Diversity of Zoanthids (Anthozoa: Hexacorallia) on Hawaiian Seamounts: Description of the Hawaiian Gold Coral and Additional Zoanthids

The Hawaiian gold coral has a history of exploitation from the deep slopes and seamounts of the Hawaiian Islands as one of the precious corals commercialised in the jewellery industry. Due to its peculiar characteristic of building a scleroproteic skeleton, this zoanthid has been referred as Gerardia sp. (a junior synonym of Savalia Nardo, 1844) but never formally described or examined by taxonomists despite its commercial interest. While collection of Hawaiian gold coral is now regulated, globally seamounts habitats are increasingly threatened by a variety of anthropogenic impacts. However, impact assessment studies and conservation measures cannot be taken without consistent knowledge of the biodiversity of such environments. Recently, multiple samples of octocoral-associated zoanthids were collected from the deep slopes of the islands and seamounts of the Hawaiian Archipelago. The molecular and morphological examination of these zoanthids revealed the presence of at least five different species including the gold coral. Among these only the gold coral appeared to create its own skeleton, two other species are simply using the octocoral as substrate, and the situation is not clear for the final two species. Phylogenetically, all these species appear related to zoanthids of the genus Savalia as well as to the octocoral-associated zoanthid Corallizoanthus tsukaharai, suggesting a common ancestor to all octocoral-associated zoanthids. The diversity of zoanthids described or observed during this study is comparable to levels of diversity found in shallow water tropical coral reefs. Such unexpected species diversity is symptomatic of the lack of biological exploration and taxonomic studies of the diversity of seamount hexacorals

An Indo-Pacific coral spawning database.

The discovery of multi-species synchronous spawning of scleractinian corals on the Great Barrier Reef in the 1980s stimulated an extraordinary effort to document spawning times in other parts of the globe. Unfortunately, most of these data remain unpublished which limits our understanding of regional and global reproductive patterns. The Coral Spawning Database (CSD) collates much of these disparate data into a single place. The CSD includes 6178 observations (3085 of which were unpublished) of the time or day of spawning for over 300 scleractinian species in 61 genera from 101 sites in the Indo-Pacific. The goal of the CSD is to provide open access to coral spawning data to accelerate our understanding of coral reproductive biology and to provide a baseline against which to evaluate any future changes in reproductive phenology

Vagus nerve stimulation: a new promising therapeutic tool in inflammatory bowel disease

International audienceInflammatory bowel disease (IBD), that is Crohn's disease (CD) and ulcerative colitis, affects about 1.5 million persons in the USA and 2.2 million in Europe. The pathophysiology of IBD involves immunological, genetic and environmental factors. The treatment is medico-surgical but suspensive. Anti-TNFα agents have revolutionized the treatment of IBD but have side effects. In addition, a non-negligible percentage of patients with IBD stop or take episodically their treatment. Consequently, a nondrug therapy targeting TNFα through a physiological pathway, devoid of major side effects and with a good cost-effectiveness ratio, would be of interest. The vagus nerve has dual anti-inflammatory properties through its afferent (i.e. hypothalamic-pituitary-adrenal axis) and efferent (i.e. the anti-TNFα effect of the cholinergic anti-inflammatory pathway) fibres. We have shown that there is an inverse relationship between vagal tone and plasma TNFα level in patients with CD, and have reported, for the first time, that chronic vagus nerve stimulation has anti-inflammatory properties in a rat model of colitis and in a pilot study performed in seven patients with moderate CD. Two of these patients failed to improve after 3 months of vagus nerve stimulation but five were in deep remission (clinical, biological and endoscopic) at 6 months of follow-up and vagal tone was restored. No major side effects were observed. Thus, vagus nerve stimulation provides a new therapeutic option in the treatment of CD

Vagal tone: effects on sensitivity, motility, and inflammation

International audienceThe vagus nerve (VN) is a key element of the autonomic nervous system. As a mixed nerve, the VN contributes to the bidirectional interactions between the brain and the gut, i.e., the brain-gut axis. In particular, after integration in the central autonomic network of peripheral sensations such as inflammation and pain via vagal and spinal afferents, an efferent response through modulation of preganglionic parasympathetic neurons of the dorsal motor nucleus of the vagus and/or preganglionic sympathetic neurons of the spinal cord is able to modulate gastrointestinal nociception, motility, and inflammation. A low vagal tone, as assessed by heart rate variability, a marker of the sympatho-vagal balance, is observed in functional digestive disorders and inflammatory bowel diseases. To restore a normal vagal tone appears as a goal in such diseases. Among the therapeutic tools, such as drugs targeting the cholinergic system and/or complementary medicine (hypnosis, meditation…), deep breathing, physical exercise, VN stimulation (VNS), either invasive or non-invasive, appears as innovative. There is new evidence in the current issue of this Journal supporting the role of VNS in the modulation of gastrointestinal functions

Phylogenetic tree of the Hawaiian gold coral (<i>Ku. haumeaae</i>) and related zoanthids.

<p>Bayesian tree based on concatenated 18S, COI and 16S genes. Values at the nodes represent posterior probabilities and bootstrap values respectively. “<b>S</b>” indicate the ability to secrete a skeleton. Values below posterior probabilities of 0.5 or 50% bootstrap were considered as unresolved. Hawaiian zoanthids described here are indicated in bold. Epizoanthidae are used as outgroup. Vertical bars indicate the species belonging to Epizoanthidae and Parazoanthidae respectively.</p

Distribution, type, relative abundances and size ranges of cnidae in the new zoanthids species described here.

<p>Abbreviations: r: rare, u: uncommon, rc: relatively common, c: common, vc: very common. Capital letters refer to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052607#pone-0052607-g003" target="_blank">figure 3</a>. Number ranges indicate cnidae dimensions (length x width) in µm.</p>*<p>Several types of small homotrichs are distinguished; however they might be extremes of a wide morphological variation range of a single type.</p><p>Cnidae nomenclature differs according to different authors. Here is a list of correspondant terms: Spirulae ( = b-mastigophore; Basitrichs), Penicilli ( = P-mastigophore), Penicilli A ( = p-mastigophore A), Penicilli E ( = Holotrichs; Homotrichs; p-mastigophores E), Penicilli E Special (p-mastigophore E special; Homotrichs, Holotrichs), Homotrichs (Holotrichs).</p

Genetic signatures of <i>Savalia</i> and related zoanthid genera.

<p>This figure shows the V5 region sensu Sinniger et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052607#pone.0052607-Sinniger3" target="_blank">[21]</a> with characteristic insertion/deletion pattern specific to each genus. This region is located in the second half of the mt16S rDNA gene. Sequences are represented from 5′ to 3′ and the sequences used are AY995925, EU035623, KC218431, KC218438, KC218434, KC218433, KC218435.</p

Cnidae of the different species.

<p>Cnidae in the different tissues of the zoanthids described here. Letters correspond to the cnidae listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052607#pone-0052607-t002" target="_blank">table 2</a>.</p