Voranop Viyakarn

Chulalongkorn University · Department of Marine Science

Allelopathy is commonly found in marine sponges. However, information on allelopathic activities of sponge extracts is limited. In this study, variations of nutritional values of Xestospongia sp. were investigated. Xestospongia did not unequally distribute its nutritional values for predatory defense. Carbon–nitrogen contents and renieramycin M con...

The density and diversity of Symbiodiniaceae associated with corals can be influenced by seasonal changes. This study provided the first annual investigation of Symbiodiniaceae density and diversity associated with Acropora humilis and Pocillopora cf. damicornis corals in the Gulf of Thailand using both zooxanthellae cell count and next-generation...

Southeast Asia is considered to have some of the highest levels of marine plastic pollution in the world. It is therefore vitally important to increase our understanding of the impacts and risks of plastic pollution to marine ecosystems and the essential services they provide to support the development of mitigation measures in the region. An inter...

As seawater temperature rises, repeated thermal bleaching events have negatively affected the reefs of the Andaman Sea for over decades. Studies on the coral-associated microbial diversity of prokaryotes and microbial eukaryotes (microbiome) in healthy and bleached corals are important to better understand the coral holobionts that involved augment...

In this study, coral disease was first reported in the coral hatchery in Thailand. Disease were usually found on corals aged two to five years old during the months of November to December of each year. To identify bacterial strains, culture-based methods for strain isolation and molecular techniques of the 16S rRNA gene analysis were used. The res...

At Samaesan Island, which is in Chon Buri Province, the Upper Gulf of Thailand, in 2018 we found skunk anemonefish (Amphiprion akallopisos) previously only known from the Andaman Sea that have been establishing their populations in the area at a 4-m depth [...]

Improved access to field survey infrastructure throughout South-East Asia has allowed for a greater intensity of biodiversity surveys than ever before. The rocky bottoms and coral reef habitats across the region have been shown to support some of the highest sea slug biodiversity on the planet, with ever increasing records. During the past ten year...

A symbiosis of bacterial community (sometimes called microbiota) play essential roles in developmental life cycle and health of coral, starting since a larva. For examples, coral bacterial holobionts function nitrogen fixation, carbon supply, sulfur cycling and antibiotic production. Yet, a study of the dynamic of bacteria associated coral larvae d...

Global warming has caused elevated seawater temperature and coral bleaching, including events on shallow reefs in the upper Gulf of Thailand (uGoT). Previous studies have reported an association between loss of zooxanthellae and coral bleaching. However, studies on the microbial diversity of prokaryotes and eukaryotes (microbiome) as coral holobion...

A novel bacterium, designated strain ANT13_2 T , was isolated from a phenanthrene-degrading consortium enriched from a soil sample collected near the Great Wall Station located in the southwestern area of King George Island, Antarctica. Following a polyphasic taxonomic study, a novel species belonging to the genus Paeniglutamicibacter was described...

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 Spaw...

Two new species of the genus Chironephthya, C. sirindhornae sp. nov. and C. cornigera sp. nov., are described based on three specimens collected from the Gulf of Thailand. Both species are well distinguished from the previously described species of the genus Chironephthya by their colonies consisting of multiple stems that stand upright from a comm...

We determined the complete mitochondrial genome sequences of an asteroid Linckia laevigata belonging to the order Valvatida. The complete mitogenome of L. laevigata was 16,371 bp in length and consisted of 13 protein-coding genes (PCGs), two rRNA, and 22 tRNA. The orders of PCGs and rRNAs were identical to those of the recorded mitogenomes of aster...

In this present study, we investigated the effects of increase and decrease of light intensity and photoperiods on growth, survival, and photosynthetic efficiency in three different corals, Pocillopora damicornis (Linnaeus, 1758), Acropora millepora (Ehrenberg, 1834) and Platygyra sinensis (Milne Edwards and Haime, 1849) with different ages (6-, 12...

Populations of sea cucumbers in Thailand have been declining because of overfishing in recent years; however, little is known about the possible long-term effects of this decline on the sea cucumber population and reef communities. The purpose of this study was to examine the distribution patterns and habitat compositions of Holothuria atra in the...

An interlaboratory comparison exercise was conducted to assess the consistency of microplastic quantification across several laboratories. The test samples were prepared by mixing one liter seawater free of plastics, mi-croplastics made from polypropylene, high-and low-density polyethylene, and artificial particles in two plastic bottles, and analy...

Reefs at Ko Samae San (S), Khao Ma Cho (K), and Ko Tao Mo (T), in the Gulf of Thailand (GoT) represent a biodiversity hotspot, and bacteria play significant roles in maintaining the health of these coral reefs and their biogeochemical cycles. Therefore, this study analyzed bacterial communities (microbiota) from healthy corals and nearby seawater a...

Reef sites of Ko Samae San (S), Khao Ma Cho (K) and Ko Tao Mo (T) in the upper Gulf of Thailand have abundant corals and represent a hotspot of marine biodiversity. Coral reefs serve as major networks of food and energy, where bacteria, microbial eukaryotes (fungi) and small eukaryotes play significant roles as primary producers that convert inorga...

