Polychaete fauna of the Northwest Portuguese Coastal Shelf: ecology, diversity and distribution

Polychaetes are one of the larger groups of macroinvertebrates with more than 9000 species recognised, distributed worldwide. Thanks to the broad ecological adaptability and high abundaces, this taxon plays a leading role and is considered an important component of all benthic assemblages. Our knowledge about the West Iberian Coast polychaete fauna are scarce, and the only studies are recent. In this sense, the aim of this work was to investigate the composition and the spatial distribution of the polychaete fauna along the NW Portuguese Coastal Shelf, focusing on their relationship to environmental factors (depth, grain size, longitude and latitude) and to add new data to the existing biological dataset. A total of 39 sites were analysed, collected in an area of about 5665 km², between 20 and 150 m depth, distributed in a way to cover the overall grain size gradient. A total of 9352 specimens belonging to 41 families were found, and the analysis based on the abundance of polychaete species revealed five affinity groups: (a) nearshore medium sand characterised by Pisione parapari and Hesionura elongata; (b) very coarse sand that showed the highest abundance of Syllidae and was characterised by Protodorvillea kefersteini and Syllis garciai; (c) fine sand dominated by Spiophanes bombyx and Glycera tridactyla; (d) very fine sand with Nepthys assimilis and Amage sp. and the highest abundance of Paraonidae; (d) mud characterised by Labioleanira yhleni and Ampharete finmarchica. The combination of the environmental variables and the biological data, done with BIOENV routine, demonstrated that depth, grain size and fine contents were the best related with the biological data (rho=0.598). In general, the results agree with the composition and the spatial distribution of the polychaete fauna in other parts of the world; further polychaete assemblages related to mud sediments were firstly recorded in the Northwestern Portuguese Coastal Shelf

Comparative and integrative approaches to assess the connectivity of four estuarine annelid species : osmoregulation strategies

