Polychaete Research Articles

Infestation of wild bay scallops Argopecten irradians on Nantucket Island by the shell-boring polychaete Polydora neocaeca.

Shell-boring polychaete worms can severely impact shellfish aquaculture by reducing growth rates and compromising tissue quality of their molluscan hosts. In this study we report the first known instance of shell-infestation of commercially important scallops on Nantucket Island by the cryptogenic polydorid Polydora neocaeca. Additional analyses indicate a high level of genetic connectivity between worms from Nantucket Island and the US mainland, forming a distinct haploclade which is genetically isolated from populations from South Africa and Japan. While transportation of infected seed could have introduced the worm to Nantucket, limited sampling and the paucity of sequence data available makes it impossible to definitely determine its origins.

Isolation and Identification of Hydrocarbon-Degrading Bacteria from Polychaete Marphysa moribidii

Marine contamination caused by anthropogenic activities has side effects and causes severe contamination to the environment. Polychaetes are benthic organisms that live in the sediment and can be a good indicator of sediment contamination by organic compounds. In this study, bacterial strains were isolated and identified from the gut of polychaete worm Marphysa moribidii and the potential of the bacteria was evaluated to degrade hydrocarbon compounds. The isolated bacteria were primary and secondary screened on Minimal Salt Media (MSM) agar supplemented with 1% v/v of diesel oil. Diesel degradation analysis was performed by inoculating potential bacterium into MSM broth with 1% v/v diesel oil and incubated at 37 oC for 20 days. Diesel degradation percentage was analyzed using the gravimetric method, while the bacteria cell densities were measured using the standard plate count method. Then, the selected isolates were identified based on their morphological characteristics and 16S rDNA sequences. As a result, two bacteria isolates coded as Isolate 6 and Isolate 8 were able to degrade diesel oil up to 52.29% and 39.24% after 20 days of incubation. The 16S rDNA sequence analysis revealed that it was identified as Bacillus sp. strain UMTFA1 (RB) and Staphylococcus kloosii strain UMTFA2 (RS). Our result showed that these strains have the potential in oil-degrading processes, which will provide new insight into bioremediation process and decrease environmental pollution in soil and water contaminated with hydrocarbons.

New records for associations between peritrich protozoan ciliates (Ciliophora, Sessilida) and polychaete worms (Annelida) from off the southeastern coast of India.

We report herein three epibiotic associations between peritrich ciliate protozoans and polychaete worms, as observed in Tamilnadu, southeastern coast of India. Epibiont ciliates Epistylis sp.1 were found all over the integument of individuals of the terebellid polychaete Terebella sp., collected from Vellar estuary. Epistylis sp.2 ciliates were observed attached to Namalycastis abiuma polychaetes, on both sides of parapodia. Cothurnia sp. ciliates were found on anterior most paleae and hooks of Sabellaria sp. polychaetes, both latter associations from material from the Uppanar estuary. Those epibiont/basibiont associations are all new to science and discussed herein, together with a review on the previous reports of epibiont ciliate protozoans in Indian waters.

Experiments in sandscaping: Liminal entanglements on the Norfolk and South Holland Coast

This hybrid creative-critical article explores how new ways of living beyond the current environmental crisis are forged on two sandscaping schemes that have been constructed as new experimental measures against coastal erosion. The Zandmotor, created in 2011, is an artificial peninsula built out of sand on the coast of South Holland. The success of this project inspired a similar sandscaping scheme at Bacton on the coast of Norfolk, constructed in 2019. The strange liminal landscapes that are the result of these projects are not just symbols of adaptive, nature-based water management in times of rising sea levels, they also become time machines, making fossils of different times emerge out of the sand taken from the seabed of the North Sea. In addition, the sandscapes are symbols of the artificialization of the coastal landscape, given the fact that sand suppletions disrupt not only life on the beach, but also destroy much bottom-dwelling life on the seabed from which the sand is harvested. However, these unique liminal landscapes between land and sea also create new ecological opportunities. At the Zandmotor, for example, rare bristle worms and Baltic clams have made their unexpected appearance. Moreover, the sandscape invites people not just to look for fossilized mammoth teeth, but also inspires them to create sense-altering art projects specifically adapted to the unique conditions in the area. In this article, I trace these various significances of both sandscaping schemes and argue that they cannot be reduced to any of these different meanings. Instead, I describe the Zandmotor as an example of Donna Haraway’s idea of ‘staying with the trouble’ (: 4) and Anna Lowenhaupt Tsing’s concept of ‘contaminated diversity’ (: 30). For although enormous amounts of animal and plant life have been destroyed for the creation of the Zandmotor, this does not discredit the fact that this new liminal environment has opened up new ecological opportunities for multispecies flourishing, creating unexpected combinations of landscapes and creatures. These new combinations inspire a shift in thinking about coastal environments and present new ways of living that may emerge beyond the current environmental crisis.

