Coral Biogeography Research Articles

Rugose Coral Biogeography of the Western Palaeotethys During the Mississippian

The Mississippian was an epoch of strong earth system changes, both tectonic and climatic. During the Mississippian, the marine faunas experienced a recovery after the late Devonian mass extinctions, and the rugose corals are a conspicuous example. This study tries to give a general view of the utility of rugose coral to reconstruct the palaeogeography in the Western Palaeotethys during the Mississippian. The methodology includes a database with the genera and species recorded in that area and time period, compiled using more than 700 articles and revisions of several collections in Europe. We worked with the six sub-provinces defined in previous studies for the Western Palaeotethys. A generic-level analysis was performed using paired group hierarchical clustering, building clusters for the Tournaisian, early Visean, late Visean and Serpukhovian. With that information, palaeomaps for those intervals have been illustrated and discussed. The rugose corals have some deficits for the reconstruction of the biogeography because of their strong palaeoecologic control and their insufficient and unequal record, but they provide important information that improves the knowledge on the palaeogeography of the studied region.

A tenuis relationship: traditional taxonomy obscures systematics and biogeography of the ‘Acropora tenuis’ (Scleractinia: Acroporidae) species complex

Abstract Molecular phylogenetics has fundamentally altered our understanding of the taxonomy, systematics and biogeography of corals. Recently developed phylogenomic techniques have started to resolve species-level relationships in the diverse and ecologically important genus Acropora, providing a path to resolve the taxonomy of this notoriously problematic group. We used a targeted capture dataset (2032 loci) to investigate systematic relationships within an Acropora clade containing the putatively widespread species Acropora tenuis and its relatives. Using maximum likelihood phylogenies and genetic clustering of single nucleotide polymorphisms from specimens, including topotypes, collected across the Indo-Pacific, we show ≥ 11 distinct lineages in the clade, only four of which correspond to currently accepted species. Based on molecular, morphological and geographical evidence, we describe two new species; Acropora rongoi n. sp. and Acropora tenuissima n. sp. and remove five additional nominal species from synonymy. Systematic relationships revealed by our molecular phylogeny are incongruent with traditional morphological taxonomy and demonstrate that characters traditionally used to delineate species boundaries and infer evolutionary history are homoplasies. Furthermore, we show that species within this clade have much smaller geographical ranges and, consequently, population sizes than currently thought, a finding with profound implications for conservation and management of reef corals.

Data on coral species occurrences in Japan since 1929

AbstractThis paper describes the species occurrence record of zooxanthellate reef‐building corals at 1047 sites on the Japanese coast, recorded from 1929 to 2017. The dataset includes 484 confirmed scientific species names compiled from 152 literature sources, most of which were written in Japanese and published as gray literature in local journals or individual reports. Scientific names were consolidated under currently accepted nomenclature based on the World Register of Marine Species. Further revision of species names was made by referring to monographs on temperate coral species of Japan, along with expert knowledge. The dataset includes the coral species recorded each year at each study site, the geographical location of each site, and the scientific names of the corals. Three supporting datasets were created, containing a list of literature, the names of the sites and synonymization and confirmation of the coral names. This up‐to‐date collection of data is a contribution to the study of coral biogeography and conservation planning, as well as long‐term changes in coral species distributions in response to climate change.The complete data set for this abstract published in the Data Paper section of the journal is available in electronic format in MetaCat in JaLTER at http://db.cger.nies.go.jp/JaLTER/metacat/metacat/ERDP-2020-08.1/jalter-en.

