Short-necked Clam Research Articles

Paper-based colorimetric sensor using a single-atom nanozyme for the ultrasensitive detection of Cr(VI) in short-necked clams.

Single-atom nanozymes (SAzymes) as a class of highly active nanozymes with the advantages of high atom utilization, high catalytic activity and stability have attracted great attention. In this work, Fe-N-C SAzymes with exceptional oxidase (OXD)-like activity were achieved utilizing polyvinylpyrrolidone (PVP) as a template. The Fe-N-C SAzymes with remarkable OXD-like activity could oxidize TMB to blue oxTMB, but 8-hydroxyquinoline (8-HQ) as a metal chelator is capable of discoloring oxTMB. Thus, the addition of 8-HQ decolorized the solution. However, upon the introduction of Cr(VI) ions, 8-HQ preferentially chelated with the Cr(VI) ions, reversing the inhibition of the color reaction and restoring the blue color. Based on this phenomenon, we constructed a novel paper-based analytical device (PAD) that exhibited a linear range of 5-1000 μM and an LOD of 1.2 μM. Importantly, the PAD used in this study shows the merits of simplicity, low preparation costs, and rapid reaction times. When combined with smartphone RGB analysis, it enables the simultaneous analysis of eight different Cr(VI) concentrations without the need for large-scale instrumentation. Moreover, the proposed PAD displays high selectivity, accuracy and utility in testing actual short-necked clam samples. This work not only provides a simple and cost-effective method to detect Cr(VI) but also makes a contribution to rapid food testing.

Mitogenomic profiling of Marcia recens (Holten, 1802): a step towards taxonomic resolution of India's Ashtamudi short-neck clam

ABSTRACT The Ashtamudi short-neck clam forms a significant fishery resource holding India’s first Marine Stewardship Council Certification. The taxonomic classification of this particular clam has engendered debate regarding its proper nomenclature. The present study aims to provide its first comprehensive mitogenome profile from the type locality to address the existing taxonomic ambiguity. The mitogenome assembled using the genome skimming method had 17,991 base-pair length with 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs and control region. Phylogenetic analysis based on the concatenated data set of PCGs and rRNAs from 47 representative species of Veneridae grouped all species including short-neck clams from the subfamily Tapetinae into a single clade. This analysis also revealed the polyphyly of the genus Marcia. Nevertheless, the short-neck clam co-clustered with Marcia recens from Chinese waters. Subsequent mitochondrial gene order, genetic distance and morphological analyses substantiated the closer relationship of this clam to the genus Marcia, analogous to the phylogenetic output. The genomic data from the type locality provides additional molecular and phylogenetic evidence for the classification of short-neck clam in the genus Marcia. This will also help to address long-standing taxonomic uncertainties surrounding this species, offering valuable information critical for management and conservation of the resource.

The gametogenic cycle and spawning of the short-necked clam, Paphia undulata Born, 1778 (Bivalvia: Veneridae) from Timsah Lake, Suez Canal, Egypt

BackgroundPaphia undulata, The Short-Necked Clam, is an edible marine bivalve that is consumed internationally and locally in Egypt. Overfishing and pollution have caused population declines in Egyptian fisheries during the last decade. Accurate reproductive biology knowledge is critical for designing long-term exploitation strategy for this resource. P. undulata spawning and gametogenic cycle research were carried out from January to December 2020 along Timsah Lake, Suez Canal, Egypt.ResultsThese clams are functionally dioecious with a very low incidence of hermaphroditism. The sex ratio of the clam population was 1.0:1.07:0.04 for male, female and hermaphrodite respectively. The shell lengths of the collected clams were 4.64 ± 0.83 cm in males, 4.55 ± 0.9 cm in females and 4.19 ± 0.3 cm in hermaphrodite clams. The sizes at the onset of sexual maturity in both males and females were 2.1 cm and 2.5 cm respectively.ConclusionsReproductive studies revealed that this species has a prolonged spawning season that is not restricted to a specific period.

