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Aquatic Toxicology (Amsterdam,... Oct 2021Oligochaetes feed on bulk sediment and penetrate the sediment through the construction of burrows, making them especially vulnerable to sediment metal contamination....
Oligochaetes feed on bulk sediment and penetrate the sediment through the construction of burrows, making them especially vulnerable to sediment metal contamination. However, the few oligochaete species that have been tested to date are almost exclusively temperate test species. Although the warmwater adapted species Branchiura sowerbyi has been indicated as a promising candidate for tropical sediment toxicity testing, few (especially chronic) studies have been conducted so far to confirm this. Therefore, the aim of the present study was to evaluate the bioaccumulation and chronic 28d lethal and sublethal toxicity of arsenic (As) and zinc (Zn) to both the warmwater-adapted B. sowerbyi and the coldwater-adapted oligochaete Tubifex tubifex for comparison. Arsenic was more toxic to both oligochaete species than Zn. Inter- and intra-species variability in toxicity values of the two test species and other benthic invertebrates was within an order of magnitude. However, B. sowerbyi was the most sensitive species to As even for sediment concentration (EC: 36.6 ± 2.1 µg/g and 147.1 ± 21.7 µg/g, for B. sowerbyi and T. tubifex, respectively) and for tissue concentration (ER: 9.2 ± 0.9 µg/g and 887.0 ± 35.0 µg/g, for B. sowerbyi and T. tubifex, respectively). Finally, the Tissue Residue-effects Approach (TRA) using Effective Tissue Residues appears to be a promising way forward in advancing in this since it considers internal body concentrations.
Topics: Animals; Arsenic; Bioaccumulation; Geologic Sediments; Oligochaeta; Water Pollutants, Chemical; Zinc
PubMed: 34500378
DOI: 10.1016/j.aquatox.2021.105955 -
Biochimica Et Biophysica Acta.... Oct 2023Aquatic single-cell organisms have long been believed to be unique primary producers of omega-3 long-chain (≥C) polyunsaturated fatty acids (ω3 LC-PUFA). Multiple...
Aquatic single-cell organisms have long been believed to be unique primary producers of omega-3 long-chain (≥C) polyunsaturated fatty acids (ω3 LC-PUFA). Multiple invertebrates including annelids have been discovered to possess methyl-end desaturases enabling key steps in the de novo synthesis of ω3 LC-PUFA, and thus potentially contributing to their production in the ocean. Along methyl-end desaturases, the repertoire and function of further LC-PUFA biosynthesising enzymes is largely missing in Annelida. In this study we examined the front-end desaturase gene repertoire across the phylum Annelida, from Polychaeta and Clitellata, major classes of annelids comprising most annelid diversity. We further characterised the functions of the encoded enzymes in selected representative species by using a heterologous expression system based in yeast, demonstrating that functions of Annelida front-end desaturases have highly diversified during their expansion in both terrestrial and aquatic ecosystems. We concluded that annelids possess at least two front-end desaturases with Δ5 and Δ6Δ8 desaturase regioselectivities, enabling all the desaturation reactions required to convert the C precursors into the physiologically relevant LC-PUFA such as eicosapentaenoic and arachidonic acids, but not docosahexaenoic acid. Such a gene complement is conserved across the different taxonomic groups within Annelida.
Topics: Animals; Ecosystem; Fatty Acid Desaturases; Fatty Acids, Omega-3; Fatty Acids, Unsaturated; Annelida
PubMed: 37517549
DOI: 10.1016/j.bbalip.2023.159377 -
Zootaxa Feb 2023The last extensive exploration of Nereididae diversity within coastal waters of Western Australia was done in 1975-1984. We collected Nereididae associated with...
