Hermatypic Research Articles

Transcriptome analysis reveals limited toxic effects of the UV-filter benzophenone-3 (BP-3) on the hermatypic coral Acropora tenuis and its symbiotic dinoflagellates

This study aimed to investigate the toxic and transcriptomic effects of the ultraviolet filter benzophenone-3 (BP-3) on Acropora tenuis and its symbiotic dinoflagellates while using acetone as a solvent. Seven-day exposure to 50 and 500 μg/L, which is higher than most BP-3 records from coastal waters, did not affect coral colour or dinoflagellate photosynthesis. Differentially expressed genes (DEGs) between seawater and solvent controls were <20 in both corals and dinoflagellates. Eleven coral DEGs were detected after treatment with 50 μg/L BP-3. Fourteen coral DEGs, including several fluorescent protein genes, were detected after treatment with 500 μg/L BP-3. In contrast, no dinoflagellate DEGs were detected in the BP-3 treatment group. These results suggest that the effects of 50–500 μg/L BP-3 on adult A. tenuis and its dinoflagellates are limited. Our experimental methods with lower acetone toxicity provide a basis for establishing standard ecotoxicity tests for corals.

Algal symbiont genera but not coral host genotypes correlate to stony coral tissue loss disease susceptibility among Orbicella faveolata colonies in South Florida

Stony coral tissue loss disease (SCTLD) has spread throughout the entirety of Florida’s Coral Reef (FCR) and across the Caribbean, impacting at least 30 coral species. The threatened hermatypic coral, Orbicella faveolata, demonstrates intraspecific variation in SCTLD affectedness with some colonies experiencing chronic disease lesions, while other nearby O. faveolata colonies appear unaffected with no disease signs over long monitoring periods. This study evaluated potential genotypic underpinnings of variable disease responses to SCTLD by monitoring and sampling 90 O. faveolata colonies from southeast Florida and the lower Florida Keys. High resolution analyses of &amp;gt;11,000 single nucleotide polymorphisms (SNPs) generated from 2bRAD sequencing indicated there were no SNP loci or genetic lineages significantly associated with O. faveolata SCTLD affectedness. Genotypic differences may still contribute to SCTLD susceptibility; however, these differences were not captured using this reduced representation sequencing approach. Algal symbiont community structure characterized from 2bRAD data revealed that the presence of Durusdinium spp. corresponded with SCTLD-affected colonies as compared to unaffected colonies, suggesting that algal symbiont community make-up may play some role in SCTLD resistance. Data generated by this study will be combined with complementary molecular and physiological approaches to further investigate the complex drivers of intraspecific SCTLD susceptibility and resilience.

Eocene-Oligocene large-scale circulation of the East Asian summer monsoon recorded in neritic carbonates of the proto-South China Sea

When the modern features of large-scale Asian monsoonal circulation were set-up is poorly constrained and pre-Neogene monsoonal archives are rare. This study investigates the temporal evolution of neritic carbonates in the proto-South China Sea to reconstruct East Asian monsoonal currents and winds during the middle to late Paleogene. Analysis of three-dimensional seismic and well core data from the North-West Palawan block reveals the occurrence of a set of thick (>125 m), aggrading Halimeda bioherms, early Oligocene in age. By analogy with Holocene green algal buildup counterparts, they are interpreted to form in nutrient-rich areas subject to upwelling currents and reflect the early presence of a strong coastal jet in the Proto-South China Sea, as seen today during the summer monsoonal season. The analysis of the underlying mixed carbonate–siliciclastic ramp shows that mesotrophic conditions already prevailed during the late Eocene, thus suggesting that modern-like summer East Asian Monsoon large-scale circulation was possibly active as early as the late Eocene in the Proto-South China Sea. Evidence for upwelling currents vanishes in late early Oligocene carbonate-producing biota, that are characterized by the significant development of euphotic hermatypic coral communities reflecting lower nutrient concentrations. This turnover coincides with the opening of the modern South China Sea and is interpreted to result from the southward drift of the North-West Palawan block which placed the area away from the Chinese margin and the coastal jet. Our results highlight therefore that many of the features of the summer East Asian Monsoon large-scale circulation are rooted in the middle Paleogene.

