Black Coral Species Research Articles

Healthy assemblages of Isidella elongata unintentionally protected from trawling offshore of Asinara Island (northwestern Sardinia, NW Mediterranean Sea)

Deep-sea coral assemblages are marine biodiversity hot spots. Because of their life history traits, deep-sea corals are highly vulnerable to the impacts of human activities such as fishing. The critically endangered “bamboo coral” Isidella elongata is a key structuring species of deep muddy bottoms that is susceptible to habitat destruction, particularly from trawling. A shallow population of this species was recently discovered by a multibeam and ROV survey offshore of the Asinara Island marine protected area (MPA) (northwestern Sardinia, NW Mediterranean Sea). This vulnerable marine assemblage has been found under healthy conditions at depths ranging from 110 to 298 m. Isidella elongata occurs on a muddy seafloor locally characterised by boulders associated with black coral species (Parantipathes larix and Antipathes dichotoma). The lush colonies of I. elongata seem to be related to natural protection from bottom trawling activity; nevertheless, the presence of lost fishing artisanal nets has been observed in the study area. These structuring species are indicators of vulnerable marine ecosystems, and their conservation is essential for preserving marine biodiversity. Therefore, enlarging the perimeter of the Asinara Island MPA into its deeper western waters is suggested to ensure the protection of these valuable and vulnerable marine ecosystems.

Alternatipathes longispina sp. nov. and Bathypathes longicaulis sp. nov., two black corals (Antipatharia, Schizopathidae) from seamounts in the Western Pacific

Members of the order Antipatharia Milne-Edwards & Haime, 1857 are important structural components of hard bottom communities in the shallow and deep seas. However, their diversity in the Western Pacific is poorly known. Here we describe two new species of black corals within the family Schizopathidae Brook, 1889 from the tropical Western Pacific seamounts: Alternatipathes longispina sp. nov. and Bathypathes longicaulis sp. nov. The new species Alternatipathes longispina is characterized by a monopodial and unbranched corallum with the maximum width nearly two times as long as the height, the lower unpinnulated section of stem slightly shorter than the upper pinnulated one, the pinnules decreasing in length from the lowermost ones to the uppermost, and the prominent polypar spines ranging from 0.29 mm to 0.58 mm high, such a feature make the species differ from all congeners. Bathypathes longicaulis sp. nov. is characterized by a monopodial and unbranched corallum with a much longer unpinnulated stem and alternately arranged pinnules along the upper part of stem. It can be distinguished from congeners by its much longer unpinnulated stem, the alternately arranged pinnules, and the number of pinnules. Phylogenetic analyses based on the nuclear internal transcribed spacer region (ITS1-5.8S-ITS2) and three mitochondrial fragments cox3-IGR-cox1, trnW-IGR-nad2 and nad5-IGR-nad1 shows that A. longispina sp. nov. clusters with the type species A. bipinnata, and the genus Alternatipathes is closely related to Umbellapathes. The present phylogenetic trees confirm the polyphyly of Bathypathes and show that B. longicaulis sp. nov. is sister to Telopathes cf. magna MacIsaac & Best, 2013.

New species of black corals (Cnidaria: Anthozoa: Antipatharia) from the New Zealand region, part 3

ABSTRACT Five new species of antipatharian corals are described from the New Zealand region. Differential diagnoses are given and comparisons are made to related nominal species. Described as new are: Anozopathes psednocrada, Aphanipathes rosemariae, and Acanthopathes candelabra in the family Aphanipathidae; Triadopathes trilix in the family Stylopathidae; and Lillipathes ventalina in the family Schizopathidae.