Orientador: Prof. Dr. Paulo Da Cunha LanaCoorientador: Prof. Dr. Maikon Di DomenicoTese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Zoologia. Defesa : Curitiba, 26/02/2021Inclui referênciasResumo: As distribuições populacionais atuais e a diversidade genética dos organismos estuarinos são o resultado de uma combinação de fatores históricos e contemporâneos, que influenciam a dispersão e o fluxo gênico entre populações. Devido às rápidas mudanças climáticas que influenciaram direta e indiretamente o nível do mar e a linha de costa em todo o globo, o Pleistoceno afetou profundamente a distribuição e a diversidade genética de vários táxons. Os estuários são ambientes altamente dinâmicos, caracterizados por grandes flutuações de salinidade. Os organismos estuarinos desenvolveram adaptações fisiológicas e ecológicas para lidar com tais variações estuarinas diárias ou sazonais. Este trabalho visa investigar como fatores contemporâneos e históricos modelaram e modelam os atuais padrões de distribuição e a composição gênica de quatro espécies-alvo de anelídeos em três estuários subtropicais do sul do Brasil, explorando vários níveis de organização biológica por meio de uma abordagem bastante integrativa. As espécies-alvo foram escolhidas em função da sua abundância e maior ou menor tolerância às variações de salinidade ao longo de baixios entre-marés dos estuários. Testamos duas espécies com nichos de salinidade mais amplos, os nereidídeos a priori chamados de Alitta succinea e Laeonereis culveri, e espécies com nichos de salinidade mais restritas, o neftídeo Nephtys fluviatilis e o melinídeo Isolda pulchella. A tese foi dividida em quatro capítulos, que avaliaram a importância de forçantes históricas e contemporâneas na distribuição e composição genica das quatro espécies, em diversos níveis de organização biológica: - O primeiro capítulo investigou a tolerância à variação da salinidade e a espessura do tegumento das quatro espécies alvo. Ambos os nereidídeos apresentaram estabilidade de peso corporal e tegumento espesso, compatível com sua eurihalinidade. O neftideo foi nitidamente menos eurihalino, mas tolerou baixas salinidades e água doce, enquanto o melinídeo apresentou um comportamento estenohalino marinho e não tolerou diluição da água do mar. Ambas as espécies apresentaram um tegumento fino. - O segundo capítulo revelou a expressão e localização do cotransportador NKCC por imunofluorescência nos corpos das quatro espécies de anelídeo. Sua expressão não foi homogênea, refletindo claramente o estilo de vida dos anelídeos. Os anelídeos de vida livre (ambos os nereidídeos eurihalinos e o neftídeo estenohalino), exibiram um sinal para NKCC espalhado e detectado ao longo de seus corpos, em contraste com o melinídeo sedentário, no qual o sinal foi restrito às regiões anteriores do corpo em contato direto com a coluna d'água. - O terceiro capítulo investigou a presença das aquaporinas em anelídeos por meio de uma abordagem in sílico, através de uma busca nos bancos de dados públicos, e a confirmou experimentalmente em A. succinea. A filogenia de MIPs dos anelídeos foi reconstruída, potenciais ortólogos das aquaporinas dos vertebrados AQP1-like, AQP8 e as AQP11-like foram recuperados, e a presença de três parálogos de A. succinea foram confirmados por RT-PCR. - O quarto capítulo investigou os padrões de diferenciação genética de populações das quatro espécies-alvo em três estuários subtropicais do sul do Brasil. Alto fluxo gênico foi recuperado para os nereidídeos entre as baías, resultado congruente com os dados do primeiro capítulo e esperado em função de sua eurihalinidade. Marcada segregação foi recuperada para as populações de neftídeo da Baía da Babitonga, como reflexo de seu baixo grau de eurihalinidade e de sua distribuição limitada aos setores oligohalinos mais confinados. Panmixia entre os estuários foi recuperada para o melinídeo, refletindo seu comportamento "marinho" e sua ocorrência restrita aos setores euhalinos. As análises moleculares indicaram a existência de uma nova espécie de Alitta, ainda por ser formalmente descrita. Validaram ainda trabalhos recentes que haviam mostrado que populações antes referidas ao nome específico Laeonereis culveri, pertencem de fato a Laeonereis acuta e Laeonereis pandoensis, ocorrendo em simpatria ou alopatria.Abstract: Present-day distribution and genetic diversity of estuarine animals are the result of a combination of historical and contemporary factors that have influenced both their dispersal and gene flow. For instance, Pleistocene glaciations influenced sea-level and the coastal lines worldwide, strongly affecting the distribution patterns of coastal and estuarine species belonging to different taxa. Estuaries are highly dynamic environments, characterised by regular or irregular salinity fluctuations, and estuarine organisms share a variety of physiological and ecological adaptations to face such daily or seasonal variations. This work aimed to investigate how contemporary and historical factors have modelled and are still modelling the current distribution of four estuarine annelid species from different sectors of three subtropical estuaries of southern Brazil, by exploring different biological organization levels through an integrated approach. The target species were chosen considering their distribution and the variability in the salinity regimes of their ranges of occurrence. We tested two species with broader salinity niches, the nereidids treated a priori as Alitta succinea and Laeonereis culveri, and two species with narrower salinity niches, or more restricted spatial ranges in the bay, the nephtyid Nephtys fluviatilis and the melinnid Isolda pulchella. The thesis was articulated into four chapters, assessing contemporary or historical drivers which potentially led to genetic structure, or lack of it, at diverse organization levels: - Chapter one investigated the tolerance to salinity variation and the integument thickness of the four annelid species. Both nereidids displayed body weight stability and a thick integument, compatible with their high euryhalinity. The nephtyid was distinctly less euryhaline but tolerated low salinities and fresh water, while the melinnid presented a marine stenohaline behaviour and did not tolerate seawater dilution. Both species have a thin integument. - Chapter two revealed the expression and localization of the NKCC cotransporter through immunofluorescence in the bodies of the four annelids. NKCC expression was not homogeneous, and clearly reflected the lifestyle of each species. The free-living/burrowers (both euryhaline nereidids and the stenohaline nephtyid) displayed a widespread signal for NKCC along their bodies, in contrast to the stenohaline sedentary melinnid, in which the signal was restricted to the body regions exposed to the surrounding environment. - Chapter three investigated the presence of aquaporins in annelids through an in silico approach against online databases and experimentally confirmed for the first time their expression in A. succinea. The phylogeny of annelid MIPs was reconstructed, putative orthologs of the vertebrate AQP1-like, AQP8 and the AQP11- like subfamilies were recovered, and three paralogs of A. succinea were confirmed by RT-PCR. - Chapter four investigated patterns of genetic differentiation in populations of the four selected annelid species along three subtropical estuaries from southern Brazil. High genetic flow among the bays was reported for the nereidids, congruent with their high euryhalinity. Segregation was recovered for the nephtyid populations from Babitonga Bay, reflecting their low degree of euryhalinity and their limited distribution to the more confined, oligohaline sectors. Panmixia among the estuaries was recovered for the melinnid, reflecting its "marine" behaviour and its restricted occurrence in the euhaline sectors. As a result of our molecular analyses, we found a putative new species related to the complex A. succinea, and validated the recent findings from other authors that the species name L. culveri, as yet used for local populations of Laeonereis, corresponds in fact to two distinct species, Laeonereis acuta and Laeonereis pandoensis

