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No description available.

No description available.

No description available.

The population of harbour ragworms, Nereis diversicolor, inhabiting the upper reaches of Restronguet Creek in the Fal Ria, UK, are known to be resistant to the acute, toxic effects of copper, zinc and cadmium. This research aimed to establish whether metabolic and reproductive performance costs were associated with the resistance phenomenon and what the biochemical mechanisms of resistance were, by comparing animals from the Creek with two comparable study sites in the South West of England: Froe Creek and the Teign estuary. There was a significant metabolic cost, measured as a reduction in Scope for Growth, associated with the resistance phenomenon. As no differences in energy intake or uptake were found between resistant and non-resistant animals it was concluded that this cost was covered by demand-side regulation of energetics. A reduction in the amount of biochemical energy reserves in the form of lipids and sugars was also observed in resistant animals suggesting that resource allocation had been shifted away from this endpoint and towards maintenance and activity. The perturbed metabolism and physiology of resistant N. diversicolor is shown to have detrimental consequences for their life-history. Sexually mature, resistant females were significantly smaller than non-resistant ones, indicating that they had either matured at a younger age or grown more slowly. Both total fecundity and mass-specific fecundity were significantly reduced in resistant females, likely as a direct result of the metabolic costs of resistance reducing the resources available to fuel gametogenesis. No differences were found in the energetic reserves stocked within each gamete by resistant and non-resistant animals, suggesting that this trait is heavily selected for. Synthesis of reduced glutathione [GSH] in resistant animals’ tissues appeared to be elevated. Glutathione peroxidase activity was also increased, likely to remediate the effects of Reactive Chemical Species [RCS] that result from the inevitably incomplete binding of intracellular metals. As GSH functions in metal detoxification to covalently binding metals entering resistant animals’ cells, preventing their involvement in toxic interactions and their catalysis of the production of RCS, it is proposed that together there two phenomena comprise the fundamental mechanism of resistance to metal toxicity. Ultimately, this research revealed a hierarchy of health and reproductive performance across the three study populations, with significant associations evident between measured biological endpoints and the degree of metal contamination, illustrating the consequences of anthropogenic pollution for the biology of wild animals.

The aim of this thesis was to review the current state of knowledge, occurrence and distribution of two polydorid (Polychaeta: Spionidae) genera, Polydora and Dipolydora, in estuaries of subtropical eastern Australia. The existing taxonomy of the polydorid group is confused and descriptions include many relative terms. A numerical taxonomy approach using Primer 6 was taken to identify species groups and characters. A standardized set of multivariate morphological characters was developed and resemblance analysis functions used to create species cluster groups. SIMPER (similarity percentages) analysis on the same dataset was used to identify the diagnostic characters for each of these species cluster groups and to identify new characters which could be useful in species diagnosis, particularly for frequently occurring incomplete specimens.Prior to this study 3 Polydora species and 4 Dipolydora species were recorded from subtropical eastern Australia. The present study found 12 Polydora species and 10 Dipolydora species from estuaries and bays of subtropical eastern Australia.Two Polydora species are new (Polydora sp. P1 and Polydora cf. woodwicki) and 7 are potentially new species (P. cf. latispinosa; P. cf. websteri; P. sp. P2S; P. sp. P3S; P. sp. P4S; P. sp. P5S and P. sp. P6S) having been described from single specimens. Polydora cornuta Bosc, 1902 is recorded from New South Wales for the first time. Polydora cf. calcarea is reported from mudblisters in oysters. The Australian form of Polydora hoplura Claparède, 1870 and P. haswelli Blake and Kudenov, 1978 are described more fully than in existing literature.Three Dipolydora species are new (Dipolydora sp. D1; D. cf. flava and D. sp. D2) and 4 from single specimens are potentially new (D. cf. aciculata/ cf. giardi; D. sp. D3S; D. sp. D4S and D. sp. D5S). Dipolydora tentaculata (Blake and Kudenov, 1978) and Australian forms of Dipolydora flava (Claparède, 1870) and Dipolydora socialis (Schmarda, 1861) are described more fully than in existing literature.Prior to this study one Dipolydora and no Polydora were recorded from the Tweed- Moreton bioregion. This study reports 6 species of Dipolydora and 5 species of Polydora from this bioregion.Dipolydora penicillata (Hutchings and Rainer, 1979) and Carazziella victoriensis Blake and Kudenov, 1978 are recommended for synonymy.It is recommended that Polydora ciliata (Johnston, 1838) be reinstated and Dipolydora ciliata (Johnson, 1838) removed from the Australian polychaete checklist following identification of an error in description translation.Important gaps in collections were identified for polydorids associated with oysters from estuaries over the whole subtropical region; and for polydorids from the Tweed-Moreton IMCRA bioregion.