The Nekton Maldives taxonomic workshop: Exploring the biodiversity of shallow, mesophotic and deep-sea communities in Maldives

The Nekton Maldives Taxonomic Workshop took place at the Maniyafushi Research Station in the Maldives between 12 and 23 February 2023. This workshop had two primary objectives. Firstly, it aimed to identify species from biological samples and underwater imagery collected during the Nekton Maldives Mission in 2022. Secondly, it sought to facilitate training and knowledge exchange sessions between early career researchers from the Maldives and international taxonomists. These sessions were designed to share knowledge and introduce fundamental taxonomy concepts and enhance practical identification skills for common reef benthic groups and major zooplankton taxonomic groups. A total of 24 people from 10 different countries were directly or indirectly involved with the workshop comprising nine taxonomic experts, eleven trainees and four organisers. Collectively, we identified 278 biological specimens including potentially undescribed species of hydroids, black corals, sponges and octocorals, 318 morphotypes for underwater footage and zooplankton composition congruent with previous reports from the Indian Ocean Region. Next steps will involve depositing the specimens into a more a permanent facility to facilitate the process of specimen description and knowledge transfer.

Five new species of black coral (Anthozoa; Antipatharia) from the Great Barrier Reef and Coral Sea, Australia

We describe five new species of black corals from the Great Barrier Reef and Coral Sea, collected at depths ranging from 14 to 789 m: two in the family Antipathidae (Antipathes falkorae sp. nov. and Antipathes morrisi sp. nov.), two in the family Aphanipathidae (Aphanipathes flailum sp. nov. and Rhipidipathes helae sp. nov.), and one in the family Cladopathidae (Hexapathes bikofskii sp. nov.). We also present a phylogeny of 80 black corals reconstructed from a target capture dataset of ultraconserved elements and exons, to show the systematic relationships among new and nominal species. This phylogeny also represents a backbone for future species descriptions and research into the evolutionary history of the Antipatharia.

Proteomic Profiling of Black Coral (Antipatharia) Skeleton Reveals Hundreds of Skeleton-Associated Proteins Across Two Taxa

Black corals, ecologically important cnidarians found from shallow to deep ocean depths, form a strong yet flexible skeleton of sclerotized chitin and other biomolecules including proteins. The structure and mechanical properties of the chitin component of the skeleton have been well-characterized. However, the protein component has remained a mystery. Here we used liquid chromatography-tandem mass spectrometry to sequence proteins extracted from two species of common Red Sea black corals following either one or two cleaning steps. We detected hundreds of proteins between the two corals, nearly 70 of which are each other’s reciprocal best BLAST hit. Unlike stony corals, only a few of the detected proteins were moderately acidic (biased toward aspartic and/or glutamic acid residues) suggesting less of a role for these types of proteins in black coral skeleton formation as compared to stony corals. No distinct chitin binding domains were found in the proteins, but proteins annotated as having a role in protein and chitin modifications were detected. Our results support the integral role of proteins in black coral skeleton formation, structure, and function.

Perspectives on working underwater with black coral nubbins (Cnidaria: Antipatharia): The case of Cirrhipathes anguina (Dana, 1846)

In order to test the feasibility of transplantation of the whip black coral species Cirrhipathes anguina (Dana, 1846) from Madagascar, transplants were installed on cultivation tables in two sites (the North Pass and the Grande Vasque) characterized by distinct environmental conditions. Following transplantation, the transplants were followed for short-term (20 days) healing capacities and medium-term (200 days) mortality and growth rates. Results show a successful transplantation in both sites with 0% mortality (except in the form of missing fragments) and a certain growth over 200 days. Maximum growth rates were 3.4 cm/month and 2.0 cm/month in the North Pass and in the Grande Vasque, respectively. In addition, mean time to total healing was delayed in the Grande Vasque compared to the transplants in the North Pass (10 days). Differences between sites are likely to be related to differences in environmental parameters. Altogether, the promising results obtained with the easy protocol used in this study encourage the use of black coral transplants in further in situ experiments and restoration projects.

Description of two new genera and two new species of antipatharian corals in the family Aphanipathidae (Cnidaria: Anthozoa: Antipatharia).