The last extensive exploration of Nereididae diversity within coastal waters of Western Australia was done in 1975-1984. We collected Nereididae associated with macroalgae from 38 rocky intertidal shores of Western Australia (18°S to 34°S). Eighteen species belonging to seven genera are described and illustrated. Two new species, Nereis edentata n. sp. and Nereis yuedensis n. sp., were found. Nereis edentata n. sp. differs from other Nereis species having one row of paragnaths on Areas VII-VIII and smooth notopodial homogomph falcigers in posterior chaetigers. Nereis yuedensis n. sp. differs from other Nereis species having one row of paragnaths on Areas VII-VIII and notopodial homogomph falcigers with at least one large lateral tooth, and also species having notopodial homogomph falcigers starting from chaetiger 3. The distribution of N. yuedensis n. sp. was found to be restricted within temperate Australia and N. edentata n. sp. appears to be transitional between temperate and tropical regions. Also, we remove from synonymy the probable Western Australian endemic species, Pseudonereis rottnestiana (Augener, 1913), and provide a key to all known genera and species of Nereididae from Western Australian waters.
Topics: Animals; Western Australia; Australia; Annelida; Polychaeta; Xenarthra
PubMed: 37045103
DOI: 10.11646/zootaxa.5239.2.1 -
BMC Genomics Jan 2022Leeches are classic annelids that have a huge diversity and are closely related to people, especially medicinal leeches. Medicinal leeches have been widely utilized in...
BACKGROUND
Leeches are classic annelids that have a huge diversity and are closely related to people, especially medicinal leeches. Medicinal leeches have been widely utilized in medicine based on the pharmacological activities of their bioactive ingredients. Comparative genomic study of these leeches enables us to understand the difference among medicinal leeches and other leeches and facilitates the discovery of bioactive ingredients.
RESULTS
In this study, we reported the genome of Whitmania pigra and compared it with Hirudo medicinalis and Helobdella robusta. The assembled genome size of W. pigra is 177 Mbp, close to the estimated genome size. Approximately about 23% of the genome was repetitive. A total of 26,743 protein-coding genes were subsequently predicted. W. pigra have 12346 (46%) and 10295 (38%) orthologous genes with H. medicinalis and H. robusta, respectively. About 20 and 24% genes in W. pigra showed syntenic arrangement with H. medicinalis and H. robusta, respectively, revealed by gene synteny analysis. Furthermore, W. pigra, H. medicinalis and H. robusta expanded different gene families enriched in different biological processes. By inspecting genome distribution and gene structure of hirudin, we identified a new hirudin gene g17108 (hirudin_2) with different cysteine patterns. Finally, we systematically explored and compared the active substances in the genomes of three leech species. The results showed that W. pigra and H. medicinalis exceed H. robusta in both kinds and gene number of active molecules.
CONCLUSIONS
This study reported the genome of W. pigra and compared it with other two leeches, which provides an important genome resource and new insight into the exploration and development of bioactive molecules of medicinal leeches.
Topics: Animals; Genome; Genomics; Hirudo medicinalis; Humans; Leeches
PubMed: 35073842
DOI: 10.1186/s12864-022-08290-5 -
In Vitro Cellular & Developmental... Jun 2023Developing blood vessels from the existing vasculature is vital for the growth of the organism, as well as for systematic wound healing and the repair process. In this...
Developing blood vessels from the existing vasculature is vital for the growth of the organism, as well as for systematic wound healing and the repair process. In this study, we investigated the role of angiogenesis during the regeneration process in the earthworm, Eudrilus eugeniae, animal model. Briefly, the morphological examination of blood vessels in juvenile and mature worms is documented, along with the development of new blood vessels in regenerating blastema. However, in vivo and in vitro experiments with juvenile worms revealed that geraniol retards blastemal regeneration growth with undeveloped blood vessels, as compared to the control. The results of qRT-PCR, western blotting, and immunohistochemistry confirmed a reduced expression of VEGFR2 and WNT5A in the day 3 regenerating blastema of geraniol-treated worms, as compared to the control. We conclude that geraniol acts as a potent natural inhibitor of angiogenesis, thereby retarding the regeneration process in earthworms. In addition, for studying angiogenesis and screening effective angiogenesis inhibitors as drug candidates, the earthworm is an ambient animal model system.