Food-web modification in the eastern Gulf of Finland after invasion of Marenzelleria arctia (Spionidae, Polychaeta)

The paucity of data on non-indigenous marine species is a particular challenge for understanding the ecology of invasions and prioritising conservation and research efforts in marine ecosystems. Marenzelleria spp. are amongst the most successful non-native benthic species in the Baltic Sea during recent decades. We used stable isotope analysis (SIA) to test the hypothesis that the dominance of polychaete worm Marenzelleria arctia in the zoobenthos of the Neva Estuary after its invasion in the late 2000s is related to the position of this species in the benthic food webs. The trend towards a gradual decrease in the biomass of Marenzelleria worms was observed during 2014–2020, probably due to significant negative relationships between the biomass of oligochaetes and polychaetes, both of which, according to SIA, primarily use allochthonous organic carbon for their production. The biomass of benthic crustaceans practically did not change and remained very low. The SIA showed that, in contrast to the native crustacean Monoporeia affinis, polychates are practically not consumed either by the main invertebrate predator Saduria entomon, which preys on M. affinis, oligochaetes and larvae of chironomids or by benthivorous fish that prefer native benthic crustaceans. A hypothetical model for the position and functional role of M. arctia in the bottom food web is presented and discussed. According the model, the invasion of M. arctia has created an offshoot food chain in the Estuary food webs. The former dominant food webs, associated with native crustaceans, are now poorly developed. The lack of top-down control obviously contributes to the significant development of the Marenzelleria food chain, which, unlike native food chains, does not provide energy transfer from autochthonous and allochthonous organic matter to the upper trophic levels. The study showed that an alien species, without displacing native species, can significantly change the structure of food webs, creating blind offshoots of the food chain.

Tube dwelling gastropod an indicator of coral reef status at the tropical reef of Palk Bay region, southeast coast of India

Porites coral colonies at Olaikuda reef, Palk Bay region were observed with pink spot and covered with mucus. Close examination of these spots revealed the presence of polychaete tubeworm and vermitid snail. The polychaete worm made aberrant growth with pink spot and this would change the growth pattern or morphology of coral colonies. In addition to that, mucus produced by vermetid snail stressed the corals in the Palk Bay region by covering the corals with their sediment trapped mucus. This is the first report of stresses imposed by coral associates on coral colonies from the Indian waters. The presence of tube dwelling vermetid snail, the stressor factors could be an indication to understand the health status of coral reefs.

Behavioral traits and territoriality in the symbiotic scaleworm Ophthalmonoe pettiboneae

Among marine invertebrates, polychaete worms form symbiotic associations showing a wide variety of host use patterns. Most commonly, they live solitary on hosts, likely resulting from territorial behavior, yet little is known of the precise nature of the involved interactions. Based on field and laboratory observations, we described the symbiotic association between Ophthalmonoe pettibonae and Chaetopterus cf. appendiculatus from Nhatrang Bay (Vietnam). Then, by experimentally manipulating the competitor-to-resource ratio, we analyzed symbiont behavior and we assessed whether the 1:1 uniform distribution observed in nature could be driven by agonistic territorial behavior. Hosts and symbiont populations had low densities, lacked size relationships and showed higher prevalence when denser. Symbiont behavior included territoriality, expressed through conspecific recognition and intraspecific aggressive interactions (pursuit and escaping, hiding, choosing position, aggressive fighting, and targeting a specific bite zone). Our experiments proved that territoriality led to host monopolization by a single symbiont, provided the first empirical evidence that symbiont body injuries were caused during territorial contests, and allowed us to first suggest that a marine symbiotic invertebrate may control a territory extending beyond its host, even including neighboring hosts. Overall, this is the first report of such a complex symbiotic behavior for an annelid polychaete.