Finding aquaporins in annelids : An evolutionary analysis and a case study

Funding Information: This research was funded by PRIN2017 Programmi di Ricerca Scientifica di Rilevante Interesse Nazionale 2017 (grant # 2017J92TM5) by Italian MUR to G.C. and by the Molecular Bio-diversity Laboratory of the Italian node of Lifewatch (CNR, Consiglio Nazionale delle Ricerche) to C.G.Peer reviewedPublisher PD

First Glimpse at the Diverse Aquaporins of Amphipod Crustaceans

The importance of aquaporins (AQPs) in the transport of water and solutes through cell membranes is well recognized despite being relatively new. To date, despite their abundance, diversity, and presence in disparate environments, amphipods have only been mentioned in studies about the AQPs of other animals and have never been further investigated. In this work, we aimed to recover from public data available AQPs of these crustaceans and reconstruct phylogenetic affinities. We first performed BLAST searches with several queries of diverse taxa against different NCBI databases. Then, we selected the clades of AQPs retrieving the amphipod superfamily Gammaroidea as monophyletic and ran phylogenetic analyses to assess their performances. Our results show how most of the AQPs of amphipods are similar to those of other crustaceans, despite the Prip-like displayed different paralogs, and report for the first time a putative Aqp8-like for arthropods. We also found that the candidate genes of Prip-like, Bib-like, Aqp12-like, and Glp-like help solve deeper relationships in phylogenies of amphipods while leaving uncertainties in shallower parts. With our findings, we hope to increase attention to the study of amphipods as models for AQP functioning and evolution

Habitat use in juvenile and adult life stages of the sedentary fish Hippocampus guttulatus

Understanding of the spatial distribution and habitat use in different stages of a life cycle represents the essential aspect of threatened species management and conservation. In the present paper, the spatial and temporal patterns of habitat use in juvenile and adult life stages of the long-snouted seahorse Hippocampus guttulatus in the Mar Piccolo of Taranto (Apulia—Italy) (40°28′N, 17°16′W) were examined. From October 2012 to January 2014, monthly visual censuses were conducted in six coastal habitats of a focal area (Buffoluto site). Of a total of 317 individuals of the long-snouted seahorse that were sighted, 148 were juveniles, 82 adult females and 87 adult males. Our results showed significant differences in the habitat use between adult and juvenile life stages of H. guttulatus. Adult individuals were mainly concentrated within Cladophora prolifera beds and the wood poles of a mussel farm at 2–4 m of depth, while juvenile individuals were mainly present in shallower water (0.4–1 m) on artificial hard substrates covered by a brown algae turf. Assessing and describing the habitat use within different life stages of H. guttulatus represent a useful tool to support species conservation by protecting the habitats it uses

