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Understanding reproductive traits of invasive species and their modulation by different invaded habitats is crucial for monitoring invasive processes. The invasive ecosystem engineers (IEE) affect their habitat structure, generating cascading effects that may modulate their own or other species’ reproductive traits. In this study, we aim to evaluate the reproductive activity of a nonindigenous species (NIS), the amphipod Melita palmata, in a SW Atlantic coastal lagoon whose habitat structure has been modified by the IEE (reef builder) Ficopomatus enigmaticus. Experiments showed that: (1) the frequency of M. palmata mate pairings (reproductive rate) is higher in reefs built by the IEE than in the facies formed by sediment and valves in reef-free areas (namely sediment); (2) the ratio of mate pairings relative to receptive available females (mate access ratio) is higher in sediment; (3) higher density of M. palmata increases its reproductive rate in both habitats, and (4) lower M. palmata density and reduced habitat structure enhance the mate access ratio. Results suggest that M. palmata reproduction is either density- or habitat-dependent at higher or lower population densities, respectively. This reproductive plasticity might contribute to the permanence of NIS in new systems, the recognition of new habitats, and counteract potential reproductive isolation.

Coastal lagoons are valuable sources of ecosystem services and important for regional development plans. Human pressure threats these areas, so increasing knowledge about coastal lagoons is essential to enhance their protection. Here we investigated the temporal and spatial patterns of the soundscape in the Mar Chiquita coastal lagoon (Buenos Aires, Argentina), the unique coastal lagoon of Argentina. The study was conducted during May–June and November months. Four recorders were deployed along the lagoon and one was located close to invasive polychaete aggregates to investigate their effects on the soundscape. The analysis of acoustic energy revealed a strong circadian rhythm involving the lagoon and a spatial differentiation driven by low frequency (

Community structure and abundance of benthic polychaetes along a transect on the central northern Gulf of Mexico continental slope were examined. Spatial, seasonal, short- (~1 year), and long-term (~16–17 years) temporal comparisons of assemblages were conducted with samples collected in 1983–1984 and 2000–2001. Polychaete abundance did not consistently decrease between 325 and 1500 m, but sharply decreased between 1500 and 2100 m. On the upper slope (325–1500 m) polychaete abundance approximately doubled between fall 1983 and spring 1984, but had returned to initial levels by fall 1984. On the lower slope (2500 m) seasonal variations in abundance were less pronounced. The taxonomic composition of the polychaete assemblages changed continuously along a depth gradient; however, temporal variations of the assemblages at all water depths were generally minor. This study provides a baseline for naturally occurring spatial and temporal dynamics of benthic polychaete communities on the northern Gulf of Mexico continental slope.

Worldwide, low-salinity ponds of coastal saltpans are often drained for artisanal fishing, at which time shorebirds feed opportunistically on the drained ponds. This case study sought to examine how shorebirds exploit this food supply after experimentally draining a large pond (9.1 ha) used for artisanal fishing at the Tagus estuary, Portugal. Shorebirds rapidly increased after draining (reaching 156 birds ha−1), and the pond provided a suitable foraging ground for a high density of shorebirds during 6–12 days after the study site was drained, supporting up to 6% of the total population using the estuary. The benthic invertebrate community was dominated by polychaete worms, and their high density (2215.0 ± 329.9 ind m−2) apparently explained the relatively large percentage of feeding birds in the pond. Most shorebirds fed on polychaete worms at high intake rates throughout the experiment, probably because they increased their searching effort. Bird predation contributed to the food supply decrease during the first 3–6 days, and desiccation was presumably the major factor in 8–15 days. The drainage of low-salinity ponds by artisanal fishing is a traditional activity in coastal saltpans that might play a significant role in providing suitable foraging grounds for migrating shorebirds.

In order to evaluate the effects of elevated temperature and pCO2 on the polychaete Nereis diversicolor from the Rio San Pedro estuary in Spain, multifactorial stressor experiments were performed in various combinations: at two temperatures (ambient temperature and temperature estimated for the year 2100) and at three pHNBS levels (estimated level in cases of CO2 leakage, at the level used in the high and moderate CO2 treatment, and present-day ambient pH levels). Experimental temperature treatments were designed within the context of a high-emission CO2, “business as usual” scenario, with an approximate median increase in temperature of 3.7–4.8°C by the year 2100. In this study, it was investigated whether oxidative stress occurs in cellular responses to elevated temperatures and CO2 levels in N. diversicolor. It was measured the levels of oxidative stress biomarkers, of hemoglobin, and of the carbonate system. The effects of ocean acidification on these organisms are almost unknown. This study has shown that when subject to pH and temperature stress, the Nereidid polychaete N. diversicolor exhibits reduced survival rates. Also the biomarker (Lipid Peroxidation—LPO) was also found to be sensitive to the pH versus temperature relationship.

