Meiofauna Biodiversity and Ecology

Meiofauna are small organisms ranging 30–500 μm in body size, inhabiting marine sediments and other substrata all over the world, even the most extreme ones. We can find many different meiofaunal species in a very small handful of sediment, with the most varied and curious shapes, that share peculiar lifestyles, ecological relationships, and evolutionary traits. They contribute significantly to the processes and functioning of marine ecosystems, thanks to their high abundance and taxonomical diversity, fast turnover and metabolic rates. Some meiofaunal taxa have also revealed their considerable utility in the evaluation of the ecological quality of coastal marine sediments in accordance with European Directives. Therefore, understanding the distribution patterns of their biodiversity and identifying the factors that control it at a global level and in different types of habitats is of great importance. Due to their very small morphological characteristics utilized for the taxonomical identification of these taxa, the suite of necessary skills in taxonomy, and the general taxonomic crisis, many young scientists have been discouraged to tackle meiofauna systematics. The papers collected in this book, however, bring together important themes on the biology, taxonomy, systematics, and ecology of meiofauna, thanks to the contribution of researchers from around the world from the USA, Brazil, Costa Rica, Mexico, Cuba, Italy, Belgium, France, Denmark, Russia, Kuwait, Vietnam, and South Korea. This was certainly an additional opportunity to build a more solid network among experts in this field and contribute to increasing the visibility of these tiny organisms. A special thanks to Prof. Wonchoel Lee for the wonderful taxonomic drawings of the species described in this volume that contribute to make our cover unique

The global research on meiofauna associated to seagrasses: a bibliometric network analysis

To better understand the state of the art of the research on meiofauna (small metazoan between 500 and 30μm) and seagrasses, a bibliometric network analysis was performed exploring the period from 1981 to 2021 from the Scopus database. The indexed global scientific literature on this topic was explored using VOSviewer software, which allowed us to obtain a comprehensive overview on these topics. A total of 101 publications were identified, revealing that scientific research on meiofauna related to seagrasses is still relatively limited. Results showed that the scientific documents were published by 15 countries, leaded by Australia, Italy, and USA, 50 researchers, and only 7 journals (with a maximum of 8 documents each). De Troch was the most productive author with 14 published documents. Following the most common keywords (meiofauna, seagrass, nematode, and copepoda), “community structure” occurred 25 times, suggesting that the main research field linked to meiofauna and seagrasses is community ecology. The analysis of co-authorship (among researchers and countries), the co-occurrence of keywords and cited journals showed an increasing attention to this topic worldwide and over time. Indeed, although meiofauna is still relatively poorly studied, the awareness of its crucial role in key coastal habitats, such as seagrass beds, is growing

Assessment of the ecological quality (EcoQ) of the Venice lagoon usingthe structure and biodiversity of the meiofaunal assemblages

partially_open3noTransitional Environments (TEs) have been deeply modified to meet human requirements, and for thisreason are currently ranked among the most endangered aquatic ecosystems. The Adriatic basin hosts alarge number of TEs of which the Lagoon of Venice is the largest one, but information on its meiofauna arevery dated or focused to localized areas. The present study is the first to document the spatial distributionof meiofauna in the whole Venice lagoon. Furthermore, the health status of the TE of Venice has beenassessed by means of several faunal parameters (richness, diversity indices, structure of the entire meio-faunal assemblage and only rare taxa). All the univariate meiofaunal parameters (i.e. richness, diversityindices, Ne:Co ratio) were consistent in highlighting the worst ecological quality of the Porto Margheradistrict. Instead, the structure of the entire meiofaunal assemblage as well as that of rare taxa seemed todetect variations not directly related to pollution and likely due to the different hydrodynamic conditionsof Lido and Malamocco inlets. On the basis of our results, we have also critically discussed the usefulnessof the various faunal parameters in the monitoring assessment of the TEs.openSemprucci, Federica; Balsamo, Maria; Sandulli, RobertoSemprucci, Federica; Balsamo, Maria; Sandulli, Robert

Coralligenous assemblages: research status and trends of a key Mediterranean biodiversity hotspot through bibliometric analysis

Coralligenous assemblages are biogenic calcareous formations endemic of the Mediterranean Sea, produced by the aggregation of calcareous red algae and other calcifying organisms in dim light conditions. Due to their high structural complexity, they are considered benthic biodiversity hotspots that provide several ecosystem functions and services. In this study, we conducted a comprehensive overview integrated with a bibliometric network analysis of the academic literature related to coralligenous assemblages. Analyses were performed using VOSviewer software. The bibliographic search on the Scopus database resulted in 339 documents published in a timeframe ranging from 1965 to 2022, with an increasing trend over time. Italy resulted the most productive country, with 202 documents and 4004 citations on this topic. The total number of authors publishing on coralligenous was 948. Piazzi was the most productive author in terms of number of documents (33), while Ballesteros was the most cited one (1109). The keyword “biodiversity” had the largest occurrence (86) and total link strength (735), highlighting the key role of these structurally-complex and heterogenic habitats. Among taxa, “algae”, “anthozoa”, and “bryozoa” were the keywords with the largest occurrence (58, 55, 31, respectively), which correspond to the main coralligenous calcifying and structuring taxa. A shift from taxonomic and ecologically-based studies, on species richness/diversity and community composition/structure, to conservation ecology ones, on anthropogenic impacts and ecosystem management, has been observed over time. These outcomes highlight the growing socio-economic awareness on the importance and vulnerability of coralligenous assemblages. Indeed, these coastal habitats have been recently recognized by the scientific and political communities for their role in providing ecosystem goods and services, although further research efforts are needed to deeply comprehend, value and protect them

