Polychaete Research Articles

Comparison of methods: Micro-CT visualization method and epoxy cast-embedding reveal hidden details of bioerosion in the tube walls of Cretaceous polychaete worms

Comparison of methods: Micro-CT visualization method and epoxy cast-embedding reveal hidden details of bioerosion in the tube walls of Cretaceous polychaete worms

Pliocene bivalves (Pteriomorphia) of Algiers Sahel (Algeria): Systematics and palaeoecology.

A hundred specimens of pteriomorph bivalves were collected from the marine deposits of the marly-sandy formations of Algiers Sahel, which correspond to transitional facies between the Piacenzian deep marly deposits and the Astian molassic deposits. They are herein analysed from a systematic, taphonomic, palaeoecological and paleoenvironmental point of view. The preliminary inventory list consists of 27 species belonging to eight families: Arcidae, Nuculidae, Glycymeridae, Spondylidae, Pectinidae, Plicatulidae, Gryphaeidae, and Ostreidae. Two sedimentary units with different bivalve biodiversity are recognized: the first: a shallow infralittoral unit characterised by large Flabellipecten alessii, Aequipecten angelonii, Ostrea lamellosa and O. edulis; the second: A deeper unit of circalittoral environment mainly includes Amusium cristatum. These bivalve shells display sclerobiont traces. Bioerosion traces are mostly assignable to clionid sponges (Entobia isp.), polychaete worms (Maeandropolydora isp. and Caulostrepsis isp.), bivalves (Gastrochaenolites isp.) and predatory gastropods (Oichnus isp.). Identified encrusting organisms are juvenile oyster shells, cirripedes, polychaete worms (serpulids), and indeterminate bryozoans. Analysis of boring and encrusting traces indicate a progressive environmental change from a relative high energy setting to a lower energy and deeper water setting, and correspond to a shallow sea with well-oxygenated waters.

The oxidative cost of competing for egg fertilization exceeds the cost of egg production.

Measuring reproductive costs is crucial to understanding sexual conflict and its evolutionary outcomes. Sexual conflict is thought to originate from anisogamy-the size difference between male and female gametes; if sperm are tiny and not produced in vastly greater numbers than eggs, at any mating females' gametic investment is larger than that of males. Testing this prediction has proven difficult, especially because males and females differ in many more traits than just gamete size. We overcame this difficulty by exposing simultaneously hermaphroditic polychaete worms Ophryotrocha diadema (two sexual functions in the same body) to two social conditions, pairs, and groups >2, where hermaphrodites invest either relatively more in the female function or relatively more in the male function, respectively. Then we measured four markers of cellular oxidative status, a physiological mediator of life-history strategies. Less female-biased hermaphrodites produced fewer eggs but, unexpectedly, had lower levels of antioxidant protection than more female-biased hermaphrodites, which produced more eggs. Male-biased hermaphrodites compete for mating as males (hermaphrodites in pairs do not) suggesting that in the short-term male competition might be costlier than egg production in terms of regulation of oxidative status. These results highlight the need of including behavioral traits, namely competition over egg fertilization, in the measures of reproductive costs.

Fossil molluscan shells and polychaeta tubes from the Yudinovo and Eliseevichi Upper Paleolithic settlements of: taxonomy, possibilities of palaeogeographical and archaeological reconstructions