Azaspiracid accumulation in Japanese coastal bivalves and ascidians fed with Azadinium poporum producing azaspiracid-2 as the dominant toxin component.

The filter-feeding bivalves often accumulate marine toxins by feeding on toxic dinoflagellates that produce marine toxins. Azaspiracids (AZAs) are a group of lipophilic polyether toxins which have been detected in a variety of organisms in many countries. In our present study, accumulation kinetics and toxin distributions in the tissues of seven bivalve species and ascidians relevant to Japanese coastal waters were investigated by experimentally feeding a toxic dinoflagellate Azadinium poporum, which produces azaspiracid-2 (AZA2) as the dominant toxin component. All bivalve species and ascidians investigated in this study had the capability to accumulate AZA2 and no metabolites of AZA2 were detected in the bivalves and the ascidians. Japanese short-neck clams, Japanese oysters, Pacific oysters and ascidians accumulated AZA2 with the highest concentrations on the hepatopancreas, whereas the highest concentrations of AZA2 were found on the gills in surf clams and horse clams. Hard clams and cockles accumulated high levels of AZA2 in both the hepatopancreas and the gills. As far as we know, this is the first report describing detailed tissue distribution of AZAs in several bivalve species other than mussels (M. edulis) and scallops (P. maximus). Variation of accumulation rates of AZA2 in Japanese short-neck clams on different cell densities or temperatures were observed.

Temporal Dynamics in Energy Fluxes and Trophic Structure of a Portunus trituberculatus Polyculture Ecosystem During Different Culture Periods

Swimming crab (Portunus trituberculatus) are an important aquaculture species in eastern coastal areas of China. To improve the understanding of P. trituberculatus culture ecosystem functioning, the dynamics of energy flow and trophic structure of a P. trituberculatus polyculture system (co-culture with white shrimp Litopenaeus vannamei and short-necked clam Ruditapes philippinarum) were investigated in this study. Three Ecopath models representing the early, middle, and late culture periods of a P. trituberculatus polyculture ecosystem, respectively, were constructed to compare ecosystem traits at different culture periods. The results demonstrated that detritus was the main energy source in this polyculture ecosystem, and most of the total system throughput occurred at trophic levels I and II. Artificial food input and consumption by the culture organisms increased from early to middle and late periods, which produced marked impacts on biomass structure and primary production. R. philippinarum was considered to have a dominant influence on phytoplankton community dynamics which changed from nano- to pico-phytoplankton predominance, from the middle to the late period. Considering the low utilization efficiency of pico-phytoplankton production, large amounts of detritus accumulated in the sediment in the late period, which may constitute a potential risk for the ecosystem. Ecological network analyses indicated that the total energy flow and level of system organization increased from the early to the middle and late periods, whereas food web complexity and system resilience decreased from early to middle and late periods, which may indicate a trend of decreasing ecosystem stability. The system may be further optimized by increased stocking density of R. philippinarum and by introducing macro-algae at a suitable biomass to increase ecosystem stability, energy utilization efficiency, and aquaculture production.

Characteristics of the Components of Mussel Extracts Compared to those of Oysters, Hard Clams, and Short-Necked Clams

Characteristics of the Components of Mussel Extracts Compared to those of Oysters, Hard Clams, and Short-Necked Clams

Evaluation of sources of metal contamination in freshwater and short-neck clams marketed in Japan based on lead isotope ratios

Evaluation of sources of metal contamination in freshwater and short-neck clams marketed in Japan based on lead isotope ratios

Nutritional Composition and Taste Properties of Abalone and Short-Neck Clam in Wando

Nutritional Composition and Taste Properties of Abalone and Short-Neck Clam in Wando

Simultaneous determination of ten paralytic shellfish toxins and tetrodotoxin in scallop and short-necked clam by ion-pair solid-phase extraction and hydrophilic interaction chromatography with tandem mass spectrometry

