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Foundation species and invasive species strongly influence community diversity and structure, but typically in different ways. However, when widespread invasive species provide novel habitat within a community, their net effect may depend on both the environment and community composition. Fouling communities in northern and southern California harbors were surveyed to determine whether there was variation between two locations in the percent cover of an invasive bryozoan, Watersipora subtorquata (d’Orbigny, 1852), and its relationship to community diversity and composition in these two environments. Diversity significantly differed between locations and had a location-dependent association with W. subtorquata abundance. Communities were significantly dissimilar between locations, and W. subtorquata abundance had the highest percent contribution to community dissimilarity when compared to other species in the community. These results suggest that invasive species may have both facilitative and inhibitive relationships with species in a community, but that the net balance of these interactions depends on both the environmental and community context.

The current work aims to present systematic information about encrusting fouling bryozoan fauna collected from Hurghada, Egyptian Red Sea. During September 2015, scraped fouling samples were collected from beneath the jetty of the National Institute of Oceanography and Fisheries, Red Sea branch, Egypt. Five species of encrusting bryozoan are recorded in the present study. These are Celleporaria aperta , Parasmittina egyptiaca , Watersipora subtorquata , Hippopodina feegeensis and Scorpiodinipora costulata , affiliating to 5 families, which belong to the suborder Neocheilostomina. Parasmittina egyptiaca , Hippopodina feegeensis and Scorpiodinipora costulata are new records from Hurghada, Red Sea waters. Descriptions of the recorded species are given with illustrative photos as well as their geographical distribution and habitats.

Offspring size varies at all levels of organisation, among species, mothers and clutches. This variation is thought to be the result of a tradeoff between offspring quality and quantity, where larger offspring perform better but are more costly to produce. Local environmental conditions alter the benefits of increased offspring size and thereby mediate selection on this trait. For sessile organisms, dispersal is a crucial part of the offspring phase, and in animals, bigger offspring tend to better endure longer dispersal distances than smaller offspring because they have more energy. Theory predicts that increasing distances between suitable habitats strengthens selection for larger offspring. We manipulated the dispersal duration of offspring of different sizes in the bryozoan Watersipora subtorquata and then examined the relationship between offspring size and post-metamorphic performance in the field. We found that selection on offspring size is altered by larval experience. Larger offspring had higher post-settlement performance if the larval period was short but, contrary to current theory, performed worse when the larval period was extended. The reversal of the relationship between offspring size and performance by extending the larval phase in Watersipora may be due to the way in which offspring size affects growth in this species. Regardless of the mechanism, it appears that experiences in one life-history stage alter selection on offspring size in another stage, even when they occupy identical habitats as adults. This article is protected by copyright. All rights reserved.

Both foundation species and introduced species have exceptional influence on community diversity and structure, though they have historically been thought to have opposite effects. However, when introduced species can provide novel habitat within a community, their benefit to the community as a foundation species may outweigh their cost as an invader. The magnitude or direction of species interactions can depend on the environment, thus the net effect of introduced foundation species can vary across different environmental factors. A settlement tile experiment was conducted on the fouling communities of California harbors to determine whether the effects of a widespread invasive bryozoan, Watersipora subtorquata, vary between two locations in its California range, Alamitos Bay and Bodega Harbor. Treatments with live and dead colonies and two sizes of blank tiles were used to evaluate the effects of colony structure and available bare substrate on both mobile and sessile species in the community. Though mobile invertebrate communities in each location across treatments were not significantly dissimilar to each other, communities on large tiles were significantly dissimilar to other communities in each location. Mobile species richness was greatest on live colony and small tiles in Bodega, but greatest on dead colony and large tiles in Alamitos. Both the diversity and community structure of sessile invertebrates across treatments differed significantly between regions. Diversity was greatest on dead colony tiles in Alamitos, where communities were more dissimilar across treatments, but was greatest on live W. subtorquata tiles in Bodega where communities were less dissimilar across treatments. These results highlight the potential for W. subtorquata to have location-dependent net effects on the community throughout its invasive range as a foundation species.

For organisms with complex life cycles, longer time spent in the plankton by dispersing propagules can cause reduced survival, growth and fecundity, which could alter interactions between neighbours in the post-dispersal environment. We compared post-settlement performance of bryozoan Watersipora subtorquata colonies that developed from larvae of different natural and experimental planktonic durations over ca. 15 wk of colony growth. Settlers were situated either near established adults of the ascidian Botrylloides leachii or without competition. In creased larval planktonic durations reduced colony growth in the absence of competition; colonies that developed from longer or delayed larval durations were 2 to 3 times smaller than those that developed from shorter durations. Colonies that developed from longer larval periods (natural or experimental) also experienced higher mortality (75 to 100%) than those that settled quickly (20 to 42%), but these effects varied between experiments and seasons. In winter, W. subtorquata colonies of longer larval planktonic durations experienced greater mortality when adjacent to established B. leachii, whereas differences in colony growth due to planktonic duration were reduced by adjacent B. leachii. The influence of B. leachii varied between experiments in different seasons, however, and did not alter colony performance in summer. Our findings demonstrate that while increased larval planktonic duration can be costly for post-dispersal growth and survival, some differences can be mediated by species inter-actions and environmental variability. This suggests that while connectivity among populations that take longer to disperse may be limited, it may also be influenced in complex ways by the post-recruitment environment and not simply dispersal duration.

1.Population density affects individual performance, though its effects are often mixed. For sessile species, increases in population density typically reduce performance. Still, cases of positive density dependence do occur in sessile systems and demand explanation. The stress gradient hypothesis (SGH) predicts that under stressful conditions, positive effects of facilitation may outweigh the negative effects of competition. 2.While some elements of the SGH are well studied, its potential to explain intraspecific facilitation has received little attention. Further, there have been questions regarding whether the SGH holds if the stressor is a resource. Most studies of interactions between the environment and intraspecific facilitation have relied on natural environmental gradients; manipulative studies are much rarer. 3.To test the effects of intraspecific density and resources, we manipulated resource availability over natural population densities for the marine bryozoan Watersipora subtorquata. 4.We found negative effects of density on colony performance in low resource environments, but mainly positive density-dependence in high resource environments. By adding resources, competition effects were reduced and the positive effects of facilitation were revealed. 5.Our results suggest that resource availability mediates the relative strength of competition and facilitation in our system. We also suggest that intraspecific facilitation is more common than may be appreciated and that environmental variation may mediate the balance between negative and positive density-dependence. This article is protected by copyright. All rights reserved.

Two invasive bryozoan species were discovered at Dun Laoghaire Harbour, Dublin during a bryozoan survey. Watersipora subtorquata (d’Orbigny, 1852) and Tricellaria inopinata d’Hondt and Occhipinti Ambrogi, 1985 were discovered in Dun Laoghaire marina. Research shows that this is a first record for W. subtorquata in Ireland and a range extension for T. inopinata. In recent years the numbers of invasive marine species in Ireland has increased. The presence of these species within the marina and not in areas surrounding the marina suggests that they have been spread via shipping activities.

Summary 1. The global transfer of species by human vectors is continuing despite the use of managerial controls such as antifouling biocides and pesticide applications. The process of introduction now exposes species to novel conditions which may select for tolerance to a contaminant. Invader establishment success is influenced by both the supply of invasive propagules and disturbance. Therefore, it is important to understand whether tolerance to an anthropogenic disturbance, such as contamination, can change the parameters of supply in a way that inadvertently augments the invasion process. 2. To test whether the invasion process is influenced by a widespread contaminant, we investigated how recruitment of the invasive hull-fouling bryozoan Watersipora subtorquata is affected by exposure to copper-based antifouling paint. We quantified settlement patterns in control and copper environments and then assessed post-settlement survival and fitness components. 3. Copper significantly increased total recruitment success despite greater post-settlement mortality. Surviving recruits differed morphologically, with shorter ancestrulae and smaller colonies in high copper treatments. These results show a strong positive affiliation between larval W. subtorquata and high levels of copper although there are associated fitness costs. 4. Syntheses and applications. We found a direct positive effect of contamination on recruitment of a common invasive species. This process is likely to be relevant to other non-indigenous species (NIS) that exhibit a positive affiliation with metal contamination. Copper can potentially enhance success at multiple stages of the invasion process, including facilitating transport and establishment, by increasing the supply and retention of individuals into anthropogenically disturbed environments. Identification of tolerance to contamination as a species trait may also aid in predicting a species invasiveness and spread. Management of metal pollution through remediation and alternative copper-free antifouling techniques would help prevent the spread and establishment of many marine NIS.

The global spread of invasive species may be facilitated by adaptation to the practices that humans use to manage those species. For example, marine invertebrates that adapt to metal-based antifouling biocides on ship hulls may be more likely to be introduced to and establish in metal-polluted environments. We tested this idea by studying clonal variation in tolerance to, and ability to recover from, exposure to copper in a widespread invasive marine bryozoan, Watersipora subtorquata. We cloned colonies of this organism to independently test multiple environments in a genotype by environment design, and then created a genetic variance–covariance matrix. Genotypes were exposed to a gradient of copper concentrations and growth measured during exposure and after a recovery period. There was a significant genotype × environment interaction in growth during exposure and recovery. We found clonal variation in tolerance and ability to recover from exposure to copper, with growth during exposure apparently trading off against growth after exposure. A weak genetic correlation between growth during and after exposure further indicated that they are separate traits. Overall, the genetic variation within this population indicates that there is considerable potential for adaptation to copper, but this comes at a cost to growth in unpolluted environments.