In the article we presents the results of the study of the mollusks and polychaetes remains collected during more than 80 years of excavations of the Yudinovo and Eliseevichi 1 Upper Paleolithic settlements (Dnieper region). The Yudinovo and Eliseevichi 1 sites, located on the right bank of the Sudost’ River 45 km from each other are two large settlements with mammoth bone dwellings. The sites belonging to different cultural traditions have been excavated over a large area. The analysis of 238 fossil invertebrate samples revealed the presence of mollusks shells from 33 genera and calcareous tubes of at least 1 genus of polychaete worms. Overall 26 taxa have been reliably determined at the species level. Among them are representatives of marine, brackish-water, freshwater and terrestrial animals — mainly gastropods (20 species), less frequently bivalves (5 species) mollusks, and one species of polychaetes. The shells of non local genera used by the Yudinovos settlement inhabitants as decoration include Nucula, Cerastoderma, Steromphala, Tritia, Cerithium and Melarhaphe. These shells were most likely brought to the settlement from the northwestern coast of Black Sea. The material from the Eliseevichi 1 settlement consists mainly of processed fragments of calcareous polychaet’s tubes, most likely originating from Cretaceous deposits in the Podeseniye region. The Eliseevichi shell set differs sharply from the Yudinovo one consisting of isolated shells of Theodoxus fluviatilis, whose origin is difficult to determine. They could be either collected in nearby rivers contemporary to this settlement and or they could be associated with culturally and temporally different horizon of the cultural layer of the Eliseevichi 1 settlement.

Boring in vein: a new direction in ichnological research

Unusual conjunctions of geological phenomena in the modern environment may alert us to their potential presence in the rock record. Two erratics of Carboniferous limestone from the beach at Cleveleys on the Irish Sea coast, Lancashire, northern England bored by sponges and polychaete worms, are suggestive of potential occurrences of borings in ancient conglomerates. Such distinctive patterns of boring, commoner in crystalline veins than in limestone, are certainly unfamiliar. But borers are well‐known for invading crystalline organic substrates, such as belemnites and oysters.

Seascape genetics in a polychaete worm: Disentangling the roles of a biogeographic barrier and environmental factors

AbstractAimSeascape genomic studies aim to understand how environmental variables shape species diversity through genotype–environment associations. Identifying these effects on lecithotrophic larval species that live in intertidal zones is particularly challenging because they are subject to environmental heterogeneity and anthropogenic events. Here, we evaluate how biotic and abiotic features in the Southwest Atlantic littoral zone can affect a high dispersal species' present and historical demography.LocationBrazilian coast, covering more than 3000 km.Taxon Perinereis ponteni. MethodsWe investigated population genetic diversity, connectivity and past dynamics using 23,300 single‐nucleotide polymorphisms (SNPs) generated using genotyping by sequencing. We tested whether environmental abiotic variables could explain the variance found in genotype frequencies using isolation‐by‐environment (IBE) and landscape association approaches. These data, combined with palaeodistribution simulations and oceanic circulation modelling, were used to infer species demographic history and connectivity patterns.ResultsAlong with high levels of connectivity detected, we found a genetic boundary in the southeastern region of Brazil around Cabo Frio (Rio de Janeiro), and a cline trend for some loci. The palaeodistribution simulations reveal a spatial refuge in the southeast during the Last Glacial Maximum (21 kya), with the expansion of the northern region. We identified 1421 SNPs with frequencies associated with eight environmental variables, most of which were related to temperature—the main environmental factor determining IBE.Main ConclusionsPerinereis ponteni, a polychaete with high gene flow capability responds to biogeographic barriers, highlighting the importance of biotic and abiotic factors in shaping population connectivity. Furthermore, the effect of temperature indicates that future climate change and ocean warming can hugely impact this species.