Topics: Animals; Oligochaeta; Immunohistochemistry
PubMed: 37468693
DOI: 10.1007/s11626-023-00782-2 -
Biology of Reproduction Jun 2022The syncytial groups of germ cells (germ-line cysts) forming in ovaries of clitellate annelids are an attractive model to study mitochondrial stage-specific changes....
The syncytial groups of germ cells (germ-line cysts) forming in ovaries of clitellate annelids are an attractive model to study mitochondrial stage-specific changes. Using transmission electron microscopy, serial block-face scanning electron microscopy, and fluorescent microscopy, we analyzed the mitochondria distribution and morphology and the state of membrane potential in female cysts in Enchytraeus albidus. We visualized in 3D at the ultrastructural level mitochondria in cysts at successive stages: 2-celled, 4-celled, 16-celled cysts, and cyst in advanced oogenesis. We found that mitochondria form extensive aggregates-they are fused and connected into large and branched mitochondrial networks. The most extensive networks are formed with up to 10 000 fused mitochondria, whereas individual organelles represent up to 2% of the total mitochondrial volume. We classify such a morphology of mitochondria as a dynamic hyperfusion state and suggest that this can maintain their high activity and intensify the process of cellular respiration within the syncytial cysts. We found some individual mitochondria undergoing degradation, which implies that damaged mitochondria are removed from networks for their final elimination. As growing oocytes were shown to possess less active mitochondria than the nurse cells, the high activity of mitochondria in the nurse cells and their dynamic hyperfusion state are attributed to serve the needs of the growing oocyte. In addition, we measured by calorimetry the total antioxidant capacity of germ-line cysts in comparison with somatic tissue, and it suggests that antioxidative defense systems, together with mitochondrial networks, can effectively protect germ-line mitochondria from damage.
Topics: Animals; Annelida; Female; Mitochondria; Oocytes; Oogenesis; Ovary
PubMed: 35156116
DOI: 10.1093/biolre/ioac035 -
Evolution & Development Nov 2020In the animal kingdom, behavioral traits encompass a broad spectrum of biological phenotypes that have critical roles in adaptive evolution, but an EvoDevo approach has... (Review)
Review
In the animal kingdom, behavioral traits encompass a broad spectrum of biological phenotypes that have critical roles in adaptive evolution, but an EvoDevo approach has not been broadly used to study behavior evolution. Here, we propose that, by integrating two leech model systems, each of which has already attained some success in its respective field, it is possible to take on behavioral traits with an EvoDevo approach. We first identify the developmental changes that may theoretically lead to behavioral evolution and explain why an EvoDevo study of behavior is challenging. Next, we discuss the pros and cons of the two leech model species, Hirudo, a classic model for invertebrate neurobiology, and Helobdella, an emerging model for clitellate developmental biology, as models for behavioral EvoDevo research. Given the limitations of each leech system, neither is particularly strong for behavioral EvoDevo. However, the two leech systems are complementary in their technical accessibilities, and they do exhibit some behavioral similarities and differences. By studying them in parallel and together with additional leech species such as Haementeria, it is possible to explore the different levels of behavioral development and evolution.
Topics: Animals; Behavior, Animal; Biological Evolution; Leeches; Models, Animal; Species Specificity
PubMed: 33226195
DOI: 10.1111/ede.12358 -
Proceedings. Biological Sciences Feb 2023The principal animal lineages (phyla) diverged in the Cambrian, but most diversity at lower taxonomic ranks arose more gradually over the subsequent 500 Myr. Annelid...
