Palythoa Species Research Articles

An Overview on the Worlds Dead Liest Poison (Palytoxin and its Analogs)

Abstract: Palytoxin is a marine toxin found originally in soft corals Palythoa species of the Pacific Ocean. It is a thermostable, non-protein, coronary vasoconstrictor that leads to death by diminishing the supply of O2 to the Myocardium. Several analogs of PTX or PTLX such as Ostreocin-D, Ovatoxin are found in several dinoflagellates and other marine species such as Crabs (Demania reynaudii) and Smoked Fishes (Decapterus macrosoma) found in same ecological regions. Toxicological studies of PTX showed low lethal dose values in different mammals revealing the acute toxicity due to different routes of exposure. On exposure to PTX, symptoms such as Rhabdomyolysis (high dose), Na+- K+ pump and heart failure & other symptoms including abdominal cramps, vomiting, bradycardia, etc. are seen in Pescatarians. There is no particular antidote for the PTX compounds, but these compounds can be neutralized by the household bleach solution. Activated Carbon absorbed 99.7% of palytoxin in aquarium waters. In this paper, we review the current knowledge on Palytoxin & its analogs. In recent years, many methodologies have been described for the development of new techniques for the detection of palytoxin based on LC-MS/MS and a bio-technique Immunoassay.

First Report with Molecular Confirmation of the Colonial Sphenopid Palythoa mutuki (Cnidaria: Anthozoa: Zoantharia: Sphenopidae) Forming Massive Colonies in Southern Jeju Island, Korea

As the global sea surface water temperature increases due to climate change, some zooxanthellate species have extended their habitat range to higher latitudes. Palythoa species, a colonial zooxanthellate cnidarian, is one such example of a range-extending animal. Recently, massive colonies of zoantharians that appeared to be of Palythoa spp. were discovered in a subtidal area of southern Jeju Island. Because a zoantharian-dominated ecosystem could indicate an unhealthy status, the documentation of its occurrence and species identification are crucial for subsequent studies. In this study, we report and confirm the presence of massive Palythoa colonies in Taeheung and Topyeong, off the southern coast of Jeju Island, using in situ underwater images and identify the species by sequencing the internal transcribed spacer rDNA. The resulting Bayesian inference tree clearly demonstrates that the massive colonies consist of Palythoa mutuki and are closely related to P. mutuki collected from the Ryukyu Archipelago in southern Japan. These records provide evidence of the northward expansion of subtropical and tropical marine organisms.

Comparison of Symbiodiniaceae diversities in different members of a Palythoa species complex (Cnidaria: Anthozoa: Zoantharia)-implications for ecological adaptations to different microhabitats.

In this study we compared genotypes of zoantharian host-associating algal symbionts among Palythoa species, which are among the dominant benthic reef organisms in the Ryukyu Archipelago, Japan, and evaluated Symbiodiniaceae diversities of closely related congeneric Palythoa species. We targeted a species complex of the zoantharian genus Palythoa (P. tuberculosa, P. sp. yoron, P. mutuki) living among different microhabitats in a narrow reef area of Tokunoshima Island. For phylogenetic analyses, we used two DNA marker regions; nuclear internal transcribed spacer (ITS) and plastid mini-circle non-coding region (psbAncr), both of which have previously been used to determine Symbiodiniaceae genotypes of zoantharian species. Our results showed that all Palythoa species hosted symbionts of the genus Cladocopium, with genotypic compositions of this genus showing some variations among the three different Palythoa species. Additionally, we found that the Cladocopium genotypic composition was statistically different among Palythoa species, and among P. tuberculosa specimens in different microhabitats. Our results suggest that ecological divergence among these three Palythoa species may be related to differing Symbiodiniaceae diversities that may in turn contribute to eco-physiological adaptation into different microhabitats on coral reefs.

Speciation among sympatric lineages in the genus Palythoa (Cnidaria: Anthozoa: Zoantharia) revealed by morphological comparison, phylogenetic analyses and investigation of spawning period.

Zoantharians are sessile marine invertebrates and colonial organisms possessing sexual and asexual reproductive ability. The zooxanthellate zoantharian genus Palythoa is widely distributed in coral reef ecosystems. In the Ryukyu Archipelago, Japan, sympatric Palythoa tuberculosa and P. mutuki are the dominant species of this genus in the intertidal zone. Previous phylogenetic analyses have shown that these two species are closely related, and additionally revealed a putative sympatric hybrid species (designated as Palythoa sp. yoron). In this study, we attempted to delineate Palythoa species boundaries and to clarify the relationships among these three groups plus another additional putative sympatric species (P. aff. mutuki) by multiple independent criteria. The morphology of these four lineages was clearly different; for example the number of tentacles was significantly different for each species group in all pairwise comparisons. From observations of gonadal development conducted in 2010 and 2011, P. sp. yoron and P. aff. mutuki appear to be reproductively isolated from P. tuberculosa. In the phylogenetic tree resulting from maximum likelihood analyses of the ITS-rDNA sequence alignment, P. tuberculosa and P. sp. yoron formed a very well supported monophyletic clade (NJ = 100%, ML = 95%, Bayes = 0.99). This study demonstrates that despite clear morphological and/or reproductive differences, P. tuberculosa and P. sp. yoron are phylogenetically entangled and closely related to each other, as are P. mutuki and P. aff. mutuki. Additionally, no single molecular marker was able to divide these four lineages into monophyletic clades by themselves, and a marker that has enough resolution to solve this molecular phylogenetic species complex is required. In summary, the morphological and reproductive results suggest these lineages are four separate species, and that incomplete genetic lineage sorting may prevent the accurate phylogenetic detection of distinct species with the DNA markers utilized in this study, demonstrating the value of morphological and reproductive data when examining closely related lineages.

