Plankton food for benthic fish: de visu evidence of trophic interaction between rainbow wrasse (Coris julis) and pelagic tunicates (Pegea confoederata)

Salps (pelagic tunicates) are rarely observed in nature and trophic interactions involving them mainly rely on the inspection of stomach contents of their potential predators. Moreover, salps have soft bodies that are hardly identified in potential consumers. We involved recreational SCUBA-divers and photographers in collecting de visu evidence of i) massive occurrence of salps and ii) trophic interactions involving salps as preys and benthic animals as consumers. Direct evidence of trophic interactions between salps and benthic fish was documented by photographic frames. We detected a long colony of the salp Pegea confaederata being transported by currents close to the substrate on top of Banco di Santa Croce, an underwater rocky outcrop in the Gulf of Naples (Italy). An individual of the rainbow wrasse Coris julis attacked the above-mentioned salp colony by selectively detaching individuals and biting their stomach. Our report of a trophic interaction between labrids and salps is the second in fifty years and the previous one was only indirect. In this study, citizen science allowed detecting both neglected marine animals like salps and trophic interactions involving them. Visual, direct evidence of predation on salps by benthic fish adds further knowledge about patterns of living-matter fluxes between plankton and benthos, opening new questions on the potential of global change in modifying the efficient circulation of organic matter in marine systems

New records of rarely reported species in the Mediterranean Sea (March 2024)

This Collective Article presents information about 30 species with records in eight countries (Greece, Israel, Italy, Montenegro, Slovenia, Spain, Syria and Türkiye) and six ecoregions extending from the Alboran to the Levantine Seas. The recorded species belong to eight Phyla (4 Chlorophyta, 1 Rhodophyta, 1 Porifera, 3 Cnidaria, 2 Platyhelminthes, 2 Arthropoda, 2 Mollusca and 15 Chordata) as follows: Chlorophyta: Didymosporangium repens, Ochlochaete hystrix and Phaeophila hirsuta are reported for the first time from the Aegean coasts of Türkiye and Penicillus capitatus is firstly recorded in Slovenian coastal waters; Rhodophyta: Ptilophora dentata is recorded for the first time in Turkish coasts, from the entrance of a marine cave; Porifera: Tethya meloni is reported from Montenegrin waters; Cnidaria: Savalia savaglia and Dendrophyllia ramea are firstly observed north of the Almeria-Oran front in the southeastern Iberian Peninsula, while Spinimuricea cf. atlantica is firstly recorded in the Gulf of Lion constituting the easternmost record of the species in the Mediterranean Sea; Platyhelminthes: the polyclad flatworms Thysanozoon brocchii and Planocera graffi are reported for the first time from Greek waters, observed inside marine caves; Mollusca: Ascobulla fragilis is firstly reported from the Eastern Levantine Sea while the blanket octopus Tremoctopus violaceus is recorded in Izmir Bay constituting its fifth sighting in the Aegean Sea after a quarter of a century; Arthropoda: the copepod Ditrychocorycaeus africanus is firstly recorded in the Ionian Sea while the tufted ghost crab Ocypode cursor is detected further north in the Tyrrhenian Sea; Chordata: the bothid flounder Arnoglossus grohmanni is firstly reported in Spain while specimens of the rare bythitid Bellottia apoda are presented for the Adriatic Sea; the chondrichthyans Chimaera monstrosa, Dalatias licha, Heptranchias perlo, Leucoraja circularis, Mustelus mustelus, Oxynotus centrina, Squatina aculeata and Torpedo marmorata are presented as collected within 13 continuous years in the bathyal zone of the Antalya Bay; the speleophilic fish Grammonus ater is firstly recorded in the Alboran Sea, observed in a marine cave; the critically endangered sandy ray Leucoraja circularis is reported from the eastern Ionian Sea; the crested oarfish Lophotus lacepede is reported for the first time from Sardinia, based on evidence dating back 20 years; the white trevally Pseudocaranx dentex is firstly recorded in Tremiti Islands (Adriatic Sea, Italy) while the phaeton dragonet Synchiropus phaeton and the gobid Zebrus pallaoroi are firstly reported from Syrian and Italian waters, respectively

The NEREA Augmented Observatory: an integrative approach to marine coastal ecology

The NEREA (Naples Ecological REsearch for Augmented observatories) initiative aims to establish an augmented observatory in the Gulf of Naples (GoN), designed to advance the understanding of marine ecosystems through a holistic approach. Inspired by the Tara Oceans expedition and building on the scientific legacy of the MareChiara Long-Term Ecological Research (LTER-MC) site, NEREA integrates traditional physical, chemical, and biological measurements with state-of-the-art methodologies such as metabarcoding and metagenomics. Here we present the first 10 months of NEREA data, collected from April 2019 to January 2020, encompassing physico-chemical parameters, plankton biodiversity (e.g., microscopy and flow cytometry), prokaryotic and eukaryotic metabarcoding, a prokaryotic gene catalogue, and a collection of 3818 prokaryotic Metagenome-Assembled Genomes (MAGs). NEREA’s efforts produce a significant volume of multifaceted data, which enhances our understanding of marine ecosystems and promotes the development of scientific hypotheses and ideas

