Accumulation of hepatotoxic microcystins in freshwater mussels, aquatic insect larvae and oligochaetes in a large, shallow eutrophic lake (Lake Chaohu) of subtropical China

This paper studied the seasonal changes of two common microcystins (MCs), MC-RR and -LR, in the commercially important mussel Corbicula fluminea in Lake Chaohu, where there occurred dense cyanobacteria. Occasional measurements were also made for MC in the mussel Arconaia lanceolat, the oligochaete Limnodilus hoffineisteri and the insect larva Chironomus sp. Mean MC of C. fluminea was much higher in hepatopancreas than in intestine and foot. Our study is the first to report accumulation of MCs in oligochaetes and aquatic insect larvae. The hi-h contents of MCs in the insect larvae suggest a great possibility for the transfer of MCs to benthos-feeding omnivores like common carp. According to the provisional standard by the WHO, 28.6% of the collected C. fluminea were harmful for human consumption, assuming a daily consumption of 300 by a person. It is recommended that edible mussels should not be collected for human consumption during toxic cyanobacterial blooms in Lake Chaohu.

Seawater carbonate chemistry and calcification during incubation experiments with Mytilus edulis and Grassostrea gigas, 2006

Ocean acidification resulting from human emissions of carbon dioxide has already lowered and will further lower surface ocean pH. The consequent decrease in calcium carbonate saturation potentially threatens calcareous marine organisms. Here, we demonstrate that the calcification rates of the edible mussel (Mytilus edulis) and Pacific oyster (Crassostrea gigas) decline linearly with increasing pCO2. Mussel and oyster calcification may decrease by 25 and 10%, respectively, by the end of the century, following the IPCC IS92a scenario (?740 ppmv in 2100). Moreover, mussels dissolve at pCO2 values exceeding a threshold value of ?1800 ppmv. As these two species are important ecosystem engineers in coastal ecosystems and represent a large part of worldwide aquaculture production, the predicted decrease of calcification in response to ocean acidification will probably have an impact on coastal biodiversity and ecosystem functioning as well as potentially lead to significant economic loss.

The morphometrics and the proximate composition of the edible fresh water mussel Lamellidens lamellatus (Lea) from Bathalagoda tank, a man made reservoir in Sri Lanka

Morphometric characteristics of Lamellidens lamellatus were studied using a random sample of 138 individuals collected from Bathalagoda reservoir in Kurunegala district. The largest number of individuals in the collection was between 40-50 mm in length. They had a body weight between 60-80 gm. The most abundant bio-chemical component in the adductor and in the foot was protein. Carbohydrate and lipid quantities were almost equal while ash showed the least value. The total protein content ranged from 48.8% to 73.4%; the carbohydrate content from 12.64% to 23.8%; and lipid content from 12.0% to 28.1% of their dry weight. It was found that there were significant relationships between the length and the body weight; and between length and volume.

Technological aspects of processing of edible mussels, clams and crabs. Pt. 1. Spoilage during ice storage

Rate and pattern of spoilage of some of the economically important edible species of shell fishes Mytilus edulis (Mussel), Villorita cornucopia (Clam), Neptunus pelagicus (Crab) and Scylla serrata (Crab) have been discussed in this communication. Chemical indices used for objective evaluation of quality were water extractable nitrogen (WEN), non-protein nitrogen (NPN), free α-amino nitrogen (α - NH2 -N), glycogen, lactic acid and inorganic phosphorus in addition to the subjective tests. No significant difference in the spoilage pattern of the species during ice storage was observed and these species could be preserved in ice in organoleptic acceptable condition up to 8 days, 9 days, 8 days and 11 days respectively.