Increased temperature is arguably the most important facet of global climate change, as temperature influences processes across all biological scales. In terrestrial systems, the influence of warming on community dynamics has been investigated through field manipulations of temperature but, in contrast, there have been very few warming experiments conducted in the sea. Here, we used heated settlement panels to manipulate microhabitat temperature in situ for >3 wk, to examine how short-term warming affects community development. We conducted 2 independent experiments in contrasting subtidal habitats in the Perth (Australia) metropolitan area, to determine the usefulness of the field-based approach and to examine consistencies in community-level response to warming. In the first experiment (Swan River estuary), a ~2°C warming treatment resulted in a lower space coverage of a tube-building amphipod and higher coverage of a solitary ascidian, Ciona intestinalis, which contributed to significant differences in community structure. In a second experiment (Hillarys Harbour), the bryozoan Watersipora subtorquata, spirorbid polychaete worms, and C. intestinalis covered less space on warmed surfaces than controls. This was associated with greater biomass of a colonial ascidian and widespread marine pest, Didemnum perlucidum, under warmer conditions, which overgrew and probably outcompeted other taxa. Our results show that community responses to short-term warming are variable and are influenced by individual responses of assemblage dominants. We discuss limitations of the study and highlight the importance of community-level, field-based manipulations of environmental change factors which examine interactions between all available members of the local species pool.

The species composition, density, and frequency of recruitment into any given habitat are highly variable in most biological systems that rely on dispersive propagules (larvae, seeds, spores, etc.). There are few direct experimental studies of how recruitment variation between single species influences the composition and assembly of whole communities in many of these systems. We manipulated recruitment of a variety of single taxa and followed their effects on the subsequent development of hard-substrate communities of sessile animals living in temperate marine waters. The effects of recruitment on communities were complex. Patterns of recruitment of individual species influenced community structure, but these effects varied greatly depending on the identity of species recruits, the time of community development, and location across three different sites. Variable recruitment of arborescent bryozoans and didemnid ascidians had little effect on community structure. At one site, recruitment of the colonial ascidian Botryllus schlosseri had short-lived effects on community structure, while barnacles had more persistent effects. At another site, recruitment of B. schlosseri and the bryozoan Watersipora subtorquata had strong persistent effects on community structure, dominating space where they recruited and influencing the abundances of a variety of different taxa. Differences in the effects of species recruitment on communities appear to be caused by differences between the ecology and life history of recruiting species as well as differences in background processes between sites. These results demonstrate that discrete recruitment events that vary between single species can be important drivers of community composition but are likely to be heavily influenced by the local environment, even within a single species.

Native and exotic sessile invertebrates can act as habitat modifiers and influence the diversity and composition of associated epifaunal communities. Theory and empirical research pre- dict that greater habitat structural complexity will generally result in higher abundance, richness, and diversity of epifaunal species. We evaluated the impact of a recently introduced, structurally complex bryozoan, Watersipora subtorquata, by comparing its associated epifaunal communities with those of primary substrate, other habitat modifiers (tunicates and mussels), and structurally sim- ilar mimics. Community composition differed between Watersipora and other treatments for both mobile and sessile epifaunal communities, but species richness and diversity were significantly higher on Watersipora for mobile animals only. Differences in mobile community composition and diversity were driven by polychaete worms, which were found in greater abundance and higher diversity in Watersipora. Crustaceans, although equally abundant, were more evenly distributed across treatments. Sessile epifaunal communities differed little in richness or abundance among treatments, suggesting that while Watersipora provides biogenic surfaces for colonization that adequately compensate for the primary substrate it exploits, its high structural complexity does not correspond to an increase in sessile epifaunal abundance relative to less complex habitat modifiers. Our results suggest that neutral or facilitative effects of exotic species may be common; the strength and direction of the impact of a novel habitat-forming species on epifaunal communities will depend on the quality of the resource it provides, the strength of ecological interactions between habitat- forming species and epifauna, epifaunal habitat preferences, and whether habitat is a limiting resource for a particular species or group.

The phylogenetic position of the Bryozoa has long been controversial. In this paper, we have determined the complete mitochondrial genome of the Watersipora subtorquata (Bryozoa, Gymnolaemata, Ctenostomata). It is a circular molecule of 14,144 bp, relatively small compared with most other metazoan mitochondrial genomes, and bears some unusual features. All genes in the W. subtorquata mtDNA, unlike those in two bryozoan mtDNAs and most other metazoan mtDNAs published previously, are transcribed from the same strand. It has a unique gene order which differs radically from that of other metazoans. Drastic gene rearrangements were also found among bryozoan mtDNAs. To investigate the phylogenetic position of Bryozoa, analyses based on amino acid sequences of 11 protein-coding genes (excluding atp6 and atp8) from 25 metazoan mtDNAs were made utilizing ML and Bayesian methods. Lophotrochozoa was recovered as monophyletic with strong support in our analyses. Lophophorate was undoubted within Lophotrochozoa, but appears as polyphyletic, which indicates that the lophophores of this group may be of different origin. The existence of Phoronozoa was rejected. Our analyses indicated that Phoronida is more closely related to Annelid instead of Brachiopod. Chaetognatha appeared as the sister group of Bryozoa and they formed a clade together with strong support. More evidence is needed to clarify the relationship of these two phyla.

Page, H. M., Culver, C. S., Dugan, J. E., and Mardian, B. 2008. Oceanographic gradients and patterns in invertebrate assemblages on offshore oil platforms. – ICES Journal of Marine Science, 65: 851–861. We explored variability in the composition and cover of subtidal macroinvertebrate assemblages, and the recruitment and growth rates of selected invertebrate species, on seven offshore oil and gas platforms arrayed across a gradient in oceanographic conditions in the Santa Barbara Channel, CA, USA. The major macroinvertebrate taxa (sea anemones, mussels, barnacles, tubiculous amphipods, hydroids, and sponges) were common to all platforms. However, discriminant function analysis (DFA) revealed that the assemblages of two platforms (Gilda and Gail) clearly differed from the other platforms, a pattern attributable, in part, to the presence of conspicuous exotic species (the anemone, Diadumene sp., and encrusting bryozoan, Watersipora subtorquata) on these platforms. If these exotic species were excluded from the analysis, platforms in proximity to each other generally tended to have invertebrate assemblages more similar to each other than to platforms located farther away. Spatial variation in barnacle recruitment onto ceramic plates and mussel growth rate reflected prevailing oceanographic gradients. The existence of along-channel patterns in the composition of platform invertebrate assemblages, and in invertebrate recruitment and growth associated with oceanographic gradients, suggests that assemblages attached to platforms or other artificial structures may be useful barometers of short and perhaps longer term change in ocean climate.

We report the presence of 3 exotic invertebrate species inhabiting offshore oil and gas platforms on the Pacific offshore continental shelf (POCS) of central and southern California, USA. These exotic species occur in high cover or density and may negatively affect populations of native species on the platforms. Conspicuous exotic species (the bryozoan Watersipora?subtorquata and the anemone Diadumene sp.) were detected on 2 of 7 platforms surveyed. An inconspicuous exotic species (the amphipod Caprella mutica) was detected on 2 of 2 platforms surveyed for such smaller species. In addition to serving as a potential source of exotic species to natural reef habitats, the presence of exotic species on oil platforms may influence the degree to which these structures provide the ecological services of natural reefs. The presence of exotic species on platforms also has consequences for various platform decommissioning options in California and elsewhere (there are an estimated 7000 offshore platforms/installations worldwide), including the removal and transport of platforms for use as artificial reefs, if removals are conducted without regard for the potential transport/dispersal of these species. Further knowledge of the identity of exotic species on oil platforms, their potential for dispersal and interaction with native species, and whether these species can also occur on artificial reefs, will improve our understanding of the effects that artificial structures in general have on the ecological functioning of coastal ecosystems.

Resistance to copper by some fouling species may have the 2-fold effect of both facilitating the introduction of nonindigenous species via the painted hulls of vessels, and providing these species with a competitive advantage in ports or estuaries already exposed to anthropogenically elevated copper concentrations. This study tested the tolerance of 4 introduced bryozoans, Bugula neritina, Watersipora subtorquata, Schizoporella errata and Tricellaria occidentalis, to a range of Cu concentrations (0, 10, 50,100 and 500 μg l -1 ). Larval attachment after 24 h was not found to be a reliable indicator of post-metamorphic survival. Recruits of all species survived in 0 and 10 μg 1 -1 Cu for 20 d, with only Bugula neritina and Watersipora subtorquata recruits surviving exposure to 50 and 100 μg 1 -1 Cu. B. neritina and W. subtorquata colonies exhibited reduced post-metamorphic growth in 50 μg l -1 Cu compared to controls, with no growth observed in 100 μg l -1 Cu. Growth for S. errata and T. occidentalis was higher at 0 pg l -1 than 10 μg l -1 Cu. Post-exposure growth of surviving colonies was assessed by transplanting colonies to the field. W. subtorquata colonies exposed to 50 μg l -1 Cu were the only colonies to show decreased survival and growth post Cu-exposure. Overall, B. neritina and W. subtorquata showed the greatest tolerance to Cu. These findings have important implications for the management, control and assessment of invasion potential of these invasive marine hull-fouling species.

