presence of the cold-water T. maccoyii and the warm-water T. orientalis suggests a long migration from common species ranges that could be influenced by climate change. These results imply a readjustment of spatial management structures for these species.

Background: Enhanced biological phosphorus removal (EBPR) systems utilize phosphorus-accumulating organisms (PAOs) to remove phosphorus from wastewater since excessive phosphorus in water bodies can lead to eutrophication. This study aimed to characterize a newly isolated PAO strain for its potential application in EBPR systems and to screen for additional biotechnological potential. Here, sequencing allowed for genomic analysis, identifying the genes and molecules involved, and exploring other potentials. Additionally, assessing the phosphorus removal performance of the PAO strain in common effluents is essential for its potential application in large-scale systems. Methods: A strain designated LAMA1607 was isolated from activated sludge and selected based on its ability to remove total phosphate from the culture medium. Genomic DNA was extracted and sequenced using the Illumina NovaSeq 6000 platform. Assembly and annotation were performed using CLC Genomics Workbench v.24.0 (QIAGEN®) and Rapid Annotation using Subsystem Technology (RAST)/Pathosystems Resource Integration Center (PATRIC) server tools. Functional prediction of uncharacterized proteins was completed using PHYRE2, and secondary metabolite identification was performed using antiSMASH. Further, additional enzymes with biotechnological applications were manually curated through the Association of Manufacturers and Formulators of Enzyme Products (AMFEP) list. The phosphorus removal capability was assessed in domestic and fishery effluents under enriched and unenriched conditions, where pH, microbial growth, and total phosphorus were monitored over 48 hours. Results: The genome sequence comprised 5,234,874 bp divided into 20 contigs, 5540 coding sequences, and a GC content of 38.0%; subsequently, LAMA1607 was identified through Basic Local Alignment Search Tool (BLAST) analysis as Priestia megaterium. Genome annotation revealed 27 genes potentially involved in phosphorus removal, including eight encoding transport proteins, three regulatory proteins, twelve enzymes, and others related to phosphorus incorporation and polyphosphate (polyP) granule formation. Moreover, other enzymes of interest were identified, such as hydrolases, lipases, proteases, and amylases, alongside secondary metabolite gene clusters, such as Non-ribosomal peptide synthetase-independent siderophore. P. megaterium LAMA1607 effectively removed up to 70% of the total phosphorus from the fishery effluent. Conclusions: Genomic analysis suggests that P. megaterium LAMA1607 possesses the mechanistic functions for phosphorus uptake, transport, and storage while also identifying additional biotechnologically relevant enzymes and capabilities. Meanwhile, tests on the effluent demonstrated significant phosphorus removal. These findings support the biotechnological potential and application of P. megaterium LAMA1607 in EBPR systems.

The green mussel Perna viridis, native to the Indo-Pacific, has demonstrated significant invasive potential in various coastal regions worldwide, posing threats to both aquaculture and native ecosystems. In Brazil, mollusk farming is primarily concentrated in Santa Catarina, with an annual production exceeding 13,000 tons. This study aimed to confirm the occurrence of P. viridis in the region, specifically within the mollusk farming park of Itapocoroy Bay. A total of 210 individuals were collected, and molecular analyses confirmed the species’ presence through COI gene amplification, with sequences showing 99.85% similarity to those from China and India. The phylogenetic analysis supported this identification, placing the sample within a highly supported P. viridis clade. Biometric analysis revealed shell lengths ranging from 5.94 mm to 24.72 mm, with 38% of individuals’ sex indeterminate due to the absence of external sexual dimorphism. This represents an 800 km southward range expansion of P. viridis along the Brazilian coast over a six-year period. In Brazil, Perna viridis is likely introduced via ballast water and hull fouling, with secondary dispersal facilitated by coastal vessel movement. Mariculture systems are especially vulnerable due to abundant substrate and resources. The study underscores the importance of early detection to prevent further spread, given P. viridis’ ability to compete with native or commercial species, such as Perna perna, for space and food resources.

Blackwater streams are unique environments characterized by dark, acidic, and nutrient-poor waters, supporting highly specialized aquatic communities. This study presents an inventory of the ichthyofauna of such systems in the northern region of Santa Catarina state, based on surveys conducted between 2020 and 2024. A total of 22 sites were sampled, including perennial rivers, intermittent streams, and temporary pools, located both within and outside protected areas. In total, 30 fish species were recorded, representing 13 families and five orders. The order Characiformes showed the highest richness and was represented mainly by small-characins of the family Acestrorhamphidae. Nine species were identified as endemic to blackwater environments of the Atlantic Forest, five of which officially listed as threatened. The guppy Poecilia reticulata was recorded for the first time in blackwater environments of the region, as well as Brachyhypopomus cf. draco, representing the first record of Hypopomidae (knifefish) in the region. DNA barcoding (using COI) provided molecular information, in addition to the morphological identification of 12 species, providing new local sequences for them. Results indicated a high similarity between the ichthyofauna of this region and that of blackwater streams in the southern coast of São Paulo. Endemic and threatened species were recorded both inside and outside legally protected areas, highlighting gaps in current conservation efforts. Furthermore, intermittent streams and temporary pools proved to be critical habitats for maintaining species with extremely restricted distributions. The continued degradation of riparian vegetation, combined with climate change, poses an additional threat to the persistence of these communities. These findings underscore the urgent need to expand conservation actions targeting blackwater ecosystems along the southern Brazilian coastal plain.