Claw removal and feeding ability in the edible crab, Cancer pagurus: Implications for fishery practice

Feeding ability and motivation were assessed in the edible crab, Cancer pagurus, to investigate how the fishery practice of de-clawing may affect live crabs returned to the sea. Crabs were either induced to autotomise one claw, or were only handled, before they were offered food. Initially, autotomised and handled crabs were offered mussels, Mytilis edulis, a large part of their natural diet. After 3 days, both autotomised and handled crabs were then offered fish, a more readily handled food source. Autotomy induced crabs consumed significantly fewer mussels and less mussel mass, but ate significantly more mass of fish. This indicates that the effect of autotomy was a reduction of ability to feed on mussels rather than a general reduction of feeding motivation. The discontinuation of claw removal needs to be considered, both for the sustainability of the fishery and animal welfare concerns. (C) 2008 Elsevier B.V. All rights reserved.

Sub lethal mercuric chloride toxicity induced stress related alterations in the epithelial lining of foot of the freshwater mussel Lamellidens marginalis (Lamarck)

Sub lethal (0.2 ppm) mercuric chloride induced stress related histopathological alterations in the epithelial linings of foot (podium) of the edible freshwater mussel Lamellidens marginalis (Lamarck) were studied using histochemical techniques up to 60 days of exposure. The histomorphological changes were manifested only slowly and its intensity was somewhat proportional to the duration of exposure. The immediate response of the exposed mussels was the altered mucous secretion. There was a progressive incorporation of sulphated glycoproteins into the secretory contents of the mucous cells especially in the first half of the experiment. Marked histopathological changes including necrosis, appearance of pyknotic nuclei, sloughing of epithelial cells and appearance of non-tissue spaces, etc., started appearing during the later half of the experiment. The fag end of the experiment, which witnessed prominent histomorphological changes, was accompanied by highly decreased mucous secretion. KEYWORDS: heavy metal toxicity, mercuric chloride, Lamellidens marginalis, freshwater mussel, histopathology.

Mussel-inspired porous SiO2 scaffolds with improved mineralization and cytocompatibility for drug delivery and bone tissue engineering

Porous SiO2 scaffolds with mesopore structure (named as MS scaffolds) have been proposed as suitable for bone tissue engineering due to their excellent drug-delivery ability; however, the mineralization and cytocompatibility of MS scaffolds are far from optimal for bone tissue engineering, and it is also unclear how the delivery of drugs from MS scaffolds affects osteoblastic cells. The aims of the present study were to improve the mineralization and cytocompatibility of MS scaffolds by coating mussel-inspired polydopamine on the pore walls of scaffolds. The effects of polydopamine modification on MS scaffolds was investigated with respect to apatite mineralization and the attachment, proliferation and differentiation of bone marrow stromal cells (BMSCs), as was the release profile of the drug dexamethasone (DEX). Our results show that polydopamine can readily coat the pore walls of MS scaffolds and that polydopamine-modified MS scaffolds have a significantly improved apatite-mineralization ability as well as better attachment and proliferation of BMSCs in the scaffolds, compared to controls. Polydopamine modification did not alter the release profile of DEX from MS scaffolds but the sustained delivery of DEX significantly improved alkaline phosphatase (ALP) activity of BMSCs in the scaffolds. These results suggest that polydopamine modification is a viable option to enhance the bioactivity of bone tissue engineering scaffolds and, further, that DEX-loaded polydopamine MS scaffolds have potential uses as a release system to enhance the osteogenic properties of bone tissue engineering applications.

Mechanical properties of mussel byssus threads

The byssus threads of the common mussel, Mytilus edulis L., have been tested mechanically and the results from the tests related to the ecology of the animal. The threads are mechanically similar to other crystalline polymers such as polyethylene having a modulus of about 108N m−2 and a long relaxation time. Resilience of 60% is similar to tendon; ultimate strain is about five times that of tendon at 0.44. The thread is laid down with a prestrain of 10% and so guys the mussel in position. Calculation shows that a mussel with 50 byssus threads would be able to resist all but severe winter storms.

