Short-necked Clam Research Articles

Taste-active components in some foods: A review of Japanese research

Japanese research of taste-active components in seafoods, meat and tomatoes is reviewed. The omission (or addition) test with synthetic extracts simulating natural extracts was employed in most of that research. In abalone, sea-urchin, snow crab, scallop and short-necked clam, glutamic acid (Glu) and glycine were recognized commonly to be taste-active. It was also reported that the synergism between Glu and 5′-ribonucleotides and the presence of sodium and chloride ions were required to produce the characteristic taste of each food. In dried skipjack meat and salted salmon eggs, umami substances such as Glu and inosine 5′-monophosphate (IMP) were found to be important contributors to their tastes as well. The brothy taste of beef, pork and chicken soups could be reproduced by free amino acids, IMP and sodium chloride, indicating their important roles in producing the taste. A potential effect of Glu and aspartic acid on the taste of tomatoes was observed. Studies of the flavor-enhancing effects on soups and umami solutions of sulfur-containing compounds in garlic are also described.

The Relationship Between Abundance of the short-necked Clams Ruditapes Philippinarum and Wave Action in Banzu Tidal Flat in Tokyo Bay

The Relationship Between Abundance of the short-necked Clams Ruditapes Philippinarum and Wave Action in Banzu Tidal Flat in Tokyo Bay

Novel tetraamines, pentaamines and hexaamines in sea urchin, sea cucumber, sea squirt and bivalves

1. 1. Polyamines were extracted from the guts and ovaries of the sea urchin Anthocidoris crassispina, and the guts and flesh of the sea cucumber Stichopus japonicus and the sea squirt Halocynthia roretzi, the oyster Crassostrea gigas and the short-necked clam Tapes philippinarum, and analyzed by ion-exchange high-performance liquid chromatography and gas chromatography-mass spectrometry. 2. 2. Norspermidine and norspermine as well as putrescine, cadaverine, spermidine, spermine and agmatine were the ubiquitous polyamines in these invertebrates. These results suggest the widespread distribution of norspermidine and norspermine in invertebrates. 3. 3. Thermopentamine, thermohexamine and homothermohexamine were found in the sea urchin. This in the first report on the occurence of thermopentamine and hexaamine in invertebrates. 4. 4. Homospermidine, canavalmine, aminopropylhomospermidine, homospermine, caldopentamine, homocaldopentamine and aminopropylcanavalmine were found in the sea cucumber. Homospermidine, aminopropylhomospermidine and homospermine were found in the squirt. This is the first report on the occurence of canavalmine, aminopropylhomospermidine, homospermine, homocaldopentamine and aminopropylcanavalmine in invertebrates.

Changes in fatty acid composition in ruditapes philippinarum A & R (veneridae) fed on industrial yeast

1. 1. The fatty acid composition of short-neck clams ( Ruditapes philippinarum A & R) was compared in animals (a) fed on industrial yeast, (b) fed on natural phytoplankton, (c) after starvation. 2. 2. Marked deficiencies in polyunsaturated fatty acids were found in the case of a yeast diet as well as after starvation. 3. 3. Metabolic changes are discussed.

Volatile components of boiled and roasted short-necked clam Tapes philippinarum.

The volatile components were experimentally produced by heating short-necked clam (Tapes philippinarum) with glass beads. Three flavor concentrates, obtained by distillation at three temperature ranges (98-101, 101-115, and 115-160°C), were analyzed by GC-MS. A total of 76 compounds were identified. They included 9 acyclic nitrogen compounds, 9 pyrazines, 6 pyridines, 6 pyrroles, 5 pyrrolidines, 5 acyclic sulfur compounds, and 1-methylpyrrolidine-2, 5-dione. The last concentrate (115-160°C) gave a pleasant roasted odor of short-necked clam was char-acterized by the following flavor components: 3, 4, 5, 6-tetrahydro-2, 4, 6-trimethyl-2H-1, 3, 5-thiadiazine, 5, 6-dihydro-2, 4, 6-trimethyl-4H-1, 3, 5-dithiazine, 2-methyl-2-thiazoline, 3-hydroxy-2-methyl-4H-pyrone (maltol), and N, N-dimethylglycine methyl ester. While the second concen-trate (101-115°C) having the boiled odor of the clam contained some pyrazines, some pyridines, and the ester as major flavor components.