Corals are sensitive to minute changes to their ecosystem; therefore, their sustainability is substantially threatened by the increasing number of destructive anthropogenic activities and unprecedented climate change. Although cryopreservation is an excellent method for cell preservation and conservation, coral cryopreservation has started only in...

Fish diversity and abundance were investigated at reefs around Royal Thai naval base, Sattahip area. A total of 46 species in 17 families were recorded in the area. Hin Luk Bet had the highest number of fish species (32 species) while the lowest number of fish species was found at Ko Kham (14 species). Most abundance families were Pomacentridae fol...

This study aims to conduct a quantitative ecological risk assessment of human exposure to polycyclic aromatic hydrocarbons (PAHs) in terrestrial soils of King George Island, Antarctica. Generally, the average PAH concentrations detected in King George Terrestrial Soils (KGS) were appreciably lower than those of World Marine Sediments (WMS) and Worl...

Coral reefs can be found in both tropical and subtropical oceans. They provide valuable and vital ecosystem services. Coral reefs also serve as habitat, shelter, and food sources for variety of organisms. Yet some estimated put the total diversity of life found in and on coral reefs at up to two million species. This biodiversity can be transformed...

This study examined the capture rates and prey digestion of three corals species in two genera (Acropora and Pocillopora) found dominantly in Thailand and the Federated States of Micronesia using Artemia salina nauplii as a food source. In addition, feeding during day and night times of corals was investigated. Results showed that all three coral s...

In this study, the ultrastructure of the oocytes of 6 types of scleractinian corals was observed by transmission electron microscopy (TEM). Moreover, histological and ultrastructural analyses were performed to improve our understanding of the organelles involved in coral oocyte formation. In all 6 stony coral species, the microvilli were tubular an...

The Pacific white shrimp Litopenaeus vannamei (Boone, 1931) is native to the Pacific coast of Central and South America. This species was first introduced to Thailand in 1998 for aquaculture and as a replacement for Penaeus monodon Fabicius, 1798 because of problems with disease outbreaks and poor growth performance of the latter. Escapes of cultur...

The feeding habits of the Antarctic fish Pseudotrematomus bernacchii (Previous name: Trematomus bernacchii) under the fast ice around Japanese Syowa Station were investigated in the summers of 2004/2005 and 2009/2010. The results showed that amphipods and krill were the major prey. However, there was a significant difference in the proportions of l...

The effects of pH reduction on the settlement and development of the coral Pocillopora damicornis were investigated. Three different pH treatments (pH = 7.6, 7.9, and 8.1) were used. In addition, water quality (temperature, salinity, total alkalinity) around the study site was monitored. The results showed significant differences in the settlement...

This study investigated the effects of temperature and salinity on growth, survival, and photosynthetic efficiency of three coral species, namely, Pocillopora damicornis, Acropora millepora and Platygyra sinensis of different ages (6 and 18 months old). The experimental corals were cultivated via sexual propagation. Colonies were exposed to 5 diffe...

Gorgonian corals are slowly declining due to human interaction and environmental impacts. Cryopreservation of gorgonian corals is an ex-situ method of conservation, ensuring future reproduction. The present study assessed the vitrification properties of cryoprotectant (CPT) mixtures using the cryotop, cryoloop and open pulled straw (OPS) cryoperese...

The effect of mineral accretion induced by electric current on settlement, growth, and survival of planula larvae and juvenile corals of Pocillopora damicornis was examined by both laboratory and field experiments. The laboratory experiment showed that the numbers of larvae settling on tiles with coralline algae and steel plates encrusted with lime...

Hydrocarbon catabolic genes were investigated in soils and sediments in nine different locations around Syowa Station, Antarctica, using conventional PCR, real-time PCR, cloning, and sequencing analysis. Polycyclic aromatic hydrocarbon ring-hydroxylating dioxygenase (PAH-RHD)-coding genes from both Gram-positive and Gram-negative bacteria were obse...

The lipid phase transition (LPT) from the fluid liquid crystalline phase to the more rigid gel structure phase that occurs upon exposure to low temperatures can affect physical structure and function of cellular membranes. This study set out to investigate the membrane phase behavior of oocytes of three gorgonian corals; Junceela fragilis, J. junce...

The diversity and occurrence of nudibranchs were studied during a 10-year survey in the Andaman Sea and the Gulf of Thailand, Thailand. We recorded 96 species in 40 genera and 17 families at 0–20 m depth, which resulted in a total of 136 species in Thai waters in combination with previous studies. The largest group was the suborder Doridina (81 % o...

Fish assemblages at 3 different coral communities at Chao Lao Beach, Chanthaburi province, Thailand were investigated using fish visual census and line intercept transect techniques. Three different coral communities were surveyed; included Ai Lao Nai reef, Ai Lao Klang reef and Ai Lao Nok reef, which were located from the nearshore to outward resp...

