Priscilla T Y Leung

City University of Hong Kong | CityU · State Key Laboratory of Marine Pollution (SKLMP)

Canopy-forming macroalgae can construct extensive meadow habitats in tropical seascapes occupied by fishes that span a diversity of taxa, life history stages and ecological roles. Our synthesis assessed whether these tropical macroalgal habitats have unique fish assemblages, provide fish nurseries, and support local fisheries. We also applied a met...

The mandarinfish Synchiropus splendidus is extensively collected in Southeast Asia (mainly in the Philippines) and highly favoured for the marine aquarium trade. Males are more popular than females for their large first dorsal fins and the fishery is not managed. To examine possible population replenishment dynamics arising as a result of selective...

A total of 40 juveniles belonging to a temperate deepwater gnomefish species, Scombrops boops, were sampled from littoral habitats (2–5 m depth) of eastern Hong Kong waters in April and May 2017 and March 2019. The presence of gnomefish juveniles in subtropical southern China is reported for the first time at a record low latitude of 22º11'–22º21'N...

Both beach seine (BS) and line transect-based underwater visual census (UVC) methods were applied to investigate fish assemblages of the West Sand (Xisha Islands, South China Sea) seagrass meadows and their relationship with seagrass coverage. The West Sand seagrass meadows were divided into four survey areas, two (areas A and B) to the north and t...

There is growing contamination of copper (Cu) in the marine environment, particularly after the ban of organotin compounds and the increase of the use of Cu-based antifouling paints. Although there are increasing research interests in temperature-dependent chemical toxicity to aquatic organisms, most existing studies focused on acute impacts of che...

Marine ecosystems are currently subjected to dual stresses of chemical pollution and climate change. Through a series of laboratory experiments, this study investigated the impact of exposure to chemical contaminant such as DDT or copper (Cu), in combination with cold or warm temperature extremes on the marine medaka fish Oryzias melastigma. The re...

Macroalgae‐dominated reefs are a prominent habitat in tropical seascapes that support a diversity of fishes, including fishery target species. To what extent, then, do macroalgal habitats contribute to small‐scale tropical reef fisheries? To address this question we: (1) Quantified the macroalgae‐associated fish component in catches from 133 small‐...

Triphenyltin (TPT) is widely used as an active ingredient in antifouling paints and fungicides, and continuous release of this highly toxic endocrine disruptor has caused serious pollution to coastal marine ecosystems and organisms worldwide. Using bioassays and transcriptome sequencing, this study comprehensively investigated the molecular toxicit...

Coolia tropicalis is a species of benthic and epiphytic toxic algae, which can produce phycotoxins that intoxicate marine fauna. In this study, the potential toxic effects of C. tropicalis on fish were investigated using larval marine medaka (Oryzias melastigma) as a model to evaluate fish behavior, physiological performance, and stress-induced mol...

In this paper, we used a convolutional neural network to study the classification of marine microalgae by using low-resolution Mueller matrix images. Mueller matrix images of 12 species of algae from 5 families were measured by a Mueller matrix microscopy with an LED light source at 514 nm wavelength. The data sets of seven resolution levels were g...

Coolia malayensis is one of the commonly found benthic dinoflagellates in Hong Kong which can produce biotoxins and threaten the early life stages of marine invertebrates. Seawater temperature has been recognized as one of the primary environmental factors that affect the formation of harmful algal blooms. The present study evaluated the responses...

Ciguatera fish poisoning (CFP) is prevalent around the tropical and subtropical latitudes of the world and impacts many Pacific island communities intrinsically linked to the reef system for sustenance and trade. While the genus Gambierdiscus has been linked with CFP, it is commonly found on tropical reef systems in microalgal assemblages with othe...

Benthic dinoflagellates produce a diverse range of phycotoxins, which are responsible for intoxication events in marine fauna. This study assessed the hemolysis associated toxicities of six species of benthic dinoflagellates from the genera Coolia, Fukuyoa, Amphidinium and Prorocentrum. Results demonstrated that Amphidinium carterae, Coolia tropica...

The Mekong River endemic Sinomytilus harmandi possesses an internal anterior shell septum. It is thus superficially similar to the marine representatives of the, as currently defined, Septiferinae (Mytilidae) although species of the latter possess an anterior adductor muscle located between their septa and are characterised by accessory posterior a...