Mussel-inspired bioceramics with self-assembled Ca-P/polydopamine composite nanolayer : preparation, formation mechanism, improved cellular bioactivity and osteogenic differentiation of bone marrow stromal cells

The nanostructured surface of biomaterials plays an important role in improving their in vitro cellular bioactivity as well as stimulating in vivo tissue regeneration. Inspired by the mussel’s adhesive versatility, which is thought to be due to the plaque–substrate interface being rich in 3,4-dihydroxy-L-phenylalamine (DOPA) and lysine amino acids, in this study we developed a self-assembly method to prepare a uniform calcium phosphate (Ca-P)/polydopamine composite nanolayer on the surface of b-tricalcium phosphate (b-TCP) bioceramics by soaking b-TCP bioceramics in Tris–dopamine solution. It was found that the addition of dopamine, reaction temperature and reaction time are three key factors inducing the formation of a uniform Ca-P/polydopamine composite nanolayer. The formation mechanism of a Ca-P/polydopamine composite nanolayer involved two important steps: (i) the addition of dopamine to Tris–HCl solution decreases the pH value and accelerates Ca and P ionic dissolution from the crystal boundaries of b-TCP ceramics; (ii) dopamine is polymerized to form self-assembled polydopamine film and, at the same time, nanosized Ca-P particles are mineralized with the assistance of polydopamine, in which the formation of polydopamine occurs simultaneously with Ca-P mineralization (formation of nanosized microparticles composed of calcium phosphate-based materials), and finally a self-assembled Ca-P/polydopamine composite nanolayer forms on the surface of the b-TCP ceramics. Furthermore, the formed self-assembled Ca-P/polydopamine composite nanolayer significantly enhances the surface roughness and hydrophilicity of b-TCP ceramics, and stimulates the attachment, proliferation, alkaline phosphate (ALP) activity and bone-related gene expression (ALP, OCN, COL1 and Runx2) of human bone marrow stromal cells. Our results suggest that the preparation of self-assembled Ca-P/polydopamine composite nanolayers is a viable method to modify the surface of biomaterials by significantly improving their surface physicochemical properties and cellular bioactivity for bone regeneration application.

Biodiesel production from non-edible beauty leaf (Calophyllum Inophyllum) oil : process optimization using response surface methodology (RSM)

In recent years, the beauty leaf plant (Calophyllum Inophyllum) is being considered as a potential 2nd generation biodiesel source due to high seed oil content, high fruit production rate, simple cultivation and ability to grow in a wide range of climate conditions. However, however, due to the high free fatty acid (FFA) content in this oil, the potential of this biodiesel feedstock is still unrealized, and little research has been undertaken on it. In this study, transesterification of beauty leaf oil to produce biodiesel has been investigated. A two-step biodiesel conversion method consisting of acid catalysed pre-esterification and alkali catalysed transesterification has been utilized. The three main factors that drive the biodiesel (fatty acid methyl ester (FAME)) conversion from vegetable oil (triglycerides) were studied using response surface methodology (RSM) based on a Box-Behnken experimental design. The factors considered in this study were catalyst concentration, methanol to oil molar ratio and reaction temperature. Linear and full quadratic regression models were developed to predict FFA and FAME concentration and to optimize the reaction conditions. The significance of these factors and their interaction in both stages was determined using analysis of variance (ANOVA). The reaction conditions for the largest reduction in FFA concentration for acid catalysed pre-esterification was 30:1 methanol to oil molar ratio, 10% (w/w) sulfuric acid catalyst loading and 75 °C reaction temperature. In the alkali catalysed transesterification process 7.5:1 methanol to oil molar ratio, 1% (w/w) sodium methoxide catalyst loading and 55 °C reaction temperature were found to result in the highest FAME conversion. The good agreement between model outputs and experimental results demonstrated that this methodology may be useful for industrial process optimization for biodiesel production from beauty leaf oil and possibly other industrial processes as well.