Negative responses of infauna close to rocky substrates are well known to subtidal bottoms, but there are few studies addressing similar intertidal habitats. We tested the hypothesis that the proximity to rocky shores negatively affects the density and richness of intertidal infauna of tidal flats by assessing infaunal variation across the increasing distances from rocky shores in two tidal flats (Pasto and Limoeiro) of a subtropical estuary in southern Brazil. Total density decreased significantly with the proximity to rocks only in Pasto due to density variations in the two numerically dominant species, the bivalve Anomalocardia flexuosa and the polychaete Armandia hossfeldi. Richness decreased significantly with the proximity to the rocky shores only in Limoeiro. Multivariate analyses revealed significant differences in species and functional groups composition between assemblages near and far from the rocky shores. Assemblage variability patterns were mostly explained by sediment variables. Our hypothesis was partially refuted because negative effects on the infauna were spatially inconsistent, due to differences in species composition between tidal flats, and to distinct responses of individual taxa. Even with the absence of consistent response patterns, the proximity to the rocky shores emerged as a relevant structuring factor of the surrounding intertidal infauna.

The main aim of this study was to compare the polychaete communities in two similar polar areas: an Arctic fjord, Hornsund (Svalbard) and an Antarctic fjord, Ezcurra Inlet (South Shetlands). This is the first attempt to compare Arctic and Antarctic diversity based on fully comparable datasets. Forty van Veen grab samples were collected in each fjord: twenty replicates were taken in each of two fjord areas characterized by a different level of glacial disturbance—in the inner (glacial bay) and outer (fjord mouth) region of both fjords, from depths of about 100 m in 2005 (Hornsund) and in 2007 (Ezcurra Inlet). In the glacial bays, species richness and diversity were significantly higher in Distinct or similar? Soft bottom polychaete diversity in Arctic and Antarctic glacial fjords - Springer Ezcurra Inlet than in Hornsund due to higher rate of glacial disturbance in the latter one. In the outer areas, species richness was similar in both fjords, although diversity values were higher in Ezcurra Inlet. Polychaete species richness in the habitats characterized by similar level of disturbance (outer areas of the fjords) was the same in both polar regions. At this small scale, where community drivers are very similar, the species richness seems to be independent from the local or regional species pool. This study was supported by an International Polar Year related project (Structure, evolution, and dynamics of lithosphere, cryosphere and biosphere in European Sector of Arctic and in Antarctic No. PBZ-KBN-108/PO4/2004) to Jan Marcin Węsławski and Jacek Siciński. K. Pabis was also partially supported from the University of Lodz internal funds, M. Kędra received financial support from the Polish Ministry of Science and Higher Education (540/N–AODP/2009/0).

Patterns of long-term changes in fouling communities developing on artificial substrates in the White Sea are reviewed. The most significant shifts occurring in these communities are caused by biological successions that can last for several decades. Terminal stages of succession are the communities of a mussel Mytilus edulis or a solitary ascidian Styela rustica which can periodically replace one another within a narrow range of depths: from 1–1.5 to 5 m. Sporadic local invasion of a sponge Halichondria panicea can transiently modify the composition and performance of fouling communities. Sudden invasion of species that are not a typical component of fouling communities (infaunal polychaetes and molluscs, crabs) is not rare phenomenon but these organisms do not play a significant role there. Representatives of the associated polychaete fauna in fouling communities show long-term cyclic fluctuations in their abundances. Duration of these cycles is 7–8, 11–14, or 20 years.