The aim of this thesis was to review the current state of knowledge, occurrence and distribution of two polydorid (Polychaeta: Spionidae) genera, Polydora and Dipolydora, in estuaries of subtropical eastern Australia. The existing taxonomy of the polydorid group is confused and descriptions include many relative terms. A numerical taxonomy approach using Primer 6 was taken to identify species groups and characters. A standardized set of multivariate morphological characters was developed and resemblance analysis functions used to create species cluster groups. SIMPER (similarity percentages) analysis on the same dataset was used to identify the diagnostic characters for each of these species cluster groups and to identify new characters which could be useful in species diagnosis, particularly for frequently occurring incomplete specimens.Prior to this study 3 Polydora species and 4 Dipolydora species were recorded from subtropical eastern Australia. The present study found 12 Polydora species and 10 Dipolydora species from estuaries and bays of subtropical eastern Australia.Two Polydora species are new (Polydora sp. P1 and Polydora cf. woodwicki) and 7 are potentially new species (P. cf. latispinosa; P. cf. websteri; P. sp. P2S; P. sp. P3S; P. sp. P4S; P. sp. P5S and P. sp. P6S) having been described from single specimens. Polydora cornuta Bosc, 1902 is recorded from New South Wales for the first time. Polydora cf. calcarea is reported from mudblisters in oysters. The Australian form of Polydora hoplura Claparède, 1870 and P. haswelli Blake and Kudenov, 1978 are described more fully than in existing literature.Three Dipolydora species are new (Dipolydora sp. D1; D. cf. flava and D. sp. D2) and 4 from single specimens are potentially new (D. cf. aciculata/ cf. giardi; D. sp. D3S; D. sp. D4S and D. sp. D5S). Dipolydora tentaculata (Blake and Kudenov, 1978) and Australian forms of Dipolydora flava (Claparède, 1870) and Dipolydora socialis (Schmarda, 1861) are described more fully than in existing literature.Prior to this study one Dipolydora and no Polydora were recorded from the Tweed- Moreton bioregion. This study reports 6 species of Dipolydora and 5 species of Polydora from this bioregion.Dipolydora penicillata (Hutchings and Rainer, 1979) and Carazziella victoriensis Blake and Kudenov, 1978 are recommended for synonymy.It is recommended that Polydora ciliata (Johnston, 1838) be reinstated and Dipolydora ciliata (Johnson, 1838) removed from the Australian polychaete checklist following identification of an error in description translation.Important gaps in collections were identified for polydorids associated with oysters from estuaries over the whole subtropical region; and for polydorids from the Tweed-Moreton IMCRA bioregion.

Plastic debris is an emerging environmental issue, with >10 million tons of plastics debris per annum entering the sea. Exposure to marine conditions facilitates the exponential fragmentation of plastic to micro-sized particles (microplastics). Marine and coastal sediments are a sink for microplastic pollution. Consequently, the ingestion of microplastics by a range of benthic marine invertebrates, including polychaete worms, has been reported in situ. Microplastics are vectors for priority pollutants capable of eliciting adverse health effects. However, the particle and chemical toxicity which microplastics could incur to ecologically-important marine invertebrates is unknown. This thesis aims to determine the potential for microplastics to cause harm in the marine environment, with a focus on benthic polychaete worms. Specifically, it assesses the potential particle toxicity which could arise from chemical-free microplastics; and the potential chemical toxicity which could arise from leached endogenous chemical additives or sorbed chemical pollutants. To address these, an integrative approach was employed, primarily using laboratory-based whole-sediment in vivo exposures, established cellular and whole-tissue toxicity assays, and analytical chemistry. For the first time, this thesis reports that chemical-free microplastics cause particle toxicity in the lugworm Arenicola marina. Feeding activity was reduced during exposure to 5% microscopic unplasticised polyvinylchloride (UPVC) by sediment weight, whilst exposure to ≥1% UPVC by sediment weight significantly reduced energy reserves relative to control animals. Evidence for the transfer and toxicity of endogenous additives from PVC to lugworms is provided. Lugworms exposed to 1% PVC by sediment weight exhibited a 70% increase in additive concentration, coinciding with inhibited mucus production and enhanced lipid reserves and oxygen consumption, compared to control lugworms. Ragworms (Hediste diversicolor) exposed to leached toxicants from bioplastic cigarette debris were found to exhibit significantly longer burrowing times, >30% weight loss, and >2-fold increase in DNA damage compared to control ragworms. Bio-concentration factors for nicotine – the biomarker of exposure - were 500 fold higher from leachates in seawater than from microfibres in sediment. Overall, this thesis provides evidence to suggest that the incorporation of microplastics into marine sediments can significantly impact the health of marine polychaete worms due to both particle and chemical effects. This emphasises the need to reconsider the classification of plastic as non-hazardous and questions whether we as humans are also at risk.