Paralytic shellfish toxins and tetrodotoxin (puffer-fish toxin), the latter of which was recently found in bivalves from Europe, Japan, and New Zealand, are potent neurotoxins. A simple and effective clean-up procedure was developed for the simultaneous determination of ten paralytic shellfish toxins (gonyautoxins 1–6, decarbamoylgonyautoxins 2 and 3, and N-sulfocarbamoylgonyautoxins 2 and 3) and tetrodotoxin in the scallop, Mizuhopecten (Patinopecten) yessoensis, and the short-necked clam, Ruditapes philippinarum. To reduce matrix effects, 1% aqueous acetic acid extracts of the bivalves were cleaned up by ion-pair solid-phase extraction using a graphite carbon cartridge with tridecafluoroheptanoic acid as the volatile ion-pair reagent, followed by fourfold dilution. The ten paralytic shellfish toxins and tetrodotoxin were then separated on a hydrophilic interaction chromatography column and quantified by tandem mass spectrometry. The limits of detection and the limits of quantification for the ten PSTs ranged from 0.09 to 13.0 µg saxitoxin equivalents/kg and from 0.26 to 39.4 µg saxitoxin equivalents/kg, respectively. The limit of detection and the limit of quantification for tetrodotoxin ranged from 27.4 to 27.9 µg/kg and from 83.1 to 84.4 µg/kg, respectively. The proposed method yielded minimal matrix effects for the 11 analytes, thus allowing their quantification by simple external calibration. The proposed method also gave good mean recoveries of the 11 analytes ranging from 75.7 to 96.2% with relative standard deviations less than 16% at three fortification levels for the ten paralytic shellfish toxins (total concentrations of 277, 554, and 1107 µg saxitoxin equivalents/kg) and tetrodotoxin (100, 200, and 400 µg/kg) in the two bivalve samples. Finally, the proposed method was applied for the determination of the ten paralytic shellfish toxins and tetrodotoxin in scallop and short-necked clam samples.

Presence of Microplastics in Four Types of Shellfish Purchased at Fish Markets in Okayama City, Japan.

The worldwide microplastic pollution in our environment is a matter of great concern. Harmful effects of plastics have been reported in various types of organisms including murine animals. We examined the presence of microplastics in four types of shellfish purchased from fish markets in Okayama, Japan and served to the public: short-neck clam (Ruditapes philippinarum, asari in Japanese), hard-shell clam (Meretrix lusoria, hamaguri), brackishwater clam (Cyrenidae, shijimi), and oyster (Crassostrea gigas, kaki). Our analyses demonstrated that approx. 3 pieces of microplastics were present per single shellfish, based on the division of the total number of pieces of microplastic obtained from all 4 types of shellfish by the total number of shellfish examined. Since health problems in humans due to microplastics have not yet been confirmed, further examinations of the effects of ingested microplastics are needed.

EVALUATION OF THE RELATIONSHIP BETWEEN THE SEVERITY OF SOLID FOOD PROTEIN-INDUCED ENTEROCOLITIS SYNDROME AND POST-EMETIC SERUM THYMUS AND ACTIVATION-REGULATED CHEMOKINE LEVELS

We reported that post-emetic serum thymus and activation-regulated chemokine (TARC) levels may be a potential biomarker to diagnose solid food protein-induced enterocolitis syndrome (FPIES). However, there are no reports on the relationship between FPIES severity and serum TARC levels. The subjects were 13 cases of FPIES (hen's egg=10, Wheat=1, rice=1, short-neck clam=1) for a total of 22 events (7 emergency outpatient visits, 9 positive and 6 negative results of oral food challenge test). Serum TARC levels at 6 and 24 h after antigen ingestion were compared between the symptomatic and asymptomatic events and the mild-moderate and severe events. We also evaluated the correlation between vomiting duration and serum TARC levels. The median serum TARC (pg/ml) in the asymptomatic, mild-moderate, and severe events were 546, 1093, and 3127 at 6 h after ingestion, and 910, 2053, and 6496 at 24 h after ingestion, respectively. The serum TARC level was significantly higher in the symptomatic events than the asymptomatic events, and it was significantly higher in the severe events than the mild-moderate events (p < 0.01). There was a moderate correlation between serum TARC levels and vomiting duration. Post-emetic serum TARC correlates with the severity of FPIES. It is expected that this information will lead to an objective evaluation of the severity of FPIES.

