First report of the benthic dinoflagellate, Gambierdiscus belizeanus (Gonyaulacales: Dinophyceae) for the east coast of Sabah, Malaysian Borneo (original) (raw)
Related papers
Harmful Algae, 2017
This study confirms the presence of the toxigenic benthic dinoflagellates Gambierdiscus belizeanus and Ostreopsis spp. in the central Red Sea. To our knowledge, this is also the first report of these taxa in coastal waters of Saudi Arabia, indicating the potential occurrence of ciguatera fish poisoning (CFP) in that region. During field investigations carried out in 2012 and 2013, a total of 100 Turbinaria and Halimeda macroalgae samples were collected from coral reefs off the Saudi Arabian coast and examined for the presence of Gambierdiscus and Ostreopsis, two toxigenic dinoflagellate genera commonly observed in coral reef communities around the world. Both Gambierdiscus and Ostreopsis spp. were observed at low densities (<200 cells g À1 wet weight algae). Cell densities of Ostreopsis spp. were significantly higher than Gambierdiscus spp. at most of the sampling sites, and abundances of both genera were negatively correlated with seawater salinity. To assess the potential for ciguatoxicity in this region, several Gambierdiscus isolates were established in culture and examined for species identity and toxicity. All isolates were morphologically and molecularly identified as Gambierdiscus belizeanus. Toxicity analysis of two isolates using the mouse neuroblastoma cell-based assay for ciguatoxins (CTX) confirmed G. belizeanus as a CTX producer, with a maximum toxin content of 6.50 AE 1.14 Â 10 À5 pg P-CTX-1 eq. cell À1. Compared to Gambierdiscus isolates from other locations, these were low toxicity strains. The low Gambierdiscus densities observed along with their comparatively low toxin contents may explain why CFP is unidentified and unreported in this region. Nevertheless, the presence of these potentially toxigenic dinoflagellate species at multiple sites in the central Red Sea warrants future study on their possible effects on marine food webs and human health in this region.
Diversity of Potentially Toxic Benthic Dinoflagellates in Indonesian Waters
Marine Research in Indonesia, 2022
Ciguatera Fish Poisoning (CFP) is a syndrome caused by ciguatoxin-producing benthic dinoflagellate, which are typically attached to macroalgae. The toxin is responsible for the human poisoning symptom observed after the consumption of contaminated reef fish. Research on the composition and abundance of benthic dinoflagellate on macroalgae had been conducted within the 2010-2015 at several coral reef areas in Indonesian waters, such as Weh Island-Aceh, Belitung Island, Lampung Bay, Seribu Islands, and Lombok Island. This study reviewed all the references concern on benthic dinoflagellate researches in Indonesia, with aims to raise awareness on the presence of potentially toxic benthic dinoflagellates in Indonesian waters, also to create an inventory of the species discovered. The study revealed four of the six genera which are potentially toxic, namely Amphidinium, Gambierdiscus, Ostreopsis, and Prorocentrum. The Prorocentrum cells were identified in a larger number than any other genera in all the sampling locations. The relatively high number of benthic dinoflagellates were observed in Lampung Bay and Seribu Islands, which might be due to the high level of human activities. These findings are essential to compile a database on the CFP-causing species and to monitor the affected areas, specifically in highly populated locations or tourist sites.
Toxicity of benthic dinoflagellates found in coral reef
NIPPON SUISAN GAKKAISHI, 1980
Five species of dinoflagellates and three microalgae of benthic habitat collected in French Polynesia were grown in unialgal state and tested for toxicity on mice and for hemolytic activity. Two diethyl ether soluble toxins (PL toxin-I, Il) and one fast-acting toxin soluble in 1-butanol (PL toxin-HI) were found in Prorocentrum lima. The chromatographic behaviors of PL toxin-I and II closely resembled those of scaritoxin and ciguatoxin prepared from ciguateric fishes. Potent hemolytic substance was present in Amphidinium sp. This species was also toxic to mice. No remarkable activity was detected in the following species: Coolia monotis, Amphidinium sp.-2, and Gymnodinium sp. (dinoflagellates); Chloococcopsis sp. and Isochrysis sp. (blue-green algae); and Nitzschia panduriformis (diatom). A number of toxic animals have been reported to occur in coral reef areas1,2).