A 12 month in situ experiment-assessed colonisation behaviour of Nereis diversicolor (Nereis) using cores of defaunated sediment; either raised 5 cm above the mudflat surface (colonisation by swimming only) or flush with it (colonisation by crawling and swimming). Recruitment and dispersal occurred throughout the year but were highest in the summer. During the summer peak dispersal period the densities of worms in the raised cores were about half of those in the flush cores indicating approximately equal levels of dispersal by swimming and crawling. Colonisation of the raised cores, by swimming only, was by Nereis less than 6 cm in length. The length frequencies of worms in the flush treatments were similar to those of the natural population, including worms up to 12 cm in length indicating that larger worms disperse only by crawling. In the spring and summer the abundances of the smallest Nereis in the raised cores were between 60 and 80% of the total abundances in the flush cores, indicating that most small worms had also colonised the flush treatments by swimming. The densities of worms in the flush treatments were lower than, but not significantly different to, the natural population (with the exception of November and December). It is concluded that in most months worms undergo dispersal, mainly by swimming when small, and by crawling thereafter.

A literature review of Polychaeta (Annelida) including Aphanoneura (the oligochaete-like Aeolosomatidae and Potamodrilidae), living in freshwater yielded 168 species, 70 genera and 24 families representing all of the major polychaete clades, but less than 2% of all species. The best-represented families were, in order, Nereididae, Aeolosomatidae, Sabellidae, Spionidae and Histriobdellidae. Fourteen families were represented by a single species and genus. Regions supporting the highest diversity of freshwater polychaetes were in order, Palaearctic, Neotropical, Oriental, Nearctic, Australasian, and Afrotropical. More than half of all species and genera inhabitat lakes and rivers, followed by lagoons/ estuaries, which have a high proportion of euryhaline species, and inland seas. Less common, atypical polychaete habitats include subterranean waters, the hyporheic zone of rivers and plant container habitats (phytotelmata). At least three distinct ecological/ historical processes appear to account for the colonisation of continental waters: invasion of a clade prior to the break-up of Gondwana, as in Aphanoneura, Namanereis, Stratiodrilus, and Caobangia; relatively recent stranding of individual species (relicts); and the temporary visitation of euryhaline species.

Estuarine benthic organisms are frequently subjected to disturbance events caused by hydrodynamic processes that disrupt and move the sediment in which the animals reside, however the mechanisms by which physical disturbance processes affect infaunal and epifaunal populations and communities remain poorly resolved. The responses of three infaunal and two epifaunal estuarine benthic species to sediment disturbance (burial) were compared in laboratory experiments. Overburden stress (kPa) was calculated to quantify the force exerted on organisms by sediment burial for 6 d. At the levels tested (0–16 kPa), increasing overburden stress did not significantly decrease survival or growth of juvenile burrowing bivalves, Macoma balthica (Linnaeus). Survival of juveniles and adults of the tubiculous polychaete Streblospio benedicti (Webster) and neonates of the burrow-forming amphipod Leptocheirus plumulosus (Shoemaker) declined exponentially with increasing overburden stress. The mean S. benedicti survival rate was 4% of the control at an overburden stress of ≈4 kPa, while an overburden stress of 12 kPa was necessary to comparably reduce survival of L. plumulosus. At the low levels of overburden stress used in the experiments with epifauna (≤0.2 kPa), juvenile oyster Crassostrea virginica (Gmelin) did not suffer significant mortality at an overburden stress of 0.1 kPa. In contrast, the epifaunal tunicate Molgula manhattensis (DeKay) exhibited significant mortality when partially (one or two siphons exposed) or completely buried under sediment with an overburden stress of 0.2 kPa. Species-specific response to burial varied as a function of motility, living position, and inferred physiological tolerance of anoxic conditions while buried. We conclude that some benthic species exhibit mechanical and possibly physiological adaptations that may allow them to survive deposition events of the magnitude commonly encountered in estuarine environments.

The mytilid Brachidontes rodriguezii (d’Orbigny, 1846) is the dominant organism on intertidal rocky substrata in warm-temperate shores of Argentina. Beds of this mussel were sampled at Quequen (Q) and Necochea (N) (Argentina), in order to test whether the structure of the associated assemblage shows significant changes among different times of the year, between horizontal and vertical surfaces and between localities situated in the vicinity or away from a source of sewage pollution. Twenty-three macrobenthic invertebrates and 3 species of macroalgae were found in association with B. rodriguezii. Temporal trends in diversity differed according to substrate slope: a significant minimum occurred in November only in horizontal, but not in vertical substrata. This decrease is coincident with massive bleaching and subsequent demise of intertidal algae, suggesting a strong temporal impact of desiccation stress. Significant differences in community structure were found between localities, and between vertical and horizontal samples. Differences in structure were much greater between localities than among replicates within each locality. The polychaete Boccardia polybranchia was extremely abundant at Q, but rare at N, probably reflecting the impact of organic enrichment due to the presence of a neighbouring sewage outfall. Production of B. rodriguezii was significantly higher on horizontal than on vertical substrata. On the other hand, production of the associated biota was an order of magnitude higher on vertical than on horizontal substrata. Organic enrichment, disturbance and competitive interactions are probably the main processes determining structure in this intertidal rocky shore community.

