A polyp from nothing: The extreme regeneration capacity of the Atlantic invasive sun corals Tubastraea coccinea and T. tagusensis (Anthozoa, Scleractinia)

The regenerative capacity of cnidarians plays an essential role in the maintenance and restoration of coral reef ecosystems by allowing faster recovery from disturbances and more efficient small-scale dispersal. However, in the case of invasive species, this property may contribute to their dispersal and success in nonnative habitats. Given that four Indo-Pacific members of the coral genus Tubastraea have invaded the Atlantic, here we evaluated the ability of three of these species (Tubastraea coccinea, Tubastraea diaphana, and Tubastraea micranthus) to regenerate from fragments of undifferentiated coral tissue to fully functional polyps in response to differences in food supply and fragment size. For comparative purposes, another colonial dendrophylliid (Dendrophyllia sp.) was included in the analyses. All dendrophylliids displayed regenerative ability and high survival rates that were independent of whether or not food was supplied or fragment size. However, regeneration rates varied between species and were influenced by fragment size. Temporal expression of key genes of the regenerative process (Wnt and FGF) was profiled during whole-body regeneration of T. coccinea, suggesting a remarkable regenerative ability of T. coccinea that points to its potential use as a laboratory model for the investigation of regeneration in colonial calcified anthozoans.

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 175:109-119 (1998) - doi:10.3354/meps175109 Moulting and growth of the early stages of two species of Antarctic calanoid copepod in relation to differences in food supply Rachael S. Shreeve*, Peter Ward British Antarctic Survey, Natural Environment Research Council, Madingley Road, Cambridge CB3 OET, United Kingdom *E-mail: rssh@pcmail.nerc-bas.ac.uk ABSTRACT: Instantaneous measurements of moulting and growth of the early copepodite stages of 2 species of Antarctic copepod, Rhincalanus gigas and Calanoides acutus, were made at 4 regions around South Georgia during austral summer 1996/1997. Sea surface temperature was ~3°C across the study area whereas chlorophyll a concentrations were considerably higher towards the western end of the island. Despite this, moulting rate experiments showed that stage durations of both species were invariably short with no significant regional differences. Stage durations of R. gigas CI, CII and CIII averaged 9, 28 and 15 d respectively, and those of CII, CIII and CIV C. acutus were 4, 7, and 16 d respectively. Daily mass-specific growth rates were lower and less variable in R. gigas (mean 0.05 d-1) than in C. acutus (mean 0.14 d-1), and showed no measurable regional differences. Those for C. acutus however, were higher off-shelf at the western end of the island where the copepodites were heavier than elsewhere. In addition to variations in concentration of chlorophyll a, qualitative differences in the microplankton food supply may also have influenced growth rates. Large diatoms were far more abundant off-shelf at the western end of the island compared to elsewhere, where micro-flagellates and small diatoms dominated. It is suggested that the more opportunistic feeding mode of R. gigas gave stability to its growth rate, whereas C. acutus, which is predominantly herbivorous, was affected by the fluctuations in phytoplankton concentrations and species composition. Moulting occurred within a narrow range of carbon and dry mass for both species, although this range varied between stations. KEY WORDS: Rhincalanus gigas · Calanoides acutus · Moulting rates · Growth · Production · Southern Ocean · South Georgia Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 175. Publication date: December 17, 1998 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1998 Inter-Research.

The impact of invasive species has been increasing in recent decades due to globalization, threatening marine biodiversity. Tubastraea spp. (sun corals) have been spreading worldwide, showing rapid increases in abundance and/or spatial occupancy and adverse effects on recipient native ecosystems. In Brazil, they have become major invaders, extending discontinuously for more than 3000 km along the coast. Despite increased research efforts on sun coral ecology/biology over the last decade, information about the species’ environmental tolerance and interactions with native species is still scarce. In this context, temperature may be an important driver, as it affects species interactions, primarily through its influence on organismal physiology. Thus, in the present study we assessed the effects of temperature in the invasive T. coccinea and the native zoanthid Palythoa caribaeorum, as well as on their interactions, via a 3-week mesocosm experiment, exposing the species (individually and grafted together) to a temperature range of 16–31 °C. This was accompanied by measuring key physiological traits (metabolism, growth, feeding rates and competitive behavior) that underlie species performance, and hence, competitive strength. The results showed that at Arvoredo Island, Brazil, currently the southern distribution limit of both species, (1) T. coccinea exhibited limited capacity to adjust to sudden temperature changes, (2) T. coccinea’s physical attacks did not affect P. caribaeorum, but induced increased metabolic costs in the former, while triggering increased growth in the latter, leading to eventual overgrowth of the sun coral and (3) that temperature interacted synergistically with the presence of the competitor in both species under high-temperature stress. These findings suggest that T. coccinea’s successful invasion is mainly associated with r-selected life-history traits, rather than competitive strength or a high plasticity to temperature changes, and thus, communities with specific native competitors and/or a variable thermal regime may be more resistant to sun coral invasion.