Body colourations affect predation risk from fish in fiddler crabs

Many animals show conspicuous colour patterns that inform potential predators about their unprofitability due to their toxicity or unpalatability (aposematism). However, no systematic work has evaluated the colouration of crabs in terms of aposematism, even though many species exhibit conspicuous colouration. We conducted a laboratory study to compare predation risk from a fish predator, the barred mudskipper (Periophthalmus argentilineatus), in two sympatric fiddler crab species with different body colour patterns: Austruca perplexa with brownish-white colourations and Paraleptuca crassipes with red-and-black colour patterns. Fiddler crabs and mudskippers are active on tidal flats during low tides. A predation trial by stocking one crab and one mudskipper in a test arena was repeated five times for each species–sex combination. The animal behaviour was video recorded for 24 h, and crabs were confirmed to be alive or dead after 72 h. A. perplexa females were most vulnerable to predation from mudskippers. The attack intensity from mudskippers was stronger during the nighttime than daytime against P. crassipes females and males and A. perplexa males, suggesting that mudskippers may avoid them by visually detecting the body colouration in P. crassipes and the body structure in males of both species (i.e. a large weaponry claw) during the daytime. Mudskippers eventually preyed on and consumed some individuals in both species–sexes. Mudskippers are known to shift their main food components from small crustaceans through polychaete worms to crabs, such as fiddler crabs, and unpalatable polychaete worms tend to be brightly coloured. We suggest that the red colouration of P. crassipes may be incidental mimicry of the unpalatable red/orange-coloured polychaete worms that mudskippers might have learned to avoid.

A Cryptochrome adopts distinct moon- and sunlight states and functions as sun- versus moonlight interpreter in monthly oscillator entrainment

The moon’s monthly cycle synchronizes reproduction in countless marine organisms. The mass-spawning bristle worm Platynereis dumerilii uses an endogenous monthly oscillator set by full moon to phase reproduction to specific days. But how do organisms recognize specific moon phases? We uncover that the light receptor L-Cryptochrome (L-Cry) discriminates between different moonlight durations, as well as between sun- and moonlight. A biochemical characterization of purified L-Cry protein, exposed to naturalistic sun- or moonlight, reveals the formation of distinct sun- and moonlight states characterized by different photoreduction- and recovery kinetics of L-Cry’s co-factor Flavin Adenine Dinucleotide. In Platynereis, L-Cry’s sun- versus moonlight states correlate with distinct subcellular localizations, indicating different signaling. In contrast, r-Opsin1, the most abundant ocular opsin, is not required for monthly oscillator entrainment. Our work reveals a photo-ecological concept for natural light interpretation involving a “valence interpreter” that provides entraining photoreceptor(s) with light source and moon phase information.

Sex steroid profile during oocyte development and maturation in the intertidal worm Marphysa madrasi (Polychaeta: Eunicidae) from the east coast of India

Marphysa madrasi is a commercially valuable maturation diet in crustacean aquaculture. This study presents the first detailed investigation of oogenesis in the intertidal polychaete worm M. madrasi and reports the steroid profile during oocyte growth and development. Oogenesis is extraovarian type I, originating from coelomic epithelial cells, with four stages of development - primary growth, early vitellogenic, late vitellogenic, and maturation. The primary growth phase contains oogonial cells and previtellogenic oocyte clusters in the early, mid, and late stages of development form a dispersed ovary attached to blood vessels. The late previtellogenic oocytes detach from the ovary at the onset of vitellogenesis. The detached oocytes complete vitellogenesis and final maturation in the coelomic fluid as solitary free-floating cells without any connection with follicle cells. The worms display asynchronous reproduction with a heterogeneous population of developing oocytes. Steroid extracts from the polychaete homogenates in different stages of oogenesis were identified by HPLC and confirmed by LC-MS/MS. In M. madrasi, two vertebrate-type steroids, pregnenolone (P5) and 17α-hydroxyprogesterone (17-OHP) were detected and quantified. The P5 levels were low in immature worms but increased significantly by ∼ 8.3-fold in the previtellogenic stage and peaked during oocyte maturation. 17-OHP levels were low in immature worms but gradually increase as the oogenesis progress to the primary growth and early vitellogenic phase, with a significant increase (p < 0.001) during the late vitellogenic phase. Although an increase in the concentration of P5 and 17-OHP during vitellogenesis and maturation of oocytes points to a possible role in reproduction, the absence of other vertebrate-type steroids in the investigated polychaete signifies a plausible uptake of P5 and 17-OHP from the environment.

Utilizing Pyrolysis-Gas Chromatography/Mass Spectrometry for Monitoring and Analytical Characterization of Microplastics in Polychaete Worms.