Viable Putative Vibrio vulnificus and parahaemolyticus in the Pensacola and Perdido Bays: Water Column, Sediments, and Invertebrate Biofilms

Vibriosis is the general term for human illnesses caused by infection of pathogenicVibriospecies.Vibrio vulnificus(Vv) andparahaemolyticus(Vp) are two problematic waterborne pathogens that have yet to be enumerated in northwest Florida coastal Gulf of Mexico estuaries. In this regionally novel study, we surveyed 43 locations in two subtropical estuarine systems, Perdido Bay and Pensacola Bay, over seven dates in winter 2020. Sampling included three substrate types: surface waters, sediments, and invertebrate biofilms. We determined baseline abundances of presumptive viableVvandVpappearing as colonies on CHROMagar (Vv, blue;Vp, purple).Vvwas detected in 37 out of 43 water samples, with maximum levels of 3,556 CFU/mL.Vpwas only detected in 15 water samples, with a maximum concentration of 8,919 CFU/mL. Sediments containedVvin all but one sample, with concentrations ranging from 121 to 607,222 CFU/mL. In contrast,Vpwere only detected in 33 sediment samples, where concentrations ranged from 28 to 77,333 CFU/mL. Opportunistically-sampled surface swabs (biofilms), collected from shells (either oyster or barnacle) and polychaete worms found in sediment samples, contained on average 7,735 and 1,490 CFU/mL ofVvandVp, respectively. Surface waterVvabundances covaried with bottom water pH, maximum prior cumulative wind speeds, and tidal coefficient on the day of sampling.Vpsurface water abundances negatively correlated with surface water salinity, surface water pH, and bottom water pH and positively correlated with total surface dissolved inorganic and total Kjeldahl nitrogen concentrations, and wind. Spatially, there was large variation inVibriodensities in surface waters; abundances of both species were strongly correlated with wind, suggesting resuspension was important. Sedimentary abundances of both putativeVvandVpshared a correlation with one parameter: salinity stratification. Due to the length of this study, temperature was not considered a major factor. This short-term (1 month) study was designed not to enumerate pathogenicVvorVp, but rather to establish the first winter baseline ofVibrioabundances for this region. Determination of these baseline winter cultivable putativeVibrioabundances will be valuable in predicting relative risk factors in each waterbody of interest.

Jaws of Platynereis dumerilii: Miniature Biogenic Structures with Hardness Properties Similar to Those of Crystalline Metals

Nanoindentation, laser ablation inductively coupled plasma mass spectroscopy and weighing ion-spiked organic matrix standards revealed structure-property relations in the microscopic jaw structures of a cosmopolitan bristle worm, Platynereis dumerilii. Hardness and elasticity values in the jaws’ tip region, exceeding those in the center region, can be traced back to more metal and halogen ions built into the structural protein matrix. Still, structure size appears as an even more relevant factor governing the hardness values measured on bristle worm jaws across the genera Platynereis, Glycera and Nereis. The square of the hardness scales with the inverse of the indentation depth, indicating a Nix-Gao size effect as known for crystalline metals. The limit hardness for the indentation depth going to infinity, amounting to 0.53 GPa, appears to be an invariant material property of the ion-spiked structural proteins likely used by all types of bristle worms. Such a metal-like biogenic material is a major source of bio-inspiration.