Expression analyses of stress-responsive genes in the hermatypic coral Acropora tenuis and its symbiotic dinoflagellates after exposure to the herbicide Diuron.

The online version contains supplementary material available at 10.1007/s42995-023-00183-0.

A “cool-water”, non-tropical, mixed volcaniclastic–carbonate ramp from the Early Cretaceous of southern Chile (45°40’S)

The Aysén-Río Mayo Basin was a back-arc/marginal basin developed in southwestern South America (43°–47°S) between the Tithonian–Aptian. Its sedimentary fill corresponds to the Coyhaique Group, which represents a transgressive–regressive succession. Six lithofacies and five microfacies were defined for three outcrops exposed south of Coyhaique (45°40’S). The outcrops have a mixed calcareous–volcaniclastic composition and were assigned to the early transgressive Toqui Formation, i.e., lowermost part of the Coyhaique Group. These mixed rocks comprise bioclastic–volcaniclastic conglomerate, gravelly allochemic sandstone, and gravelly–sandy allochem limestone. Bedding is sharp to amalgamated, sometimes rippled, depicting a wave- and storm-influenced, mixed inner- to mid-ramp. The ramp developed over a Valanginian, active volcanic terrain (Foitzick Volcanic Complex), source of the volcaniclastic sediments. Limestones are rich in reworked bioclasts, and controlled by calcitic organisms including gryphaeid oysters, non-geniculate red algae, and echinoid fragments, defining a heterozoan association (“maerl”-like sediments); less frequent are ahermatypic corals, serpulids, and carbonized wood. Based on their inferred paleolatitude (south of 45°–50°S), fossil assemblage (heterozoan), and kind of carbonate platform (ramp-type), these calcareous rocks of the Toqui Formation depict a “cool-water” (sensu lato), non-tropical setting. The fossil assemblage includes oysters (Aetostreon spp.), and abundant calcareous red algae attributed to Archamphiroa jurassica Steinmann (1930), a taxon previously known from the upper Tithonian Cotidiano Formation of Argentina. A. jurassica is here reported for the first time for the Lower Cretaceous of Chile, suggesting a broader upper Tithonian—Valanginian-Hauterivian? range for the species. The facies model presented here contrasts with the depositional environments depicted for correlative reefal rocks in Argentina (Tres Lagunas Formation), which reflect a “warm-water” setting. In the Aysén-Río Mayo Basin, the influence of sea-water key physical variables in the carbonate sedimentation, as well as the position and hydraulic regime of the carbonate platforms within the basin, and their interaction with the volcanism are still unclear.

Hidden Depths: A Unique Biodiversity Oasis in the Persian Gulf in Need of Further Exploration and Conservation

The Persian Gulf, a young and shallow epicontinental sea, is known for its unique geological and oceanographic characteristics that foster its diverse and productive marine ecosystems. A substantial portion of the Gulf’s seafloor consists of unconsolidated soft sediments, making it unsuitable for colonization by many sessile organisms. Consequently, relatively few hard grounds and submerged banks provide suitable habitats for benthic and substrate dwellers. This study documents a unique marine habitat on an offshore submerged bank, likely a raised salt dome, south of Qeshm Island, Iran. This area is home to a high concentration of ahermatypic coral species and remains relatively sheltered from human activities. The bank’s geographic location allows inflow currents from the Strait of Hormuz to transport larvae and nutrients, providing suitable substrates for various sessile invertebrates. Moreover, it causes the formation of Taylor columns, which affect fluid dynamics and circulation patterns, indirectly enhancing biodiversity. Despite facing risks from large-scale regional and localized threats, the bank’s remoteness from the main coast and its depth provide some protection. This study emphasizes the need for continued exploration and the implementation of effective conservation measures in the region, along with additional research to clarify the ecological and physical parameters supporting its diversity. It also presents the first in situ photographic evidence for the occurrence of some octocoral genera in the Gulf. Future research should investigate how the species compositions of hidden banks and shoals contribute to the overall biodiversity of the Persian Gulf.