Two new genera and two new species of black corals are recognized in the family Aphanipathidae. The new genus Anozopathes, with the species A. hawaiiensis sp. nov. and A. palauensis, sp. nov. is characterized by a sparsely and irregularly branched corallum with relatively long branches which can be straight, curved or crooked. The genus Aphanostichopathes, with the type species Cirripathes paucispina Brook, is characterized by an unbranched corallum with a long, curved stem with loose distal coils. Mitochondrial DNA data (nad5-IGR-nad1 for Anozopathes and cox3-cox1 for Aphanostichopathes) indicate that both taxa are related to the genera Aphanipathes, Phanopathes and Acanthopathes in the family Aphanipathidae, and morphologically they both share the characteristic of having spines with distinct conical tubercles. The two new species of Anozopathes are separated primarily by differences in colony growth form and in the size and shape of the skeletal spines. Species of Aphanostichopathes are separated primarily by differences in the size and shape of the spines and by size and density of the tubercles on the surface of the spines.

Potential Distribution and Environmental Niche of the Black Corals Antipathes galapagensis and Myriopathes panamensis in the Eastern Tropical Pacific1

Antipathes galapagensis and Myriopathes panamensis are black coral species (Order Antipatharia) distributed in the Eastern Pacific from the Gulf of California to the coasts of Peru, at depths from -10 m to -200 m for A. galapagensis and to -50 m for M. panamensis. Antipatharians have great ecological importance as engineer species and major constituents of “coral forests,” which are recognized as vulnerable marine ecosystems. Antipathes galapagensis has been a target of fisheries in several countries and has frequently been overexploited. Thus, the aim of this study was to compile a database of georeferenced records of A. galapagensis and M. panamensis, and use distribution data and environmental variables to construct habitat suitability models with Maxent software, in order to better understand black coral environmental requirements and potential distributions in the Eastern Tropical Pacific. The models showed good fit and performance (AUC > 0.9); key variables that drive the potential distribution of both species were chlorophyll a, nutrient concentration, and seawater temperature. The models did not predict occurrences beyond the recognized distribution range limits of the species; notwithstanding, they indicated that the Pacific coast of the Baja California Peninsula and the central and southern coasts of the Mexican Pacific have areas of high suitability for the presence of these corals. To our knowledge, no black coral records from these sites exist in the literature to date; thus, field validations are needed to verify the model predictions. With these results, it is possible to offer suggestions of new conservation sites for black corals based on the areas with the highest probability of occurrence of the species.

ITS1 variation among Stichopathes cf. maldivensis (Hexacorallia: Antipatharia) whip black corals unveils conspecificity and population connectivity at local and global scales across the Indo-Pacific

Due to the dearth of molecular markers variable enough to distinguish species of black corals, species delimitation in Antipatharia is still mainly based on morphological traits. One of the few markers available, the internal transcribed spacer (ITS) region located in ribosomal DNA, has already been used several times to infer phylogenetic relationships among antipatharians. However, this region was never considered in population-scale studies of shallow-water black corals till now. Here, we sampled two phenotypic variants of 41 specimens of the shallow-water antipatharian Stichopathes cf. maldivensis along the SW of Madagascar. The sampling area represents 200 km of shore and encompasses the runoffs of three rivers. We used direct sequencing to determine the main ITS1 types present in the genomes of the collected specimens and retrieved sequences from GenBank for Indonesian specimens. Then, we constructed a haploweb to visualize possible species boundaries using the criterion of mutual allelic exclusivity. With this method, we confirm that the previously described phenotypic variants belong to a single species that apparently extends from Indonesia to Madagascar. Likewise, the three rivers that pour freshwater in southwestern Madagascar do not appear to act as a barrier for the larval dispersal of this species. This study highlights the usefulness of ITS markers within antipatharians at both species and population levels.

Newspeciesofblackcorals(Cnidaria:Anthozoa:Antipatharia)fromdeep-seaseamountsandridgesinthe NorthPacific.

Three new species of antipatharian corals are described from deep-sea (677-2,821 m) seamounts and ridges in the North Pacific, including Antipathes sylospongia, Alternatipathes venusta, and Umbellapathes litocrada. Most of the material for these descriptions was collected on expeditions aboard NOAA Ship Okeanos Explorer that were undertaken as part of the Campaign to Address Pacific Monument Science, Technology, and Ocean Needs (CAPSTONE). One of the main goals of CAPSTONE was to characterize the deep-sea fauna in protected waters of the U.S. Pacific, as well as in the Prime Crust Zone, the area with the highest known concentration of commercially valuable deep-sea minerals in the Pacific. Species descriptions and distribution data are supplemented with in situ photo records, including those from deep-sea exploration programs that have operated in the North Pacific in addition to CAPSTONE, namely the Hawaii Undersea Research Laboratory (HURL), the Ocean Exploration Trust (OET), and the Monterey Bay Aquarium Research Institute (MBARI).