Biogeography of Holocene coral species in the western Indian Ocean

Abstract Understanding the relationship between coral biogeography and reef development is a key topic in sedimentology and paleoecology. Although the knowledge of coral reef growth and internal facies patterns during the Holocene has increased since the 1970s, the biogeography of Holocene coral species in the Indo-Pacific regions remains poorly constrained. In this study, we examined quantitative records of coral species based on data from five cores retrieved from two Holocene reefs in the western Indian Ocean: La Pointe-au-Sable reef on Mauritius Island and Toliara reef on Madagascar. Our results indicate that the dominant reef-building corals on both reefs were Isopora palifera , Acropora robusta/abrotanoides complex. Some corals (e.g., the A. robusta / abrotanoides complex and Acropora digitifera ) from 6 ka were found in Mauritius, whereas these were not identified in the cores from Madagascar before 1.5–1 ka. This delay may have been controlled by ocean currents and/or the competency period of the coral larvae. A comparison of these coral assemblages with those in other regions (Seychelles, Mayotte, Ryukyu Islands, Palau Islands, Papua New Guinea, the Great Barrier Reef, New Caledonia, and Vanuatu) showed that I. palifera was common in all of the studied regions, whereas Goniastrea retiformis probably migrated recently to Mauritius and Madagascar in response to prevailing surface ocean currents, including the South Equatorial Current and the Agulhas Current. One explanation for the late arrival of G. retiformis to the study sites could be that the competency period of G. retiformis larvae is shorter than that of I. palifera . Moreover, our quantitative analysis suggests that a given population size during the Holocene may have contributed to the abundance of species in modern reefs. This study emphasizes the need for further quantitative research on Holocene coral species in other regions to better understand the temporal and spatial patterns of coral biogeography.

Global ocean conveyor lowers extinction risk in the deep sea

General paradigms of species extinction risk are urgently needed as global habitat loss and rapid climate change threaten Earth with what could be its sixth mass extinction. Using the stony coral Lophelia pertusa as a model organism with the potential for wide larval dispersal, we investigated how the global ocean conveyor drove an unprecedented post-glacial range expansion in Earth׳s largest biome, the deep sea. We compiled a unique ocean-scale dataset of published radiocarbon and uranium-series dates of fossil corals, the sedimentary protactinium–thorium record of Atlantic meridional overturning circulation (AMOC) strength, authigenic neodymium and lead isotopic ratios of circulation pathways, and coral biogeography, and integrated new Bayesian estimates of historic gene flow. Our compilation shows how the export of Southern Ocean and Mediterranean waters after the Younger Dryas 11.6kyr ago simultaneously triggered two dispersal events in the western and eastern Atlantic respectively. Each pathway injected larvae from refugia into ocean currents powered by a re-invigorated AMOC that led to the fastest postglacial range expansion ever recorded, covering 7500km in under 400 years. In addition to its role in modulating global climate, our study illuminates how the ocean conveyor creates broad geographic ranges that lower extinction risk in the deep sea.

Chapter 9 Coral biogeography in the Late Ordovician (Cincinnatian) of Laurentia

Abstract During the Late Ordovician, Cincinnatian, the epicontinental seas and continental margin of Laurentia provided habitats that were suitable for corals. Biogeographical differentiation occurred within this equatorially placed continent, when corals were introduced to areas that had fundamentally different environments. There were four biogeographical divisions, characterized by distinctive faunas that included some endemic taxa: the Red River–Stony Mountain Province, Richmond Province, Edgewood Province and the less well understood, informal ‘Continental Margin’ Area. In each division, the potential for diversification and the capacity for diversity were determined by factors such as the duration and size of the division, the amount of immigration, the extent of evolution and biogeographical differentiation, faunal responses to changes in sea-level and climate, and the complexity of the ecological structure. The development of multiple biogeographical divisions, each contributing to overall diversity, enhanced the ‘Great Ordovician Biodiversification Event’. During the latest Ordovician mass extinction, there was a reduction of diversity and loss of biogeographical divisions within Laurentia. The divisions were terminated when their characteristic taxa disappeared, in response to major environmental changes associated with glaciation in Gondwana and subsequent global warming.

Cold-water coral distributions in the drake passage area from towed camera observations--initial interpretations.