The Miocene record of the Betic Cordillera uplift in Los Guájares valley (Granada province, S Spain)

The Los Guájares valley is located about 35 km south of Granada in the Internal Zones of the Betic Cordillera. The Miocene deposits in this area consist of six sedimentary units separated by unconformities, which are exposed in small and laterally discontinuous outcrops overlying metamorphic rocks of the Alpujárride Complex. The lowest unit comprises upper Serravallian marls with planktonic foraminifera filling neptunian dykes and covering Triassic dolomitic marbles of the Alpujárride Complex. These marls reflect deep marine deposition on the Betic basement under a local extensional regime. Uplift of the region led to emergence and deposition of continental red alluvial-fan conglomerates and foothill breccias. The overlying unit, a shoreline conglomerate with small oyster banks, indicates relative sea-level rise. Shallow-marine conditions continued during the deposition of the following unit, early Tortonian in age, which consists of calcareous sandstones with hermatypic corals. Small patch reefs developed in the overlying unit composed of sandy limestones with corals (Porites, Tarbellastraea, Thegioastraea) and oysters, and sandy limestones with coralline algae in the most distal areas. The coral reefs in Los Guájares and some coral heads in Albuñuelas, a near locality, are the only record of early Tortonian coral buildups in the Mediterranean. The last marine unit comprises lower Tortonian conglomerates, sandstones and siltstones accumulated in the front of a small delta. Oyster banks and concentrations of Turritelines suggest high nutrient levels in the delta-front paleoenvironments. The Los Guájares valley area emerged afterwards, following the onset of a compressional geodynamic regime in the central Betic Cordillera and since the early Tortonian only small bodies of foothill and alluvial-fan deposits formed in a predominantly erosional context.

Coral assemblage structure and condition of the San Felipe Keys National Park, Cuba

Coral reefs provide ecosystem services to humans, essential to protection through different conservation strategies. However, planning and implementing marine conservation management actions must be based on the best available science. Information gaps have resulted in limited knowledge of conservation priorities and a weak conflict resolution and decision-making capacity. The San Felipe Keys National Park (SFKNP), located in the southwestern region of Cuba, is an understudied area with 40 km long forereefs, providing services mainly associated with fisheries (lobster and finfish). This work analyzed the hermatypic coral assemblage structure and condition within the SFKNP and the influence of geographic and environmental factors in its variation. Using stereo videos, we assessed nine coral reef sites between 2013 and 2015, generating 597 transects, in which 10341 colonies, 46 species, and 17 functional entities were found. The dominant species (Siderastrea siderea, Porites astreoides, Agaricia agaricites, and Orbicella faveolata) are mainly massive species with higher depth range, and that visibility in the bottom and habitat heterogeneity explained 57% of coral assemblages’ variation. Besides, the percentage of living coral cover (10%–15%), the prevalence of small-sized colonies (22 cm average), and the high incidence of recent mortality (2%–8% of colonies) indicate the presence of environmental stressors in the SFKNP, such as water turbidity, generated by the natural runoff from the Gulf of Batabanó. These results highlight the importance of enhancing the awareness of the competent authorities and promoting integrated management of the entire western region of the Gulf of Batabanó.