First Identification of Palytoxin-Like Molecules in the Atlantic Coral Species Palythoa canariensis.

Palytoxin (PLTX) is a complex marine toxin produced by Zoanthids (Palyhtoa), dinoflagellates (Ostreopsis), and cyanobacteria (Trichodesmium). Contact with PLTX-like compounds present in aerosols or marine organisms has been associated with adverse effects on humans. The worldwide distribution of producer species and seafood contaminated with PLTX-like molecules illustrates the global threat to human health. The identification of species capable of palytoxin production is critical for human safety. We studied the presence of PLTX analogues in Palythoa canariensis, a coral species collected in the Atlantic Ocean never described as a PLTX-producer before. Two methodologies were used for the detection of these toxins: a microsphere-based immunoassay that offered an estimation of the content of PLTX-like molecules in a Palythoa canariensis extract and an ultrahigh-pressure liquid chromatography coupled to an ion trap with a time-of-flight mass spectrometer (UPLC-IT-TOF-MS) that allowed the characterization of the toxin profile. The results demonstrated the presence of PLTX, hydroxy-PLTX and, at least, two additional compounds with PLTX-like profile in the Palythoa canariensis sample. The PLTX content was estimated in 0.27 mg/g of lyophilized coral using UPLC-IT-TOF-MS. Therefore, this work demonstrates that Palythoa canariensis produces a mixture of PLTX-like molecules. This is of special relevance to safeguard human health considering Palythoa species are commonly used for decoration by aquarium hobbyists.

Zooxanthellate zoantharians (Anthozoa: Hexacorallia: Zoantharia: Brachycnemina) in the northern Red Sea

The Red Sea was one of the first areas of the Indo-Pacific to be investigated by marine taxonomists, and the literature on suborder Brachycnemina (Anthozoa: Hexacorallia: Zoantharia) for this region dates from the early nineteenth century. However, in the last 100 years there has been only one focused study on this group in the Red Sea. In the present study, specimens collected from the Saudi Arabian coast of the northern half of the Red Sea were phylogenetically analyzed by sequencing nuclear internal transcribed spacer regions of ribosomal DNA (ITS-rDNA), mitochondrial cytochrome oxidase subunit I (COI), and 16S ribosomal DNA (16S–rDNA). The new results were compared with historical data in the literature and recent results from the Persian Gulf and the southeastern coast of Africa. Results show the presence of six to seven potential Brachycnemina species in the Red Sea; five to six Palythoa species (Palythoa mutuki, P. tuberculosa, P. cf. heliodiscus, P. aff. heliodiscus, and one to two species within the P. sp. “sakurajimensis” group) together with Zoanthus sansibaricus. While P. mutuki, P. tuberculosa, and Z. sansibaricus are known to be widely distributed in the Indo-Pacific, P. cf. heliodiscus and P. sp. “sakurajimensis” have not been reported from the Persian Gulf or the southeastern coast of Africa, and the current results represent large range extensions for these two species. Only one of the observed species, P. aff. heliodiscus, is potentially endemic to the Red Sea, further demonstrating the generally wide distributions of most zooxanthellate Brachycnemina species.

Descriptions of two azooxanthellate Palythoa species (Subclass Hexacorallia, Order Zoantharia) from the Ryukyu Archipelago, southern Japan.

Two new species of zoantharians (Hexacorallia, Zoantharia, Sphenopidae), Palythoa mizigama sp. n. and Palythoa umbrosa sp. n., are described from the Ryukyu Archipelago, southern Japan. Unlike almost all other known Palythoa spp., both species are azooxanthellate and inhabit low-light environments such as floors or sides of caves, crevasses, or hollows of shallow coral reefs. The two species were initially considered to be the same species from their similar habitat environments and highly similar morphological features. However, phylogenetic analyses of nuclear internal transcribed spacer (ITS) ribosomal DNA, mitochondrial 16S ribosomal DNA, and cytochrome oxidase subunit I (COI) sequences revealed that these two species have a genetically distant relationship within the genus Palythoa. Morphological characteristics, including polyp size, tentacle number, external/internal coloration, and types and sizes of cnidae were examined in this study. As a result, only tentacle coloration was found to be useful for the morphological distinction between the two species. Palythoa mizigama possesses white tentacles with black horizontal stripes while Palythoa umbrosa possesses white tentacles without any stripe patterns. Considering their distant phylogenetic relationship, it can be assumed that their unique yet similar morphological and ecological characteristics developed independently in each species as an example of parallel evolution.