Temora Baird, 1850

This leaflet presents taxonomic keys with diagnostic morphological characters to distinguish between female and males of the most abundant species of the Temora genus under a stereomicroscope. Information on biological and ecological traits is presented

Ecology of Marine Zooplankton

Marine ecosystems, from coastal areas to open waters, teem with a multitude of heterotrophic and mixotrophic organisms collectively forming the zooplankton, the animal component of the plankton [...

Metazoan diversity and seasonality through eDNA metabarcoding at a Mediterranean long-term ecological research site

Abstract Metabarcoding of environmental DNA has provided striking insights into marine microbial diversity. With this approach, we assessed the diversity of metazoan assemblages and their temporal variations at the Long-Term Ecological Research site MareChiara (LTER-MC) in the Gulf of Naples (Mediterranean Sea). The Illumina sequencing of the V4-18S rRNA fragment from 48 surface samples collected from 2011 to 2013 produced a total of 5 011 047 marine metazoan reads. The normalized dataset was generally dominated by copepods (60.3%), followed by annelids (34.7%) mostly represented by the invasive benthic polychaete Hydroides elegans. Non-copepod holoplankton was mainly represented by siphonophores, rotifers, and appendicularians, with occasional mass occurrences of jellyfish. The rest of meroplankton (mainly molluscs, annelids, and anthozoans) showed a high diversity, covering all 11 zooplankton phyla, from Porifera to Craniata. A high number of copepod genera were identified, with seasonal recurrence matching patterns observed in 30 years of studies in the Gulf of Naples. Despite limitations related to the molecular marker resolution and reference dataset, the study provided valuable insights into diversity and seasonal patterns of the whole metazoan assemblage, expanding the knowledge on rare or hardly identifiable taxa and confirming DNA metabarcoding as a powerful approach to be integrated at LTER sites.</jats:p

Chemosensory-Related Genes in Marine Copepods

Living organisms deeply rely on the acquisition of chemical signals in any aspect of their life, from searching for food, mating and defending themselves from stressors. Copepods, the most abundant and ubiquitous metazoans on Earth, possess diversified and highly specified chemoreceptive structures along their body. The detection of chemical stimuli activates specific pathways, although this process has so far been analyzed only on a relatively limited number of species. Here, in silico mining of 18 publicly available transcriptomes is performed to delve into the copepod chemosensory genes, improving current knowledge on the diversity of this multigene family and on possible physiological mechanisms involved in the detection and analysis of chemical cues. Our study identifies the presence of ionotropic receptors, chemosensory proteins and gustatory receptors in copepods belonging to the Calanoida, Cyclopoida and Harpacticoida orders. We also confirm the absence in these copepods of odorant receptors and odorant-binding proteins agreeing with their insect specificity. Copepods have evolved several mechanisms to survive in the harsh marine environment such as producing proteins to respond to external stimulii. Overall, the results of our study open new possibilities for the use of the chemosensory genes as biomarkers in chemical ecology studies on copepods and possibly also in other marine holozooplankters

Integrative approach to monitoring metazoan diversity and distribution in two Mediterranean coastal sites through morphology and organismal eDNA

Abstract Marine and coastal ecosystems respond to climate change in various ways, such as the type of ecosystem, the species composition, interactions, and distribution, and the effect of local stressors. Metazoan organisms, particularly zooplankton, are important indicators for monitoring the effects climate-driven warming in marine coastal ecosystems over the long term. In this study, the diversity and distribution of zooplankton communities in the Mediterranean Sea (Canyon Dohrn and LTER-MareChiara, Gulf of Naples), a known biodiversity and climate changes hotspot, have been assessed using the integration of morphological-based identification and organismal eDNA. Our findings showed that the multi-locus strategy including the mitochondrial cytochrome c oxidase I (COI) gene and the hypervariable region V9 of the 18S rDNA (18S V9) as targets, improved the taxonomic overview, with the COI gene being more effective than the 18S V9 region for metazoans at the species level. However, appendicularians were detected only with the 18S V9 region. Overall, organismal eDNA is a powerful approach for revealing hidden biodiversity, especially for gelatinous and meroplankton components, and provided new insights into biodiversity patterns. The ecological importance of calanoid copepods in coastal ecosystems has been confirmed. In contrast, the discovery of 13 new metazoan records in the Mediterranean Sea, including two non-indigenous copepod species, suggested that local stressors affect zooplankton community structure and resilience, highlighting the importance of biomonitoring and protecting marine coastal ecosystems