The contribution of assisted coral restoration to calcium carbonate production in Eastern Pacific reefs

Introduction: Hermatypic corals have the capacity to construct the physical reef-framework and maintain the balance of coral reef functionality. However, in the past three decades, coral communities have been menaced by natural and anthropic pressures, resulting in an abrupt coral cover decline, and slow natural recovery. To mitigate coral reef collapse, assisted restoration techniques has been implemented and improved worldwide, However, the long-term effects of such interventions on ecological attributes have been scarcely reported. &#x0D; Objective: This study evaluated the effect of assisted coral intervention on calcium carbonate production (kg CaCO3 m-2 yr-1) and ecological volume (cm3) yielded by branching and massive corals from the central Mexican Pacific. &#x0D; Methods: We used colony size, extension rate, and skeletal density measurements of direct outplanted Pocillopora and Pavona coral species to calculate coral carbonate production, ecological volume, and model their long-term potential. &#x0D; Results: Coral carbonate produced after one-year of outplanting increased by 42 % (1.17 kg CaCO3 m-2 yr-1), where Pocillopora spp. and Pavona clavus corals contribute with 0.97 and 0.20 kg CaCO3 m-2 yr-1, respectively. The ecological volume also increased by 384 cm3 for Pocillopora and 56 cm3 for Pavona after one year period. Furthermore, the results suggest that long-term coral restoration actions (10 years) have the potential to significantly increase carbonate production. &#x0D; Conclusions: our data indicate that coral restoration initiatives have the potential to help mitigate the current low calcium carbonate production of Mexican Pacific reefs and may significantly contribute to the long-term maintenance of reef-framework based on ecological engineering tools, such initiatives represent essential functional properties related to reef ecosystem services provision.

Production and accumulation of reef framework by calcifying corals and macroalgae on a remote Indian Ocean cay

Abstract. Coral reefs face increasing pressures in response to unprecedented rates of environmental change at present. The coral reef physical framework is formed through the production of calcium carbonate (CaCO3) and maintained by marine organisms, primarily hermatypic corals, and calcifying algae. The northern part of Western Australia, known as the Kimberley, has largely escaped land-based anthropogenic impacts and this study provides important metabolic data on reef-building organisms from an undisturbed set of marine habitats. From the reef platform of Browse Island, located on the mid-shelf just inside the 200 m isobath off the Kimberley coast, specimens of the dominant coral (six species) and algal (five species) taxa were collected and incubated ex situ in light and dark shipboard experimental mesocosms for 4 h to measure rates of calcification and production patterns of oxygen. During experimental light and dark incubations, all algae were net autotrophic producing 6 to 111 mmolO2m-2d-1. In contrast, most corals were net consumers of O2 with average net fluxes ranging from −42 to 47 mmolO2m-2d-1. The net change in pH was generally negative for corals and calcifying algae (−0.01 to −0.08 h−1). Resulting net calcification rates (1.9 to 9.9 gCaCO3m-2d-1) for corals and calcifying algae (Halimeda and Galaxura) were all positive and were strongly correlated with net O2 production. In intertidal habitats around Browse Island, estimated relative contributions of coral and Halimeda to the reef production of CaCO3 were similar at around 600 to 840 gm-2yr-1. The low reef platform had very low coral cover of &lt; 3 % which made a smaller contribution to calcification of ∼ 240 gCaCO3m-2yr-1. Calcification on the subtidal reef slope was predominantly from corals, producing ∼ 1540 gCaCO3m-2yr-1, twice that of Halimeda. These data provide the first measures of community metabolism from the offshore reef systems of the Kimberley. The relative contributions of the main reef builders, in these undisturbed areas, to net community metabolism and CaCO3 production is important to understand exclusively climate-driven negative effects on tropical reefs.

An assessment of Ryukyu Archipelago's coral communities over a wide latitudinal range

Japan's coral reefs have changed dramatically over the last several decades due to climate change and anthropogenic impacts. Due to its dynamic location, the islands of Ryukyu Archipelago offer a unique environmental gradient to study the interactions between environmental variations, connectivity, resilience, climate change and adaptation of marine biodiversity along a wide latitudinal gradient. To obtain detailed baseline assessments of the reefs of Ryukyu Islands, we carried out Point Intercept Transect surveys to compare the assemblages of benthic communities in six regions of Ryukyu Archipelago, examining the influence of latitude gradient and emphasising on regional features. A total of 69 individual reef sites were surveyed for this study. The overall hard coral cover for Ryukyu archipelago was 22.41% ± 7.98 (Mean ± SD) from pooled dataset. The most abundant benthic assemblage for Ryukyu Archipelago was turf algae (39.72% ± 7.21) with all regions except Amami Oshima Island having overall cover above 40%. A total of 2607 individual colonies of hermatypic corals were recorded and identified up to genus level for this study where 55 genera of corals belonging to 17 families were recorded for Ryukyu Archipelago. The overall relative abundance was highest for Acroporidae family (32.22%), followed by Merulinidae family (27.69%) and Poritidae family (14.38%). Our results highlight the current condition of the reefs of Ryukyu archipelago and offers baseline data on broad scale ecosystem where future ecological change could be compared.