The introduction of exotic species is one of the major causes for biodiversity loss in marine environments. Introduced species can change habitat complexity, impacting local communities and altering ecosystem functioning. Since the 1980s, the scleractinian species Tubastraea coccinea and Tubastraea. tagusensis (commonly known as sun corals) have been spreading in the south‐western Atlantic, posing a major threat to local biodiversity and marine ecosystems. Nowadays, these species are reported from more than 3,500 km along the Brazilian coast and on at least 21 oil and gas offshore platforms. Considering the great environmental pressure resulting from sun coral invasion, this study verified the effectiveness of manual removal of Tubastraea spp. along a rocky shore in Alcatrazes Wildlife Refuge, one of the most pristine marine regions in Brazil. Results indicate that removal is indeed effective as a control technique; however, as invaders have high regeneration capabilities and recruitment rates, successive management efforts are essential. In order for management to be effective against Tubastraea's year‐round release of clonal larvae, results suggest invaded areas should receive at least two management actions per year. Successive management efforts, in addition to the development of new techniques and prevention of new invasions should be priorities for mitigating sun coral impacts.

Abundance and growth ofEchinocardium cordatum at 28 stations on the Dogger Bank were analysed in May 1996–1998 and compared to data from 1985–1988 in order (i) to investigate the large-scale spatial variability of abundance and size ofE. cordatum in the late 80s and 90s, (ii) to relate abundance and growth ofE. cordatum to the quantity and quality of its food and (iii) to compare differences in results from the 80s and the 90s in relation to food supply and environmental changes due to hydroclimate change. In addition, phytopigment contents in the guts of sea urchins were analysed in May 1999 and compared to those in the surrounding sediments along a transect from the German Bight towards the Dogger Bank to detect differences in food supply. Differences in growth and size of the sea urchins were found to be positively correlated with total organic carbon (TOC) contents in the sediment fine fraction (<63 µm), but negatively correlated with the sediment fine fraction as well as with TOC content and C/N ratio of the total sediments. Abundances of adultE. cordatum were positively correlated with the fine fraction and sediment bulk parameters. Phytopigment analyses showed no significant differences of chlorophylla contents in the guts between the different sites, but differences in quality of the ingested material were detected. That indicates that abundance ofE. cordatum was related to food quantity, whereas growth was dependent on food quality. With regard to the long-term comparison, the decrease in abundance ofE. cordatum in the eastern shallow part of the Dogger Bank corresponded to the increased hydrodynamics which resulted in reduced food supply for surface deposit feeders such asE. cordatum.

Invasive engineering species impact local biodiversity and ecosystem services as they often change habitat complexity while displacing native species, ultimately altering fundamental processes such as secondary production and the energy flow through trophic levels. The sun corals Tubastraea coccinea and T. tagusensis have successfully invaded reef habitats along the Brazilian coast, drastically reducing the diversity of benthic fouling invertebrates and macroalgae at places where colonies had taken large fractions of the available space. Yet, there is no consistent information on the effects of this invasion on assemblages of mobile invertebrates. We sampled shallow vertical reef areas at Buzios Island, SP, Brazil, and compared univariate and multivariate attributes of these assemblages at different levels of sun-coral cover (no cover, half and full cover), at two sites separated by a few km, and two areas within sites separated by several tens of meters. Consistent declines of overall abundance and biomass with increasing coral cover were found at one sampled site, while richness responded only to small-scale heterogeneity with no sun-coral effects. Changes in assemblage structure were area-specific, but similarity analyses most often grouped no coral and half coral cover, leaving aside full coral plots. Tanaids, ostracods and harpacticoid copepods were among the most important groups where sun corals were absent or covering only half of the reef habitat. However, these groups became almost absent in coral saturated habitats. Polychaetes also contributed substantially to dissimilarities, but effects on this group were less clear. Overall, results suggest a negative tipping point between partial to nearly full coral cover, especially at sites where physically complex macroalgae, capable to retain sediments and hence the invertebrates therein, are displaced by the establishment and growth of sun-coral colonies. As important prey for reef fishes, the collapse of small crustacean populations may alter whole-reef ecosystem functioning and negatively impact local fisheries.