Las ciudades de nivel inferior chinas como destino en los procesos de internacionalización de las marcas extranjeras

Esta investigación analiza los mercados chinos localizados en las ciudades denominadas Tier inferiores. Estudiamos dichos mercados desde un punto económico, estructural y social con el objetivo de descubrir si estas áreas, hasta ahora consideradas como menos desarrolladas y, en consecuencia, menos expuestas a los productos de Occidente, son igual de propicias para los productos y marcas extranjeras que las ciudades Tier 1. El objetivo de la tesis es, por lo tanto, estudiar el ascenso de las ciudades Tier inferiores y su impacto en los procesos de internacionalización de las empresas extranjeras. Las conclusiones nos muestran, no solo que el presente y el futuro del consumo en China está en estas ciudades de nivel inferior, sino que además estas localizaciones cuentan las características más importantes indicadas en los principales modelos de internacionalización. Por lo tanto, aquellas marcas y empresas que aprovechen esta oportunidad sin duda podrán participar en el futuro desarrollo económico chino

Meiofauna y diversidad de nemátodos en algunas áreas submareales mediterráneas de los mares Adriático y Jónico

Sediments of three different subtidal areas (15-705 m depth) of the Italian coasts (Manfredonia, Brindisi and Gallipoli) were investigated to study meiofauna and nematode composition. The nematodes were identified to the genus level and their abundances compared using multivariate analysis. Our data showed an evident depth gradient in meiofauna abundance: the shallowest sites had more diverse and abundant meiobenthic communities than the deeper ones. Nematodes were the dominant taxon (83-100%) at all sites, followed by Copepoda (0.5-8%). Sabatieria, Astomonema, Dorylaimopsis, Terschellingia and Daptonema were among the dominant nematode genera in the three areas. Nematode genus H’ diversities were not significantly dissimilar, though at community level some differences were detected among the study areas. The greatest differences were observed in the comparison of the communities from Manfredonia and Gallipoli. Furthermore, there was a difference between shallow (<200 m) and deep sites due to high differential abundances of common genera, i.e. Astomonema, Dorylaimopsis, Sabatieria and Terschellingia.Los sedimentos de tres áreas submareales (15-705 m de profundidad) de la costa italiana (Manfredonia, Brindisi, Gallipoli) se investigaron para estudiar la meiofauna y composición de nemátodos. Los nemátodos se identificaron a nivel de género y sus abundancias se compararon usando análisis multivariantes. Nuestros datos mostraron un evidente gradiente de profundidad en la abundancia de la meiofauna: los lugares más someros tuvieron comunidades del meiobentos más diversas y abundantes que los más profundos. Los nemátodos fueron el taxon dominante (83-100%) en todos los lugares, seguido por los copépodos (0.5-8%). Sabatieria, Astomonema, Dorylaimopsis, Terschellingia y Daptonema fueron los géneros de nemátodos dominantes en las tres áreas. Las diversidades de géneros de nemátodos (H’) no fueron significativamente disimilares; incluso a nivel de comunidad se detectaron algunas diferencias entre areas de estudio. Las mayores diferencias se observaron cuando se compararon comunidades de Manfredonia y Gallipoli. Además, hubo diferencia entre sitios someros (<200 m) y profundos debido a las grandes diferencias en la abundancia de géneros comunes, i.e. Astomonema, Dorylaimopsis, Sabatieria, Terschellingia

Diversity Loss in Coralligenous Structuring Species Impacted by Fishing Gear and Marine Litter

Coralligenous structuring species (CSS) form a group of marine megabenthic species with an engineering capacity. Since they are highly vulnerable to anthropogenic activities, they have been selected for the Marine Strategy Framework Directive (MSFD) monitoring programs. The pressure and impact of fishing gear and marine litter on these species were evaluated through the image analysis of 54 remotely operated vehicle (ROV) routes along the Campania coasts (Tyrrhenian Sea, Italy). CSS density was calculated as the number of colonies/100 m2. Anthropogenic pressure was estimated as the frequency of frames showing longline, nets, other gear, plastic objects, metal objects, and other litter; while the impact was expressed as the frequency showing necrosis/epibiosis, broken/upturned and covered/entangled colonies. Cnidaria dominate in the Napoli, Campanella and Capri areas, while Bryozoa dominate in Cilento N and Cilento S areas. Campanella and Capri appeared to be the least heterogeneous despite their higher CSS densities, which was possibly related to the dominance of a few species. These areas were the most affected by showing the highest numbers of fishing gear (longlines) and marine litter (metal objects) recorded, amongst which longlines are the most abundant. In addition, these fishing areas are either close to a large urban center or located along popular touristic routes. In all the areas, colonies with necrosis/epibiosis (CNE) impact are present with low-moderate values, while the category gears covering/entangling (GCE) impact prevails in the Campanella and Capri areas, and this is strictly connected to the high presence of fishing gear