To address the functional contributions of capillary chaetae in the maldanid polychaete Clymenella torquata, we compared irrigation efficiency and tube structure for animals with intact and trimmed capillary chaetae. We measured pumping rates for worms before and after they were anaesthetized and subjected either to capillary trimming or mock trimming, i.e. handling without trimming. Worms with trimmed chaetae were significantly less effective at moving water through their tubes than those with intact chaetae. There were no significant differences in the ability of control worms to move water within their tubes. No significant changes in rates of peristalsis were observed among experimental or control groups. These data strongly suggest that body musculature and capillary chaetae work in concert to hold worms in position within tubes during peristaltic pumping. When chaetae are shortened, the body musculature must contract to a greater degree, increasing the functional diameter of the worm to achieve the necessary traction with the tube wall, resulting in less efficient irrigation. We also compared the inner diameters of original field tubes to tubes built by control worms or worms after capillary trimming. The inner diameters of new tubes built by worms with shortened chaetae were larger than their original tubes, while those of both control groups were not. One possible explanation is that the chaetae have a sensory role and shortened chaetae send the false message that the nascent tube walls are farther away than they are, the body contracts in compensation and the tube is widened, however this idea has not been tested.

The effect of environmental factors on spatial variation of the polychaete community of the alga Halopteris scoparia in Algeciras Bay (Spain) was investigated. Environmental gradients (outer and inner areas) were detected, based fundamentally on hydrodynamism, solids in suspension,% of organic matter in the sediment, and structural complexity of the plant. Polychaetes can give information on strong environmental gradients, especially pollution, but showed little discrimination among stations, due mainly to the great homogeneity generally showed by these communities. This homogeneity was the result of the quantitative importance of ubiquitous species, such as Platynereis dumerilii, Sphaerosyllis hystrix, Syllis prolifera, and Amphiglena mediterranea, among others. The outer zone, however, included a great number of species with few individuals and low dominance, among which the most characteristic was the terebellid polychaete Nicolea venustula. This species seems to have strong hydrodynamic requirements and may have been limited by excess of accumulated sediment on the alga. More of the collected species were exclusive to the outer areas, and did not penetrate into the inner bay, while most of the inner species were also found in the outer zone. As a whole, the great majority of the species were located in intermediate environmental conditions, indicating a generalist character of the polychaete species.

The dynamics of metazooplankton populations were studied over 3 years at the saline (43 g l−1) Salton Sea, California's largest lake. Total abundance was highest in summer following late winter/early spring phytoplankton blooms. At this time, metazooplankton consisted mostly of the copepod, Apocyclops dengizicus, and the rotifer, Brachionus rotundiformis. In August or September, severe crashes in the metazooplankton populations occurred each year in mid-lake due to strong wind events which increased mixing and caused low oxygen and high sulfide concentrations throughout the water column. Larvae of the polychaete worm, Neanthes succinea and the barnacle, Balanus amphitrite were present mostly in late winter and spring. Their scarcity in summer is due in part to persistent anoxic bottom conditions that decrease adult populations and in part to predation by tilapia, an omnivorous fish that has become abundant in the lake since the 1960s. Two Synchaeta species, rotifers not previously reported from the Sea, were abundant in winter and spring and predation on these may have permitted the copepod to persist at low levels through the winter. There were two major changes in metazooplankton dynamics since 1954–1956 in addition to the appearance of the two synchaetid rotifers in the fauna. First, there are now much lower densities of barnacle and polychaete larvae in the fall, probably due to the invasion of the zooplanktivorous fish, tilapia. Second the precipitous crashes now seen in metazooplankton densities, especially the copepod, in late summer-early fall did not occur in the 1950s possibly because fall overturn events did not result in such high sulfide levels.