Oil and natural gas (O&amp;G) industries are significant players in the global economy. The lifecycle of O&amp;G installations has reached an age at which many must be decommissioned. Biological invasion is the process by which a species is introduced into a new geographic region caused by the interference of human activities. Scientists and policymakers have identified invasive species as a significant threat to marine ecosystems affecting biodiversity. Today, O&amp;G habitats and invasive species represent only 9% of biodiversity studies relative this field. We provide an overview of invasive species linked to decommissioning operations worldwide and emphasize the Brazilian context to support the sustainable management of decommissioning operations. O&amp;G facilities have contributed to the spread of invasive species, such as the bryozoan Watersipora subatra in Santa Barbara Channel (California) and the sun coral species Tubastraea coccínea and T. tagusensis in the Gulf of Mexico and the Brazilian coast. The Brazilian case highlighted in this study shows several platforms to be decommissioning, and the presence of sun coral along the coast which poses biodiversity in risk. Measures must be taken to control the sun coral dissemination and some recommendations were made in this study to support futures studies.

The spread of invasive species in marine ecosystems is a growing global concern, particularly in regions with high economic and ecological importance. Sun corals (Tubastraea spp.) are native scleractinians from the Pacific Ocean that have spread along most of the Brazilian coast. This invasive species initially established populations in Rio de Janeiro state, SE Brazil, reaching high levels of abundance. Although the ecological aspects and impacts caused by this organism have been studied in detail, the natural mechanisms that drive its dispersal have attracted little attention. In this research, we focus on the coastal dispersion of sun coral larvae between Cabo de São Tomé and Ilha Grande Bay, and the offshore transport of sun coral larvae, investigating how submesoscale oceanographic features such as filaments, fronts and eddies influence connectivity among different sites. A high-resolution numerical model was used to simulate the coastal dynamics, incorporating the influence of the Brazil Current, wind-driven circulation, and submesoscale structures. Larval dispersal was examined under different wind scenarios, including northeasterly winds that drive southward currents and enhance offshore transport via submesoscale filaments. Results show that submesoscale features, particularly filaments emerged from upwelling regions, play a significant role on sun coral larvae dispersion. These features act as pathways that connect larvae from coastal to offshore oil exploration areas, highlighting the importance of both natural and anthropogenic processes for the dispersal of this invasive species. This research provides critical insights into the mechanisms governing the spread of invasive marine species, emphasizing the need for integrated coastal management strategies. Understanding how physical processes drive larval transport is essential for developing targeted control measures to mitigate the impact of invasive species like sun coral on native ecosystems and local economies. Furthermore, the study underscores the importance of monitoring both natural and anthropogenic influences on marine bioinvasions, particularly in regions with significant offshore industrial activities.

Newly-emerged adult P. cingulatus (Steph.) in a South Swedish stream exhibited a strong correlation between the size of different body parts and total dry weight. A 40 % seasonal decrease in weight, with no changes in linear measurements, was recorded in males. Mean body size of three sub-populations along the stream exhibited great between-year differences. Newly-emerged individuals from the sub-population with the smallest adults had an energy content of 60 to 70 % in comparison with those from the sub-population with the largest ones. In the uppermost part of the stream, with the most diverse habitat, specimens were on average intermediate or rather large, and showed the smallest between-year variations. Local differences in food supply during late winter and spring are probably important for the differences in body size of adult P. cingulatus along the stream. The flight period is probably adapted to temperature and the food requirements of the larvae.