The presence and impacts of non-indigenous species (NIS) in marine areas of high conservation or World Heritage significance have rarely been examined. Case studies worldwide suggest that the potential exists for the introduction of NIS to significantly impact conservation values in regions conserved for the uniqueness and diversity of native assemblages. In this study, a preliminary investigation was conducted to provide information essential for managing marine introductions in the Shark Bay World Heritage Property. A focused fouling plate survey sampled a total of 112 encrusting taxa, of which 10 (11.2%) were classified as introduced and 10 others as cryptogenic. Eight introduced bryozoans: Aetea anguina (Linnaeus, 1758), Bugula neritina (Linnaeus, 1758), Bugula stolonifera Ryland, 1960, Conopeum seurati (Canu, 1928), Savignyella lafontii (Audouin, 1826), Schizoporella errata (Waters, 1878), Watersipora subtorquata (d’Orbigny, 1842) and Zoobotryon verticellatum della Chiaje, 1828; one tunicate, Styela plicata Lesueur, 1823; and an introduced hydroid, Obelia dichotoma (Linnaeus, 1758) were frequent, and in some cases dominant, components of encrusting communities. Of the 20 most frequently occurring species detected in the Bay, four were introduced and of the 20 species with highest average percent cover per plate, six were introduced. At one site, space occupation by NIS averaged 71.6% ± 7.4 of plate live cover. Space occupation by an individual NIS was as high as 62.4% of plate area (mean 7.82% ± 1.8). NIS were detected at sites lacking commercial traffic and ballast water discharge and isolated by distance and physical environment, suggesting that hull fouling of recreational craft may be the most important vector in the region. Seventy-five percent of NIS detected in Shark Bay are established in Australian ports to the south of Shark Bay, while 33% are established to the north, tentatively implicating temperate affinity NIS and the movement of vessels from Australian ports south of Shark Bay as a greater risk to the region.

Numerous studies have shown how interactions between nonindigenous spe- cies (NIS) can accelerate the rate at which they establish and spread in invaded habitats, leading to an "invasional meltdown." We investigated facilitation at an earlier stage in the invasion process: during entrainment of propagules in a transport pathway. The introduced bryozoan Watersipora subtorquata is tolerant of several antifouling biocides and a common component of hull-fouling assemblages, a major transport pathway for aquatic NIS. We predicted that colonies of W. subtorquata act as nontoxic refugia for other, less tolerant species to settle on. We compared rates of recruitment of W. subtorquata and other fouling organisms to surfaces coated with three antifouling paints and a nontoxic primer in coastal marinas in Queensland, Australia. Diversity and abundance of fouling taxa were compared between bryozoan colonies and adjacent toxic or nontoxic paint surfaces. After 16 weeks immersion, W. subtorquata covered up to 64% of the tile surfaces coated in antifouling paint. Twenty-two taxa occurred exclusively on W. subtorquata and were not found on toxic surfaces. Other fouling taxa present on toxic surfaces were up to 248 times more abundant on W. subtorquata. Because biocides leach from the paint surface, we expected a positive relationship between the size of W. subtorquata colonies and the abundance and diversity of epibionts. To test this, we compared recruitment of fouling organisms to mimic W. subtorquata colonies of three different sizes that had the same total surface area. Sec- ondary recruitment to mimic colonies was greater when the surrounding paint surface contained biocides. Contrary to our predictions, epibionts were most abundant on small mimic colonies with a large total perimeter. This pattern was observed in encrusting and erect bryozoans, tubiculous amphipods, and serpulid and sabellid polychaetes, but only in the presence of toxic paint. Our results show that W. subtorquata acts as a foundation species for fouling assemblages on ship hulls and facilitates the transport of other species at greater abundance and frequency than would otherwise be possible. Invasion success may be increased by positive interactions between NIS that enhance the delivery of prop- agules by human transport vectors.

Larval quality may be capable of explaining much of the variation in the recruitment and subsequent population dynamics of benthic marine invertebrates. Whilst the effects of larval nutritional condition on adult performance have received the most attention, recent work has shown that larval size may also be an important and ubiquitous source of variation in larval quality. We examined the effects of variation in larval size on the post-metamorphic survival and growth of Watersipora subtorquata in 2 very different habitats - experimental substrata and pier pilings. We found strong effects of larval size on colony performance, although these varied among experiments. For colonies on experimental substrata, larval size positively affected adult survival and, initially, growth. However, after 3 wk in the field, there was no relationship between larval size and colony size, possibly because colonies were completely surrounded by newly settled organisms. Larval size also positively affected post-metamorphic growth of colonies on pier pilings, but, surprisingly, colonies that came from larger larvae had lower survival than colonies from smaller larvae. Overall, variation in larval size will strongly affect the recruitment and subsequent performance of adults in this species, although this may vary among different habitats. This study highlights the importance of examining the effects of larval quality on adult performance in as realistic conditions as possible, because of the strong interaction between larval size effects and the environment.

Larval experience affects early post-metamorphic performance of a range of marine invertebrates, and even brief events during the larval stage can be important. One of the important larval stresses for organisms living in urban coastal environments is exposure to toxicants. Larvae may pass through patches of toxicants in their dispersal stage with the potential to affect their post- metamorphic performance. However, most studies on embryonic or larval tolerance to pollutants end at, or before, metamorphosis, have little follow-up and almost all are done under laboratory condi- tions. In this study, we tested whether short-term larval exposure to copper has short- and long-term carry-over effects in the encrusting bryozoan Watersipora subtorquata by following settlement and metamorphosis in the laboratory, then transplanting colonies into the field, in 2 seasons and at 2 sites in SE Australia. Cu at 100 µg l -1 accelerated larval attachment in winter and summer, but inhibited metamorphosis. When transplanted to the field, juveniles survived and grew well, and effects on sur- vival and growth did not appear until several weeks or months after settlement. Larval exposure to Cu reduced survival of colonies to about 2/3 that of control colonies in summer and at 1 site, reduced survival to about 20% that of controls in winter. The fall in survivorship occurred abruptly after 3 to 5 wk in summer and 14 wk in winter. The surviving colonies grew more slowly than the controls. In general, there was little temporal variation in Cu effects, but there was spatial variation in effects on survival and growth of colonies within and between sites.

For many species of marine invertebrates, variability in larval settlement behaviour appears to be the rule rather than the exception. This variability has the potential to affect larval dispersal, because settlement behaviour will influence the length of time larvae are in the plankton. Despite the ubiquity and importance of this variability, relatively few sources of variation in larval settlement behaviour have been identified. One important factor that can affect larval settlement behaviour is the nutritional state of larvae. Non-feeding larvae often become less discriminating in their 'choice' of settlement substrate, i.e. more desperate to settle, when energetic reserves run low. We tested whether variation in larval size (and presumably in nutritional reserves) also affects the settlement behaviour of 3 species of colonial marine invertebrate larvae, the bryozoans Bugula ner- itina and Watersipora subtorquata and the ascidian Diplosoma listerianum. For all 3 species, larger larvae delayed settlement for longer in the absence of settlement cues, and settlement of Bugula ner- itina larvae was accelerated by the presence of settlement cues, independently of larval size. In the field, larger W. subtorquata larvae also took longer to settle than smaller larvae and were more dis- criminating towards settlement surfaces. These differences in settlement time are likely to result in differences in the distance that larvae disperse in the field. We suggest that species that produce non- feeding larvae can affect the dispersal potential of their offspring by manipulating larval size and thus larval desperation.