In April-June 2010, a thermal anomaly developed in the Andaman Sea and in the Gulf of Thailand. Subsequently, mass coral bleaching occurred. To monitor the health of the reefs and changes in reef communities, permanent line transects that have been established since 2007, using a Reef Check method, were used to survey composition of substrates, abu...

A comparison was made of amphipod assemblages on different species of the green alga, Codium both from a protected marine area and from a disturbed area. In addition, a laboratory experiment was conducted to determine habitat selection by amphipods. A total of five species of amphipods was found on Codium species. Amphipods were more abundant in th...

Potential ecological damage caused by the introduction of Litopenaeus vannamei (Pacific whiteleg shrimp) for aquaculture in Thailand's Bangpakong watershed depends on its ability to survive environmental conditions and compete for food with local shrimp species. To examine this, we determined: (i) the physiological tolerance of L. vannamei and Pena...

This book with 33 chapters divided into five parts is a compendium of selected papers from the conference that can be broadly categorized as land and water management, fisheries and aquaculture and rice-based agriculture systems. Intensification of aquaculture and rice-based agriculture frequently produces negative effects that range from environme...

This book with 33 chapters divided into five parts is a compendium of selected papers from the conference that can be broadly categorized as land and water management, fisheries and aquaculture and rice-based agriculture systems. Intensification of aquaculture and rice-based agriculture frequently produces negative effects that range from environme...

Chavanich, S., Viyakarn, V., Loyjiw, T., Pattaratamrong, P., and Chankong, A. 2009. Mass bleaching of soft coral, Sarcophyton spp. in Thailand and the role of temperature and salinity stress. – ICES Journal of Marine Science, 66: 1515–1519.From June to October 2006 and 2007, mass bleaching of the soft coral, Sarcophyton spp., occurred for the first...

Recently, two introduced tunicate species Ecteinascidia thurstoni Herdman, 1891 and Clavelina cyclus Tokioka & Nishikawa, 1975 were discovered in the coastal waters of Thailand. E. thurstoni was found in Andaman Sea, the west coast of Thailand while C. cyclus was first recorded in the east coast, upper Gulf of Thailand. From the historical records,...

On 26 December 2004, a severe earthquake in Sumatra caused a series of tsunami waves to strike southwestern coastal areas of Thailand. In this study, we investigated the patterns of tsunami‐related damage to coral reefs at Mu Ko Similan Marine National Park. The results showed that the percent of damaged corals ranged from 7.2% to 39.7% of the tota...

In this study, the lunar periodicity of larval release and development of larvae of Pocillopora damicornis in the Gulf of Thailand were investigated. Ten colonies of P. damicornis, approximately 15 cm in diameter, were tagged and collected for observation every month. To observe the releasing period of larvae, each colony was placed in a separate t...

Amphipods identified as, Leucothoe spinicarpa (Abildgaard, 1789), were found in the colonial tunicate, Ecteinascidia thurstoni Herdman, 1891, at 1-3 m depth, within a single coral reef area on the coast of the Andaman Sea of Phuket Province in southern Thailand. This represents the first record of commensalism between this amphipod and tunicate in...

This study aimed at determining the optimal lipid:carbohydrate and protein:energy ratios for growth and survival of juvenile Penaeus monodon Fabricius. Two experiments were performed using completely randomized designs in semi-closed recirculating water systems. Juveniles of 0.4–0.8 g in weight and 4.0–5.5 cm in length stocked at a density of 80 in...

The effect of lecithin and cholesterol on growth and survival of larval and postlarval Penaeus monodon was evaluated using semi-purified diets containing four levels of lecithin (0.0, 0.5, 1.0 and 1.5%) and three levels of cholesterol (0.0, 0.5 and 1.0%). Three early stages (zoeal, mysid and postlarval) of P. monodon were fed the experimental diets...

The available phosphorus (P) content in various types of phosphates supplementedin semipurified diets at different levels was determined by the indirect method in common carp and rainbow trout, which have different digestive systems, and was compared with the amount of P extracted by deionized water (Fr. I), 80% acetic acid (Fr. II), and 0.25M hydr...

The availability of defatted soybean meal (SBM) as a substitute for fish meal in a newly de-veloped soft-dry pellet (SDP) was evaluated in juvenile (160g on average) and adult (1, 200g on average) yellowtail by feeding SDP containing 0-30% SBM for 74 and 143 days, respectively. Palatability and acceptability in both sizes of fish were not affected...

The available phosphorus (P) contents in fish meal diets with or without supplemental P were determined by the indirect method in common carp and rainbow trout, which have different digestive systems. These values were compared with the amount of P fractionated with deionized water (Fr. I), 80% acetic acid (Fr. II), and 0.25M hydrochloric acid (Fr....

The availability of defatted soybean meal (SBM) as a substitute for fish meal (FM) in a newly developed soft-dry pellet (SDP) was evaluated by feeding SDP containing 0-50% SBM to both juvenile and adult yellowtail. Palatability or acceptability of the experimental SDP was not influenced by the inclusion of SBM up to 50%. Growth and feed gain ratio...