Cadmium species in marine short-necked clam analyzed by size exclusion chromatography hyphenated respectively with inductively coupled plasma mass spectrometry and electrospray ionization quadrupole - time of flight mass spectrometry

To date, the speciation analysis of heavy metals in organs is still a challenge because these species are labile in vitro and scarce of the reference materials. In the present study, cadmium (Cd) species in marine shellfish were investigated with size exclusion chromatography (SEC) hyphenated with inductively coupled plasma mass spectrometry (ICP-MS), by which three Cd species in marine short-necked clam were observed. After pre-fractionation with a home-made Sephadex column, the Cd binding species were further characterized with SEC coupled with electrospray ionization quadrupole - time of flight mass spectrometry (ESI-Q-TOF-MS). The results showed that Cd species with 32,695 Da was the maximum Cd-binding molecule in the clam. Several metallothionein (MTs)-like Cd-binding proteins including a main species with molecular weight of 19,236 Da were observed. Some small Cd species with molecular weights less than 1000 Da were also observed in the clam. In order to verify the reliability of the two hyphenated methods, a standard reference material of Zn-binding MTs was analyzed at the same conditions. The results demonstrated that the two hyphenated methods of SEC-ICP-MS and SEC-ESI-Q-TOF-MS were practical to characterize the Cd species in marine shellfish.

Carbon budgets of two typical polyculture pond systems in coastal China and their potential roles in the global carbon cycle

The role of aquaculture systems in the global carbon cycle is poorly understood to date. We investigated the carbon budgets in 2 polyculture systems (PM: swimming crab Portunus trituberculatus with kuruma shrimp Marsupenaeus japonicus; and PMR: crab, shrimp and short-necked clam Ruditapes philippinarum) during the farming season (125 d in total). The main carbon input occurred via water (PM: 55.06%; PMR: 62.50%), followed by that via feed. PM absorbed 21.55 g C m-2 across the air-water interface, accounting for 13.27% of the total input. The carbon output via water was the main output in both PM (89.17%) and PMR (46.43%). PMR emitted 53.00 g C m-2 into the atmosphere during the farming season, accounting for 32.53% of the total output. The carbon output by harvested animals in PMR accounted for 19.48% of the total output, which was much higher than that in PM (5.71%). Carbon accumulation in the sediment was significantly higher in PM than in PMR (p &lt; 0.05), but the value of both represented a small portion of the total output. Clam farming in the polyculture system profoundly altered the carbon budgets by changing the CO2 flux direction, reducing carbon accumulation in water and sediments and increasing the carbon output by harvested animals. In terms of the global warming potential, which was calculated from the results of CO2 and CH4 fluxes across the air-water interface, PM had the potential for mitigating the greenhouse effect on the 20 yr horizon, whereas PMR exacerbated global warming. Our results suggest that PM acted as a net carbon sink in the global carbon cycle, while PMR acted as a carbon source.

Carbon dioxide fluxes from two typical mariculture polyculture systems in coastal China

During the farming season of 2013 and 2014, carbon dioxide (CO2) fluxes at the water-air interface were determined from two typical seawater polyculture systems. The mean CO2 fluxes of 2013 and 2014 were − 0.316 ± 0.0674 μmol m−2 s−1 and -0.173 ± 0.242 μmol m−2 s−1 in the bi-species polyculture system of swimming crab (Portunus trituberculatus) with kuruma shrimp (Marsupenaeus japonicus) (PM) and 0.249 ± 0.251 μmol m−2 s−1 and 0.426 ± 0.151 μmol m−2 s−1 in the tri-species polyculture system of swimming crab with shrimp and short-necked clam (Ruditapes philippinarum) (PMR) (Negative flux values refer to CO2 uptake and positive values refer to CO2 emission). During the farming season, the CO2 budgets in PM and PMR were − 113.1 g CO2 m−2 and 154.0 g CO2 m−2, respectively. Water pH seemed like a stable indicator for CO2 flux and Chlorophyll a concentration was a key factor regulating the CO2 flux. Subsequent decreasing in water pH and Chl a concentration was supposed to be the main contributor changing the carbon source/sink function from a CO2 sink of PM to a CO2 source of PMR. Under the condition of current study, pH of 8.26 could be considered to be the critical value between influxes and effluxes in seawater crab-shrimp and crab-shrimp-clam polyculture systems.