The principal animal lineages (phyla) diverged in the Cambrian, but most diversity at lower taxonomic ranks arose more gradually over the subsequent 500 Myr. Annelid worms seem to exemplify this pattern, based on molecular analyses and the fossil record: Cambrian Burgess Shale-type deposits host a single, early-diverging crown-group annelid alongside a morphologically and taxonomically conservative stem group; the polychaete sub-classes diverge in the Ordovician; and many orders and families are first documented in Carboniferous Lagerstätten. Fifteen new fossils of the 'phoronid' from the early Cambrian Chengjiang Lagerstätte challenge this picture. A chaetal cephalic cage surrounds a retractile head with branchial plates, affiliating with the derived polychaete families 'Flabelligeridae' and Acrocirridae. Unless this similarity represents profound convergent evolution, this relationship would pull back the origin of the nested crown groups of Cirratuliformia, Sedentaria and Pleistoannelida by tens of millions of years-indicating a dramatic unseen origin of modern annelid diversity in the heat of the Cambrian 'explosion'.
Topics: Animals; Annelida; Polychaeta; Estrus; Fossils; Hot Temperature
PubMed: 36722078
DOI: 10.1098/rspb.2022.2014 -
Zootaxa Sep 2021The purpose of our contribution is to propose a robust and practical order-level classification of the families of Oligochaeta, that is, non-leech Clitellata. The order...
The purpose of our contribution is to propose a robust and practical order-level classification of the families of Oligochaeta, that is, non-leech Clitellata. The order level is mandatory in Linnaean rank-based classification and is also required in many internet-based biodiversity databases. However, it has received little attention in oligochaete systematics, and the few available order-level classifications of Oligochaeta no longer represent phylogenetic relationships adequately. Our proposal is based on corroborated molecular phylogenetic evidence and takes as benchmarks class level for Clitellata, subclass level for Oligochaeta and Hirudinea, and order level for Crassiclitellata, the monophylum that includes most of the earthworm taxa. As a result, eleven orders are proposed: Alluroidida Timm Martin, 2015; Capilloventrida Timm, n. ordo; Crassiclitellata Jamieson, 1988; Enchytraeida Kasprzak, 1984; Haplotaxida Brinkhurst Jamieson, 1971; Lumbriculida Brinkhurst Jamieson, 1971; Moniligastrida Brinkhurst Jamieson, 1971; Narapida Timm, n. ordo; Parvidrilida Timm, n. ordo; Randiellida Jamieson, 1988; Tubificida Jamieson, 1978. This order-level classification is robust and easily adaptable to future insights into phylogenetic relationships.
Topics: Animals; Biodiversity; Leeches; Oligochaeta; Phylogeny
PubMed: 34811021
DOI: 10.11646/zootaxa.5040.4.9 -
Proceedings. Biological Sciences May 2021The preservation of animal behaviour in the fossil record is exceedingly rare, but can lead to unique macroecological and macroevolutionary insights, especially...
The preservation of animal behaviour in the fossil record is exceedingly rare, but can lead to unique macroecological and macroevolutionary insights, especially regarding early representatives of major animal clades. We describe a new complex ecological relationship from the middle Cambrian Burgess Shale (Raymond Quarry, Canada). More than 30 organic tubes were recorded with multiple enteropneust and polychaete worms preserved within them. Based on the tubicolous nature of fossil enteropneusts, we suggest that they were the tube builders while the co-preserved polychaetes were commensals. These findings mark, to our knowledge, the first record of commensalism within Annelida and Hemichordata in the entire fossil record. The finding of multiple enteropneusts sharing common tubes suggests that either the tubes represent reproductive structures built by larger adults, and the enteropneusts commonly preserved within are juveniles, or these enteropneusts were living as a pseudo-colony without obligate attachment to each other, and the tube was built collaboratively. While neither hypothesis can be ruled out, gregarious behaviour was clearly an early trait of both hemichordates and annelids. Further, commensal symbioses in the Cambrian may be more common than currently recognized.
Topics: Animals; Annelida; Biological Evolution; Canada; Fossils; Phylogeny; Symbiosis
PubMed: 34034516
DOI: 10.1098/rspb.2021.0061