Polychaete assemblages associated to the sponge Geodia cydonium were investigated at two sampling sites in the Mediterranean Sea: Porto Cesareo Basin (Apulia) and Marsala Lagoon (Sicily), both characterized by sheltered hydrodynamic conditions. Samples were seasonally performed during 1997, in order to compare the assemblages coming from the two localities studied, considering separately the internal and external tissues of the sponge, and with the aim of evaluating the influence of sponge size on polychaete colonization. The examined sponge is characterized by a peculiar stratification of its tissues: an external thick and hard layer, the cortex, and an internal softer one, the choanosome. Statistical analysis showed that this was the main factor controlling polychaete assemblage, with the internal tissue, less rich and diversified, appearing impoverished with respect to the external layer. A similarity in species composition was observed between sites, even though some differences were evidenced in the abundance of some species, mainly reflecting differences in local environmental conditions. Species richness and density increased with the increasing sponge size. Such a situation is particularly evident at Porto Cesareo, where sponges are covered by an algal layer which is particularly rich on the largest specimens, thus suggesting that most of the species of polychaetes were linked more to the neighbouring environment than to the sponge itself.

Temporal and spatial patterns of polychaete and oligochaete populations inhabiting intertidal sediments of the Quequen Grande estuary (Buenos Aires Province, Argentina) were analysed monthly during a yearly period. Local sediments are poorly selected, very fine sands, with a high percentage of mud. Two sites, located at both banks of the estuary were studied: (1) Site N, with a comparatively steep slope and percentage of mud increasing with sediment depth; (2) Site Q, with a gentle slope and percentage of mud increasing towards the sediment surface. The assemblage of annelids was characterised by a very low specific richness, being composed just by 4 species: the polychaetes Laeonereis acuta, Boccardiella ligerica and Capitella sp., and the tubificid oligochaete Ilyodrilus cf. frantzi. Density of the nereid L. acuta reached a peak in late summer and a minimum in spring. The population of Capitella sp. also showed maximum densities in summer, but collapsed during early fall, disappearing completely from the study area. Densities of I. cf. frantzi were highly variable in time and space. Three of the 4 species showed maximum densities at site Q, where mud content was highest at the sediment surface. At this sampling site, most of the L. acuta population occurred within the upper 8 cm of the substrate. On the contrary, at site N, where mud and organic matter content increased with depth, this species was more abundant at subsurface layers (8–16 cm) than at the sediment surface.

A new species of the genus Clausia associated with the polychaete Arenicola brasilliensis Nonata is described from intertidal sands in Korea. The new species, as a primitive member of the genus, has a large, non-transformed body and fully segmented rami on legs 1–4. This is the second record of Clausiidae in the Far Eastern seas. The genus Doviella Rocha, originally placed in the Clausidiidae, is synonymized with the genus Clausia in the Clausiidae.

In the European Wadden Sea, the nemertine Tetrastemma melanocephalumoccurs together with its prey, the amphipod Corophium arenarium, in the upper intertidal zone. T. melanocephalumleaves the sediment when the tide has receded and captures C. arenarium in its U-shaped burrow. Highest abundances of T. melanocephalumon the sediment surface were found on summer evenings, 2–4 h after high tide, when just a thin film of water was left on the flats. Laboratory Y-maze experiments indicated that gradients of substances produced by C. arenarium in this film of water play a role in tracking the prey. In the field, T. melanocephalum appeared in significantly higher numbers on experimental high density patches of C. arenarium. The amphipod in turn is able to recognize the nemertine. In aquarium experiments, significantly more amphipods escaped from the sediment into the water column when the predator was present. In the field, both predator and prey showed a high mobility by drifting in tidal waters. Benthic abundance maxima of T. melanocephalum and C. arenariumusually did not coincide spatially. It is assumed that the nemertines avoid tidal flats that dry out quickly leaving too little time for prey capture. T. melanocephalum is not able to dig into the sediment, but lives in burrows of Nereis diversicolor. The abundance of this polychaete was inversely related to C. arenarium, presenting a dilemma for T. melanocephalum: the spatial overlap of food and accommodation was rather small.