Chlorophyllone-a, a new pheophorbide-a related compound isolated from [formula omitted] as an antioxidative compound

A new pheophorbide a related compound named as chlorophyllone a ( 1), C 33H 32N 4O 3, was isolated as an antioxidative compound from the extract of the short-necked clam, Ruditapes philippinarum . It suggests a new degradative pathway of chlorophylls.

PSP components of toxified short-necked clams in Yamagawa Bay, Kagoshima Prefecture.

Our efforts were made to clarify the cause of a food poisoning in which a person provoked numbness in the mouth by ingesting the short-necked clam Tapes japonica from Yamagawa Bay, Kagoshima Prefecture.The toxic shellfish specimens which were collected from Yamagawa Bay were shucked and extracted with 80% ethanol acidified with acetic acid. After being defatted with chloroform, the aqueous extract was purified by chromatography on Bio-Gel P-2 and Bio-Rex 70. The toxins prepared were analyzed by cellulose acetate strip electrophoresis and thin-layer chromatography on silica gel. The results indicated that toxins contained protogonyautoxins (PXs) 1-4 as the major components, together with gonyautoxins (GTXs) 1-6 as the minor, on molar basis.We thus came to a conclusion that the aforementioned poisoning was caused by the paralytic shellfish poisons (PSPs) accumulated in the short-necked clam.

Bioaccumulation and Metabolic Fate of Pyrazolate and Its Hydrolysates in Guppies and Short-necked Clams

ピラゾレート [4-(2,4-dichlorobenzoyl)-1,3-dimethyl-5-pyrazolyl p-toluenesulfonate] とその加水分解物であるDTP [4-(2,4-dichlorobenzoyl)-1,3-dimethyl-5-hydroxypyrazole] およびPTSA (p-toluenesulfonic acid) のグッピーとアサリにおける生物濃縮性と代謝を14C化合物を用いて調べた. ピラゾレート0.33ppbまたは32.3ppbを含む水中でグッピーを飼育したところ, 14Cから求めた濃縮倍率 (UF値) はそれぞれ590または290倍であった. DTP 0.37ppbまたはPTSA 2.91ppbの水中でグッピーを飼育した場合には, UF値はそれぞれ15倍または1以下であった. ピラゾレート2.06ppbまたはDTP 48.4ppbを含む人工海水中で飼育したアサリの場合にはUF値はそれぞれ52または6.2倍であった. グッピーおよびアサリを薬物を含まない水中へ移すと, これらの魚貝類中の14C濃度はいずれの場合にも速やかに減少し, 生物濃縮される傾向は見られなかった. 魚貝類中においてピラゾレートは, まず, DTPとPTSAに加水分解され, DTPはさらに, 1位および3位のメチル基の酸化や4位のベンゾイル基の開裂等の代謝を受け, より極性の高い代謝物を生成することがわかった.

Using of Shell Growthline for Analysis of Relationship between Growth of Short Necked Clam, Ruditapes philippinarum (Adams and Reeve) and Environmental Factors

Using of Shell Growthline for Analysis of Relationship between Growth of Short Necked Clam, Ruditapes philippinarum (Adams and Reeve) and Environmental Factors

A comparison between arsenic contents in littoral sessile forms of mollusks from two sea areas in eastern Kyushu.

Oysters, mussels and limpets were collected from thirteen sites along the intertidal rocky shoreline of Beppu Bay and arsenic contents in the specimens were determined. On the other hand, oysters, chitons and limpets were collected along the rocky shoreline and also short-necked clams from sand bed of a site in Miyazaki Prefecture, and the contents were also determined. Potential arsenic pollution in Beppu Bay was discussed on the basis of the concentration differences between the specimens collected in common from the two areas. In the oysters and the limpets collected in common from the two areas, the arsenic contents were consistently higher in those from Beppu Bay than those from Miyazaki Pref. In Beppu Bay, the contents in oysters were rather higher in those from the two sites in Saganoseki Inlet than in those from all of the other sampling sites, and in mussels a similar phenomenon was noticed. In a single site from which the three specimens were collected in common, the order of arsenic content was as follows: limpets>oysters>mussels. Between oysters and limpets collected from all of the sampling sites in Beppu Bay, the contents were consistently higher in the latter than in the former. On the other hand, in the specimens collected from the shoreline of Miyazaki Pref., the contents in oysters were almost equal to those in limpets. The arsenic levels of chitons were nearly equivalent to those in limpets and oysters. The relatively high level of arsenic equivalent to that of the oysters from Beppu Bay was found in short-necked clams from a site in Miyazaki Pref. From these contexts, it was demonstrated that the high arsenic accumulation existed in the littoral forms in Beppu Bay, in which much grossly polluted specimens were found locally. Such high arsenic accumulation could be explained by biomagnification through arsenic level elevated to sea water.