Upper thermal tolerance of hermatypic coral Acropora digitifera collected from Sesoko Island, southern Japan, based on a laboratory experiment

Upper thermal tolerance of hermatypic coral Acropora digitifera collected from Sesoko Island, southern Japan, based on a laboratory experiment

Anchor scour from shipping and the defaunation of rocky reefs: A quantitative assessment

Anchor scour from shipping is increasingly recognised as a global threat to benthic marine biodiversity, yet no replicated ecological assessment exists for any seabed community. Without quantification of impacts to biota, there is substantial uncertainty for maritime stakeholders and managers of the marine estate on how these impacts can be managed or minimised. Our study focuses on a region in SE Australia with a high proportion of mesophotic reef (>30 m), where ships anchor while waiting to enter nearby ports. Temperate mesophotic rocky reefs are unique, providing a platform for a diversity of biota, including sponges, ahermatypic corals and other sessile invertebrates. They are rich in biodiversity, provide essential food resources, habitat refugia and ecosystem services for a range of economically, as well as ecologically important taxa. We examined seven representative taxa from four phyla (porifera, cnidaria, bryozoan, hydrozoa) across anchored and ‘anchor-free’ sites to determine which biota and which of their morphologies were most at risk. Using stereo-imagery, we assessed the richness of animal forest biota, morphology, size, and relative abundance. Our analysis revealed striking impacts to animal forests exposed to anchoring with between three and four-fold declines in morphotype richness and relative abundance. Marked compositional shifts, relative to those reefs that were anchor-free, were also apparent. Six of the seven taxonomic groups, most notably sponge morphotypes, exhibited strong negative responses to anchoring, while one morphotype, soft bryozoans, showed no difference between treatments. Our findings confirm that anchoring on reefs leads to the substantial removal of biota, with marked reductions of biodiversity and requires urgent management. The exclusion of areas of high biological value from anchorages is an important first step towards ameliorating impacts and promoting the recovery of biodiversity.

The reef fish assemblage of a coral reef system in the southwestern Gulf of Mexico

Reef fish species richness of the Veracruz Reef System National Park (VRSNP) in the SW Gulf of Mexico is well known. However, the knowledge of the assemblage structure and its spatial variability in the reef ecosystem is quite limited. For that purpose, 5 field surveys (2012-2015) were performed, using the stationary visual census method, at 10 selected reefs. The most important findings were: 116 reef species were recorded. Average total reef fish density (2.31 Ind/m2) is similar to the records for the Caribbean reefs in the 20th century. The top 5 most abundant species were: Chromis multilineata, Ocyurus chrysurus, Abudefduf saxatilis, Stegastes leucostictus, and Elacatinus jarocho. We found evidence of a spatial distribution pattern with 3 well-defined groups of reefs: (1) those near the city of Veracruz, (2) those near the outlet of the Jamapa River, and (3) those farther from the city. Higher fish densities are associated to both high hermatypic coral and low crustose coralline algae bottom covers. The assemblage structure of reef fishes is different at distinct geomorphological reef zones. As expected, with some differences in the species abundance order, the assemblage structure of reef fishes is similar at all coral reefs in the Gulf of Mexico.