Shellfish Gathering Patterns of Na Area, Yeondae-do Shell Midden

본 연구에서는 연대도 패총 나지구의 B피트와 G10피트에서 채집된 패각층 시료를 바탕으로 연대도 지역 사람들의 생업경제에 중요한 역할을 하였을 패류의 채집 양상에 대하여 살펴보았다. 신석기시대부터 고려시대까지 형성된 나지구의 패각층 조성은 층위, 구역별로 고르지 않은 것으로 나타났다. B피트와 G10피트의 신석기시대 주요 패각층은 대략 50~60%의 비교적 높은 패류함량을 보여 패각층 퇴적 속도가 빠르고 패류채집이 활발하였음을 알 수 있다. G10피트의 고려시대 층도 65% 가량의 높은 패류 함량을 보였다. 패각층을 구성하는 식용패류는 부족류 7종, 복족류 16종 등 총 23종이 확인되었다. 이러한 패류는 대부분 조간대의 암초에 서식하는 종들로서 유적 인근 해안가에서 패류채집이 이루어졌을 것으로 추정된다. 그러나 대부분의 시료에서 굴과 홍합 두 패류의 합이 식용패류의 90% 이상 매우 높은 비중을 차지하여 패류 채집이 굴과 홍합에 집중된 양상을 보여주었다. 기타 암초성 패류는 주요 채집 대상은 아니었으며 굴과 홍합 채집시 부수적으로 채집되었을 것으로 추정된다. 패류 채집은 주요 패류인 굴과 홍합의 식용 가능 시기인 가을에서 봄 사이에 이루어졌을 것으로 생각된다. 한편 통일신라, 고려시대에 이르러 바지락, 전복, 소라 등 채집을 위해 좀 더 노력과 채집기술이 필요한 패류의 채집이 증가하는 변화가 있었다. 연대도 패총의 주된 채집종인 굴의 크기분포를 살펴보면 신석기시대 전반에 걸쳐 약간의 크기변화는 있으나 급격한 크기 감소는 보이지 않았다. 이로 미루어 당시 굴의 서식환경이 안정적이며 크기 감소를 가져올 만큼 채집 강도가 크지 않았던 것으로 추정된다. 고려시대에는 신석기시대에 비하여 약간의 크기 감소가 확인되었다.This research examined the shellfish gathering patterns of the Yeondae-do people, which played an important role in their subsistence economy, based on the shell layer samples collected from B pit and G10 pit of Na area in the Yeondae-do Shell Midden, Tongyeong-si, Korea. The composition of the shell midden layers was found to be different depending on layers and areas. The major Neolithic shell layers of B pit and G10 pit showed relatively high shellfish contents of around 50~60%, revealing that the rate at which shell layer decomposed was generally fast, and that shellfish were gathered actively. The Goryeo Period layers of G10 pit also showed high shellfish contents of about 65%. A total of 23 edible shellfish species, including 7 bivalves and 16 gastropoda, were identified from the shell midden layers. These shellfish species live mostly on rocks in the intertidal areas, suggesting that shellfish gathering was carried out on the reef coast near the site during low tides. The combined proportion of oysters(Crassostrea gigas) and mussels(Mytilus coruscus) was found to take up more than 90% of edible species in the majority of the midden samples, indicating a concentrated gathering of the two shell species. Other shells living on rocks are presumed to have been collected subsidiarily when collecting oysters and mussels. Gathering of shellfish in Yeondae-do seems to have occurred between autumn and spring, when the two mainly gathered shell species, oysters and mussels, are edible. By Unified Shilla and Goryeo Periods, there was an increase in gathering of shell species that required more effort and advanced techniques to collect, such as short-necked clams(Ruditapes philippinarum), abalones (Nordotis discus discus), turban shells(Batillus cornutus), and others. An examination of the size distribution of oysters, the main species composing the Yeondae-do shell midden, revealed no distinctive reduction in their size during the entire Neolithic Period. Therefore, it can be assumed that their inhabiting environment was stable throughout the Neolithic Period, and that the oyster gathering was not intensive enough to affect their size. However, a slight decrease in size was observed in the oyster shells from the Goryeo Period compared to those of the Neolithic Period.