Impacts of introduced aquaculture species on markets for native marine aquaculture products : the case of edible oysters in Australia

Economic competition between introduced and native aquaculture species is of interest for industry stakeholders since increased production can affect price formation if both aquaculture species are part of the same market or even substitutes. In this study, we focus on the Australian edible oyster industry, which is dominated by two major species—the native Sydney rock oyster (grown mainly in Queensland and New South Wales) and the non-native Pacific oyster (grown mainly in South Australia and Tasmania). We examine the integration of the Australian oyster market to determine if there exists a single or several markets. Short- and long-run own, cross-price and income flexibilities of demand are estimated for both species using an inverse demand system of equations. The results suggest that the markets for the two species are integrated. We found evidence that the development of the Pacific oyster industry has had an adverse impact on Sydney rock oyster prices. However, our results show that both species are not perfect substitutes. Demand for Sydney rock oysters is relatively inelastic in the long run, yet no long-run relationships can be identified for Pacific oysters, reflecting the developing nature of this sector.

Nearness and revealing : The edible veil of the sensible being.

Taking cues from the fragility and grace enfolded within Asian cuisine, this paper explores recent experimentation of an edible rice paper veil. The veil fashions a 'secondary skin', what Jeffery Schnapp the author of 'The Fabric of Modern Times', calls an "object for prosthetic shelf extension...bearing a uniquely intimate and direct relation to the human body" (Schnapp, 1997:197). The process reveals a layered material mutable to moisture and humidity, changing its elastic state in relation to body and surroundings. The moving, breathing, sweating surface of the body further modifies both veil and bodily experience drawing forth deeper emotional responses. The implications here offer a reciprocal affect, a revealing, where new materiality evokes the threshold to a new sensible being, one aware of the depth of material consciousness and inter-corporeal engagement, and which extends the relations between thinking and being of Heidegger and Shklovsky's seminal works.

Edible materials in design fabrication

Current practice based research explores the organic properties of edible materials such as rice-paper to contemplate possible material usage from garment manufacture, landscape interventions and temporary architectural canopies/facades. Research outcomes have been published through The International Conference on Designing Food and Designing for Food, London 2012, and in Burke, Anthony + Reinmuth, Gerard (Eds.) (2012) 'Formations: New Practices in Australian Architecture.' Australian Pavilion 13th International Architecture Exhibition la biennale di Venezia.

Blue mussel beds as biodiversity hotspots on the rocky shores of the northern Baltic Sea

ABSTRACT The Baltic Sea is a vulnerable ecosystem currently undergoing a number of changes, both natural and human induced. The changes are likely to affect the species found on these shores, e.g. their distribution and interactions with other species. Blue mussels (Mytilus trossulus x Mytilus edulis) provide one of the main biogenic hard structures on the shallow shores of the Baltic Sea where they aggregate into dense beds and provide a number of resources for over 40 associated macrofaunal species, thus functioning as ecosystem engineers. The blue mussel, being a marine species, is highly likely to be affected by any changes in sea water salinity, circulation and/or water balance. These changes could trickle down also to affect the associated macrofaunal communities. The aims of this thesis were three-fold: first, I examined and described the macrofaunal communities found within blue mussel patches since the fauna associated with mussel patches had never been described in the study area prior to this thesis. Second, I explored how changes in mussel density, size as well as patch size and shape would affect the mussel communities. Finally, I tested how general landscape theories derived from terrestrial studies function in blue mussel systems. Theories included the structural heterogeneity hypothesis, species-area relationships, edge effects and patch isolation effects. The work shows that blue mussels in the northern Baltic Sea have an indisputable function as diversity hotspots and that the faunal assemblages found in mussel patches are extremely rich and unique. Further on, it shows that changes in mussel biomass, size, patch size and amount of edge have the potential to alter the faunal assemblages and diversity within patches. Finally, it shows that although some landscape theories, such as the structural heterogeneity hypothesis, seem to apply also in blue mussel communities, others cannot be directly applied due to the different prevailing conditions in the study system. This is a pioneering work looking at diversity shaping processes on the rocky shores of the Gulf of Finland, making up over 40% of the total water basin. A focus on niche construction, positive facilitation effects and ecosystem engineering could provide new insights and methods for conservation biology, but before this can be done, we need to fully understand the circumstances under which a species becomes an ecosystem engineer and recognize the systems in which it functions.