Watersipora subtorquata (d'Orbigny, 1852) (Fig. 5 A–C; Table 6) Cellepora subtorquata d’Orbigny, 1852: 399. Watersipora subtorquata: d’Hondt 1988: 199, figs 6.1– 2; Taylor & Gordon 2002: 536, fig. 1; Chimenz Gusso et al. 2004: 101, figs 9–13; Abdel Salam & Ramadan 2008: 9, fig. 3; Vieira et al. 2014: 155, figs 1–5, 12 – 16, 18–24, 67, 70. Non Watersipora subtorquata: Gordon 1989: 40, pl. 20 B–H; Gordon & Mawatari 1992: 31, fig. 8 E; Ryland et al. 2009: 55, figs 1, 3, 4 A, B, E, F, 5. (More complete synonymy in Vieira et al. 2014). Watersipora subovoidea: Ryland et al. 2009: 54, figs 4 C, D, G, H. Non Cellepora subovoidea d’Orbigny, 1852: 402 (nomen dubium). Material examined. Specimens from Lebanon: 1) Stn 2 A, 3 colonies on rock fragment and pottery; 2) Stn 5 A, small colonies on concretions from cavities; 3) Stn 6 A, 1 colony on Dictyopteris; 4) Stn 6 C, 2 colonies on coralline alga; 5) Stn 7 A, 5 colonies on Pinctada shell; 6) Stn 8 A, 2 colonies; 7) Stn 11 A, 1 small colony on rocky fragment; 8) Stn 12 C, several colonies on rocks; 9) Stn 13 B, several colonies on shells, concretions and pebbles; 10) Stn 14 A, 2 colonies on Spondylus shell; 11) Stn 15 A, several colonies on various substrata. Other material examined: 1) France, Marseille, commercial harbour, Pinede, 3 February 1971, on mussels; same station, 11 December 1982, 6 m, on barnacles; 2) Spain, Tarifa, port, 3 July 1982, 5 m, on Cladocora; 3) Italy, Savona, port, October 1972, 5 m, on barnacles. Description. Colonies small in the collected material, encrusting, unilamellar, moderately pigmented (not observed alive), except for opercula (see below). Zooids subrectangular to hexagonal, relatively short (average L/ W ratio = 1.6) but ranging widely in size (coefficient of variation SD* 100 /X: 14.1% for Az L, 16.1% for Az W). Frontal shield perforated by numerous, evenly distributed, large pseudopores. Orifice distal, large, wider than long (Table 6), with rounded anter developed on about three-quarters of a circle, poster indented by a broad sinus, rounded or sometimes slightly ogival; condyles narrow in frontal view, corresponding to slight bulging of internal arch of anter, superposed to upper side of ‘shoulders’ of sinus, with tip angular or more rounded. Operculum with dark-brown to black thickening in shape of a broad column with slightly arched sides defining a pair of round to oval fenestrae. Tentacles not observed. Remarks. According to the recent revision by Vieira et al. (2014), at least four Watersipora species occur in the Mediterranean Sea. Three of them are relatively common: Watersipora complanata (Norman, 1864), an Atlanto-Mediterranean species lacking a sinus the generic status of which is open to question (Ryland et al. 2009), W. cucullata (Busk, 1854), apparently endemic to the Mediterranean, and W. subtorquata, a non-indigenous species originally described from Brazil but now spread worldwide in tropical and warm-temperate areas (Taylor & Gordon 2002; Vieira et al. 2014). The occurrence in the Mediterranean of the fourth species, W. souleorum Vieira, Spencer Jones & Taylor, 2014, based on type material from the Cape Verde Islands, is attested by specimens collected in the early 20 th century at Naples (Vieira et al. 2014) and recorded by Waters (1909) as Lepralia? cucullata. Therefore, the current presence of this species in the Mediterranean needs to be confirmed. Identification at species-level of Watersipora colonies having a U-shaped sinus has long been a taxonomic challenge, repeatedly discussed (e.g. Ryland 1974; Soule & Soule 1975). Examination of the types of W. subtorquata and W. cucullata has made possible to specify the diagnostic value of several morphological and morphometric characters, to better characterize these species and to correct previous records (Taylor & Gordon 2002; Chimenz Gusso et al. 2004; Vieira et al. 2014). Genetic studies have shown that cryptic diversity is remarkably high in Watersipora (Ryland et al. 2009; Mackie et al. 2006, 2012), obviously in relation with human-mediated dispersal on a wide geographic scale. Particularly in this genus, molecular approaches must be conducted jointly with precise examination of morphological characters. The Lebanese specimens of Watersipora were ascribed to W. subtorquata based on orificial criteria (Chimenz Gusso et al. 2004; Vieira et al. 2014)—a rounded sinus (more quadrangular in W. cucullata), small condyles and a mean width/length ratio of the orifice up to 1.14 in the Lebanese material, i.e. a value close to that of the type specimen (1.18: data from Soule & Soule 1975). The validity of this attribution was confirmed by L.M. Vieira (pers. comm., 19 February 2014). The distribution of W. subtorquata in the Mediterranean based on published literature and examination of museum specimens (Soule & Soule 1975; Chimenz Gusso et al. 2004; Abdel Salam & Ramadan 2008; Vieira et al. 2014) includes the eastern basin (Turkey, Israel, Egypt), the Central Mediterranean (Malta), the Western Mediterranean (Tyrrhenian and Ligurian seas: Civitavecchia, Naples, Genoa, Savona), and the Strait of Gibraltar (Tangiers). The features of specimens from Marseille stored at the Station Marine d’Endoume attest that W. subtorquata was established in the commercial port before the 1970 s, presumably introduced by vessels with fouled hulls., Published as part of Harmelin, Jean-Georges, 2014, Alien bryozoans in the eastern Mediterranean Sea — new records from the coast of Lebanon, pp. 301-338 in Zootaxa 3893 (3) on pages 314-315, DOI: 10.11646/zootaxa.3893.3.1, http://zenodo.org/record/250297, {"references":["Taylor, P. D. & Gordon, D. P. (2002) Alcide d'Orbigny's work on Recent and fossil bryozoans. Comptes Rendus Palevol, 1, 533 - 547. http: // dx. doi. org / 10.1016 / s 1631 - 0683 (02) 00067 - 2","Chimenz Gusso, C., Boccia, P. & Giovannini, N. (2004) Importance of faunistic and taxonomical studies for a correct analysis of the zoogeography of Mediterranean Bryozoa. Biogeographia, 25, 93 - 108.","Abdel-Salam, K. M. & Ramadan, S. E. (2008) Fouling Bryozoa from some Alexandria harbours, Egypt. (II) Encrusting species. Mediterranean Marine Science, 9, 5 - 20. http: // dx. doi. org / 10.12681 / mms. 129","Vieira, L. M., Spencer Jones, M. E. & Taylor, P. D. (2014) The identity of the invasive fouling bryozoan Watersipora subtorquata (d'Orbigny) and some other congeneric species. Zootaxa, 3857 (2), 151 - 182. http: // dx. doi. org / 10.11646 / zootaxa. 3857.2.1","Gordon, D. P. (1989) The marine fauna of New Zealand: Bryozoa: Gymnolaemata (Cheilostomida Ascophorina) from the Western South Island continental shelf and slope. New Zealand Oceanographic Institute Memoirs, 97, 1 - 158.","Gordon, D. P. & Mawatari, S. F. (1992) Atlas of marine-fouling Bryozoa of New Zealand ports and harbours. Miscellaneous Publications. New Zealand Oceanographic Institute, 107, 1 - 52.","Ryland, J. S., De Blauwe, H., Lord, R. & Mackie, J. A. (2009) Recent discoveries of alien Watersipora (Bryozoa) in Western Europe. Zootaxa, 2093, 43 - 59.","Norman, A. M. (1864) On undescribed British Hydrozoa, Actinozoa and Polyzoa. Annals and Magazine of Natural History, Series 3, 13, 82 - 90, pls. 9 - 11.","Busk, G. (1854) Catalogue of Marine Polyzoa in the Collection of the British Museum, II. Cheilostomata (part). Trustees of the British Museum (Natural History), London, pp. i-viii, 55 - 120, pls. 69 - 124.","Waters, A. W. (1909) Reports on the marine biology of the Sudanese Red Sea. XII. The Bryozoa. Part I. - Cheilostomata. Journal of the Linnean Society, London, Zoology, 31 (205), 123 - 181. http: // dx. doi. org / 10.1111 / j. 1096 - 3642.1909. tb 00458. x","Ryland, J. S. (1974) Bryozoa in the Great Barrier Reef province. In: Cameron A. M. et al. (Eds.), Proceedings of the Second International Reef Symposium. Vol. 2. The Great Barrier Reef Committee, Brisbane, pp. 341 - 348.","Soule, D. F. & Soule, J. D. (1975) Species groups in Watersiporidae. In: Pouyet, S. (Ed.), Bryozoa 1974. Proceedings of the Third Conference, International Bryozoology Association. Documents des Laboratoires de Geologie de la Faculte des Sciences de Lyon, H. S. 3, pp. 299 - 309.","Mackie, J. A., Keough, M. J. & Christidis, L. (2006) Invasion patterns inferred from cytochrome oxidase I sequences in three bryozoans, Bugula neritina, Watersipora subtorquata, and Watersipora arcuata. Marine Biology, 149, 285 - 295. http: // dx. doi. org / 10.1007 / s 00227 - 005 - 0196 - x","Mackie, J. A., Darling, J. A. & Geller, J. B. (2012) Ecology of cryptic invasions: latitudinal segregation among Watersipora (Bryozoa) species. Scientific Reports, 2, 871. http: // dx. doi. org / 10.1038 / srep 00871"]}