The family Dendrophylliidae comprises a genus of azooxanthellate corals, Tubastraea (also known as ‘sun corals’ or ‘cup corals’), native from the Indo-Pacific and introduced into the Atlantic Ocean in the early 1940s. In Brazil, Tubastraea colonies were first registered on oil platforms on the northern coast of Rio de Janeiro state (22°S) in the late 1980s. Two decades later, these corals were for the first time identified in the Todos-os-Santos Bay (Bahia state, 13°S), a warmer environment with diverse marine ecosystems including estuaries, mangroves, and coral reefs. Intending to describe the biological cycle of exotic dendrophylliids from the Brazilian northeastern coast, histological analyses revealed three new reproductive structures for Scleractinia: (1) a mucin layer composed of acid glycoproteins surrounding immature sun coral oocytes, (2) trophonema or specialized cells connecting the oocyte to the adjacent gastrodermis, and (3) nucleolini, small condensations in nucleoli.

Charting the invasion: Predicting Tubastraea spp. next move into Brazilian marine protected areas.

In a population convergence experiment, the initial densities of adults of the predatory backswimming bug Notonecta hoffmanni were set above and below a putative equilibrium density in stock tanks. The experiment was done at two constant rates of food supply (wingless Drosophila) for the larger instars (in natural pools Notonecta feed mainly on terrestrial arthropods that fall on the water surface). It was predicted that the densities of the resulting populations would converge on an equilibrium set by the rate of food supply for the larger instars. The tanks also contained zooplankton (mainly Daphnia), which were the main food supply for the smaller instars of Notonecta. The resulting overwintering populations converged towards the appropriate equilibrium densities, via density—dependent and food—dependent fecundity and then cannibalism. However, the populations overshot their equilibria, producing overconvergence. In natural populations such overconvergence might tend to produce 2—yr cycles in abundance. Overconvergence resulted from the insensitivity of the survivorship of the original adults (at least over the short term) to differences in food supply between treatments, allowing them to continue to affect (via cannibalism and reproduction) the eventual density of the new overwintering population. Because Notonecta population density was determined by the externally supplied, locally uncoupled food supply, even though the early instars depended for food largely upon dynamic populations of zooplankton, the dynamics of the Notonecta population were simpler than a description of the food web might suggest.

SUMMARYIn spite of a considerable literature on fruit‐eating, the general evolutionary implications of fruit as a source of food for birds have been neglected. A preliminary attempt is made to explore the evolutionary and ecological consequences of fruit‐eating, considered as a mutual interaction between parent plant and dispersal agent.The relationship considered is that obtaining between fleshy fruits and the “legitimate” fruit‐eating birds which digest the fleshy part of the fruit and void the seed intact. Evolutionary aspects of seed‐eating are also briefly discussed.The “strategies” adopted by fruits for dispersal by birds result in the production of abundant food supplies which are easy of access and exploitable by many species of birds. By contrast, the predation of birds on insects leads to a heterogeneous, sparse and cryptic food supply, to exploit which many different hunting techniques are necessary. Two important evolutionary developments in birds are attributed to these differences in food supply: there tend to be more species in families of insectivorous than of frugivorous birds, and lek behaviour in tropical forest has evolved in predominantly frugivorous birds.The seasonal succession of fruits in temperate latitudes is discussed, and contrasted with the situation in the tropics, using examples from Europe and Trinidad. In general, the succession of ripe fruits in Europe seems to be adapted to the seasonal shifts of the bird populations, and the more nutritious fruits tend to have a more southerly distribution and to ripen later than the more succulent fruits. In the tropics the distinction between nutritious and succulent fruits seems to be largely one of habitat.The constant succession of ripe fruits throughout the year in the tropics probably depends on competition for dispersal by frugivorous birds, which thus ensure the maintenance of their own food supply. This may be regarded as a symbiosis at the level of the ecosystem.

A "short blanket" reality: The challenge to control sun coral invasion in a large no-take marine protected area over a decade of adaptive management.

Viability of hatching birds may be affected by the composition of the eggs from which they come. Egg composition may be influenced by the diet of the female. I examined whether wild Black-billed Magpies (Pica pica) varied the composition of their eggs in response to differences in food supply. Supplemental food was provided on some territories, and the composition of eggs from control and food-supplemented territories was compared. Supplemental feeding had few effects on egg composition. Egg size – water content relationships differed between eggs from food-supplemented and control territories and there was a greater variability in yolk and shell mass within clutches from food-supplemented territories. These results show that food supply to the female can affect the composition of an egg relative both to other eggs in the same clutch and to eggs in other clutches. However, it is not clear whether the observed variation in egg composition would have an effect on the viability of the eggs.