Ageing Deep-Sea Black Coral Bathypathes patula

Deep-sea corals are a highly diverse group of marine organisms, several of which are characterised by slow growth and extreme longevity up to thousands of years. Due to their fragile forms, skeletal composition, and location, they are vulnerable to various anthropogenic threats, with some groups expected to have little to no ability to recover. Within the New Zealand region an understanding of age and growth parameters and recovery potential for some deep-sea coral fauna is being developed, but a limited understanding remains for some of the key Antipatharian black coral fauna. Ten individual colonies of the black coral species Bathypathes patula were sourced from the National Institute of Water and Atmospheric Research Invertebrate Collection for the purposes of this age estimation study. Corals were selected based on their size, completeness of the colony (whole colony from base to tip), and the regional water mass within which they grew. Coral samples from the Chatham Rise, east of New Zealand, and the Bay of Plenty, north-eastern New Zealand, were selected as the water masses for these two regions are reasonably well understood. Thin section preparations of the main stem of the 10 specimens of B. patula were observed with compound microscopes. Two interpretation protocols were used to describe the zone structures observed, both the coarse wide zones and the thin fine zones, and counts were then made of these structures. Four of the specimens were also sampled for radiocarbon assay. The radiocarbon isotope (14C) age data results were used to independently verify if either of the developed zone counting protocols reflected annual periodicity. Neither method was verified, indicating zone counting protocols could not be used to generate reliable age estimates for B. patula. Twenty radiocarbon assays from four specimens were used to derive the age and growth rate estimates presented here. The radiocarbon results from this work show B. patula to be a long-lived species, attaining ages in excess of 385 years, with linear growth rates of 5.2-9.6 mm/yr, and radial growth rates ranging from 11.1 to 35.7 mm/yr. The delicate nature of these organisms along with their longevity and slow growth rates means a low resilience and low recoverability from anthropogenic activities such as fishing and mining.

Electrochemical Approach for Isolation of Chitin from the Skeleton of the Black Coral Cirrhipathes sp. (Antipatharia).

The development of novel and effective methods for the isolation of chitin, which remains one of the fundamental aminopolysaccharides within skeletal structures of diverse marine invertebrates, is still relevant. In contrast to numerous studies on chitin extraction from crustaceans, mollusks and sponges, there are only a few reports concerning its isolation from corals, and especially black corals (Antipatharia). In this work, we report the stepwise isolation and identification of chitin from Cirrhipathes sp. (Antipatharia, Antipathidae) for the first time. The proposed method, aiming at the extraction of the chitinous scaffold from the skeleton of black coral species, combined a well-known chemical treatment with in situ electrolysis, using a concentrated Na2SO4 aqueous solution as the electrolyte. This novel method allows the isolation of α-chitin in the form of a microporous membrane-like material. Moreover, the extracted chitinous scaffold, with a well-preserved, unique pore distribution, has been extracted in an astoundingly short time (12 h) compared to the earlier reported attempts at chitin isolation from Antipatharia corals.

Morphological and molecular characterization of a new species of black coral from Elvers Bank, north-western Gulf of Mexico (Cnidaria: Anthozoa: Hexacorallia: Antipatharia: Aphanipathidae: Distichopathes)