Watersipora subtorquata (d’Orbigny, 1852) (Figs 1–5, 12–16, 18–24, 67, 70; Table 1) Escharina torquata: d’Orbigny, 1842: pl. 4, fig. 3; 1847: 11 [Brazil]. Cellepora subtorquata d’Orbigny, 1852: 399 [Brazil].?Non Cellepora subovoidea d’Orbigny, 1852: 402 [Red Sea; nomen dubium]. Schizoporella atrofusca: Hincks 1886: 269 (part; f. labiosa), pl. 10, fig. 5 (non fig. 4) [Arabian Sea]. Non Schizoporella atrofusca Busk, 1856: 178 [Mexico]. Dakaria chevreuxi Jullien in Jullien & Calvet, 1903: 90, pl. 10, fig. 6 [Senegal]. Lepralia ? cucullata: Waters 1909: 150 (part), pl. 15, fig. 1 [Suez]. Non Lepralia cucullata Busk, 1854: 81, pl. 96, figs 4–5 [Aegean Sea]. Watersipora cucullata: Hastings 1930: 729 (part), pl. 15, figs 102 [Suez]. Watersipora cucullata: Marcus 1937: 118, pl. 24, fig. 63A, B [Brazil]. Watersipora cucullata: Marcus 1938: 46 [Brazil]. Watersipora cucullata: Osburn 1952: 472 (part), pl. 56, fig. 4 [Colombia]. Dakaria subovoidea: Harmer 1957: 1022 (part). Watersipora edmondsoni Soule & Soule, 1968: 215, pl. 2, fig. 3 [Hawaii]. Watersipora subovoidea: Ryland 1974: 345, fig. 3A [SE Australia]. Watersipora subtorquata: Soule & Soule 1975: 302, pl. 3, fig. 3 [Brazil]; 304, pl. 2, fig. 3 [Virgin Islands]; pl. 2, fig. 5 [Bermuda]. Watersipora subovoidea fide Harmer: Soule & Soule 1975: 302 (part), pl. 3, fig. 4 [Alexandria]. Watersipora subovoidea: Winston 1982: 139, fig. 66 [Florida]. Watersipora subtorquata: d’Hondt 1988: 199, figs. 6.1–2 [Israel]. Watersipora subtorquata: Seo 1999: 222 (?part), fig. 1 [Korea]. Watersipora subtorquata: Taylor & Gordon 2002: 4 (text), fig. 1A–C [Brazil]. Watersipora subtorquata: Florence et al. 2007: 39, fig. 14I, J [South Africa]. Watersipora subtorquata: Abdel Salam & Ramadan 2008: 9, fig. 3 [Alexandria]. Watersipora subovoidea: Ryland et al. 2009: 54, figs. 4C, D, G, H [Australia and Italy]. Watersipora subovoidea: Ramalho et al. 2011: 772, fig. 3 [Brazil]. Material examined. Holotype: MNHN, d’Orbigny Collection 13637, Rio de Janeiro, Brazil. Other material: MZUSP 0257, Watersipora subtorquata, Araçá, São Sebastião, São Paulo, Brazil, 7 July 2009. NHMUK 1863.8.2.41, dry, Watersipora cucullata, Alexandria, Egypt, Station 34a, Eastern Harbour, O’Donoghue coll. NHMUK 1879.4.25.23, dry slide, Schizoporella atrofusca, Naples, Italy, A.W. Waters coll. NHMUK 1884.4.21.2, dry, Watersipora cucullata, South Chinese Seas. NHMUK 1885.1.26.6–7, dry, Watersipora subovoidea, Red Sea, A. Carpenter Esq. NHMUK 1888.11.14.110, dry slide, Schizoporella sp., Port Phillip Heads, Australia, January 1887, K. Bracebridge Wilson coll. NHMUK 1888.11.14.111, dry slide, Schizoporella cucullata, Port Phillip Heads, Australia, January 1887, J. Bracebride Wilson coll. NHMUK 1888.11.14.358, dry slide, Lepralia cucullata, Port Phillip Heads, Australia, January 1887, J. Bracebride Wilson coll. NHMUK 1899.5.1.974 [one dry slide and one balsam slide], Schizoporella atrofusca form. labiosa, Type, Arabian Sea, T. Hincks coll. NHMUK 1899.7.1.139, dry slide, Lepralia cucullata, John Adams Bank, H.M.S. Herald, G. Busk coll. NHMUK 1899.7.1.5061, dry slide, Phylactella sp., Pensian Gulf?, G. Busk coll. NHMUK 1899.7.1.5214, dry slide, Lepralia cucullata, Tangiers, Morocco, 35 fm [62.18 m], HMS Shearwater, G. Busk coll. NHMUK 1913.6.4.11, dry slide, Leraplia cucullata, Muscat, Oman, 8–10 fm [14.6–18.3 m], Major S.G. Knox. NHMUK 1926.9.6.164, dry slide, Lepralia cucullata, Suez Canal, K 13, 4 November 1924, A. Hastings. NHMUK 1926.9.6.165, dry slide, Lepralia cucullata, Suez Canal, K 13, 4 November 1924, A. Hastings. NHMUK 1926.9.6.166, balsam slide, Lepralia cucullata, Suez Canal, K 13, 4 November 1924, A. Hastings. NHMUK 1929.8.31.1, balsam slide, Watersipora cucullata, Shema Creek, Malta, Mediterranean. NHMUK 1948.2.16.28, wet, Watersipora cucullata, Santos, Brazil, E. Marcus coll. NHMUK 1968.1.16.77, dry, Watersipora cucullata, St James, South Africa, 15 February 1933, F78, O’Donoghue coll. NHMUK 1963.8.2.41pt, dry, Watersipora subovoidea, J. Soule & D. Soule det., Alexandria, Egypt, Station 34a, Eastern Harbour, O’Donoghue coll. NHMUK 1973.1.10.3, dry, Accra, Ghana, No. 13B, 14 February 1949, Bassindale coll. NHMUK 1973.1.10.4pt, dry slide, Watersipora cucullata, Pram Pram 0.25 m, Gold coast [Ghana], 6 February 1950, Bassindale coll. NHMUK 1980.1.12.3, dry slide, Watersipora subovoidea, Townsville harbour, Queensland, Australia, D. Hall. NHMUK 1981.4.1.2, dry slide, Schizoporella cucullata, Hurghada, Red Sea, Yellow 935. NHMUK 1986.8.14.3, dry slide, Watersipora subovoidea, Hutchinson Island, Florida, 14 November 1974, JWD coll. NHMUK 1996.9.4.1, dry, Watersipora subtorquata,? Site 4, Punta Mochila, Venezuela, October 1971, J.S. Ryland. NHMUK 1996.9.4.2, dry, Watersipora subtorquata, Site 1, West of Punto Arrecifes, West of Caracas, Venezuela, 8 October 1971, J.S. Ryland. NHMUK 1997.3.12.7, dry, Watersipora subtorquata, Mochina Bay, nr. Naiguatá, coast of Caracas, Venezuela, Loc. 2a, West shore of Gay, 11 October 1971, J.S. Ryland. NHMUK 1997.3.12.3, dry, Watersipora subtorquata, Site 5, Playa Caribe, Juan Griego, Venezuela, 12 October 1971, J.S. Ryland. NHMUK 1998.8.5.2, dry, Watersipora subtorquata, Mughsay’, near Salalah, Southern Oman, 10 October 1983, J.D. Taylor coll. NHMUK 2012.6.30.3, dry slide A/B [part of NHMUK 1998.8.5.2], Watersipora subtorquata, Mughsay’, near Salalah, Southern Oman, 10 October 1983, J.D. Taylor coll. NHMUK 1999.3.30.11, dry slide, Watersipora sp., New Caledonia, Beach of Ile du Phare (Lighthouse), Noumea, A. Willey. NHMUK 2007.12.14.2, balsam slide, Watersipora subovoidea, J.S. Ryland det., Naples, Italy, 20 October 1960. NHMUK 2007.12.14.3, balsam slide, Watersipora subovoidea, J.S. Ryland det., Arrawarra, New South Wales, Australia, January 1972. NHMUK 2007.12.14.4, balsam slide, Watersipora subovoidea, J.S. Ryland det., Arrawarra, New South Wales, Australia, January 1972. NHMUK 2007.12.14.5, balsam slide, Watersipora subovoidea, J.S. Ryland det., Arrawarra, New South Wales, Australia, January 1972, J.S. Ryland coll. NHMUK 2007.12.14.6, balsam slide, Watersipora subovoidea, J.S. Ryland det., Genoa Harbour, Italy, 12 November 2007, M. Faimali coll. NHMUK 2007.12.14.7, balsam slide, Watersipora subovoidea, J.S. Ryland det., Genoa Harbour, Italy, 12 November 2007, M. Faimali coll. NHMUK 2007.12.14.8, balsam slide, Watersipora subovoidea, J.S. Ryland det., Genoa Harbour, Italy, 12 November 2007, M. Faimali coll. NHMUK 2012.6.30.15, dry, Watersipora subovoidea, Shaab Baraja, Sudan, Red Sea, Large lump covered in soft coral, 23m, 15 September 1978, Dumont coll. NHMUK 2012.6.30.16, dry, Watersipora subovoidea, Shaab Baraja, Sudan, Red Sea, 25º52’N, 37º24’W, coral rock, 20 m, 22 September 1978, Dumont coll. NHMUK 1926.9.6.167, balsam slide, Lepralia cucullata, Suez Canal, K 2, 17 October 1924, A. Hastings. NHMUK 2012.6.30.2, dry slide [part of NHMUK 1973.1.10.3], Watersipora subovoidea, Accra, Ghana, No. 13B, 14 February 1949, Bassindale coll. NHMUK 2012.6.30.4, dry slide [part of 1970.6.1.23], Watersipora subovoidea, Mikhmoret, Israel, 16 October 1967, G. Eitan. Description. Colony encrusting, multiserial, primarily unilamellar on flat substrata, becoming multilamellar on irregular substrata, sometimes erect, foliaceous and bilamellar; orange (Figs 20–21) to brownish-purple or black in life, dried colonies becoming dark-orange to grey. Zooids subrectangular to hexagonal, about twice as long as wide, separated by slightly raised lateral walls. Frontal shield flat to slightly convex, sometimes raised more distally than proximally, with numerous round pseudopores about 25 µm in diameter; latero-oral and disto-oral pseudopores sometimes smaller than frontal pseudopores. Latero-oral intrazooidal septula absent. Frontal shield obscured by transparent cuticle in unbleached material. Orifice large, subcircular to oval, slightly wider than long, with well-defined proximal sinus; orificial rim often with raised subtriangular projections on each side of sinus; condyles triangular, projecting distomedially, tooth-like, sometimes inconspicuous and obscured by proximal raised projections. Operculum with broad, parallel-sided dark central band demarcated by sclerites; two lucidae proximally, adjacent to condyles. Avicularia absent. Ooecia absent; orange-red embryos brooded internally, filling most of coelom of maternal zooid. Polypides bright red-orange, lophophore with 20–22 tentacles. Remarks. We figure scanning electron micrographs of specimens from Mediterranean Israel (NHMUK 1970.6.1.23, Figs 12, 18), the Indian Ocean [Oman (NHMUK 1998.8.5.2, Fig. 13)] and the Atlantic [Ghana (NHMUK 1973.1.10.3, Figs 14–16), as well as from Brazil (MZUSP 0257; Fig. 19)] to show their similarity with the holotype of W. subtorquata (Figs 1–5). Ryland et al. (2009), followed by Ramalho et al. (2011), used the name W. subovoidea in error for this species. Watersipora subtorquata is characterized by a suborbicular orifice with a sinus demarcated by triangular condyles and an operculum with a parallel-sided dark band and