In 1984, the commercial aquaculture of the polychaete Nereis virens was initiated in NE England, at about the same time similar developments took place in the Netherlands, both establishing alternative sources of this animal as a means of supplying existing markets for marine worms to be used as bait by sea anglers. The industry established in NE England has shown a sustained pattern of growth, and aquaculture has become an accepted means of supplying this niche market. The industry in NE England has fostered particularly close contacts with the academic sector having arisen as a transfer of Intellectual Properties from an institute of higher education (HEI) to a start up private company. The industry has subsequently sponsored a series of investigations that have stimulated fundamental research into the growth and reproduction of Polychaeta. This has resulted in development of techniques for the cryopreservation of the larvae of marine polychaetes, for photoperiodic manipulation of the time of breeding and optimisation of the growth process. The information derived from these studies also suggests a re-interpretation of the life cycle of the Nereididae. The ongoing development of commercial culture of Polychaeta is likely to give rise to further developments of a fundamental nature, emphasising the importance of effective links between centres of academic research and commercial exploitation.

The oligochaete fauna of different side arms and other water bodies in the Slovak–Hungarian stretch of the River Danube below Bratislava (r.km 1840 – r.km 1807) was investigated. The structure of the oligochaete assemblages is correlated with the bottom substratum of the river. From data on the composition of the oligochaete fauna, the clustering and ordination analysis divided the inland delta water bodies into three groups supporting the river classification of Roux et al. (1982), i.e. eupotamon, parapotamon and plesiopotamon, but parapotamon and plesiopotamon divided furthermore into two subgroups, which better reflects hydrological conditions, type of substratum, depth of water bodies and presence of macrophytes. Oligochaete assemblages differ in individual type of group and subgroups, not only species composition, but mainly quantitative (average abundance).

Temporal variation in macroinfaunal community structure wasassessed from monthly monitoring of the sandy substrate of theLucero reef flat in Bolinao, Pangasinan (northwesternPhilippines)between November 1990 and November 1991. The community wascomposedof 98 taxa from 10 phyla and was consistently dominated by thepolychaete family Syllidae (19–33% of monthly totalabundance).Five polychaete and crustacean taxa co-dominated with thesyllidsand exhibited monthly shifts in dominance ranks. Overall,there wasno significant change in the composition of the communityafter ayear.Results of the study show that the temporal dynamics of thecommunity was a function of the seasonality in salinity and oftherelatively consistent nature of the substrate. Abundances ofmacroinfaunal crustaceans, chaetognaths, and molluscsfluctuatedsignificantly over 12 months, and corresponded to the seasonalfluctuation in salinity. Total and polychaete abundances didnotshow significant monthly variation, but tended to beinfluenced bysalinity changes. Densities of turbellarians, nemerteans, andechinoderms appeared homogeneous across 12 months, andcorrelatedwith the consistency of substrate structure in the reef flatoverthe experimental period. In addition, sipunculid numbersseemed tobe supported by the stable amount of organic matter in thesandysubstrate.

Meiofauna were sampled from intertidal pool and vegetative hummock microhabitats at a tidal freshwater marsh on the Chickahominy River, Virginia. Nematodes, ostracods, tardigrades, oligochaetes (Naididae), copepods (Harpacticoida and Cyclopoida), and the sabellid polychaete Manayunkia spp. were numerically dominant in monthly collections. Total meiofaunal densities ranged from 169 individuals 10 cm−2 (low marsh pools, April) to 13832 individuals 10 cm−2 (low marsh hummocks, September). Highest densities of total meiofauna were observed in August–September, coincident with recruitment of oligochaetes and Manyunkia spp. to low marsh hummocks. Nematodes were generally abundant in all seasons and represented 37% of total meiofauna collected. Nematode densities were significantly greater on hummocks (p=0.0001). Ostracods were significantly more abundant in pools, Greatest densities of ostracods were observed in May. Tardigrades were abundant November through March, and September. Significantly greater abundance of tardigrades was observed on hummocks. Harpacticoid copepods were abundant from December through April and cyclopoids were abundant from May through September (low marsh only).

This study identifies the types and quantities of metals retained by Nereis diversicolor and Scrobicularia plana in a predominantly arid estuary environment.

The copepod Eurytemora affinis (Poppe, 1880) and the polychaete Manayunkia speciosa Leidy, 1858 have been found in similar habitats within the Ottawa River. As both species show strong marine affinities and co-occurrence is not restricted to the Ottawa River, but rather is the pattern for North America, present evidence supports the theory that these animals may be relict forms resulting from the most recent marine incursion.