Microplastics (the term for plastics at sizes of <5 mm) might be introduced into the environment from domestic or agricultural activities or from the breakdown of plastic pieces, particles, and debris that are bigger in size. Their presence in the aquatic environment has caused accumulation problems, as microplastics do not easily break down and can be digested by some aquatic organisms. This study was conducted to screen and monitor the level of microplastic pollution in polychaete worms using pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS). The study was conducted in Setiu Wetlands, Malaysia from November 2015 to January 2017 at five-month intervals and covered all monsoon changes. Results from physical and visual analyses indicated that a total number of 371.4 ± 20.2 items/g microplastics were retrieved from polychaete for all seasons, in which, the majority comprised transparent microplastics (49.87%), followed by brown with 138.3 ± 13.6 items/g (37.24%), 21.7 ± 1.9 items/g for blue (5.84%), and 12.9 ± 1.1 items/g for black (3.47%), while the remaining were green and grey-red colors. Statistical analysis using Kruskal–Wallis showed insignificant differences (p > 0.05) between the sampling station and period for the presence of a microplastics amount. Most of the microplastics were found in fiber form (81.5%), whereas the remaining comprised fragment (18.31%) and film (0.19%) forms. Further analysis with Py-GC/MS under a selective ion monitoring mode indicated that pyrolytic products and fragment ions for a variety of polymers, such as polyvinyl chloride, polypropylene, polyethylene, polyethylene terephthalate, polyamide, and polymethylmethacrylate, were detected. This study provides an insightful application of Py-GC/MS techniques for microplastics monitoring, especially when dealing with analytical amounts of samples.

Effect of Malathion on Protein Profile of a Polychaete Worm from Lake Burullus, Egypt.

Effect of Malathion on Protein Profile of a Polychaete Worm from Lake Burullus, Egypt.

A new alien polychaete species for the Mediterranean Sea: Glycera cinnamomea (Annelida: Glyceridae)

The present study reports the first occurrence of an alien glycerid polychaete worm, Glycera cinnamomea (Polychaeta: Glyceridae) in the Mediterranean Sea. Only one specimen of this species was collected on April 2021 on the shallow‒water sandy mud substratum (9m depth) in the western part of Mersin Bay, near Taşucu Turkey(in the Eastern Mediterranean Sea). This species is mainly characterized by having non–retractile branchiae with maximally five rami, emerging on the posterior side of the parapodia, and three types of proboscidial papillae. It is previously known from the Indo–Pacific areas and the Red Sea (Suez Bay). The species had been most probably introduced to the Mediterranean Sea via the Suez Canal (Lessepsian species) and have been unnoticed in the Levantine Sea so far. However, as the sampling area has one large international harbor (MersinHarbor), its introduction to the Mediterranean Sea via shipping cannot be ruled out. The morphological, ecological, and distributional features of this species are presented and discussed.

Below‐ground ecosystem engineers enhance biodiversity and function in a polluted ecosystem

Abstract Many important ecosystem functions are underpinned by below‐ground biodiversity and processes. Marine sediments, one of the most abundant habitats on earth, are essential to the mineralisation of organic matter. However, they are increasingly polluted by urban activities leading to the loss of biodiversity and the functions they provide. While traditional sediment remediation strategies are focussed on microbial and engineering solutions, we propose that the reintroduction of below‐ground ecosystem engineers (bioturbators) is important to rehabilitate polluted sediments and drive recovery of their functions in urban coastal ecosystems. We tested this notion by introducing bioturbators to nutrient polluted sediments to assess their survival, as well as their capacity to drive biodiversity and oxygenation and their potential to remediate nutrient pollution. Polychaete worms Diopatra aciculata and clams Katelysia sp. were added to mesocosms (ex‐situ), and the worms also added to experimental plots in‐situ. Potential for remediation was assessed with measures of nutrient content. All animals survived when introduced to polluted sediments and showed no evidence of sub‐lethal effects. Worms oxygenated sediments and reduced organic matter content by up to 50% in‐situ. The worms also drove shifts in the receiving communities at all locations and increased the number of taxa at one location. On the other hand, the effects of clams were variable, showing opposite effects in organic matter content at different sites and levels of pollution. Synthesis and applications. Global seafloor habitats are becoming increasingly degraded and novel strategies that combine biodiversity restoration with remediation are urgently needed to return function. Tube‐building bioturbators can stimulate nutrient processing in sediments proving multiple functional outcomes, but these effects are dependent on the receiving environment. In areas with medium levels of pollution, they can kick‐start recovery in a feedback loop whereby bioturbation increases oxygenation and nutrient remediation, shifting sediment biodiversity and contributing to further recovery. This can drive long‐term changes in sediment communities, particularly in urban areas where unvegetated sediments are conspicuous.