two well-defined lucidae adjacent to the condyles. Ryland et al. (2009) suggested that Lepralia cucullata of Waters (1909) comprised two species. Based on the figured specimens we suggest that the Suez specimens belong to W. subtorquata and the Naples specimens (Waters 1909, pl. 15, figs 2–4) to an undescribed species. We also found a species from Naples in the NHMUK collection (NHMUK 1912.12.21.1019, Fig. 17) that differs from W. subtorquata in the operculum and in having a wider orifice compared with the Brazilian specimens; this specimen resembles Waters’s specimens from Naples, which are here reassigned to Watersipora souleorum n. sp. (see below). Mawatari (1952) erected the ‘variety’ watersi for specimens of Lepralia cucullata reported by Waters (1909), but this name is preoccupied by a fossil, Microporella watersi de Stefani, 1884, which is supposedly a species of Watersipora (see Waters 1909). Japanese specimens assigned to W. cucullata var. watersi by Mawatari (1952, fig. 1G) lack the triangular condyles and lucidae in the operculum and probably belong to Watersipora subatra (see below). Ryland et al. (2009) noted that the rim of the orifice in W. subtorquata (as W. subovoidea) may be elevated on either side of the sinus, a character easily recognizable in colonies on algae from Israel and Brazil (Figs 18–19). Gordon (1989) showed a range of orificial morphologies in New Zealand specimens identified as W. subovoidea, which all seem to represent one species (D.P. Gordon pers. comm. to LMV, 2013). He described two latero-oral intrazooidal septula in his specimens (Gordon 1989, p. 40), a character we also saw in specimens from New Zealand deposited at the NHMUK (Fig. 47). Thus, the New Zealand specimens are here reassigned to Watersipora subatra. Hincks (1886) and Calvet (in Jullien & Calvet 1903) both independently introduced ‘ labiosa ’: as Schizoporella atrofusca f. labiosa Hincks, 1886 (p. 269, pl. 10, fig. 5), from the Arabian Sea; and Schizoporella cucullata var. labiosa Calvet in Jullien & Calvet, 1903 (p. 141, pl. 16, fig 7), from Cape Verde. The specimens identified as form labiosa by Hincks (1886) are conspecific with other specimens examined from the Arabian Sea (Fig. 13) and belong to W. subtorquata. The specimens previously identified as var. labiosa from the Azores by Calvet (in Jullien & Calvet 1903) (MOM 420379) are distinct in having a deep sinus and an operculum with a narrow, biconcave dark central band; these specimens are badly preserved, but they may be conspecific with W. souleorum n. sp. (see below). Seo (1999, 2005) figured specimens of putative Watersipora subtorquata from Korea, with reddish-brown to black colonies (Seo 2005: pls 154–156). The size of the orifice in her specimens (Seo 2005: pl. 156B) resembles W. subtorquata but the condyles are sometimes minute and obscured by the proximal peristome. Material reported as W. subtorquata by Ryland et al. (2009) has shallow, bar-shaped condyles and an operculum with a proximal biconcave band, quite distinct from W. subtorquata and W. cucullata; these specimens are here identified as Watersipora subatra (see below). Examination of the holotype material of Watersipora edmondsoni Soule & Soule, 1968 (SBMNH 96310, AHF 149; Fig. 20–22) revealed it to be W. subtorquata. We believe, however, that the additional specimens examined by Soule & Soule (1968, 1975) probably include one or more additional species from the same locality [e.g. the specimen reported as W. edmondsoni (Soule & Soule 1975, pl. 1, fig. 7)]. Specimens recently reported as Watersipora subovoidea sensu Harmer by Dick et al. (2006) belong to an undescribed species that may be conspecific with W. edmondsoni sensu Soule & Soule, 1975 (non Soule & Soule, 1968). Distribution. Atlantic (Brazil, Caribbean, Virgin Islands, Florida, Cape Verde, Senegal, Ghana and South Africa), Mediterranean (Italy, Alexandria), Red Sea, Arabian Sea and Pacific (China Sea, Korea, Hawaii and Australia)., Published as part of Vieira, Leandro M., Jones, Mary Spencer & Taylor, Paul D., 2014, The identity of the invasive fouling bryozoan Watersipora subtorquata (d'Orbigny) and some other congeneric species, pp. 151-182 in Zootaxa 3857 (2) on pages 155-162, DOI: 10.11646/zootaxa.3857.2.1, http://zenodo.org/record/4929981, {"references":["Hincks, T. (1886) The Polyzoa of the Adriatic: a supplement to Prof. Heller's ' Die Bryozoen des adriatischen Meeres', 1867. Annals and Magazine of Natural History, Series 5, 17, 254 - 271. http: // dx. doi. org / 10.1080 / 00222938609460142","Busk, G. (1856) Zoophytology. Quarterly Journal of Microscopical Science, 4, 176 - 179, pls 7 - 8.","Jullien, J. & Calvet, L. (1903) Bryozoaires provenant des campagnes de l'Hirondelle (1886 - 1888). Resultats des campagnes scientifiques accomplies sur son yacht par Albert 1 er, Prince Souverain de Monaco, 1903, 23, 1 - 188.","Waters, A. W. (1909) Reports on the Marine Biology of the Sudanese Red Sea, from collections made by Cyril Crossland, M. A., B. Sc., F. Z. S.; together with collections made in the Red Sea by Dr. Hartmeyer. XII. The Bryozoa, Part 1, Cheilostomata. Linnean Society of London Journal of Zoology, 31, 123 - 181. http: // dx. doi. org / 10.1111 / j. 1096 - 3642.1909. tb 00458. x","Busk, G. (1854) Catalogue of marine Polyzoa in the collection of the British Museum, II. Cheilostomata (part). Trustees of the British Museum (Natural History), London, 54 pp.","Hastings, A. B. (1930) Cheilostomatous Polyzoa from the vicinity of the Panama Canal collected by Dr. A. Crossland on the cruise of the S. Y. ' St. George'. Proceedings of the Zoological Society of London, 99, 697 - 740. [1929 on cover] http: // dx. doi. org / 10.1111 / j. 1096 - 3642.1929. tb 01453. x","Marcus, E. (1937) Bryozoarios Marinhos Brasileiros, 1. Boletim da Faculdade de Filosofia, Ciencias e Letras da Universidade de Sao Paulo, Zoologia, 1, 5 - 224.","Marcus, E. (1938) Bryozoarios Marinhos Brasileiros, 2. Boletim da Faculdade de Filosofia, Ciencias e Letras da Universidade de Sao Paulo, Zoologia, 2, 1 - 196.","Osburn, R. C. (1952) Bryozoa of the Pacific coast of America, part 2, Cheilostomata - Ascophora. Allan Hancock Pacific Expeditions, 14, 271 - 611. http: // dx. doi. org / 10.5962 / bhl. title. 6542","Harmer, S. F. (1957) The Polyzoa of the Siboga Expedition, Part 4. Cheilostomata Ascophora II. Siboga-Expeditie, 28 d, xv, 641 - 1147, pls. 42 - 74.","Soule, D. F. & Soule, J. D. (1968) Bryozoan fouling organisms from Oahu, Hawaii, with a new species of Watersipora. Bulletin of the Southern California Academy of Science, 67, 203 - 218.","Ryland, J. S. (1974) Bryozoa in the Great Barrier Reef province. In: Cameron, A. M. et al. (Eds.), Proceedings of the Second International Reef Symposium. Vol. 2. The Great Barrier Reef Committee, Brisbane, pp. 341 - 348.","Soule, D. F. & Soule, J. D. (1975) Species groups in Watersiporidae. Bryozoa 1974. Documents des Laboratoires de Geologie de la Faculte des Science de Lyon, h. s. 3, 2, 299 - 309.","Winston, J. E. (1982) Marine bryozoans (Ectoprocta) of the Indian River area, Florida. Bulletin of the American Museum of Natural History, 173, 99 - 176.","Seo, J. E. (1999) Taxonomic review of Korean Watersipora (Bryozoa, Gymnolaemata, Cheilostomata). Korean Journal of Systematic Zoology, 15, 221 - 229.","Taylor, P. D. & Gordon, D. P. (2002) Alcide d'Orbigny's work on Recent and fossil bryozoans. Compte Rendu Palevol, 1, 533 - 547. http: // dx. doi. org / 10.1016 / S 1631 - 0683 (02) 00067 - 2","Florence, W. K., Hayward, P. J. & Gibbons, M. J. (2007) Taxonomy of shallow-water Bryozoa from the west coast of South Africa. African Natural History, 3, 1 - 58.","Ryland, J. S., de Blauwe, H., Lord, R. & Mackie, J. A. A. (2009) Recent discoveries of alien Watersipora (Bryozoa) in Western Europe, with redescriptions of species. Zootaxa, 2093, 43 - 59.","Ramalho, L. V., Muricy, G. & Taylor, P. D. (2011) Taxonomic revision of some lepraliomorph cheilostome bryozoans (Bryozoa: Lepraliomorpha) from Rio de Janeiro State, Brazil. Journal of Natural History, 45, 757 - 798. http: // dx. doi. org / 10.1080 / 00222933.2010.535917","Mawatari, S. (1952) On Watersipora cucullata (Busk). I. Systematic study. Miscellaneous Reports of the Research Institute of Natural Resources (Tokyo), 25, 14 - 17.","Stefani, C. de (1884) Escursione scientifica nella Calabria (1877 - 78): Jejo, Montalto e Capo Vaticano. Memorie dela Regia Accademia di Scienze Fisiche, Matematiche e Naturali, Series 3, 18, 1 - 292.","Gordon, D. P. (1989) The marine fauna of New Zealand: Bryozoa: Gymnolaemata (Cheilostomida Ascophorina) from the western South Island continental shelf and slope. New Zealand Oceanographic Institute Memoir, 97, 1 - 158.","Canu, F. & Bassler, R. S. (1930) The Bryozoa of the Galapagos Islands. Proceedings of the United States National Museum, 76, 1 - 78.","Seo, J. E. (2005) Illustrated Encyclopedia of Fauna and Flora of Korea. Vol. 40. Bryozoa. Ministry of Education and Human Resources Development, Daehan Printing and Publishing, Seoul, 596 pp."]}