Seamounts are unique deep-sea features that create habitats thought to have high levels of endemic fauna, productive fisheries and benthic communities vulnerable to anthropogenic impacts. Many seamounts are isolated features, occurring in the high seas, where access is limited and thus biological data scarce. There are numerous seamounts within the Drake Passage (Southern Ocean), yet high winds, frequent storms and strong currents make seafloor sampling particularly difficult. As a result, few attempts to collect biological data have been made, leading to a paucity of information on benthic habitats or fauna in this area, particularly those on primarily hard-bottom seamounts and ridges. During a research cruise in 2008 six locations were examined (two on the Antarctic margin, one on the Shackleton Fracture Zone, and three on seamounts within the Drake Passage), using a towed camera with onboard instruments to measure conductivity, temperature, depth and turbidity. Dominant fauna and bottom type were categorized from 200 randomized photos from each location. Cold-water corals were present in high numbers in habitats both on the Antarctic margin and on the current swept seamounts of the Drake Passage, though the diversity of orders varied. Though the Scleractinia (hard corals) were abundant on the sedimented margin, they were poorly represented in the primarily hard-bottom areas of the central Drake Passage. The two seamount sites and the Shackleton Fracture Zone showed high numbers of stylasterid (lace) and alcyonacean (soft) corals, as well as large numbers of sponges. Though data are preliminary, the geological and environmental variability (particularly in temperature) between sample sites may be influencing cold-water coral biogeography in this region. Each area observed also showed little similarity in faunal diversity with other sites examined for this study within all phyla counted. This manuscript highlights how little is understood of these isolated features, particularly in Polar regions.

Early Permian location of western North American terranes based on brachiopod, fusulinid, and coral biogeography

Brachiopod, rugose coral, and fusulinid faunas present in Early Permian rocks along northern and western margins of North America, in both cratonal localities and accreted terranes, have been compared statistically, allowing refinement in placement of these terranes relative to the North American continental margin at that time. Statistical tests, including conventional and probabilistic indices of similarity, as well as multivariate analysis, show that the faunas of Wrangellia-Alexander are most similar to those of Stikinia and Quesnellia, and to the Yukon–Canadian Rocky Mountains part of the continental margin. They also show that faunas of the Eastern Klamath terrane are most similar to those of Stikinia, Quesnellia, and the central cordilleran part of the continental margin. These results suggest that during the Early Permian Wrangellia-Alexander was the northernmost of these terranes, lying west of the Yukon–Canadian Rocky Mountains region, and the Eastern Klamath terrane was the southernmost, lying west of the central Cordillera. Stikinia and Quesnellia were in intermediate positions. These relative latitudes are compatible with latitudinal determinations based on paleomagnetic data. Faunal diversity in the Eastern Klamath and Stikine terranes is similar to that at similar latitudes on the craton, whereas diversity in the Wrangellia-Alexander terrane is considerably lower than that of the latitudinally similar Yukon–Canadian Rocky Mountains area. As diversity is, in part, a function of temperature, this may suggest water around the Wrangellia-Alexander terrane was cooler than that along the continental margin. Therefore, we suggest that warm-water currents bathed the southern terranes and the southern and central parts of coastal North America, whereas cool-water currents influenced the northernmost terrane (Wrangellia-Alexander). Revised Otsuka similarity coefficients for corals show higher similarities between western North American terranes and the western continental margin than previously published, but they still are relatively low. This and the overall patterns of similarity and limits on distribution of Tethyan corals and fusulinids in the eastern Panthalassa suggest that Wrangellia-Alexander, Stikinia, and the Eastern Klamath terranes were at approximately the same distance (estimated at 2000–3000 km) from their latitudinally equivalent segments of the North American craton.