The study, for the first time, evaluated the leaching rate of zinc oxide nanoparticles (nZnO) from human skins which were applied with three commercial sunscreens that contained nZnO as an active ingredient. The leaching rate of nZnO varied greatly among the sunscreens, with a range of 8-72% (meanSD: 44.7%33.0%). We further investigated their tox...

Ciguatoxins are natural compounds produced by benthic dinoflagellates Gambierdiscus and Fukuyoa spp., which cause fish intoxication by ciguatera fish poisoning. This study aimed to assess the dietary exposure effects of ciguatoxin P-CTX-1 on the reproductive performance in marine medaka (Oryzias melastigma). Fish which in-gested > 1.16 pg·day −1 fo...

We take low resolution Muller matrix images of microalgae using a Mueller matrix microscope based on time sequential polarization measurements and obtain a characteristic average Mueller matrix (AMM) which can be evaluated for each cell from the average values of the polarization component images. Using the 136 first and second order terms of the c...

Benthic dinoflagellate were collected in the Hong Kong Eastern water for the first time. To look at the biodiversity of benthic dinoflagellate, morphological and molecular analysis has been done for species identification. For understanding the distribution of benthic dinoflagellate, samples collected from different sites in different seasons were...

The emerging threat of benthic and epiphytic toxic algae (BETA) to marine ecosystems has attracted worldwide attention. Seawater temperature is one of the major factors influencing the growth and distribution of BETA. Coolia are one of the cosmopolitan group of BETA, and are potentially toxic. There are four species of Coolia reported in Hong Kong...

Polarimetric measurements are becoming increasingly accurate and fast to perform in modern applications. However, analysis on the polarimetric data usually suffers from its high-dimensional nature spatially, temporally, or spectrally. This paper associates polarimetric techniques with metric learning algorithms, namely, polarimetric learning, by in...

Understanding the juvenile fish habitats, their contributions to adult recruits, and identifying nursery hot spots are fundamental to management and conservation of marine resources. Littoral vegetated habitats, such as macroalgal bed, seagrass bed and mangrove mudflat are generally believed as important nurseries. In Hong Kong, the complex and bio...

We present the Mueller matrix imaging system to classify morphologically similar algae based on convolutional neural networks (CNNs). The algae and cyanobacteria data set contains 10,463 Mueller matrices from eight species of algae and one species of cyanobacteria, belonging to four phyla, the shapes of which are mostly randomly oriented spheres, o...

A 96-h exposure experiment was conducted to elucidate the toxicity responses of the marine diatom Thalassiosira pseudonana upon exposure to different temperatures and copper (Cu) concentrations. Three Cu treatments (seawater control; 200 μg/L Cu, EC50 for the yield at 25 °C; and 1000 μg/L Cu, EC50 for growth inhibition at 25 °C) were conducted agai...

Coolia are marine benthic dinoflagellates which are globally distributed and potentially toxic. This study provides the first investigation of species diversity and toxicity assessment of Coolia in Hong Kong waters. Fifty-one strains of four Coolia species, including C. malayensis, C. canariensis, C. tropicalis, and C. palmyrensis, were isolated fr...

Background: The tropical green-lipped mussel Perna viridis is a common biomonitor throughout the Indo-Pacific region that is used for environmental monitoring and ecotoxicological investigations. However, there is limited molecular data available regarding this species. We sought to establish a global transcriptome database from the tissues of add...

We hypothesize that chemical toxicity to marine ectotherms is the lowest at an optimum temperature (OT) and it exacerbates with increasing or decreasing temperature from the OT. This study aimed to verify this hypothetical temperature-dependent chemical toxicity (TDCT) model through laboratory experiments. Acute toxicity over a range of temperature...

Metallothioneins (MTs) are commonly used as biomarker for metal pollution assessment in marine ecosystems. Using integrated genomic and proteomic analyses, this study characterized two types of MT isoform in the digestive gland of a common biomonitor, the green-lipped mussel Perna viridis, towards the challenges of a metal (cadmium; Cd) and a non-m...

Calcifying marine invertebrates with complex life cycles are particularly at risk to climate changes as they undergo an abrupt ontogenetic shift during larval metamorphosis. Although our understanding of the larval response to climate changes is rapidly advancing, the proteome plasticity involved in a compensatory response to climate change is stil...