Expression profile of a novel glutathione S-transferase gene in the marine polychaete Perinereis aibuhitensis in short-term responses to phenanthrene, fluoranthene, and benzo[α]pyrene

Polychaete worms can eliminate polycyclic aromatic hydrocarbons (PAHs) in environments through a mechanism that increases their water solubility. This detoxification starts with cytochrome P450 enzymes (CYPs) and then with glutathione S-transferases (GSTs). Here, a novel GST gene was identified and characterized from the widespread polychaete Perinereis aibuhitensis. The full-length cDNA of GST is 1544 bp and encodes 256 amino acids, belonging to the omega class. Gene expression patterns in P. aibuhitensis showed that its transcriptional level was positively correlated with the concentration of benzo[α]pyrene (0.5, 2, 4, and 8 μg/L) exposure but was negatively correlated with a PAH benzene ring after it was exposed to the same mass concentrations of fluoranthene (3.2 μg/L), phenanthrene (2.9 μg/L), and benzo[α]pyrene (4.0 μg/L) during the 14-day experimentation. These findings indicate that omega GST may play an important role in the phase II detoxification of PAHs in polychaete worms, and the persistence and bioavailability of PAHs may depend on benzene rings.

Symbiosis in the Cambrian: enteropneust tubes from the Burgess Shale co-inhabited by commensal polychaetes.

The in situ 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.

Structural and Functional Characterization of the FGF Signaling Pathway in Regeneration of the Polychaete Worm Alitta virens (Annelida, Errantia).

Epimorphic regeneration of lost body segments is a widespread phenomenon across annelids. However, the molecular inducers of the cell sources for this reparative morphogenesis have not been identified. In this study, we focused on the role of fibroblast growth factor (FGF) signaling in the posterior regeneration of Alitta virens. For the first time, we showed an early activation of FGF ligands and receptor expression in an annelid regenerating after amputation. The expression patterns indicate that the entire regenerative bud is competent to FGFs, whose activity precedes the initiation of cell proliferation. The critical requirement of FGF signaling, especially at early stages, is also supported by inhibitor treatments followed by proliferation assay, demonstrating that induction of blastemal cells depends on FGFs. Our results show that FGF signaling pathway is a key player in regenerative response, while the FGF-positive wound epithelium, ventral nerve cord and some mesodermal cells around the gut could be the inducing tissues. This mechanism resembles reparative regeneration of vertebrate appendages suggesting such a response to the injury may be ancestral for all bilaterians.

The first record of the genus Lamellibrachia (Siboglinidae) tubeworm along with associated organisms in a chemosynthetic ecosystem from the Indian Ocean: A report from the Cauvery–Mannar Basin

Here, we report for the first time, the genus Lamellibrachia tubeworm and associated chemosynthetic ecosystem from a cold-seep site in the Indian Ocean. The discovery of cold-seep was made off the Cauvery–Mannar Basin onboard ORV Sindhu Sadhana (SSD-070; 13th to 22nd February 2020). The chemosymbiont bearing polychaete worm is also associated with squat lobsters (Munidposis sp.) and Gastropoda belonging to the family Buccinidae. Relict shells of chemosynthetic Calyptogena clams are ubiquitous at the seep sites. The Lamellibrachia tubes were found to be firmly anchored into the authigenic carbonate crusts. The authigenic carbonate crusts (chemoherm) are packed with large Calyptogena shells (whole shell and fragments). Very high concentrations (3800–12900 µM) of hydrogen sulfide (H2S) in the interstitial waters (40 cmbsf) is responsible for the sustenance of chemosymbiont bearing tubeworms. The posterior end of the tube penetrates downwards into the H2S-rich zone. The high concentration of H2S at ~40 cmbsf is attributed to sulfate reduction via anaerobic oxidation of methane (AOM) pathway. Methane hydrate was observed within the faults/fractures in the sediments. The presence of ethane and propane along with methane in the headspace gases and δ13CCH4 values (–28.4 to –79.5‰ VPDB) suggest a contribution of deep-seated thermogenic methane.

Worming its way in-Polydora websteri (Annelida: Spionidae) increases the number of non-indigenous shell-boring polydorin pests of cultured molluscs in South Africa.