Polychaetes are among the most abundant and diverse groups in the benthic environment; however, the diversity of marine polychaetes remains underexplored. On coral reef ecosystems, scientists predict 80-90% of species are still undescribed due to low sampling efforts in certain regions and the understudied nature of smaller invertebrates, such as polychaetes. Sabellidae, a prominent family of polychaetes, are known for their widespread distribution and are recognized as an ornamental worm due to their feather-like appendages. Here, we detail the diversity of Sabellidae around the understudied Arabian Peninsula. The Arabian Peninsula is surrounded by diverse marine ecosystems (e.g., coral reefs, seagrass beds) occurring in extreme environmental conditions (e.g., higher seawater temperature and strong seasonal variation). Our samples included 178 sabellids from the Saudi Arabian Red Sea, the Arabian Sea, and the Arabian Gulf. Collected from February 2019 to February 2020, these sabellids were sampled from hard and soft substrate on coral reefs and their associated habitats. We used two molecular markers, the cytochrome c oxidase subunit I (COI) and 16S ribosomal DNA alongside an array of morphological analyses, including widely used characters, meristic counts, and morphometric measurements, to identify seven morphotypes. Environmental and biological information was also recorded to understand more about the ecology of these relatively understudied polychaetes. Our combined morphological and genetic analyses acknowledge the presence of six species from the genera Sabellastarte, Bispira, Branchiomma, and Acromegalomma. Our study identified the existence of potential undescribed species in the region and proposed expanded geographic ranges for three accepted species, Sabellastarte sanctijosephi, Branchiomma luctuosum, and Acromegalomma nechamae. The present work increases the current knowledge about the overall systematics of marine polychaetes in the Arabian Peninsula and ultimately contributes to the reassessment of the family’s biogeography.

A composição e distribuição de poliquetas foram estudadas na região da plataforma continental sudeste brasileira adjacente à Baixada Santista (Projeto temático ECOSAN), sendo realizadas coletas em 21 estações, durante dois períodos, por meio de um \'box-corer\' (0.09m2). Poliqueta foi o grupo dominante da macrofauna, totalizando 16.274 indivíduos e 214 espécies. A distribuição da fauna relacionou-se com as características do sedimento, como o tamanho médio do grão e seu grau de seleção, ao longo de um gradiente batimétrico, verificando-se a existência de três comunidades distintas: comunidade costeira, situada ao longo da costa em locais de areia muito fina e fina bem selecionadas, dominada por Apoprionospio dayi; comunidade de transição, situada em sedimentosmistos e heterogêneos, entre 50-84m e caracacterizada por Aphelochaeta sp., Levinsenia gracilis e Aricidea (A.) catherinae; comunidade de plataforma externa, situada em sedimentos lamosos profundos, caracterizada por Sigambra grubii, Sternaspis capillata e Leitoscoloplos kerguelensis. Fatores oceanográficos, como hidrodinamismo e intrusão sazonal da ACAS, foram considerados como secundários na estruturação das comunidades. De modo geral, a riqueza e diversidade de poliqueta foram altos, variando de 20 a 66, e de 2,37 a 5,45 respectivamente. A região entre 50-84m apresentou picos desses descritores, provavelmente associados ao sedimento de maior heterogeneidade e à sobreposição de comunidades. Os grupos funcionais apresentaram distribuição semelhante a da composição de espécies. Os consumidores de interface foram dominantes na região costeira, enquanto depositívoros de superfície, e sub-superfície móveis de probóscide lisa, e carnívoros móveis mandibulados, foram dominantes na região entre 50 e 100m. / Composition and distribution of polychaetes were studied in southeastern Brazilian continental shelf adjacent to Santos (ECOSAN Thematic Project). Aiming a spatio-temporal community comprehension, 21 stations were sampled in duplicates during August/2005 and February/2006, with a box-corer (0.09 m2). Polychaete was the dominant macrofauna group, totalizing 16274 individuals and 214 species. The fauna distribution along the depth gradient was related to sediment type, mean grain size and sediment sorting, which partially promoted the existence of three distinct communities: (1) a shallow community, dominated by Apoprionospio dayi, inhabiting very fine and fine well selected sand; (2) a community dominated by Aphelochaeta sp., Levinsenia gracilis and Aricidea (A.) catherinae, inhabiting mixed sediments between 50-84 m depth; (3) and a community dominated by Sigambra grubii, Sternaspis capillata and Leitoscoloplos kerguelensis, inhabiting muddy sediments in a deeper region of the continental shelf. The local hydrodynamic regime and the deep intrusion of the South Atlantic Central Water (SACW) were considered secondary factors in the distribution of polychaetes. High values of richness and diversity were observed throughout the shelf, ranging from 20 to 66, and from 2.37 to 5.45 respectively. The region between 50-84m showed peaks of these community descriptors, probably associated with greater sediment heterogeneity, and the communities overlapping. The functional groups showed a similar distribution to species distribution. Interface-feeders were dominant functional group in coastal region, while motile surface and subsurface deposit feeders with soft proboscis and motile carnivores with jaws were dominant in the region between 50 and 100m.