Ocean acidification (OA) is beginning to have noticeable negative impact on calcification rate, shell structure and physiological energy budgeting of several marine organisms; these alter the growth of many economically important shellfish including oysters. Early life stages of oysters may be particularly vulnerable to OA-driven low pH conditions...

Ocean acidification (OA) is beginning to have noticeable negative impact on calcification rate, shell structure and physiological energy budgeting of several marine organisms; these alter the growth of many economically important shellfish including oysters. Early life stages of oysters may be particularly vulnerable to OA-driven low pH conditions...

The majority of benthic marine invertebrates have a complex life cycle, during which the pelagic larvae select a suitable substrate, attach to it, and then metamorphose into benthic adults. Anthropogenic ocean acidification (OA) is postulated to affect larval metamorphic success through an altered protein expression pattern (proteome structure) and...

This study aimed to reveal the proteomic responses in the hepatopancreas and adductor muscle of a common biomonitor, Perna viridis after 14-day exposure to two model chemicals, cadmium (Cd; a toxic metal) and hydrogen peroxide (H(2)O(2); a pro-oxidant), using two-dimensional gel electrophoresis coupled with multivariate statistical analyses. Unique...

1. Traditional approaches to understanding species responses to environmental conditions have focused on the isolated effects of single stressors, despite the fact that in nature organisms experience a variety of conditions. 2. In tropical monsoonal areas, intertidal animals can face hot desiccating conditions during emersion preceded, or followed...

Variation in life history characteristics is believed to play an important role in dispersal and thus shaping the population and genetic structure of marine invertebrates. The genetic structure of Ibla cumingi, a small intertidal stalked barnacle that broods lecithotrophic larvae, was evaluated using 145 random amplified polymorphic DNA markers on...

The majority of benthic marine invertebrates have a complex life cycle, during which the pelagic larvae select a suitable substrate, attach to it, and then metamorphose into benthic adults. Anthropogenic ocean acidification (OA) is postulated to affect larval metamorphic success through an altered protein expression pattern (proteome structure) and...

The population genetic structure of the mantis shrimp, Oratosquilla oratoria, in Hong Kong waters was determined using 923 base pairs of mitochondrial DNA control region sequences. Samples were collected from six localities including the open-waters and sheltered bays in both the eastern and western waters of Hong Kong. Twenty-seven haplotypes were...

Nano zinc oxide (nZnO) is increasingly used in sunscreen products, with high potential of being released directly into marine environments. This study primarily aimed to characterize the aggregate size and solubility of nZnO and bulk ZnO, and to assess their toxicities towards five selected marine organisms. Chemical characterization showed that nZ...

Sirtuins are a family of NAD(+)-dependent protein deacetylases that regulate cellular functions through deacetylation of a wide range of protein targets. Overexpression of Sir2, the first gene discovered in this family, is able to extend the life span in various organisms. The anti-aging effects of human homologues of sirtuins, SIRT1-7, have also b...

Oriental plane trees are an important source of airborne allergens in cities of southwest Asia. In spite of extensive studies on Platanus acerifolia allergy, there are no reports on the molecular characterization of pollen allergens from Platanus orientalis trees. In this study, a newly recognized member of cyclophilin family with a molecular weigh...

Phytases are enzymes that catalyze liberation of inorganic phosphates from phytate, the major organic phosphorus in soil. Tobacco (Nicotiana tabacum) responds to phosphorus starvation with an increase in extracellular phytase activity. By a three-step purification scheme, a phosphatase with phytase activity was purified 486-fold from tobacco root e...

Previous studies on the ultrastructure of barnacle cypris larvae suggest that cypris morphology, especially the antennules which play a key role in selecting the final substratum for settlement, may show variations between species existing in different habitats. In the present study, the cypris morphology of the barnacle Fistulobalanus (Balanus) al...

Angiopoietin-like protein 4 (ANGPTL4) is a circulating protein predominantly produced from fat tissue and liver. Recent data from others and our laboratory have demonstrated this protein to be an important player in energy metabolism and insulin sensitivity. However, the molecular mechanisms underlying its metabolic actions remain elusive. In this...