Induction of phenol-sulfate conjugating activity by exposure to phenols and duration of its induced activity in short-necked clam.

Induction of phenol-sulfate conjugating activity by exposure to phenols and duration of its induced activity in short-necked clam.

風による流れと青潮との関係

Aoshio, the oxygen-deficient blue-green turbid water, which after appears in the head of Tokyo Bay from summer to autumn and occasionally causes extensive damage to the short-necked clam Ruditapes phillipinarum one of the main catches in this area. Analysis of the meteorological (wind) and the oceanagraphical records (bottom current, temp., salinity, density, sulfide and oxygen) suggested the following process: When the prevailing on-shore winds became off-shore (N-NE) for more than 2-3 days, the wind-driven surface water moving off-shore induced the sulfide-containing bottom water to move upwards at the Funabashi coastal zone at the entrance to the harbor and to create aoshio which usually appeared in Funabashi Harbor at first.

Accumulation and retention of antimony-125 in the short-necked clam.

Accumulation and retention of 125Sb by short-necked clam Tapes japonica were investigated in order to elucidate the uptake mechanism of the nuclide in marine bivalves. It was found that the accumulation of 125Sb by the clam from the environmental water showed an initially relative rapid increase, followed by a gradual increasing pattern during the experimental period. The concentration factors for 125Sb in the clam at the end of the experimental period were obtained as 1.2 for the soft part and 4.2 for the shell. The loss of 125Sb accumulated in the whole clam showed an initial decrease, followed by two slow elimination patterns. The long-lived biological half-life for 125Sb in the clam was approximately 58 days. Regarding the influence of chelating agent and co-existing element on the accumulation of 125Sb by the clam, it was observed that the addition of stable antimony to the rearing sea watere enhanced the accumulation of 125Sb by the soft part and shell of the clam to some extent; whereas, the accumulation of 125Sb by the soft part and shell was not depressed in the presence of EDTA. The accumulation of 125Sb by the shell depends mostly on the surface adsorption phenomenon rather than that via metabolic process.

アサリよりFucoxanthinolの単離

アサリよりFucoxanthinolの単離

Non-volatile amines formation and decomposition in abusively stored fishes and shellfishes.

The objective of this study was to investigate the relation of formation of non-volatile amines to spoilage of sea foods. The amounts of six non-volatile amines, histamine (His.), cadaverine (Cad.), putrescine (Put.), spermidine (Spd.), tyramine (Tyr.) and agmatine (Agm.), formed during the putrefaction were investigated, by using the muscle of various commercial sea foods. And then, the pH value and the volatile base nitrogen (VBN) contents were investigated simultaneously. Raw pacific mackerel, tuna, sardin, pacific saury, shortneck clam and boiled octopus were allowed to stand at the room temperature of 27±2°C. The analytical methods used for the determination involved the separation of non-volatile amines from sea foods by eluting through a cation-exchange resin column, the formation of their dansyl chloride or 4-fluoro-7-nitrobenzo-furazan (NBD-F) derivatives and the determination of these derivatives by high performance liquid chromatography with a fluorescene spectromonitor. The variation of pH value was found in various sea foods during the putrefaction. And, the development of VBN contents was found to be larger in quantity in tuna, octopus and pacific mackerel than others. On the other hand, when no detectable decomposition was observed by the determination of pH value and VBN contents, various non-volatile amines, His., Cad., Tyr. and Put. have already appeared. The formation of His. was observed as decomposition of pacific mackerel, tuna and sardine progressed. Particulary, its formation in pacific mackerel and tuna went up very rapidly to a higher level than either of the other amines. The large and rapid formation and the loss of Put. were also observed during the decomposition process in octopus. Therefore, these amines may serve as quality indicators of any sea food.