AbstractThe continental shelf edge of the NW Gulf of Mexico supports dozens of reefs and banks, including the West and East Flower Garden Banks (FGB) and Stetson Bank that comprise the Flower Garden Banks National Marine Sanctuary (FGBNMS). Discovered by fishermen in the early 1900s, the FGBs are named after the colourful corals, sponges and algae that dominate the region. The reefs and banks are the surface expression of underlying salt domes and provide important habitat for mesophotic coral ecosystems (MCE) and deep coral communities to 300 m depth. Since 2001, FGBNMS research teams have utilized remotely operated vehicles (e.g. ‘Phantom S2’, ‘Mohawk’, ‘Yogi’) to survey and characterize benthic habitats of this region. In 2016, a Draft Environmental Impact Statement proposed the expansion of the current sanctuary boundaries to incorporate an additional 15 reefs and banks, including Elvers Bank. Antipatharians (black corals) were collected within the proposed expansion sites and analysed using morphological and molecular methods. A new species, Distichopathes hickersonae, collected at 172 m depth on Elvers Bank, is described within the family Aphanipathidae. This brings the total number of black coral species in and around the sanctuary to 14.

Seasonal variation of the stable C and N isotopic composition of the mesophotic black coral Antipathella subpinnata (Ellis & Solander, 1786)

Trophic relationships significantly influence ecosystem functioning, ultimately affecting populations’ abundance, size structure and distribution. There is still a substantial knowledge gap on the trophic ecology of deep-sea organisms, particularly those living in the mesophotic depths (30–150 m), despite their crucial importance as ecosystem engineers. The trophic ecology of the most common mesophotic black coral species of the Mediterranean Sea, Antipathella subpinnata (Ellis & Solander, 1786), was studied by means of stable isotopes analysis in two seasons. The δ13C and δ15N analysis of the tissue of A. subpinnata, of the sediment, as well as the main planktonic fractions (pico-nanoplankton, microplankton, and mesozooplankton) indicate a diet based on pico-nanoplankton in autumn and mesozooplankton in spring. We calculated a trophic enrichment of 1‰ in δ13C and of 2.5‰ δ15N between prey and predator. Such information contributes towards drawing a complete picture of the pelagic-benthic coupling in the Mediterranean mesophotic coral forests.

New species of black corals (Cnidaria: Anthozoa: Antipatharia) from the New Zealand region, part 2

ABSTRACT One new genus and ten new species of antipatharian corals are described from the New Zealand region. Differential diagnoses are given and comparisons are made to related nominal species. Described as new is the genus Acanthosaropathes and the following species: Antipathes coronata, A. dicrocrada, A. polyhedra, Acanthosaropathes uniseriata, Phanopathes ctenocrada, Cupressopathes simplex, Stylopathes stenotes, Stauropathes stellata, Telopathes tasmaniensis, and Heteropathes intricata. This research highlights the diversity of deepsea corals for the region, improves knowledge of the distributional limits of species, which in turn can inform assessments of species prevalence for conservation initiatives and management decisions.

The complete mitochondrial genome of Tanacetipathes thamnea Warner, 1981 (Antipatharia: Myriopathidae)

Specimens of the black coral Tanacetipathes thamnea were collected from the Northwestern Gulf of Mexico. The complete mitochondrial genome of one of these specimens was obtained from genomic DNA by next-generation sequencing technology on the Illumina HiSeq 2500. Only three species of black corals have a completely sequenced mitochondrial genome. These were used to reconstruct the phylogeny for the order Antipatharia. The mitochondrial genome of T. thamnea is 17,712 base pairs and contains 13 protein-coding genes, 2 ribosomal RNAs, and 2 transfer RNAs in the following order: 16s RNA, COX3, COX1 (with intron), ND4L, COX2, ND4, ND6, ATP8, ATP6, and ND5 (with intron and copies of ND1 and ND3), tRNA-Trp, ND2, 12s RNA, CYTB, tRNA-Met. The gene arrangement is the same as that for Myriopathes japonica with a nearly identical sequence (99.35% identical). These results show that the mitochondrial genome within the family Myriopathidae is highly conserved.