Benthic Harmful Dinoflagellate Assemblages in a Fringing Reef of Sampadi Island, Sarawak, Malaysia
Marine Research in Indonesia
A study on the presence and relative abundance of benthic harmful algal bloom (BHAB) forming dinoflagellate species was carried out in the coral reefs of Sampadi Island, Sarawak, Malaysia. The study involved deployment of fiberglass screens as an artificial substrate for the benthic epiphytic microalgae. The screens were placed for 24 h above the seafloor along a 100 m transect at 10 m intervals. BHAB species attached to the screens were identified and cell abundances were enumerated under a light microscope. The BHAB community at the study site was dominated by Prorocentrum spp. and Coolia spp. Other BHAB species collected included Amphidinium spp., Gambierdiscus spp. and Ostreopsis spp. Total cell densities collected on the screens ranged from 5 to 100 cells per 100 cm2. The two BHAB groups of primary concern, Gambierdiscus spp. and Ostreopsis spp. were detected at relatively low abundances of 0.6–4.2% and 1.8–16% respectively. This study has shown that potentially toxic BHAB ...
Harmful Algae, 2014
Species of the genus Gambierdiscus are epiphytic dinoflagellates well known from tropical coral reef areas at water temperatures from 24 to 29 8C. Gambierdiscus spp. are able to produce ciguatoxins (CTXs) known to bioaccumulate in fish, and the ingestion of tropical fish that accumulated CTXs and possibly also maitotoxins (MTXs) can cause ciguatera fish poisoning (CFP) in humans. In Australia, ciguatera poisonings have been reported in tropical parts of Queensland and the Northern Territory. Here, we report for the first time the seasonal abundance (April-May 2012/13) of Gambierdiscus spp. (up to 6565-8255 cells g À1 wet weight algae) from Merimbula and Wagonga Inlets in temperate southern New South Wales, Australia (378 S) at water temperatures of 16.5-17 8C. These are popular shellfish aquaculture and recreational fisheries areas with no reports of ciguatera poisoning. Sequencing of a region of the 28S rRNA gene led to the conclusive identification of Gambierdiscus carpenteri. The cells differed however from the Belize type description, including the absence of a thecal groove, dorsal rostrum and variable hatchet-to rectangular-shaped 2 0 plate, and were morphologically more similar to Gambierdiscus toxicus. To study the dinoflagellate community structure in detail, a pyrosequencing approach based on the 18S rRNA gene was applied, which confirmed the presence of a single Gambierdiscus species only. Neither CTXs nor MTXs were detected in natural bloom material by LC-MS/MS; however, the extracts were found to be toxic via mouse-bioassay, with symptoms suggestive of poisoning by MTX-like compounds. Understanding the abundance of Gambierdiscus populations in areas with no apparent human health impacts is important towards defining the alternate conditions where sparse populations can create ciguatera problems.
2018
Seagrass ecosystems are very important nursery areas for larvae of both marine vertebrates and invertebrates. The system provides food and refuge areas for these larvae. Leaves of seagrass also can be good substrates for microorganism attachment, especially for benthic phytoplankton. Among very important epiphytic microalgae species include toxic benthic dinoflagellates that can cause ciguatera fish poisoning (CFP) symptoms. Toxins of toxic benthic dinoflagellates can transfer through the food chain from the small herbivorous fish that graze on the seagrass leaves and then to carnivorous fish and finally to humans. Little is known about toxic benthic dinoflagellates in seagrass ecosystems. In Thailand, two cases of CFP have been reported; patients had severe ciguatera like symptoms. To understand the distribution and abundance of benthic dinoflagellates in seagrass ecosystems, this study was conducted in four seagrass areas of the eastern coast of the upper Gulf of Thailand: Samaesa...