Methane fluxes from typical marine polyculture ponds of swimming crab with kuruma shrimp and short-necked clam in eastern China

AEI Aquaculture Environment Interactions Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AEI 11:63-73 (2019) - DOI: https://doi.org/10.3354/aei00295 Methane fluxes from typical marine polyculture ponds of swimming crab with kuruma shrimp and short-necked clam in eastern China Dongxu Zhang1, Xiangli Tian1,*, Shuanglin Dong1, Yan Chen2, Jie Feng1, Rui-Peng He1, Kai Zhang3 1Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, PR China 2Beijing Aquatic Product Technology Promotion Department, Beijing 100029, PR China 3Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510380, PR China *Corresponding author: xianglitian@ouc.edu.cn ABSTRACT: Methane (CH4) fluxes at the water-air interface in 2 typical seawater polyculture systems were determined during the farming season. The mean CH4 fluxes were 66.0 ± 44.1 µg m-2 h-1 in the bispecies polyculture system of swimming crab Portunus trituberculatus with kuruma shrimp Marsupenaeus japonicus (PM) and 68.7 ± 39.5 µg m-2 h-1 in the trispecies polyculture system of swimming crab with shrimp and short-necked clam Ruditapes philippinarum (PMR), and no significant differences were observed between them. CH4 emissions showed temporal variability during the farming season, peaking in mid-August. The linear mixed-effect model demonstrated that air temperature was the main regulator of CH4 fluxes rather than the internal physical and chemical properties of the systems. Air, water and sediment temperatures explained 58.9, 61.4 and 55.3% of the CH4 flux variations in the PM and 64.6, 57.1 and 60.8% of the variations in the PMR, respectively. Reducing organic matter accumulation in the sediment by means of improving feeding efficiency and the application of integrated aquaculture are likely to be effective in reducing CH4 emissions from aquaculture systems. KEY WORDS: Methane fluxes · Temperature · Sediment characteristics · Seawater polyculture systems Full text in pdf format PreviousNextCite this article as: Zhang D, Tian X, Dong S, Chen Y, Feng J, He RP, Zhang K (2019) Methane fluxes from typical marine polyculture ponds of swimming crab with kuruma shrimp and short-necked clam in eastern China. Aquacult Environ Interact 11:63-73. https://doi.org/10.3354/aei00295 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AEI Vol. 11. Online publication date: February 21, 2019 Print ISSN: 1869-215X; Online ISSN: 1869-7534 Copyright © 2019 Inter-Research.

Health risk assessment of heavy metals in shellfish collected from Fujian, China

With industrialization and human activities, shellfish may be contaminated by various pollutants such as heavy metals. This study aims at the concentrations of As, Cr, Mn, Ni, Cu, Zn, Cd, Sn, Sb and Pb in shellfish collected from Fujian of China, and the risk of heavy metals in shellfish on human health based on target hazard quotients (THQ). Results showed that the THQ values of the elements were far below 1, except for As with an average value of 1.148 in razor clam. No detrimental health effects of heavy metals on humans health was observed by daily consumption of mussel and oyster, but the exposed population to short-necked clam, scallop and razor clam might experience noncarcinogenic health risks because each of the total THQ values was above 1 for the three shellfish.

Taurine-Related Nutritional Knowledge Has a Positive Effect on Intake of Taurine and Cognitive Function in the Elderly.

