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- Optimising sealed transports of small ornamental fishPublication . Silva, Rui E.; Morais, Hugo A.; Rodrigues, Nuno V.; Reis, Tiago; Correia, João P.This paper reports on simulated long-term transports of small ornamental fish inside sealed containers. The species involved were Diplodus sargus, Gobius paganellus, Gobiusculus flavescens, Lepadogaster lepadogaster, and Lipophrys pholis. The objective of such simulations was to determine the maximum bioload that it is possible to move inside a sealed container, while ensuring 100% survivorship, ultimately resulting in financial savings for the end-receiver. Transports were simulated over 24, 48 and 72 hours, with increasing animal bioloads per bag. Fifty percent of the trials were performed with “regular” saltwater while the other half involved seawater buffered with Amquel®, sodium carbonate and sodium bicarbonate, with the objective of keeping ammonia low and pH similar to initial baseline values. At the end of each trial, temperature, dissolved oxygen, pH and ammonia were analysed and survival rates determined. L. lepadogaster endured the highest bioloads and displayed 100% survivorship (i.e. up to 30 g/L), which is not surprising given the intertidal nature of this species. D. sargus exhibited mortalities with bioloads as low as 3.23 g/L, which echoes its predominantly pelagic nature and relatively lesser ability to endure confinement. The three remaining species showed varying degrees of tolerance to increasing bioloads in transport: L. pholis, also an intertidal species, tolerated up to 20 g/L over 72 hours, while G. paganellus tolerated up to 7 g/L over 72 hours, and G. flavescens (a predominantly pelagic species) could tolerate no more than 6 g/L up to 72 hours.
- First record of a whale shark Rhincodon typus in continental EuropePublication . Rodrigues, N.V.; Correia, J. P. S.; Graças, J.T.C.; Rodrigues, F.; Pinho, R.; Hirofumi, M.A whale shark Rhincodon typus was found in a set-net in southern Portugal in October 2011. This was the first record for continental Europe and represents an increase of the species' known range. Upwelling events and increase in sea-surface temperatures are possible reasons for this occurrence.
- A new signal of tropicalization in the Northeast Atlantic: the spread of the spotfin burrfish Chilomycterus reticulatus in Madeira Archipelago and its invasion riskPublication . Castro, Nuno; Schäfer, Susanne; Parretti, Paola; Monteiro, João Gama; Gizzi, Francesca; Chebaane, Sahar; Almada, Emanuel; Henriques, Filipe; Freitas, Mafalda; Vasco-Rodrigues, Nuno; Silva, Rodrigo; Radeta, Marko; Freitas, Rúben; Canning-Clode, JoãoCurrent trends in the global climate facilitate the displacement of numerous marine species from their native distribution ranges to higher latitudes when facing warming conditions. In this work, we analyzed occurrences of a circumtropical reef fish, the spotfin burrfish, Chilomycterus reticulatus (Linnaeus, 1958), in the Madeira Archipelago (NE Atlantic) between 1898 and 2021. In addition to available data sources, we performed an online survey to assess the distribution and presence of this species in the Madeira Archipelago, along with other relevant information, such as size class and year of the first sighting. In total, 28 valid participants responded to the online survey, georeferencing 119 C. reticulatus sightings and confirming its presence in all archipelago islands. The invasiveness of the species was screened using the Aquatic Species Invasiveness Screening Kit. Five assessments rated the fish as being of medium risk of establishing a local population and becoming invasive. Current temperature trends might have facilitated multiple sightings of this thermophilic species in the Madeira Archipelago. The present study indicates an increase in C. reticulatus sightings in the region. This underlines the need for updated comprehensive information on species diversity and distribution to support informed management and decisions. The spread of yet another thermophilic species in Madeiran waters provides further evidence of an ongoing tropicalization, emphasizing the need for monitoring programs and the potential of citizen science in complementing such programs.
- Preliminary deep-sea data analysis collected at Gloria seamount, Azores-Biscay RisePublication . Tojeira, Inês; Pinto-Ribeiro, Luísa; Rafael, Teresa; Albuquerque, Mónica; Simões, Maria; Calado, António; Afonso, Andreia; Ramos, Bruno; Souto, Miguel; Bettencourt, Renato; Vasco Rodrigues, Nuno; Costa, José Lino; Cabral, Henrique; Madureira, PedroThe present study provides the first results of the exploratory research campaign to Gloria seamount (summit at 45.03°N, 15.54°W), a newly identified seamount in the NE Atlantic. New multibeam bathymetry and an 8 h remote operated vehicle footage and photography data were compiled and analyzed to give the first insights on the geological nature and benthic megafauna assemblages of Gloria seamount. Footage evidenced three distinct seafloor coverage areas, ranging from unconsolidated fine sediment with ripple marks, to increasingly coarser-grain sediment with large blocks, to outcrops with steep slopes along successive ridges, locally exhibiting volcanic structures. The deep-sea benthic assemblages differed with depth (2700−2450 m) and seafloor substrate type. In sediment habitats, pink holothurians (Elpidiidae) and brittle stars (Ophiuroidea) were recorded, whereas in hard substrates, sponges (Hexactinellida and Demospongiae) and stalked crinoids (Crinoidea) were mixed with distinct coral specimens, such as bamboo corals (Isidiidae) and Coralliidae (Scleralcyonacea). The integration of these data contribute to the geo-habitats knowledge of an unexplored seamount.