On the presence of a giant bristle worm (Eunice roussaei) IN NW Iberian Peninsula: Comments on its taxonomy and reproductive cycle

The presence of a giant “polychaete” annelid of the genus Eunice has been recently recorded in the Ría de Arousa (Galicia, NW Spain). Since Eunice spp. are highly appreciated as bait for recreational fishing in other regions of the world, representing a marine resource of high economic value, this finding may open up a new opportunity for the local bristle worm fishery. The present study aims to gain some insights into the biology of this largely unknown species, gathering information that may contribute to the sustainability and management of this potential fishery. Even though samples could not be collected on a monthly basis as initially planned, our results revealed some interesting features. First, as the taxonomic identity of giant specimens of the genus Eunice has been subject to debate, we used molecular techniques to confirm the identity of the species present in NW Spain. We also sequenced COI–5P in 9 specimens from Vrsar (Istria, Croatia), as well as in one specimen found in the facilities of the Aquarium Finisterrae of A Coruña (NW Spain) in 2015. COI–5P sequences (658 bp) revealed that Galician and Croatian individuals are conspecific and belong to the species Eunice roussaei, previously described in the Mediterranean Sea. Moreover, our data suggest a high haplotypic diversity (18 haplotypes were identified among the 20 sequences analyzed) but a low nucleotide diversity. Second, the observations on the 15 Galician specimens collected between October 2019 and September 2020 suggest that E. roussaei is a dioecious, broadcast spawner that reproduces by releasing free gametes into the water column in the autumn months of November/December. Oocytes maturated from January (mean oocyte size = 105.05 μm) to October (mean oocyte size = 202.02 μm), and oocyte size was positively correlated with water temperature (r = 0.746, p < 0.05), as well as with photoperiod (r = 0.268, p < 0.05).

The complete mitochondrial genome of Mesochaetopterus japonicus (Sedentaria: Chaetopteridae)

The benthic and tube-building polychaete worm Mesochaetopterus japonicus is abundantly present on the coast of the western Pacific. Here, we report the complete mitochondrial genome of M. japonicus, which is 19,326 bp in length and contains 13 protein-coding genes, 2 rRNA genes and 22 tRNA genes. All 37 genes are encoded on the heavy strand, and AT content is 70.17%. Phylogenetic analyses based on the M. japonicus mitogenome combined with previously published polychaete mitogenome data revealed that M. japonicus was closely related to Chaetopterus variopedatus and Phyllochaetopterus sp., all of which belong to Chaetopteridae. The mitochondrial genome of M. japonicus could provide useful molecular resources for further research on Polychaeta phylogeny and evolution.

