This study focuses on aquatic mites from the Portuguese Exclusive Economic Zone, including the mainland area, and Madeira and Azores archipelagos, aiming at compiling all existing information and generating a list of species and all their data on collecting sites. For the present work, we consider aquatic species, those that inhabit the marine, deep sea, intertidal, freshwater, transition water or brackish environments, with life-cycle occurring entirely at water habitats or their vicinity. Furthermore, breeding should take place in water aquatic lifestyles. The dataset search for this checklist started with the first descriptions of water acarids from the Azores Archipelago performed by Théodore Barrois. Primary sources for occurrence confirmation were Süßwasserfauna von Mitteleuropa book collection, The Global Biodiversity Information Facility (GBIF), complemented with an extensive Portuguese literature review and data biodiversity websites, e.g., European Water Mite Research (Watermite.org). In total, 102 valid species were found belonging to 41 genera, and 19 families, nested in the orders Mesostigmata, Sarcoptiformes and Trombidiformes. This is the first work compiling all the species of aquatic mites found in Portuguese territory, as well as data of collection, serving as the basis for future studies.

Acari are a subclass of chelicerate arthropods that includes mites and ticks. The present study focuses on the taxonomic diversity of aquatic mites in the Portuguese territory of the Minho Region. Our aim was to compile all available information and thus generate a list of species linking them to the site where they were recorded. Aquatic species were all those that live exclusively in the marine environment, deep sea, intertidal, freshwater, brackish water or in transitional environments with the terrestrial environment if their lifestyle is associated with the aquatic environment. Since the first records of Portuguese endemic mites by Lunblad in the 1950s several authors have contributed to accurately catalogue, record, and redescribe this vast group in Portugal and Minho consecutively. In our review in this work, we used the Global Biodiversity Information Facility (GBIF) to obtain previous occurrences supplemented by an extensive literature review and the book collection Süßwasserfauna von Mitteleuropa, among others. Additionally, we resorted to active sampling and by-catch sampling in the Portuguese section of the Rio Minho catchment area. The collected organisms represent 12 new records for the Minho River and among them 10 are new records for Portugal, which were deposited in the Natural History Museum of the Iberian Peninsula - NatMIP (“Museu de História Natural da Península Ibérica”), Vila Nova de Cerveira, Portugal.

The genus Patella (Patellogastropoda, Mollusca) is represented by a group of species exclusive to the Northeast Atlantic Ocean (including Macaronesian archipelagos) and Mediterranean Sea. The species Patella ulyssiponensis and Patella aspera are common in European waters, with the first inhabiting continental coast, and the second endemic to Macaronesian archipelagos. However, the acceptance of these two lineages as separate species is still highly debated. The red coralline species algae Lithophyllum hibernicum, distributed from Northeast Atlantic to the Mediterranean, is usually found as epilithic crusts or unattached forms (named rhodolith beds), although it also forms epizoic crusts on other organisms, e.g., shell surfaces. In order to study the historic dispersal and migration routes of the Patella ulyssiponensis-aspera complex, taxonomic, genetic and biogeographic approaches were employed based on haplotype network analyses and estimations for the most common recent ancestor (TMRCA), using Cytochrome Oxydase I. A synonymy for these two species is proposed, with the presence of a shared haplotype between the continental (P. ulyssiponensis) and insular (P. aspera) lineages, and with basis of morphological and nomenclatural data. We propose an evolutionary scenario for its dispersal based on a high haplotype diversity for the Mediterranean regions, indicating its possible survival during the Messinian Salinity Crisis (6–5.3 Mya), followed by a colonization of the Proto-Macaronesian archipelagos. The epizoic association of L. hibernicum on P. ulyssiponensis shell adult surface is recorded in this study, likewise the promotion of settlement conditions provided by these coralline algae to P. ulyssiponensis larvae, may explain the reach of P. ulyssiponensis distribution through rhodolith transportation.

Society in general is distant from scientific culture, it is required to bring scientific knowledge closer to the population. In this context, an effective and attractive way for scientific dissemination is the establishment of natural history museums, which are institutions of knowledge, displaying the past. Natural history museums have the natural world as their object of study; and their collections may contain the most diverse types of materials (local and/or from various parts of the world), such as zoological, botanical, geological, archaeological, among others. Scientific collections are the largest and most important source of authoritative biodiversity data, contributing to studies of biodiversity composition, evolutionary (morphological and genetic), biogeographical, phenological, as well as geological. The materials present in these collections may serve for temporal comparison, being useful to produce predictive models. Likewise, they have a fundamental role in safeguarding type specimens, i.e. the first organisms identified to describe and name a new species. In addition, there is the component available to visitors in general, in order to raise public awareness on the preservation of the local fauna and flora and of other places in the world. In this way, the museums serve both the academic-scientific public and visitors who come to these sites for recreational purposes. It is intended to promote, in Vila Nova de Cerveira, the Natural History Museum of the Iberian Peninsula - NatMIP (“Museu de História Natural da Península Ibérica”), which intends to collect materials for scientific purposes, mainly Iberian.

The macrophyte Egeria densa Planchon, 1849 is a freshwater plant native to the subtropical regions of South America. Fast vegetative reproduction and efficient dispersal allow this species to form extensive beds that produce high levels of oxygen in freshwater ecosystems, generating microhabitats that act as refuge and nursery for an array of organisms, increasing sedimentation and light availability. Despite its undisputable ecological role, it is considered invasive and is present on all continents except Antarctica with the first records in Europe occurring at the 20th century. At the international Minho River (NW Iberian Peninsula), the observation of its presence was noted in the 1990s and is now an established population in this ecosystem. This study is the first descriptive-taxonomical assessment of the associated fauna with the exotic macrophyte E. densa, using both morphological and molecular approaches, three decades after its establishment in the international Minho River. Results indicate the presence of a faunal assemblage, composed a total of 20 identified species, including platyhelminths, hydrozoans, bryozoans, molluscs (Gastropoda), annelids (Oligochaeta and Hirudinea), crustaceans (Ostracoda, Copepoda, Branchiopoda and Amphipoda), aquatic mites and insects. Paludicella aff. articulata (Ehrenberg, 1831), Girardia sinensis Chen & Wang, 2015, Lebertia insignis Neuman, 1880 and Ceriodaphnia rigaudi Richard 1894 are recorded for the first time in Portugal.

Ecological aspects, habitat preferences, demographic structure, migration patterns and productivity of the isopod Saduriella losadai were analysed from monthly sediment samples and by-catch in glass eel fishery in the Minho River estuary. This species is typically distributed within the mesohaline-oligohaline boundary, so salinity plays a large role in the distribution of this species within the estuary, with sandy sediments having higher densities. High temperatures and saline intrusion have been shown to hinder the population growth. Adult populations were strongly female-biased. Two peaks in juvenile recruitment have been recorded with higher densities occurring in the spring-summer season. Tidal drift during flood tides is used as a mean of migration. Juvenile migrations to freshwater environments occur in late spring and summer seasons and are dependent on salinity increases. Juvenile migrations to the lower estuary occur in the autumn and mature adults migrate back in the winter before the reproductive season. There was a sharp decline in abundance compared with data collected 40 years ago for the same study area, but further studies are needed to confirm the trend.