Polychaete worms of the Polydora-complex (commonly referred to as polydorins) include some of the most common pests of cultured molluscs. Modern culture of molluscs, particularly oysters, is associated with large-scale movement of stock which facilitates movement of polydorins either as "hitchhikers" on the transported molluscs or in the packaging. In 2009, a species identified as Polydora cf. ciliata Johnston, 1838 was reported from oysters in a culture facility in Port Elizabeth, South Africa. Since then, more specimens of this species were recorded on farmed oysters from Namibia, Kleinzee and Paternoster on the west coast of South Africa, but tentatively reidentified as Polydora cf. websteri Hartman in Loosanoff and Engle, 1943 based on morphology and limited genetic evidence. The main aim of this study is therefore to clarify the identity of these specimens by integrating morphological and genetic (mitochondrial COI, Cyt b and nuclear 18S rRNA) evidence. Specimens from South Africa match the morphology of the lectotype of P. websteri and are morphologically and genetically very similar to P. websteri from Australia, China, Japan, and the east, gulf and west coasts of the USA. This confirms the presence of P. websteri in South Africa, making this the second most widespread polydorin pest of aquaculture known. Understanding the full distribution range of the species will help to better understand its global route of invasion and consequently assist with preventing or at least minimising further spread. Polydora websteri increases the number of polydorin pests in South Africa to seven.

Development of indoor grow‐out practices for polychaete, Marphysa gravelyi with a note on biochemical composition

Polychaetes are multi-segmented worms, being exploited from the backwaters for shrimp hatcheries to be used as a maturation diet for shrimp broodstocks. Non-selective collection of polychaete worms poses a severe hazard to the ecosystem; hence, a grow-out system was developed for Marphysa gravelyi. Adult, M. gravelyi of 17 ± 0.4 cm length (n = 40) when reared in 100 L tanks, produced 1800 numbers of juveniles having an average length of 7 ± 0.2 cm with 80% survival in 4 months. The juveniles (7 ± 0.2 cm (n = 50) worms were reared again in 25 L tubs from which 45 adults (20 ± 0.3 cm) could be produced in 4 months with 90% survival. Juvenile, M. gravelyi (n = 500) when mass-reared in 1000 L FRP tanks by feeding Skeletonema costatum (106​ CFU/ml), produced 400 adults (20 ± 0.2 cm) as biomass with 80% survival in 4 months. The nutrient profile of adult M. gravelyi revealed protein, carbohydrate and lipid to be 33, 14 and 40 g % respectively. Crude M. gravelyi extract showed the highest bacterial inhibition on Staphylococcus aureus (18 ± 0.3 mm) and lowest on Bacillus subtilis (14 ± 0.2 mm). The present study revealed that growing polychaete worms in a controlled condition is advantageous, compared to collection of polychaete worms from wild which might seriously deplete their natural stocks, and cause physical disturbance of soil exposing heavy metals with the release of ammonia, and phosphorus compounds leading to eutrophication.

Trophic upgrading of long-chain polyunsaturated fatty acids by polychaetes: a stable isotope approach using Alitta virens

Polychaete worms are rich sources of polyunsaturated fatty acids (PUFA) and are increasingly incorporated into aquaculture broodstock diets. Conventionally, the build-up of PUFA in polychaetes was considered passive, with direct accumulation along the food web, originating with microalgae and other primary producers. However, it has been argued that polychaetes (and other multicellular eukaryotes) are capable of PUFA biosynthesis through the elongation and desaturation of precursor lipids. We further test this hypothesis in the ecologically and economically important nereid polychaete Alitta virens by adopting a stable isotope labelling approach. Worms were fed a 13C-1-palmitic acid (C16:0) enriched diet with the resulting isotopically enriched lipid products identified over a 7-day period. The data showed strong evidence of lipid elongation and desaturation, but with a high rate of PUFA turnover. A putative biosynthetic pathway is proposed, terminating with docosahexaenoic acid (DHA) via arachidonic (AA) and eicosapentaenoic acids (EPA) and involving a Δ8 desaturase.