Molecular analyses of shallow-water zooxanthellate zoanthids (Cnidaria: Hexacorallia) from Taiwan and their Symbiodinium spp

Although we previously reported on surveys of shallow-water zoanthid (Anthozoa: Hexacorallia: Zoantharia) species diversity from localities in Taiwan, no study has yet examined the molecular phylogeny of the majority of specimens, nor has any study examined zoanthid zooxanthellae (Symbiodinium spp.) diversity in Taiwan. As many phylogenetic results have been reported from Japan, a critical step in testing DNA identification of zoanthids and their symbionts is the application of these techniques to specimens from neighboring regions such as Taiwan. We utilized three DNA markers (mitochondrial cytochrome oxidase subunit I (COI), mitochondrial 16S ribosomal DNA (mt 16S rDNA), and the nuclear internal transcribed spacer region of ribosomal DNA (ITS-rDNA)) to examine the molecular phylogeny of 110 zooxanthellate specimens collected from 10 localities in Keelung, Kenting, and Green Island. Additionally, we report on the types of Symbiodinium spp. (zooxanthellae) from the three regions above plus the Penghu Islands, utilizing sequences of ITS2-rDNA. Most specimens in the suborder Brachycnemina belonged to previously reported species. However, it appears that there are still some undescribed Palythoa species groups in the northwestern Pacific that are cryptic in having small colony sizes (<5 polyps) and occurring in low numbers. With regards to Symbiodinium spp. diversity, Palythoa tuberculosa and Palythoa mutuki associated with subclade C1 and related types, Zoanthus sansibaricus associated with subclade C3-derived types, and Zoanthus kuroshio that harbored C15/C91-related Symbiodinium. Notably, 1/2 of the P. tuberculosa specimens from the Penghu Islands harbored a previously unreported clade C symbiont, and two Zoanthus. vietnamensis specimens from Keelung also had a unique symbiont type within clade C. It appears that undescribed Palythoa species in the northwestern Pacific may be widely distributed yet low in numbers, often cryptic in their habitat, and with a small colony size. As well, it is clear that much work remains to understand zoanthid-symbiont associations in Taiwan.

Diversity and evolution in the zoanthid genus Palythoa (Cnidaria: Hexacorallia) based on nuclear ITS-rDNA

Previous phylogenetic studies based on mitochondrial DNA markers have suggested that the zoanthid genus Palythoa may consist of both Palythoa species (Palythoa tuberculosa) and species formerly assigned to the genus Protopalythoa (Palythoa mutuki, Palythoa heliodiscus). In the present study various Palythoa spp. samples collected primarily from southern Japan with additional samples from the Indo-Pacific and Caribbean Sea were examined. The nuclear internal transcribed spacer of ribosomal DNA (ITS-rDNA) was sequenced and aligned for phylogenetic analyses to further investigate the relationship between P. tuberculosa, P. mutuki, and P. heliodiscus. ITS-rDNA analyses showed species groups forming monophylies with similar topology but with much higher resolution than seen for mitochondrial phylogenetic analyses. The results also confirmed the very close relationship of P. tuberculosa and P. mutuki. Some specimens appeared to be a potentially undescribed Palythoa species (designated Palythoa sp. sakurajimensis). Additionally, ITS-rDNA sequences of P. mutuki and P. tuberculosa showed additive polymorphic site, demonstrating for the first time a potential history of reticulate evolution in Palythoa.

Composition en stérols de quatre zoanthaires du genre Palythoa de la presqu-île du Cap-Vert

The sterol composition of four Palythoa species was determined. The isolated Zooxanthellae show the same sterol composition as the host-symbiot association. Campesterol (and/or dihydrobrassicasterol) is the major sterol of P. dartevellei, P. monodi and P. senegalensis, 24-methylene cholesterol that of P. variabilis. These results confirm that the genus Palythoa may be divided into two sub-groups regarding the structure of the major 3β-hydroxysterol.

Comparative study of zoanthid sterols the genus palythoa (hexacorallia, zoanthidea)

1. 1. The sterol composition of three Palythoa species has been analysed and compared with literature data. 2. 2. The mixture of sterols known as “palysterol” has been observed in all our samples suggesting that palysterol might be considered as a fingerprint of Palythoa species. 3. 3. The sterols of Palythoa caribaeorum did not show marked geographic, seasonal or sex variations and its zooxanthella showed about the same sterol composition as the host symbiont association. 4. 4. Biological implications are discussed.

A survey on the distribution of zoanthoxanthins in some marine invertebrates

1. 1. The distribution of zoanthoxanthins in more than eighty species of marine invertebrates has been studied using methods which allowed detection and identification of these pigments even at micrograms levels. 2. 2. In general the zoanthoxanthins were found only in coelenterates of the order Zoanthidea, each species possessing a distinctive pigment pattern of taxonomic significance. 3. 3. Extracts from Zoanthus and Palythoa species yielded, besides known zoanthoxanthins of natural and semisynthetic origin, two new related pigments, the structures of which are described.