- An artificial reef at the edge of the deep: An interdisciplinary case studyPublication . Ramos, Jorge; Tuaty-Guerra, Miriam; Almeida, Mariana; Raposo, Ana C.; Gaudêncio, Maria J.; Silva, Alexandra D.; Rodrigues, Nuno; Leandro, Sérgio M.; Caetano, MiguelJust nearby the largest submarine canyon in Europe – off the western coast of Portugal – is located the Nazaré artificial reef (NAR) deployed in 2010 and the first of its kind in this coast. NAR aimed to improve social and economic resilience of the local communities, mainly by creating a safer and closer area for fishing and to enhance commercially exploitable marine resources. The innovative part of this research lies on the fact that for the first time was developed a multidisciplinary approach for NAR. Scientificevidence from fieldwork shows that in 2015 the reef was already mature and colonized by abundant and diversified macrobenthic assemblages. No evidence of negative impacts of NAR on the soft bottom macrofauna was observed, as assemblage composition in the NAR area and in the vicinity areas is similar. In relation to the primary producers that support the subsequent food chain, there also seems to be a balance between NAR and the surrounding area since phytoplankton was equally abundant throughout the area. Experimental fisheries and underwater visual census results on ichthyofaunal communities in the reef revealed high abundance and low levels of species richness, pouting, Trisopterus luscus Linnaeus, 1758 being the most common fish species found. Concerning NAR socio-economic impact, results from direct site observations (DSOs) showed that only some small-scale fishing vessels were eligible to operate on the NAR area. Thus, comparatively to non-AR areas nearby reef use by fishing vessels differs according to spatial and temporal strata. In what perception was concerned, the NAR has contributed to fish aggregation, though being populated mostly by small fish. Fishers have stated that some factors seemed to have changed after reef deployment. Notwithstanding, the NAR may have been a valuable contribution to an apparently overall socio-economic positive impact on the local fishing community that can be corroborated by the presence of good biological indicators.
- Catostylus tagi (Class: Scyphozoa, Order: Discomedusae, Suborder: Rhizostomida, Family: Catostylidae) life cycle and first insight into its ecologyPublication . Gueroun, Sonia K.M.; Torres, Tatiana M.; Santos, Antonina dos; Vasco Rodrigues, Nuno; Canning-Clode, João; Andrade, CarlosJellyfish proliferations, which are conspicuous and natural events, cause blooms that may lead to severe consequences for anthropogenic activities and ecosystem structure and functioning. Although research during the last decade has focused on factors influencing the different jellyfish life stages, few species currently have their full life cycle known. In this context, we describe for the first time the developmental stages in the life cycle of Catostylus tagi, from planula to young medusa, reared in the laboratory. The species displays the typical Rhizostomida metagenetic life cycle. Mature scyphistomae display 16 tentacles and a total body length of 1.5 ± 0.2 mm. Only podocyst production and strobilation were observed. Strobilation, occurring continuously under laboratory conditions, was mainly polydisc. The eight-rayed typical ephyrae, with a total body diameter of 2.4 ± 0.4 mm at detachment, showed development typical of the Rhizostomida. As a first step in studying this species’ ecology, we also present preliminary assessments of: (i) the influence of different temperature and salinity regimes on planulae survival, settlement and metamorphosis and (ii) the effect of temperature and diet on asexual reproduction. The results showed a high tolerance of planulae to a wide range of salinities (15‰to 25‰), while polyp development was significantly faster at higher temperature (20–25º C). Strobilation onset was 2–3 times faster at 20º C (10.6 ± 5.4 to 15 ± 6.6 day at various tested diet) than at 15º C (32.2 ± 3 day). Feeding was a key factor as unfed polyps never underwent strobilation during the trial. Finally, we present the spatial and seasonal distribution of C. tagi in the Tagus estuary (Portugal) in 2019, showing its occurrence throughout the year (except in April), with most observations recorded on the northern shoreline. As C. tagi shows the ability to form blooms and a wide tolerance for temperature and salinity (for planulae and medusae stage), it is essential to understand its life cycle.
- Optimizing sealed transports of small ornamental fishPublication . Silva, Rui Esteves da; Morais, Hugo; Reis, Tiago; Vasco-Rodrigues, Nuno; Correia, João P. S.This is a report on multiple simulated long-term transports of small ornamental fish inside plastic bags. The species involved were Diplodus sargus, Gobius paganellus, Gobiusculus flavescens, Lepadogaster lepadogaster and Lipophrys pholis. The objective of such simulations was moving the maximum bioload possible while ensuring 100% survivorship, ultimately resulting in savings for the end-receiver. Transports were simulated over 24, 48 and 72 hours, with increasing animal bioloads per bag. Half of the trials were performed with “regular” saltwater while the other half involved seawater buffered with Amquel ®, sodium carbonate and sodium bicarbonate, with the objective of keeping ammonia low and pH similar to initial baseline values. At the end of each trial, temperature, dissolved oxygen, pH and ammonia were analized and the survival rate calculated and recorded. L. lepadogaster endured the highest bioloads at 100% survivorship (i.e. up to 30 g / L), which is not surprising given the intertidal nature of this species. D. sargus exhibited mortalities with bioloads as low as 3,23 g / L, which echoes its predominantly pelagic nature and relatively lesser ability to endure confinement. The three remaining species showed varying degrees of tolerance to increasing bioloads in transport: L. pholis , also an intertidal species, handled up to 20 g/L over 72 hours, while G. paganellus handled up to 7 g/L over 72 hours, and G. flavescens (a predominantly pelagic species) could deal with no more than 6 g/L up to 72 hours.