18S rDNA amplicon sequence data (V1–V3) of the Palmyra Atoll National Wildlife Refuge, Central Pacific

To address the global biodiversity crisis, standardized data that are rapidly obtainable through minimally invasive means are needed for documenting change and informing conservation within threatened and diverse systems, such as coral reefs. In this data paper, we describe 18S rRNA gene amplicon data (V1–V3 region) generated from samples collected to begin characterizing coral reef eukaryotic community composition at the Palmyra Atoll National Wildlife Refuge in the Central Pacific Ocean. Sixteen samples were obtained across four sample types: sediments from two sieved fractions (100–500 μm, n = 3; 500 μm-2 mm, n = 3) and sessile material scrapings (n = 3) from Autonomous Reef Monitoring Structures (ARMS) sampled in 2015, as well as seawater from 2012 (n = 7). After filtering and contaminant removal, 3,861 Amplicon Sequence Variants (ASVs) were produced from 1,062,238 reads. The rarefaction curves demonstrated adequate sampling depth, and communities grouped by sample type. The dominant orders across samples were polychaete worms (Eunicida), demosponges (Poecilosclerida), and bryozoans (Cheilostomatida). The ten most common orders in terms of relative abundance comprised ~60% of all sequences and 23% of ASVs, and included reef-building crustose coralline algae (CCA; Corallinophycidae) and stony corals (Scleractinia), two taxa associated with healthy reefs. Highlighting the need for further study, ~21% of the ASVs were identified as uncultured, incertae sedis, or not assigned to phylum or order. This data paper presents the first 18S rDNA survey at Palmyra Atoll and serves as a baseline for biodiversity assessment, monitoring, and conservation of this remote and pristine ecosystem.

Life history and reproductive traits of the East Atlantic deep-sea quill worm Hyalinoecia robusta Southward, 1977 (Annelida: Onuphidae)

Polychaetes or bristle worms (Annelida) are one of the best represented invertebrate groups in marine environments worldwide. Although the reproductive biology and life histories of polychaetes from many marine and estuarine habitats are well documented, our knowledge of the reproduction and life cycles of deep-sea polychaetes is still far from comprehensive. Hyalinoeciinae, a subfamily of Onuphidae, one of the most dominant and successful tubicolous deep-sea polychaete families, are characterised by their peculiar lifestyle as free-living epibenthic species, as they protrude from their tubes in a caterpillar-like fashion known as epibenthic crawling. The reproductive biology, sexual strategies and developmental modes of Hyalinoecia spp. are largely unknown. We have studied quarterly samples of the East Atlantic deep-sea quill worm Hyalinoecia robusta Southward, 1977, collected during 2012–2013, from the adjacent slope of the Avilés submarine Canyons System (Bay of Biscay) at 1500 m depth. Here we report on the annual cycle, revealing that H. robusta is iteroparous, reproducing annually during a breeding season from early spring to summer. The performed histological study revealed that the species is a simultaneous hermaphrodite with a previous adolescent male phase. This is the first evidence of the occurrence of hermaphroditism in the subfamily Hyalinoeciinae. Mature sperm was of the ent-aquasperm type and was stored in modified nephridial chambers that develop into external papillae that may detach from the worm and act as spermatophores at the time of reproduction. In H. robusta, the egg fertilisation seems to occur within intersegmental dorsal openings of the worm body wall or inside the worm tube. This hypothesis is consistent with the finding of fertilised eggs and developing embryos attached to the body wall and/or inside the worm tube in some specimens. The herein reported H. robusta reproductive traits do not support their conspecificity with populations from outside North Atlantic Ocean. Thus, the name H. robusta may be hiding other deep-water Hyalinoecia species.

Standardising English and Afrikaans common names for polychaetes harvested as bait in South Africa

Polychaete worms are used widely as bait in South Africa, but common names are not used consistently among fishers or in the literature. This can have implications for conservation, since different polychaete species will not be equally vulnerable to exploitation, and uncertainties about the names of species make it difficult to monitor harvests to assess catch rates. This study develops a consensus view of English and Afrikaans common names for known bait species, building on names already used by fishers and in the literature. The greatest (but not complete) consensus in use of names among fishers and in the literature was for species in the families Arenicolidae, Eunicidae and Nereididae. However, most species are known by multiple common names, some common names are used for multiple species in different families, and the use of at least one name has changed. By applying principles like those used to develop scientific names, we propose a binomial naming system that includes a collective common name that applies to the family or genus, and which, for most species, is already used by fishers, as well as qualifying names that apply to the individual species. The qualifying names may refer to a morphological character that can be observed in the field, its distribution, ecology or the specific name. Research is needed to develop consensus names in isiXhosa.