This is the first report about the arrival of the encrusting cheilostomatid bryozoan Watersipora subtorquata on floating seaweeds in German coastal waters of the North Sea. During summer 2012, drifting or stranded thalli of the non-indigenous brown macroalga Himanthalia elongata were investigated on the island of Helgoland showing numerous benthic species covering the holdfast of Himanthalia. Out of the 120 basal structures investigated, 8.3% had viable colonies of the invasive, non-native W. subtorquata attached to them. Himanthalia and W. subtorquata have both their nearest origin reported to be in the English Channel (La Manche), approximately 800 km away from Helgoland. Now we found W. subtorquata as a rafting species in the eastern part of the North Sea, showing its ability to distribute easily over very large distances using floating algae as a natural transport vector. This event might constitute the first step in the potential introduction of this alien species into German coastal waters.

Offshore structures provide habitat that could facilitate species range expansions and the introduction of non-native species into new geographic areas. Surveys of assemblages of seven offshore oil and gas platforms in the Santa Barbara Channel revealed a change in distribution of the non-native sessile invertebrate Watersipora subtorquata, a bryozoan with a planktonic larval duration (PLD) of 24 hours or less, from one platform in 2001 to four platforms in 2013. We use a three-dimensional biophysical model to assess whether larval dispersal via currents from harbors to platforms and among platforms is a plausible mechanism to explain the change in distribution of Watersipora and to predict potential spread to other platforms in the future. Hull fouling is another possible mechanism to explain the change in distribution of Watersipora. We find that larval dispersal via currents could account for the increase in distribution of Watersipora from one to four platforms and that Watersipora is unlikely to spread from these four platforms to additional platforms through larval dispersal. Our results also suggest that larvae with PLDs of 24 hours or less released from offshore platforms can attain much greater dispersal distances than larvae with PLDs of 24 hours or less released from nearshore habitat. We hypothesize that the enhanced dispersal distance of larvae released from offshore platforms is driven by a combination of the offshore hydrodynamic environment, larval behavior, and larval release above the seafloor.

A colonial lifestyle necessitates communica- tion between colony members to coordinate functions and enable resource sharing through physiological integration. Colonial integration is predicted to increase with both the size of the colony and the level of specialization (polymor- phism). In modular colonies, although integration might be reflected in structural characteristics such as module spacing or branching patterns, physiological integration is funda- mentally dependent on the level of connectedness between modules. In cheilostome bryozoans, funicular tissue links adjacent zooids through pores within zooid walls and is the most likely means of nutrient transport within colonies. We sought to determine whether the relative numbers of pores (septulae) and pore plates (septal chambers) per zooid dif- fered across colony regions in a monomorphic species, Watersipora subtorquata, and one showing some polymor- phism, Mucropetraliella ellerii. Within each species, the morphology of pore plates corresponded to functional pre- dictions based on their position within the zooid, and con- nection numbers per zooid increased with colony size. Con- trary to expectations, however, the more complex species, M. ellerii, had significantly fewer porous connections per zooid than W. subtorquata. Physiological connectedness was therefore not predicted by simple assessment of poly- morphism in these species and may not be sufficient to infer colonial integration in related taxa.

The global spread of fouling invasive species is continuing despite the use of antifouling biocides. Furthermore, previous evidence suggests that non-indigenous species introduced via hull fouling may be capable of adapting to metal-polluted environments. Using a laboratory based toxicity assay, we investigated tolerance to copper in the non-indigenous bryozoan Watersipora subtorquata from four source populations. Individual colonies were collected from four sites within Port Hacking (Sydney, Australia) and their offspring exposed to a range of copper concentrations. This approach, using a full-sib, split-family design, tests for a genotype by environment (G×E) interaction. Settlement and complete metamorphosis (recruitment) were measured as ecologically relevant endpoints. Larval sizes were also measured for each colony. Successful recruitment was significantly reduced by the highest copper concentration of 80 μg L −1 . While there was no difference in pollution tolerance between sites, there was a significant G×E interaction, with large variation in the response of colony offspring within sites. Larval size differed significantly both between sites and between colonies and was positively correlated with tolerance. The high level of variation in copper tolerance between colonies suggests that there is considerable potential within populations to adapt to elevated copper levels, as tolerance is a heritable trait. Also, colonies that produce large larvae are more tolerant to copper, suggesting that tolerance may be a direct consequence of larger size.