Suppression subtractive hybridization PCR isolation of cDNAs from a Caribbean soft coral

Transcriptomic studies of marine organisms are still in their infancy. A partial, subtracted expressed sequence tag (EST) library of the Caribbean octocoral Erythropodium caribaeorum and the sea fan Gorgonia ventalina has been analyzed in order to find novel genes or differences in gene expression related to potential secondary metabolite production or symbioses. This approach entails enrichment for potential non-housekeeping genes using the suppression subtractive hybridization (SSH) polymerase chain reaction (PCR) method. More than 500 expressed sequence tags (ESTs) were generated after cloning SSH products, which yielded at least 53 orthologous groups of proteins (COGs) and Pfam clusters, including transcription factors ( Drosophila Big Brother), catalases, reverse transcriptases, ferritins and various hypothetical protein sequences. A total of 591 EST sequences were deposited into GenBank [dbEST: FL512138 - FL512331, and GH611838]. The results represent proof of concept for enrichment of unique transcripts over housekeeping genes, such as actin or ribosomal genes, which comprised approximately 17% of the total dataset. Due to the gene and sequence diversity of some ESTs, such sequences can find utility as molecular markers in current and future studies of this species and other soft coral biogeography, chemical ecology, phylogenetics, and evolution.

Comments on coral reef regeneration, bioerosion, biogeography, and chemical ecology: future directions

This paper represents a brief review of three processes operating on coral reefs and the results of studies of a fourth process, and how those results may be applied to the benefit of humankind. The areas are reef regeneration processes; bioerosion; dispersal, recruitment and biogeography of corals; and chemical ecology and natural products chemistry of reef organisms. Possible future directions for research will also be considered in each area. Regarding reef regeneration processes, coral reefs are degrading rapidly on a global scale due to over-fishing, fishing techniques causing habitat destruction, deforestation, mass mortalities of key reef species, nutrient enrichment and sedimentation. Seeding of reefs with the larvae of corals and other key reef organisms, such as echinoids, may help to promote and enhance reef regeneration in the future. Such techniques will be made possible by studies of the embryology, larval ecology, dispersal and recruitment processes, and related local physical oceanographic processes. Regarding bioerosion, both internal and external bioerosion are affected by grazers and predators. Bioerosion is also affected by nutrient enrichment, as shown through correlative studies (Great Barrier Reef) and studies of opportunity (Kaneohe Bay). Ongoing experiments such as ENCORE will help to answer questions about the role of dissolved nutrients in enhancing internal bioerosion. Questions still remain, however, regarding the role of particulates in promoting internal bioerosion and the resultant weakening of and negative growth in the reef framework. Regarding dispersal, recruitment and the biogeography of corals, it is now known that most species of coral reproduce via broadcasting, although there appear to be proportionally more brooders in the Caribbean than in the western Pacific. Differential extinctions in the western Pacific vs. the western Atlantic have contributed to the biogeographic distribution of corals we observe today and the concentric isoclines of species diversity in numerous reef organisms in the western Pacific. The role of reproductive mode in contributing to these patterns is, however, still not understood. Investigations into the roles of different larval longevities and reproductive modes may help us answer questions regarding their differential distribution and the potential effects of major perturbations such as global warming on future distributions. With respect to the chemical ecology of alcyonacean octocorals (soft corals), four functions have been determined thus far for secondary metabolites in this group, anti-predation, anti-competition (allelopathy), anti-fouling, and enhancement of reproductive success. Investigations of alcyonacean reproduction has revealed that it may be necessary for several secondary metabolites to be present simultaneously before a function may be realized or fully manifested. This raises questions regarding the manner in which novel compounds are tested by medical laboratories for bioactivity using a single compound. Simultaneously testing of multiple compounds derived from a single organism may be necessary in the future to reveal potential valuable synergistic bioactivity. Also, some novel secondary metabolites may have other valuable commercial applications, as is the case with the UV-absorbing compounds of corals and other reef organisms found on the Great Barrier Reef. In order to avoid overlooking medically or commercially valuable functions of these compounds, broader testing may be necessary.