High‐Resolution Coral Records of Cadmium in Surface Seawater: Biogeochemical Cycling and a Novel Proxy for Winter Monsoon

AbstractCadmium (Cd) geochemical cycle plays a significant role in the composition and function of the marine ecosystem. Skeletal cadmium‐to‐calcium (Cd/Ca) ratios in hermatypic corals have been applied to reconstruct the historical changes of oceanic and climatic processes, yet there was no systematic evaluation of this tracer's natural variability in high resolution over time. Here, we reported a coral skeletal Cd/Ca record in monthly resolution from 1999 to 2008 CE and reconstructed the history of Cd contents in surface seawater in the northern South China Sea. A significant seasonal variation (higher in the winter but lower in the summer) of Cd contents in surface seawater can be identified. We found that the seasonal variations in coral skeletal Cd/Ca ratios exhibited significant trends coupled with the surface wind speeds, indicating that strong winds had likely driven the vertical seawater mixing process and then induced the process of sediment remobilization on the shelf, which significantly increased Cd contents in surface seawater. The reduction in Cd contents in surface seawater due to biological processes might be masked by the impacts of surface winds. Importantly, we also observed that coral skeletal Cd/Ca records in the winter showed significant correlations with the winter monsoon index, highlighting the possibility as a new proxy of winter monsoon in the non‐upwelling shelf environments.

Simulating cyanide fishing: photosynthetic effects of short-term cyanide exposure in three different hermatypic coral species

ABSTRACT Since the 1960s the demand for ornamental aquarium fish has grown steadily and consequently cyanide fishing is still a popular fishing method despite its prohibition. This poses a severe threat to coral reefs in Southeast Asia. This study aimed to investigate the short-term stress reaction on photosynthetic yield in the tissues of three different hard coral colonies (branching growth forms Pocillopora damicornis and Seriatopora hystrix, and massive Porites lobata) to initially high and then decreasing cyanide exposure, mimicking cyanide fishing by fishermen. Experiments were performed both in situ in the coral reefs of the Marine Protected Area Pulau Pieh, West Sumatra, Indonesia, and in the aquaria facilities of ZMT in Germany. A Diving-PAM fluorometer was used for in vivo stress assessment of the holobiont. While in all species the photosynthetic efficiency was significantly reduced right after cyanide application, the massive species displayed much lower ΔF/Fm’ values. After three days in cyanide-free water all three coral species recovered to initial values of Fv/Fm, except for P. lobata. No bleaching or discolouration was detected by the conclusion of the experiment after 38 days. Especially Indonesian reefs with massive corals may be therefore more severely impacted by cyanide fishing since the retention time of the water in these reefs is longer than in reefs that consist primarily of branching corals. This might have implications for the management of different reef parts of the MPA.

Histological characterization of sexual reproduction in the coral Pocillopora damicornis (Coelenterata: Scleractinia) from the Red Sea

The scleractinian coral is common along the Red Sea coast, and its reproductive mode and period of reproduction were assessed using histological preparations. the sexuality, and reproductive mod timing of reproductive of pocillopora damicornis from adjacent to the fringing reefs of the Ubhur Creek in the Red Sea, were assessed using a serial histological section. Sexual reproduction in pocillopora damicornis a shallow water hermatypic coral was studied from December 2011 to November 2012. pocillopora damicornis is a simultaneous hermaphrodite with ovary and testis in the project into the body cavity on the same mesentery. Sperm and eggs were usually released simultaneously from the same polyp. The onset of the reproductive period of pocillopora damicornis was found to be limited (April to May). In the number of eggs and testes observed in this period, the gonads were found in the polyps. The pocillopora damicornis egg size ranged from 49.80 µm (in March) to 125.0 µm (in May). Four stages were chosen, to reflect very immature ovaries, the early stages of oocyte development, ova near maturity, and mature ova, and also four distinct stages of sperm development were identified. The state of gonads development (eg. testis and eggs) was measured by a calibrated eyepiece micrometer of a compound light microscope. Zooxanthellae were presented in the mature oocytes in pocillopora damicornis. This study aimed to examine the reproduction mode and timing of pocillopora damicornis.