Variability in the degree of euryhalinity of neotropical estuarine annelids

Estuaries are highly dynamic, spatially complex systems showing large daily fluctuations in salinity. Estuarine organisms, especially small animals with limited locomotory capacities, are thus expected to have variable ecological and morphophysiological strategies. This paper evaluates the responses to salinity challenges in four species of neotropical annelids along a subtropical estuarine gradient by assessing mortality (i.e., tolerance) and changes in body weight (proxy for water fluxes). We selected the nereidids Alitta sp. and Laeonereis acuta, with broad salinity niches, and the nephtyid Nephtys fluviatilis and the melinnid Isolda pulchella, with either narrow salinity niches or a more restricted spatial range. Worms were weighed, exposed to salinities ranging from fresh water to full-strength seawater (0, 5, 15, 25, and 35) for 1, 6, 12, and 24 h, and weighed again after these exposure times. Their mortality (as absence of body movements or vascular circulation) rates were recorded to assess their ranges of tolerance to these treatments or their degree of euryhalinity. Their integument was characterized histologically to show possible morphological links to their tolerances. Both nereidids displayed stable body weights and thick integuments, compatible with the wide range of salinity tolerance and capacity to maintain body hydration. Body weight of Alitta sp. returned to initial values after 1 h at salinities ≥5. Body weight did not change in L. acuta at salinities ≥15; mortalities occurred only at salinity 0 after 12–24 h. Nephtys fluviatilis showed a thin integument and less variation in weight throughout the whole range of tested salinities, but mortality occurred after 24 h at salinity 0, at its reference salinity (3) and at 35. Isolda pulchella showed a lower capacity to maintain body weight/hydration and a thin integument, compatible with its relative stenohalinity and presence restricted to polyhaline marine sectors. Its weight variation was significant at all salinities except 35; mortality occurred at extreme salinities: 0 and 35. Responses of the four species were compatible with their distribution along the estuarine gradient, as an interesting outcome of their autecological traits, morphophysiological adaptations and evolutionary histories

Reappraisal of the hyperdiverse Platynereis dumerilii (Annelida: Nereididae) species complex in the Northern Atlantic, with the description of two new species

Morphologically similar species are often overlooked but molecular techniques have been effective in signalling potential hidden diversity, boosting the documentation of unique evolutionary lineages and ecological diversity. Platynereis dumerilii and Platynereis massiliensis are part of a recognised species complex, where differences in the reproductive biology have mainly been highlighted to date. Analyses of DNA sequence data (COI, 16S rDNA and D2 region of the 28S rDNA) of populations of the apparent morphotype of P. dumerilii obtained from a broader sampling area along European marine waters, including the Azores and Webbnesia islands (Madeira and Canaries), provided compelling evidence for the existence of at least 10 divergent evolutionary lineages. Complementing the genetic data, morphological observations of the better represented lineages revealed two major groups with distinctive paragnath patterns. Two new Platynereis species were erected: P. nunezi sp. nov., widespread in the Azores and Webbnesia islands, and P. jourdei sp. nov., restricted to the western Mediterranean. The new combination P. agilis is also proposed for Nereis agilis, previously unaccepted for one of the lineages present both in the Northeast Atlantic and western Mediterranean. Platynereis dumerilii is redescribed based on topotypic material. However, uncertainty in the identity of P. massiliensis due to the original brief description and the absence of type and topotypic material prevents the unequivocal assignment to the lineage assumed in this and previous studies. The remaining five lineages are represented by only a few small specimens with morphological features poorly preserved and were therefore not described in this study.This study was supported by the project Next generation monitoring of coastal ecosystems in a scenario of global change (NextSea, NORTE-01-0145-FEDER-000032), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). Thanks are due, for the financial support of CESAM – Centro de Estudos do Ambiente e do Mar (UIDB/50017/2020+UIDP/50017/2020), to Portuguese Foundation for Science and Technology and Ministry of Education and Science (FCT/MEC) through national funds, and the co-funding by the FEDER, within the PT2020 Partnership Agreement and Compete 2020. The research leading to these results also received partial funding, from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 730984, ASSEMBLE Plus project (application n. 8229, 4th CALL, "Crypticism in the marine realm: DNA barcode-based outlook into selected invertebrate taxa of the Eastern Mediterranean"). Marcos AL Teixeira was supported by a PhD grant from FCT co-financed by ESF (SFRH/BD/131527/2017) and from the DNAqua-Net STSM grant "Rich and hidden biodiversity not yet barcoded in the Canary archipelago (Spain) as an opportunity to enrich the DNA barcode reference library for European polychaetes", under the EU Cost action CA15219 - Developing new genetic tools for bioassessment of aquatic ecosystems in Europe. Pedro Vieira work was supported by national funds through the Portuguese Foundation for Science and Technology (FCT, I.P.) in the scope of the project (Early detection and monitoring of non-indigenous species in coastal ecosystems based on high-throughput sequencing tools, PTDC/BIA-BMA/29754/2017). Ascensão Ravara was funded by national funds, through FCT, I.P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19. Financial support to Arne Nygren from the Norwegian Taxonomy Initiative [http://www.biodiversity.no/Pages/135523] (Cryptic polychaete species in Norwegian waters, knr 49-13, pnr 70184228), the Swedish Taxonomy Initiative [https://www.artdatabanken.se/en/the-swedish-taxonomy-initiative/] (Polychaete species complexes in Swedish waters, dnr 140/07 1.4 and 166/08 1.4), and Kungliga Fysiografiska sällskapet Nilsson-Ehle donationerna [https://www.fysiografen.se/sv/]. Financial support to Torkild Bakken from the Norwegian Taxonomy Initiative project Polychaetes in Norwegian Ports project no. 70184238