Permian longitudes of Wrangellia, Stikinia, and Eastern Klamath terranes based on coral biogeography

Trend-surface analysis of biogeographic data and probabilistic estimates of diversity and similarity provide a new approach to understanding the origin of North American suspect terranes. Results from Permian corals indicate that (1) the eastern boundary of the Tethyan coral province was about 2000 km west of the North American craton; (2) Eastern Klamath and Stikinia were close to one another and were up to 6700 km west of North America during the Early Permian; (3) Wrangellia was situated to the southeast of Stikinia, as much as 5000 km west of the craton; (4) the Late Permian location of the Eastern Klamath terrane was 3000-5800 km west of the craton and between 11° and 21°N; and (5) the Eastern Klamath terrane moved westward during the Permian, possibly as a result of back-arc spreading.

Mangrove Biogeography: The Role of Quaternary Environmental and Sea-Level Change

Mangroves and corals have broadly similar pat- terns of global distribution with a major disjunction between New World and Old World populations. However, while palaeogeographic interpretations of present coral dis- tributions have emphasized the role of environmental and sea-level fluctuations during the Quatemary, the traditional explanation of mangrove distributions has invoked gradual dispersal over the Tertiary and Quatemary from a Southeast Asian centre of origin. The distribution of mangroves at their latitudinal limits and on oceanic islands is examined. These observations together with palynological evidence for substantial changes in mangrove extent in the Holocene are used to suggest that sea-level fluctuations in particular have caused major disruptions to mangrove distributions during the Quatemary. Many species of mangroves have re- colonized oceanic islands during the Holocene and their present distribution is, at least in part, a function of their successful transoceanic dispersal to these islands. Although little evidence of Pleistocene distributions of mangroves is preserved, environmental and especially sea-level fluctuations are likely to have played a similar role in the biogeography of mangroves as they have in influencing the biogeography of corals.

Late Ordovician and early Silurian rugose coral biogeography and world reconstruction of palaeocontinents

Two epochs of Early Palaeozoic rugose coral diversification, Caradocian-Ashgillian and Middle Llandoverian-Early Wenlockian, are chosen for biogeographical analysis at the generic level, following an overall revised classification of the Rugosa (Wang et al., 1989a). World reconstruction maps are based on palaeomagnetic, palaeotectonic and palaeoblogeographic data, and were constructed through an autograph programme on an IBM PC-AT microcomputer. The Caradocian and Ashgillian rugose corals are in 16 families and 71 genera, including 15% Cystiphyllida, 40% Streptelasmatida and 44% Columnariida, in addition to the zaphrentoidid genus Protozaphrentis. Two biogeographical realms, the West Prototethyan and the East Prototethyan, may be discerned. The West Prototethyan Realm includes three provinces, the Siberian, the North American and the Kazakhstan-Hinganian. The East Prototethyan Realm also includes three provinces, the Southeast Asian (Yangtzean), the East Australian and the North European. The third area, the Gondwanan, is devoid of corals. In Middle and Late Llandoverian and Early Wenlockian, the rugose corals have 27 families and 130 genera, of which 26% are Cystiphyllida, 32% are Streptelasmatida and 41% are Columariida, in addition to the zaphrentoidid genus Duncanella. The West Prototethyan Realm contains three provinces, the Siberia-Mongolian, the North European and the North American. The East Prototethyan Realm consists of two provinces, the Southeast Asian (Yangtzean) and the Kazakhatan-Sinokorean, both bearing Ceriaster and Amplexoides.