Spawning record of hermatypic coral &lt;i&gt;Acropora digitifera&lt;/i&gt; documented by the action camera at one-minute interval

Spawning record of hermatypic coral &lt;i&gt;Acropora digitifera&lt;/i&gt; documented by the action camera at one-minute interval

Coral calcification and carbonate production in the eastern tropical Pacific: The role of branching and massive corals in the reef maintenance.

Hermatypic corals have the potential to construct calcium carbonate (CaCO3 ) reef-framework, maintain habitats tridimensionality and contribute to both the biogeochemical and the geo-ecological functionality of coral reefs. However, in the past decades, coral reef growth capacity has been affected by multiple and cumulative anthropogenic stressors, threating the reef functionality and their ecosystem goods and services provision to humankind. This study evaluated temporal changes in geobiological growth characteristics as a function of live coral cover, calcification rate (extension rate and skeletal density) and coral carbonate production at Islas Marias archipelago from the eastern tropical Pacific, using historical data obtained in 2007 (López-Pérez et al., 2015, Marine Ecology, 37, 679) and data obtained through field and laboratory research between 2015 and 2018. Overall, live coral cover decreased (82%), where Pocillopora spp. corals reduced from 26% in 2007 to 4% in 2018, in contrast, Pavona spp. declined from 4.1% to 3.7% over the same period. Coral carbonate production ranged between 1.78 and 10.65kg CaCO3 m-2 yr-1 , with a significant difference (threefold) between reef zones (shallow vs deep), highlighting the higher carbonate production at deep-reef sites. Coral cover, carbonate production and sclerocronological characteristics showed a decrease rate (between 30 and 60%) associated with thermal anomaly events such as La Niña (2010-2011) and El Niño (2014-2016), with positive sights of recovery (twofold) during the following years 2017-2018. This study provides evidence that massive Pavona and branching Pocillopora corals are key reef-building species at Islas Marias archipelago, due to their capability of sustaining live coral coverage and carbonate through thermal disturbance periods. Revealing, that corals at mid-water depths (>10m) may significantly contribute to the long-term stability of biogenic reef-framework, and geo-ecological functionality of the eastern tropical Pacific reefs.

Cheilostomatida (Bryozoa) from the Ionian Apulian coast (Italy) with the description of new species

The mesophotic zone is a relatively poorly studied area of the Mediterranean Sea, drawing great interest by the scientific community in the last years. This zone represents a connection between the shallow water and the deep-sea communities, in which photophilic framework builders (e.g. coralline red algae) are gradually replaced by heterotrophic ones, such as ahermatypic corals and the bivalve Neopycnodonte cochlear. In this habitat the framework-forming organisms produce a hard substrate with a high topographic complexity, hosting a great biodiversity of secondary structuring taxa like bryozoans. During a survey on coralligenous banks in the mesophotic zone in c. 60 m depth off Gallipoli (southern Apulia), epibiotic aggregations of N. cochlear were found on the fans of the hexacoral Savalia savaglia. In the present paper the diversity of cheilostomatid bryozoans hosted by these bivalve aggregations is described and compared with published information on similar nearby habitats. A total of 48 taxa were found, six of which are newly described: Crassimarginatella matildae sp. nov., Micropora biopesiula sp. nov., Haplopoma celeste sp. nov., Schizomavella (Schizomavella) cerranoi sp. nov., Schizomavella (Calvetomavella) biancae sp. nov., and Schizoporella adelaide sp. nov. The species richness known from the southern Apulian shelf at this depth (47 species) is hereby raised to 83 cheilostomatid bryozoans. Moreover, only 12 species are shared with the other localities studied previously, while 36 are restricted to Gallipoli, supporting the hypothesis of a high rate of exclusivity among Apulian sites in terms of species composition. The differences in faunal composition, and particularly the presence of several new species discovered at Gallipoli, show once more that our knowledge of the bryozoan fauna in certain Mediterranean habitats is still incomplete and warrants further studies. https://doi.org/urn:lsid:zoobank.org:pub:DDC82039-EF44-4169-8198-C67F60B14BA0