Watersipora subtorquata (d���Orbigny, 1852) (Figs 3, 4 A, C, E, F) Escharina torquata [Milne] Edwards: d���Orbigny 1842, pl. 4, fig. 3; 1847: 11. Schizoporella atrofusca Busk: Hincks 1868: 269, pl. 10, figs 4���5. Schizoporella aterrima Ortmann, 1890: 49, pl. 3, fig. 36. Lepralia ? cucullata: Waters 1909: 150, pl. 15, figs 1, 5 [pars]. Watersipora cucullata: Hastings 1930: 729 [pars], pl. 15, figs 102���104 only. Watersipora cucullata: Marcus 1937: 118, pl. 24, fig. 63 A, B. Watersipora cucullata: Mawatari 1952: 14, fig. 1 A���E (not 1 F). Watersipora cucullata var. watersi Mawatari, 1952: 16, fig. 1 G [?] Dakaria subovoidea: Harmer 1957: 1022, pl. 69, figs 11���13. Watersipora subtorquata: Ryland 1974: 345, fig. 3 C. ��� Watersipora subovoidea ��� fide Harmer: Soule & Soule 1976: 302, pl. 3, fig. 4; pl. 4, fig. 4. Watersipora subtorquata: Soule & Soule 1976: 302, pl. 2, fig. 3; pl. 3, fig. 3; Gordon 1989: 40, pl. 20, B���H); Seo 1999: 222, fig. 1; Taylor & Gordon 2002: 4, reproducing d���Orbigny���s original figures (fig. 1 A, B) and giving an SEM of the holotype (Fig. 1 C); Florence et al. 2007: 39, fig. 14 I J. Material examined. All specimens are in the Natural History Museum, London. Low Isles, Queensland, Australia (Great Barrier Reef), July 1972, JSR (2 slides: 1 intact, NHM 2007.12.14.9; 1 cleaned, NHM 2007.12.14.10) (Ryland 1974); Bay of Arcachon, on shell (NHM 2007.12.14.11), HDeB, August 2003 (1 slide, decalcified, NHM 2007.12.14.12); St-Jacut-de-la-Mer, Brittany, France, HDeB, April 2005 (on oyster shell, NHM 2007.12.14.13; SEMs; 2 slides: 1 cleaned, NHM 2007.12.12.14; 1 decalcified, NHM 2007.12.14.15); St Peter Port harbour, Guernsey, Channel Islands, May 2007, RL (SEM; 3 slides: 1 intact, NHM 2007.12.14.16; 1 cleaned, NHM 2007.1.14.17; 1 decalcified, NHM 2007.12.14.18). Description. Colonies encrusting, subcircular or with broad, spreading lobes, often overgrowing older layers; or erect with bilaminar lobes; sometimes with a broad and extensive orange-red cortical zone, paling and becoming greyish away from the edges; or dark sepia, black or deep purple with a narrow, orange growing margin (colours fade with drying). Zooids subrectangular or slightly hexagonal, sometimes narrower proximally (usually when associated with row division); large, distinct, about twice as long as wide, 750���1100 (mean ~ 950) �� 300���600 (mean ~ 430) ��m (globally), variable within and between colonies. Frontal skeletal wall rather flat, perforated by numerous large round pseudopores, 20���30 ��m diameter; covered by a rather transparent layer with a shiny cuticle. Orifice large, oval, somewhat wider than long; 130���260 (mean ~ 230) ��m; occupying> 10 % of the total zooid area; with a proximal sinus demarcated by condyles, ~ 55 �� 115 ��m; surrounding rim variably developed, sometimes in the form of paired mucrones beside the sinus, often crestlike distally; a pair of areolae proximolateral to the orifice, one each side, about the size of a pseudopore but containing a multiporous septulum. Condyles in the form of narrow shoulders distal to and slightly deeper than the angle of the orifice rim that separates anter from sinus. Operculum strongly pigmented, with a dark broad, biconcave band proximally, gradually spreading around paired clear areas. Polypides with orange lophophores 740���850 ��m long, ~ 24 tentacles (Gordon 1989). Variation and remarks. The operculum, with the dark biconcave central band that spreads distally around a pair of subcircular lateral ���windows���, is diagnostic but the details cannot be seen clearly without special preparation. In the orange colonies from Guernsey the dark band is narrow, about the width of the sinus at the waist (Fig. 4 F); in the black colonies from St-Jacut and the Bay of Arcachon the dark band is noticeably broader, greater than the width of the sinus, and its lateral margins are more sharply defined (Fig. 4 E). Hincks (1886) named a variety labiosa from the Arabian Sea, with the orificial rim raised as mucrones on either side of the sinus, which appears referable to this species and the counterpart of W. subovoidea var. labiosa Calvet (see above). Ortmann���s (1890) Schizoporella aterrima, clearly belonging to Watersipora, is unrecognizable to species. It was included by Mawatari (1952) in the synonymy of W. cucullata but his account is clearly based on W. subtorquata (distinguished as var. watersi, see above) as well as W. subovoidea (as W. cucullata). The illustrated Japanese specimens are W. subtorquata and it is unclear whether any of his local material was W. cucullata., Published as part of Ryland, John S., Blauwe, Hans De, Lord, Richard & Mackie, Joshua A., 2009, Recent discoveries of alien Watersipora (Bryozoa) in Western Europe, with redescriptions of species, pp. 43-59 in Zootaxa 2093 on pages 55-56, DOI: 10.5281/zenodo.274831, {"references":["Hincks, T. (1868) The Polyzoa of the Adriatic: a supplement to Prof. Heller's ' Die Bryozoen des adriatischen Meeres', 1867. Annals and Magazine of Natural History, ser. 5, 17, 254 - 271.","Ortmann, A. (1890) Die Japanische Bryozoenfauna. Bericht uber die von Herrn Dr. L. Doderlein im Jahre 1880 - 81 gemachten Sammlungen. Archiv fur Naturgeschichte, 54, 1 - 74.","Waters, A. W. (1909) Cheilostomata. Reports on the marine biology of the Sudanese Red Sea. XII. The Bryozoa. Part I. Cheilostomata. Journal of the Linnean Society (Zoology), 31, 123 - 181.","Hastings, A. B. (1930) Cheilostomatous Polyzoa from the vicinity of the Panama Canal collected by Dr. C. Crossland on the cruise of the S. Y. ' St. George'. Proceedings of the Zoological Society of London, 1929, 697 - 740.","Marcus, E. (1937). Bryozoarios Marinhos Brasileiros I. Boletim da Faculdada de Filosofia Ciencias e Letras Universidada de Sao Paulo, Serie Zoologica, 1, 5 - 224.","Mawatari, S. (1952) On Watersipora cucullata (Busk). I. Systematic study. Miscellaneous Reports of the Research Institute of Natural Resources (Tokyo), 25, 14 - 17.","Harmer, S. F. (1957) The Polyzoa of the Siboga Expedition. Part 4. Cheilostomata Ascophora II. Siboga Expeditie, 28 D, 641 - 1147.","Ryland, J. S. (1974) Bryozoa in the Great Barrier Reef province. In: Proceedings of the Second International Reef Symposium Volume 2. Cameron, A. M. et al. Brisbane, The Great Barrier Reef Committee. Pp. 341 - 348.","Soule, D. F. & Soule, J. D. (1976) Species groups in Watersiporidae. Bryozoa 1974. Documents des Laboratoires de Geologie de la Faculte des Science de Lyon, h. s. 3, 2, 299 - 309.","Gordon, D. P. (1989) The marine fauna of New Zealand: Bryozoa: Gymnolaemata (Cheilostomida Ascophorina) from the western South Island continental shelf and slope. New Zealand Oceanographic Institute Memoir, 97, 1 - 158.","Seo, J. E. (1999) Taxonomic review of Korean Watersipora (Bryozoa, Gymnolaemata, Cheilostomata). Korean Journal of Systematic Zoology 15, 221 - 229.","Taylor, P. D. & Gordon, D. P. (2002) Alcide d'Orbigny's work on Recent and fossil bryozoans. Comptes Rendus Palevol, 1, 533 - 547.","Florence, W. K., Hayward, P. J. & Gibbons, M. J. (2007) Taxonomy of shallow-water Bryozoa from the westcoast of Africa. African Natural History, 3, 1 - 58."]}

The historical focus on offspring size has been to explain variation among populations, but there have been few attempts to determine whether variation is greatest at population scale. Offspring size variation is typically viewed as an adaptive response to changes in the relationship between offspring size and performance, yet direct tests remain elusive. We partitioned natural variation in offspring size for a marine invertebrate, Watersipora subtorquata, at a range of spatial and temporal scales across southeastern Australia, and we estimated the relationship between offspring size and performance at each population and time. There was significant variation in offspring size among populations, but regional differences explained only approximately 25% of the observed variation, suggesting that there should be a greater focus on small-scale variation in offspring size. We used our data to parameterize an optimality model to generate predictions of offspring size among different populations and times. Differences in the relationship between offspring size and postmetamorphic performance (and therefore changes in size of offspring that were predicted to maximize maternal fitness) among populations and times were associated with differences in offspring sizes among those populations and times. We suggest that interpopulation variation in offspring size can be an adaptive response to local conditions, but the optimal offspring size is surprisingly dynamic.

As larvae of marine invertebrates age, their response to settlement cues can change. This change can have significant consequences to both the ecology of these organisms, and to their response to antifouling coatings. This study examines how larval age affects the settlement response of larvae to two naturally derived settlement inhibitors, non-polar extracts from the algae Delisea pulchra and Dilophus marginatus, the former of which contains compounds that are in commercial development as antifoulants. Two species of marine invertebrates with non-feeding larvae were investigated: the bryozoans Watersipora subtorquata and Bugula neritina. Larval age strongly affected larval settlement, with older larvae settling at much higher rates than younger larvae. Despite having strong, inhibitory effects on young larvae, the non-polar extracts did not inhibit the settlement of older larvae to the same degree for both species studied. The results show that the effects of ecologically realistic settlement inhibitors are highly dependent on larval age. Given that the age of settling larvae is likely to be variable in the field, such age specific variation in settlement response of larvae may have important consequences for host-epibiont interactions in natural communities. © 2006 Taylor & Francis.

Polystyrene test panels immersed half a meter deep in the water were used to collect the fouling, encrusting Bryozoa at three harbours in Alexandria city. These were Abu Qir Harbour, the Eastern Harbour and El-Dekheila Harbour. Four species of encrusting bryozoa are recorded in the present study. These are Conopeum reticulum, Watersipora subtorquata, Cryptosula pallasiana and Schizoporella errata. The first species is affiliated to the Membraniporidae family , belonging to the suborder Anasca while the other three species are affiliated to the Watersiporidae, Cryptosulidae and Schizoporellidae families respectively. These families belong to the suborder Ascophora. A re-description, supplied with full structural illustrations of the recorded species is given. Moreover, the temporal and spatial distributions of the species recorded are provided