Quantitative sampling of macrobenthos and fouling organisms in the estuarine reaches of the Calliope River and Auckland Creek, Gladstone, Australia has been conducted since November 1974, and includes the recovery period (1974–1981) following severe flooding (and flood-induced scouring) in December 1973/January 1974. Changes in numbers of the 18 most abundant species of benthic polychaetes and one encrusting serpulid (Ficopomatus uschakovi) are examined. Numbers of F. uschakovi settling on fouling panels showed a regular seasonal pattern, with a late summer maximum and a winter minimum throughout this period. The total numbers of individuals for all taxa in benthic samples followed a clear colonization pattern, with super-imposed seasonality; plateau densities were reached five years after flooding. Total numbers of the 18 most abundant polychaetes showed a similar recolonizational pattern including the seasonal variation.

Trace metal concentrations were determined in six species of intertidal organisms common to the coast of Ras Beirut, Lebanon. Lead, cadmium, nickel, iron, and zinc were highest in the polychaete,Hermodice carunculata, but the eggs of the sea urchin,Arbacia lixula, had similar iron levels and the sea anemone,Actinia equina, had zinc concentrations which also approached levels in the polychaete. The highest copper occurred in the shore crab,Pachygrapsus transversus, while chromium was highest in the eggs ofArbacia lixula.Cystoseira spinosa, the only alga studied, had average copper and iron concentrations similar to those found in the same species in another study. Together with the sea urchin eggs,C. spinosa exhibited the most variable zinc levels in the present investigation. The fish,Thalassoma pavo, which is rather common along the rocky coastal areas of Lebanon, appeared to have fairly high concentrations of certain elements in relation to levels reported in species of fish from other locations.

Two new localities are reported for the fresh-water polychaete worm Manayunkia speciosa. Details of the two lakes from the investigations in the summers of 1961, 1963 and 1964 are given. A short summing up of the various Manayunkia species is presented, viz. M. speciosa Leidy 1858, M. aestuarina (Bourne) 1883, M. baicalensis (Nusbaum) 1901, M. caspicaAnnenkova 1920, and M. brasiliensisBanse 1956. The opinion of Zenkevich (1935) and Kozhov (1963) that the genus may be rather old is accepted, but it is emphasized that other theories must rest, until much more is known about the various species.

1. By means of columnar and thin-layer chromatography, the acetone extract of the Polychaete Nereis zonata Mal. from the Black Sea was separated into eight fractions. 2. On the basis of absorption maxima of the various fractions and Rf values of the various spots, most of the carotenoids were identified. 3. It was found that α-carotene, β-carotene, cryptoxanthin, lutein, zeaxanthin, neoxanthin and astacene are present in Nereis zonata Mal. It was not possible to identify the fifth fraction.

Anomalous individuals in five species of marine polychaetes are described. The anomalies fall into three structural types, viz, duplication, bifurcation and common variation. Included in the first are double ventral cirrus in Perinereis nuntia vallata and duplicate operculum in Hydroides homoceros. Bifid antenna in Lysidice collaris and forked anal papilla in Armandia leptocirris constitute the second type. The third includes supernumerary eyes in Arabella iricolor iricolor and variations in opercular crown in, again, Hydroides homoceros.

The ampharetid, Melinna palmata is a common member of the polychaete infauna occurring along the north shore of Galway Bay, (O'Connor, 1981). A high density population at one location was the focus for a two year study (April, 1983 to March, 1985). Five samples were taken each month with a modified 0.12 m2 van Veen grab (hinged 0.5 mm mesh doors fitted to the top to reduce bow wave). Samples were sieved on a 0.5 mm mesh and fixed in 10% buffered formalin. They were subsequently divided into 2 mm, 1 mm and 0.5 mm fractions. M. palmata were sorted from the 2 mm and 1 mm fractions and measured (10th setiger width) for construction of size frequency histograms. Monthly examination of coelomic contents from anaesthetised worms revealed the principal events of the reproductive cycle. Melinnapalmata in Galway Bay was shown to be polytelic with a breeding season extending from May to July. This is earlier than reported for the Breton coast (Retiere, 1979; Guillou & Hily, 1983). Adult worms were gravid in May with spawning taking place until August when water temperatures were at their maxima, (approx. 17 OC). Simultaneously, proliferation of the following season's population of gametes commenced and increased