ТРОФОЛОГИЯ ГРЕБНЕВИКА MNEMIOPSIS LEIDYI ПОСЛЕ НАТУРАЛИЗАЦИИ В ЭКОСИСТЕМЕ КАСПИЙСКОГО МОРЯ

Trophological studies of ctenophore Mnemiopsis leidyi conducted in the Caspian Sea more often included species at the later stage of development, as a result, juveniles, metamorphic larvae and larvae were ignored. Ctenophore is known to start feeding since the moment the larva emerges from the egg. Studying the availability of food resources and their size range allowed to trace a certain dependence in the diet of ctenophore, and to determine at which stage of development the jellylike organism in the population feeds most intensively. During the period of naturalization of invasion in the Caspian Sea (1998-2016) there has been registered an increasing number of species with an empty gastrovascular cavity (GVC) in the Mnemiopsis population. According to the analysis results obtained during the study period, the share of individuals with empty GVC 
 in the North Caspian increased to 77.8%, which is associated not with the climatic or hydrological factors, as in 2015 and 2016, but with the availability of food items and internal competition for food resources. There has been found the diversity of the items making food stuff of Mnemiopsis in nature. The main food component is mesozooplankton, as well as meroplankton (cirriped nauplii, larvae of polychaete worms). In food requirements ctenophore does not show selectivity of food resources, the basis of its food make the most available forms of zooplankters.

Small-molecule mimicry hunting strategy in the imperial cone snail, Conus imperialis.

Venomous animals hunt using bioactive peptides, but relatively little is known about venom small molecules and the resulting complex hunting behaviors. Here, we explored the specialized metabolites from the venom of the worm-hunting cone snail, Conus imperialis Using the model polychaete worm Platynereis dumerilii, we demonstrate that C. imperialis venom contains small molecules that mimic natural polychaete mating pheromones, evoking the mating phenotype in worms. The specialized metabolites from different cone snails are species-specific and structurally diverse, suggesting that the cones may adopt many different prey-hunting strategies enabled by small molecules. Predators sometimes attract prey using the prey's own pheromones, in a strategy known as aggressive mimicry. Instead, C. imperialis uses metabolically stable mimics of those pheromones, indicating that, in biological mimicry, even the molecules themselves may be disguised, providing a twist on fake news in chemical ecology.

A comparative study on the nutritional value of three Polychaete species used in Shrimp Aquaculture

The potential use of polychaete worms are as a dietary source of protein, lipid, amino acids, and vitamins for aquaculture species and also used for alternative feeds of fish meal and fish oils. Many recent studies have been documented the nutritional benefits of polychaetes for aquaculture species, for their satisfactory food intake and reproductive performance in brood stock.Most of the polychaetes were used in hatcheries are wild caught. The commercial harvesting of polychaetes may leads to the disturbance in the benthic community and the ecosystem and also may leads to the depleting population in the ecosystem. Further the development of polychaete culture is therefore of economic importance beyond that the associated bait supply industry which is acted as the initial catalyst for this development. Hence, the present study has been made with three different polychaete species, to assess the nutritional value of the three species, one from imported (Nereis virens) and two locally available species (Perenereis cultrifera and Glycera sp) for commercial uses of the shrimp aquaculture industry.Key words : Polychaete worms, Perenereis species, fatty acids. amino acids, Minerals.

Understanding the feeding ecology of Cynoglossus joyneri in Haizhou Bay based on stable isotope analysis.

We analyzed the feeding ecology of Cynoglossus joyneri by carbon and nitrogen stable isotope analysis based on the samples collected from the bottom trawl surveys during spring and autumn of 2018 in Haizhou Bay, China. The results showed that the δ13C and δ15N values of C. joyneri ranged from -20.75‰ to -15.91‰ and from 5.98‰ to 12.02‰, respectively. The mean values of the δ13C and δ15N were (-17.79±1.00)‰ and (9.37±1.33)‰, respectively. There was a significantly negative correlation between the δ13C values and standard length and a positive correlation between the δ15N values and standard length. The mean trophic level of C. joyneri was (3.43±0.97). There was a significantly positive correlation between the trophic level and standard length. The dominant prey groups of C. joyneri were fish, crabs, shrimps, mollusca, polychaeta, plankton and particle organic matter (POM). The trophic contribution of shrimps was the highest among these prey groups. The trophic contribution of fish, crabs and shrimps was higher in autumn than those in spring. This study would help to understand the role of C. joyneri in the material cycling and energy flow in Haizhou Bay ecosystem, and provide scientific basis for the protection and rational utilization of this species.