New records of rarely reported species in the Mediterranean Sea (July 2023)

This Collective Article presents new information about the occurrence of 23 marine taxa that belong to five Phyla: two Chlo-rophyta, one Annelida, six Mollusca, three Arthropoda, eleven Chordata (one Ascidiacea, one Elasmobranchii and nine Teleostei) and extending from the Western Mediterranean to the Levantine Sea. All these records were reported from nine countries from the western to the eastern Mediterranean Sea, with a broad biogeographical coverage as follows: Spain: first records of the sacoglos-sans Cyerce graeca and Placida tardyi for the Alboran Sea and first records of the nudibranch Marionia gemmii for the Mediter-ranean waters of Spain; first records of nudibranch Algarvia alba in the Mediterranean Sea. Italy: First report of the long-legged crab Paragalene longicrura, a further new Mediterranean record of the rare offshore rockfish Pontinus kuhlii, first documented record of the spiny butterfly ray Gymnura altavela in Sardinia (Tyrrhenian Sea), new record of the red-spotted wrasse Lappanella fasciata from the Messina Strait, first documented record of the rarely observed brown moray Gymnothorax unicolor in the Ionian coast, first record of the colonial ascidian Botrylloides israeliensis, first record of the Morocco dentex Dentex maroccanus, first record of mottled shore crab Pachygrapsus maurus and of an adult specimen of barracudina Lestidiops sphyrenoides in the Adri-atic Sea, and further new Mediterranean records of Ross worm Sabellaria spinulosa along the same coast. Tunisia: second record of smalleye squaretail Tetragonurus cuvieri from the African Mediterranean coast. Slovenia: first records of the sea slug Trapania graeffei and Melanochlamys wildpretii, with the last one also representing the northernmost finding of this species. Croatia: northernmost record of the endangered twaite shad Alosa fallax in the Adriatic coast. Albania: first records of the Mediterranean spearfish Tetrapturus belone. Turkiye: first record from the Aegean coasts for Turkiye of the green macroalgae Cladophora bat-tersii and Valonia aegagropila. Israel: first record of the skeleton shrimp Caprella acanthifera in the Southeastern Mediterranean Sea. Syria: first record of the Smooth grenadier Nezumia aequalis from Syrian marine waters