Association between deep-water scale-worms (Annelida: Polynoidae) and black corals (Cnidaria: Antipatharia) in the Southwestern Atlantic

Polynoid scale-worms have been found living as commensals with deep-water antipatharians (commonly known as black corals) in the Potiguar Basin, off Rio Grande do Norte State, Northeastern Brazil. In this paper two polychaete species and four black corals species are redescribed. Benhamipolynoecf.antipathicola and Parahololepidellacf.greeffi, and the black coral Stylopathesadinocrada Opresko, 2006 are recorded for the Southwestern Atlantic. Benhamipolynoecf.antipathicola was first described from off New Zealand and the Malay Archipelago, as symbiont with the black coral Stylopathestenuispina (Silberfeld, 1909). It was later reported for the North Atlantic, off Florida, associated with Stylopathescolumnaris (Duchassaing, 1870). In our study, B.cf.antipathicola was found in association with the black coral S.adinocrada. Parahololepidellacf.greeffi was first described as a free-living from shallow waters off São Tomé and Cabo Verde Islands, West Africa, and later reported as symbiont with the black coral Tanacetipathescf.spinescens in the same location. Our data expand both the geographical distribution and the host range of this species which is reported for the first time as symbiont with Tanacetipathesbarbadensis (Brook, 1889), T.tanacetum (Pourtalès, 1880) and T.thamnea (Warner, 1981) in Brazil. The aim of this study is to discuss commensal associations between two species of scale-worm polynoids and black corals found in the Southwestern Atlantic, and also reporting their global distribution. Finally, we provided an updated list of the commensal polynoids and their black coral hosts.

The Diversity and Ecological Role of Non-scleractinian Corals (Antipatharia and Alcyonacea) on Scleractinian Cold-Water Coral Mounds

Cold-water coral carbonate mounds, created by framework-building scleractinian corals, are also important habitats for non-scleractinian corals, whose ecology and role are understudied in deep-sea environments. This paper describes the diversity, ecology and role of non-scleractinian corals on scleractinian cold-water coral carbonate mounds in the Logachev Mound Province, Rockall Bank, NE Atlantic. In total ten non-scleractinian species were identified, which were mapped out along eight ROV video transects. Eight species were identified as black corals (three belonging to the family Schizopathidae, one each to the Leiopathidae, Cladopathidae, and Antipathidae and two to an unknown family) and two as gorgonians (Isididae and Plexauridae). The most abundant species were Leiopathes sp. and Parantipathes sp. 2. Areas with a high diversity of non-scleractinian corals are interpreted to offer sufficient food, weak inter-species competition and the presence of heterogeneous and hard settlement substrates. A difference in the density and occurrence of small vs. large colonies of Leiopathes sp. was also observed, which is likely related to a difference in the stability of the substrate they choose for settlement. Non-scleractinian corals, especially black corals, are an important habitat for crabs, crinoids, and shrimps in the Logachev Mound Province. The carrier crab Paromola sp. was observed carrying the plexaurid Paramuricea sp. and a black coral species belonging to the genus Parantipathes, a behavior believed to provide the crab with camouflage or potentially a defense mechanism against predators. More information on the ecophysiology of non-scleractinian corals and fine-scale local organic matter supply are needed to understand what drives differences in their spatial distribution and community structure.

Fragmentation, re-attachment ability and growth rate of the Mediterranean black coral Antipathella subpinnata

Cnidarians are known for their simple body plan and their complex life cycles, involving high regenerative and asexual-reproduction potential. In particular, several asexual reproductive strategies are known for anthozoans, including fragmentation, carried out by tentacles, by groups of polyps or by portions of colonies. Here, we report the first observation of an extensive event of fragmentation in the Mediterranean black coral species Antipathella subpinnata (Antipatharia: Myriopathidae) in rearing conditions. Once detached, fragments lose their polarity and new anchorages are rapidly created with polyps and cnidocysts participating in the adhesion phases. Multiple attachments are frequently observed, with new skeletal plates produced through the expansion of spines. Dendritic spines gradually arise on these new plates. Fragments start to generate numerous new branchlets orientating upward and with a fixed arrangement. In 7 months of monitoring, fragments revealed fast growth rates, up to 1.85 and 1.58 cm month−1, for the whole fragments and new branchlets, respectively. Attachment of black coral fragments has never been recorded in the field; nevertheless, frequent adhesions observed in aquaria suggest that fragmentation could be a successful reproductive strategy in these anthozoans.