Gut associated culturable bacterial community in intertidal polychaete worms (Annelida: Polychaeta), their characterization and implications in captive shrimp aquaculture

Polychaetes supplements play a crucial role in the dietary requirements of shrimps reared under captive culture. Due to their high demand, wild captured worms are used extensively as supplementary feed for the broodstocks. However, the gut microbiota composition of the polychaetes is rarely investigated. In the present study, the culturable fraction of gut microbiota of two native polychaete species, Marphysa madrasi and Namalycastis sp., that are currently used as live supplemental feed by shrimp brooders, were analysed. The culture-dependent technique yielded a total of 39 bacterial isolates, which grouped into 23 unique phylotypic clusters based on amplified ribosomal DNA restriction analysis (ARDRA) profiling. The 16S rRNA gene sequencing of these 23 gut isolates revealed bacterial communities with probiotic potential and a few shrimp and human pathogens. The gut-associated bacterial community is dominated by three bacterial phyla, the Firmicutes, Actinobacteria, and Proteobacteria, composed of 10 different genera. Moreover, there were differences in the bacterial communities between the two polychaetes investigated in this study. The Shannon, Simpson, Chao1 and Abundance-based Coverage Estimator (ACE) index revealed that M. madrasi have significantly higher species diversity and richness than Namalycastis sp. in the gut. Screening for hydrolytic enzyme production revealed several bacterial species with probiotic applications, such as Bacillus subtilis, B. licheniformis, B. pumilus, B. megaterium, and B. halotolerans. On the other hand, a few opportunistic human pathogens, such as B. cereus, Gordonia terrae, Microbacterium paraoxydans, Staphylococcus epidermidis, and Staphylococcus gallinarum, were also identified. Overall, the results of this study revealed that the bacterial assemblages associated with the gut of intertidal polychaete worms can serve as excellent probiotic candidates.

Identification of a novel CYP4V gene in the polychaete Perinereis aibuhitensis: transcriptional comparison with a CYP4B gene exposed to PAHs.

Polychaete worms can biotransform polycyclic aromatic hydrocarbons (PAHs) in environments, and the cytochrome P450 (CYP) enzyme plays an important role in this process. Herein, a novel cytochrome P450 gene was identified and characterized from the polychaete worm Perinereis aibuhitensis. The full-length cDNA, which is named CYP4V82, is 1709bp encoding a protein of 509 amino acids and has high similarity to CYP4V. The expression levels of CYP4V82 and CYP4BB4 (a CYP gene identified from P. aibuhitensis in a previous study, Chen et al. Mar Pollut Bull 64:1782-1788, 2012) exposure to various concentrations of benzo[a]pyrene (B[a]P) (0.5, 2, 4, and 8μg/L) and same mass concentrations of fluoranthene (Flu, 3.2μg/L), phenanthrene (Phe, 2.9μg/L), B[a]P (4.0μg/L) were detected to identify the function of the CYP4 family in P. aibuhitensis. Compared with CYP4BB4, CYP4V82 mRNA was minimally expressed on day 7 but highly sensitive on day 14. Notably, the expression levels of CYP4V82 and CYP4BB4 were relatively different in short-term responses to PAHs with different benzene rings of the same concentration. The expression of CYP4V82 in the B[a]P group was the highest, while that of CYP4BB4 in the Phe group was relatively higher than the two other groups. These findings suggest that PAHs are associated with the induction of CYP4V82 and CYP4BB4 expressions in P. aibuhitensis, which may have different efficiencies in the detoxification of PAHs.