Indo-Pacific coral biogeography: a case study from the Acropora selago group

We develop species-level biogeographic hypotheses for Acropora, the largest extant coral genus and the dominant scleractinian coral of Indo-Pacific reefs, based on morphometric and phylogenetic analyses of the Acropora selago group. Fourteen morphometric characters differentiated species from this group with an accuracy of 95%. When the Tukey test was administered, 11 of these characters displayed nonoverlapping subsets. The most resolved phylogenetic tree resulted from an analysis based on both morphometric and qualitative characters. Cladistic-biogeographic analysis using this tree and areas derived from species-distribution patterns showed that species with the greatest degree of endemism within the A. selago group possess the most derived character states, while the most primitive species (A. yongei) is the most widespread. Within the range of the group, four areas are recognised: (1) the Red Sea, (2) western to central Indian Ocean, (3) eastern Indian Ocean and (4) western to central Pacific Ocean. Species ranges overlap in a stepwise fashion from west to east. Areas adjacent to one another are biogeographically more closely related than non-adjacent areas. Whilst we offer a scenario for the history of distribution patterns of the A. selago group, we propose that biogeographical hypotheses based on Acropora be tested using a number of different species-groups. Similar distributional ranges for other Acropora species-groups, as well as separate distributional ranges for further groups, suggest that Acropora will provide an appropriate taxon to examine the biogeography of the tropical marine realm.

Marine invertebrates of the Pitcairn Islands: species composition and biogeography of corals, molluscs, and Echinoderms

Marine invertebrates of the Pitcairn Islands: species composition and biogeography of corals, molluscs, and Echinoderms

Biogeography of Corals, Seagrasses, and Mangroves: An Alternative to the Center of Origin Concept

McCoy, E. D., and K. L. Heck, Jr. (Department of Biological Science, Florida State University, Tallahassee, Florida 32306) 1976. Biogeography of corals, seagrasses, and mangroves: an alternative to the of concept. Syst. Zool. 25:201-210.-A center of origin explanation for the distribution and diversity patterns of the organisms comprising the principal shillow-water habitats in the tropics-hermatypic corals, mangroves, and seagrasses-is highly unlikely, based on fossil data and the dispersal capabilities of the organisms. Instead, these biogeographic patterns are better explained by the existence of a previously widely-distributed biota which has since been modified by tectonic events, speciation, and extinction, in accordance with modern geological and biogeographical theory. [Corals; seagrasses; mangroves; biogeography; vicariance.] The center of origin concept-that a taxon's place of is the region in which it is most diverse-is nearly axiomatic (Rotramel, 1973). Briggs (1961, 1966, 1967), Darlington (1957), and Mayr (1965) have all been active proponents of this assumption, although Darlington has warned against its application when a thorough fossil record does not exist to verify it. Other biogeographers (e.g. Cain, 1944, Croizat, 1958; Croizat et al., 1974) also have strongly questioned the uncritical application of the of concept. Despite these warnings and criticisms the concept has a facile appeal, and remains viable (for a recent example, see Muller, 1973). The of concept was originally conceived on the assumption that the positions of the continents remained constant through time. This implied that closely-related organisms inhabiting widelyseparated land masses or bodies of water must have somehow dispersed over long distances. Of course, it can no longer be accepted that the continents have remained stationary, and as a result, it is necessary to critically reevaluate the validity of earlier conclusions involving the of concept. In place of the notion that 1 Order of authorship was determined by the toss of a coin. centers of can be identified by centers of diversity, we advocate acceptance of the following ideas which take into account current biogeographical, ecological, and geological reasoning: (1) Longterm climatic and tectonic events cause environmental changes with important biotic consequences; hence, present centers of diversity may not have always been so (cf. Carson, 1970); and (2) localized ecological processes, such as extinction and species-area relationships, are significant determinants of species diversity independently of where the taxon originated; thus, present distributions and diversity patterns represent more than long-term, monotonous radiation of species from some point of origin. An important ancillary point is that the evidence for long-distance dispersal of widely-distributed organisms is often tenuous, though it is rarely presented as such. To illustrate how these newer ideas can be applied in explaining biographical patterns, we use three important groups of marine organisms and compare results obtained from them with those generated by the of concept. We have chosen hermatypic corals, seagrasses, and mangroves for a number of reasons: (1) They are the principal shallow-water sessile assemblages throughout the world's tropics; (2) they presently co-occur throughout the tropics, and their diversity patterns and