The purpose of this study was to investigate the correlations among taurine-related nutritional knowledge (TNK), taurine intake frequency (TIF), and cognitive function (CF) in Korean elderly. Subjects of this cross-sectional study were 278 elderly persons in Korea without dementia (men 76, women 202). The subjects were divided into two groups: a group with a lower than average TNK score (LAG) and a group with a higher than average TNK score (HAG). Data were obtained via questionnaires and 1: 1 interviews. Correlation analysis available in SPSS 20.0 was used to analyze associations among the three factors. Average TNK score of all subjects was 4 out of 10 points, while that of the LAG (1.9 points) was significantly lower than that of the HAG (6.6 points) (p<0.001). Average TIF score in the HAG (195.3 points) was significantly higher than that of the LAG (180.8 points) (p<0.001). Compared to the LAG, the HAG members more frequently consumed foods such as webfoot octopus, whelk, dried anchovy, dried shrimp, mackerel, anglerfish, skate, short-necked clam, shrimp, and dried squid (p<0.01). There was no significant difference in CF scores between the LAG and HAG. There was positive correlation between TNK and TIF scores in all the subjects (p<0.01). There was no significant difference, but there was a tendency for a positive correlation, between TNK and CF scores (p=0.072). These results suggest that nutritional education of the elderly about taurine is needed, and it is strongly recommended that the elderly frequently consume taurine-containing foods and supplements to prevent dementia.

Recovering value from waste: biomaterials production from marine shell waste

Marine shell waste is rich in calcium carbonate \((\hbox {CaCO}_{3})\), which can be a good source for the synthesis of hydroxyapatite (HAP). HAP is a potential component in bone tissue engineering as it possesses similar elements to bone structure. In this study, three different species of marine shells that are normally found in Malaysia, namely short-necked clam (Paphia undulate), blood cockle (Anadara granosa) and hard clam (Meretrix lyrata) were used to produce \(\hbox {CaCO}_{3}\) and HAP. The characterization results indicate that the produced \(\hbox {CaCO}_{3}\) consists of mainly aragonite polymorph. Subsequently, the produced \(\hbox {CaCO}_{3}\) was used as the calcium source for the formation of HAP through the wet slurry precipitation method. The results from the analyses on crystallinity, functional group, surface morphology and elemental analysis of the synthesized HAP powders that were obtained through X-ray diffraction (XRD), Fourier-transform infrared (FTIR), scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) have confirmed that HAP is comparable with other studies. Overall, the results obtained through this study indicate that it is possible to produce \(\hbox {CaCO}_{3}\) and HAP from various marine-based shell waste through greener synthesis routes with less chemicals and reactiontime.

The Ashtamudi Lake short-neck clam: re-assigned to the genus Marcia H. Adams & A. Adams, 1857 (Bivalvia, Veneridae).

The economically valuable bivalve mollusc, known as the short-neck clam, is the major fishery resource of the brackishwater Ashtamudi Lake in Kerala, India. This fishery carries a Marine Stewardship Council certification for sustainability wherein it and all hitherto published reports identify the short-neck clam or yellow-foot clam as Paphiamalabarica (Dillwyn, 1817). It is noted that this name does not conform with current nomenclature and is now correctly referred to Protapesgallus (Gmelin, 1791). Furthermore, it is shown that the identification is also incorrect. Comparative shell morphology of venerid clams of the subfamily Tapetinae from the south Indian coast demonstrates that the short-neck clam in Ashtamudi Lake is Marciarecens (Holten, 1802). Small numbers of M.opima (Gmelin, 1791) were found in Ashtamudi Lake but appear not to be part of, or contribute significantly to, the fishery. The venerid clams Protapesgallus and P.ziczac (Linnaeus, 1758) are not found in Ashtamudi Lake but are inhabitants of the shallow coastal waters of south India. Descriptions of the four confused species M.recens, M.opima, P.gallus, and P.ziczac are given. On the basis of this study, the species involved in Marine Stewardship Council (MSC) certification may be better considered at the generic level of Marcia or at the species level as Marciarecens, the most dominant species in the Ashtamudi Lake clam fishery zone.