高速液体クロマトグラフィーによる貝類，底質および海水中の多環芳香族炭化水素類の分析

A simple method for the determination of 10 polynuclear aromatic hydrocarbons (PAHs), i. e., anthracene (An), fluoranthene (Flu), pyrene (Py), benz (a) anthracene (B (a) A), benzo (e) pyrene (B (e) P), perylene (Per), benzo (k) fluoranthene (B (k) F), benzo (a) pyrene (B (a) P), dibenz (a, h) anthracene (diB (a, h) A) and benzo (ghi) perylene (B (ghi) Per), in shellfish by high performance liquid chromatography (HPLC) has been developed. The method consists of alkali cleavage of the sample, extraction with n-hexane, clean-up by SEP-PAK Silica Cartridge column chromatogpaphy and determination by HPLC.Recoveries of 10 PAHs added to 20g of short-necked clams at levels of 100-400ng ranged from 92.3 to 99.6% The present method was applied for the determination of PAHs in shellfishes, seabottom sediments and sea water, and correlations between concentrations of PAHs in the samples were investigated. Close correlations were found between concentrations of PAHs in the sample groups except for sea water.

Recent innovations in cultivation of edible molluscs in Taiwan, with special reference to the small abalone Haliotis diversicolor and the hard clam Meretrix lusoria

Annual production and culture area of small abalones and hard clams have surprisingly increased in recent years. The factors contributing to this increase, aside from heavy demand and high price, include new techniques in catching the tiny clam seed (0.5 mm in size), success in mass production of seed of both species in hatcheries, better understanding of the molluscs' biology as well as their response to environmental changes, improved management of water quality to provide the optimal growth conditions, cheap and easy supply of Gracilaria for abalone feed, use of powdered formulated feed for hard clams, application of chicken manure and rice bran to enrich the water, intermediate harvest of animals of marketable size, and control of predators. However, major constraints to further development and expansion of molluse cultivation remain, including water pollution from industrial wastes, limited area with suitable water supply, strict regulations on the use of seashore land and littoral zone, and the lack of export market. Other species of molluscs, including the oyster Crassostrea gigas, the short-necked clam Comphina veneriforms, the purple clam Soletellina diphos, the cockle anadara granosa, and the small freshwater clam Corbicula, have potential for further expansion if problems of seed supply, water pollution, control of disease, and market price are properly solved.

The present levels of heavy metals in some molluscs of the upper gulf of Thailand

This investigation was carried out as part of Thailand's participation in the global ‘Mussel Watch’ program. The levels of Cd, Cr, Cu, Pb, and Zn in the green mussel, Perna viridis, oyster, Crassostrea commercialis, and the cockle, Anadara granosa, were studied from July 1982 to November 1982. Comparison was made with the previous study in August 1981 which also included the short necked clam, Paphia undulata and moon scallop, Amusium pleuronectes. It was found that the metal levels were sufficiently low that the molluscs could be consumed without any danger to health. The salinity of the water appeared to influence the uptake as higher levels of metals were found during the flood season when salinity was lower.

Behavior of cadmium in short-necked clam.

In studies on the concentration of cadmium in invertebrates, especially limpets, it is required to know how many samples are to be averaged. In studies on Cd-binding proteins, it is necessary to know in what organ Cd is concentrated. Short-necked clams Tapes japonica were kept in sea water which contained stable Cd and radioactive 115mCd. The amount of Cd accumulated by a clam was measured with NaI (Tl) scintillation counter one by one, without sacrificing the clam. The distribution of Cd in the body of a clam was made clear by “Macroautoradiograph” which was seldom used on limpets. The results obtained were as follows: 1) The accumulation of Cd by clams differs considerably from each other. 2) A main Cd-accumulating organ in a clam is the Bojanus' organ, as well as the mid-gut gland which accumulated Cd considerably.

Trochicola japonicus sp. nov., a mytilicolid copepod parasitic in the short neck clam (Tapes philippinarum) from Lake Hamana, Japan.

A new mytilicolid copepod, Trochicola japonicus, parasitic in the intestine of the short neck clam, Tapes philippinarum, from Lake Hamana (semi-enclosed coastal bay) is described for both female and male.