• Korean Journal of Food Science and Technology
• /
• v.3 no.1
• /
• pp.48-51
• /
• 1971

The raw surf clam meat was pretreated with BHA, EDTA or $NaHSO_3$. The pretreated meat was chopped with chopper, and spread the chopped meat on nylon net, and then dehydrated with cabinet type hot air dryer. In the surf clam meat flake process, the pretreating and the copping steps prior to final dehydration improved the pigment retention and texture of the products. The chopping steps prior to dehydration reduced the dehydration time of surf clam meat. The BHA treatment prior to dehydration of mashed surf clam meat had an outstanding effect on the pigment retention during a process of dehydration and storage. The surf dam meat flakes reabsorbed water more rapidly about two times than the dehydrated natural surf clam meat products. The surf clam meat flakes stored for three months in the dark place showed less pigment loss than the exposed ones, and the former reabsorbed water more rapidly than the latter.

• Fisheries and Aquatic Sciences
• /
• v.18 no.4
• /
• pp.417-420
• /
• 2015

We investigated the relationship between viability and IGF-1 receptor (IGF-1R) activity in D-shaped and umbo larvae of the surf clam Spisula sachalinensis after treatment with vitrification solution (VS) or freezing. In a toxicity assay, VS1, containing 5 M dimethyl sulfoxide (DMSO), was very harmful to D-shaped and umbo larvae. However, VS2, containing 5 M ethylene glycol (EG), was not harmful to either larval stage. Although VS2 had a promising toxicity test outcome, none of the larvae survived vitrification. After immersion into VSs and freezing, IGF-1R ${\beta}$-subunits were detected in all larvae; however, tyrosine phosphorylation of intracellular ${\beta}$-subunits was detected only in the control and live groups. These results suggest that activation of IGF-1R may influence surf clam larvae viability.

• Korean Journal of Veterinary Service
• /
• v.40 no.4
• /
• pp.265-275
• /
• 2017

The production of enzymes that help digestion, assimilation of essential nutrients, and prevent pathogenic bacteria are important for probiotics used in aquaculture. The objective of this study was to investigate enzyme activities for macromolecular organic matters and antimicrobial properties of the selected potential probiotics isolated from gut of surf clam (Tresus keenae) against well-known shellfish-pathogenic bacteria. Among 65 isolates from guts of 60 surf clams, seven Bacillus strains with outstanding degradation capability of macromolecule organic matter were selected as potential probiotics as follows: TKI01 (B. vietnamensis), TKI02, TKI26 (B. thuringiensis), TKI14, TKI32, TKI42 (B. amyloliquefaciens), and TKI18 (B. stratosphericus). After in vitro antimicrobial activity test was performed against five shellfish-pathogenic bacteria including Listonella anguillarum, Vibrio parahaemolyticus, V. splendidus, V. harveyi, V. tubiashii, PCR assay was performed to detect bacteriocin-producing strain. PCR results revealed that the five Bacillus strains possessed diverse bacteriocin genes including ericinA, coagulin, surfactin, iturin, bacyllomicin, fengycin, bacylisin, subtilin, and lantibiotics. In the present study, the selected seven Bacillus strains showed different enzyme activities according to types of macromolecule organic matters. And their antimicrobial activities varied based on the species of pathogenic bacteria. In addition, at least five Bacillus strains had genetic potential to produce several natural lipopeptide antibiotics that may help biological control of surf clam aquaculture. Therefore, mixed use of probiotics might show co-operative effect and increase the efficiency of probiotics rather than separate use. To the best of our knowledge, it is the first report on antimicrobial properties of Bacillus species isolated from surf clam.

• Journal of fish pathology
• /
• v.24 no.1
• /
• pp.19-27
• /
• 2011

The production of surf clam, Mactra veneriformis, an important fishery resource in Korea, has recently been decreasing. This study was carried out to examine effects of spawning on immune functions of this species. Total hemocyte count (THC), phenoloxidase (PO) activity, phagocytic activity, neutral red retention (NRR) time and antibacterial activity were assessed. Spawned clams showed reduction in THC, PO, phagocytic activity and NRR times compared with unspawned ones. While spawning event did not elicit any change of antibacterial activity in both spawned and unspawned ones. This study indicates that spawning process decreases immune functions in the surf clams which could cause mortality increment and yield reduction.

• Korean Journal of Food Science and Technology
• /
• v.17 no.3
• /
• pp.223-226
• /
• 1985

The taste compounds including glycogen, nucleotides and their related compounds and free amino acid content of Raw, Boiled and Sun-dried and Boided and 1lot-air dried surf clam(Mactra veneriformis) were investigated. Crude protein and crude lipid content changed little after processing, but ash content of processed surf clam was increased 21.5%. Glycogen content was increased 6.7% in a processed surf clam. In nucleotides and their related compounds there are much ATP, ADP, IMP and Hypoxannthine in raw material, ATP, ADP, IMP content was decreased and Hypoxannthine disappeared after processing, In the raw extract, glycine, alanine, arginine were abundant, holding 85% of total free amino acid contents. After processing, generally 60% of raw material free amino acids content were existed.

• Korean Journal of Food Science and Technology
• /
• v.3 no.1
• /
• pp.52-56
• /
• 1971

The cooked surf clam meat was treated with BHA or EDTA, and then dehydrated by means of hot-air dehydration or sun drying. The dehydrated products were packed in glass bottle and stored for three months in the dark place. After three month storage, the pigment loss and water absorbing capacity of dehydrated products were compared with those of directly after dehydration. Both of the sun dried and hot-air dehydrated surf clam products showed a great deal of pigment loss during storage. The BHA treatment prior to dehydration of surf clam meat had good effects on the pigment retention, and the EDTA treatment had a weak effect on it during storage. The rate of rehydration of dehydrated surf clam products had markedly decreased during storage. And it could be seen that there was little difference among the rate of rehydration of the BHA or EDTA treated product and untreated one during storage.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.4 no.1
• /
• pp.17-21
• /
• 1971

The effect of EDTA or BHA pretreatment upon the color preservation of canned surf clam meat during canning and storage was studied. The steamed surf clam meat was soaked in BHA solution, $0.1\%$ BHA in $5\%$ salt solution, or EDTA solution, $0.5\%\;Na_2$ EDTA in $5\%$ salt solution, for 30 minutes. The pretreated surf clam meat was packed in a round enameled can that is 223.2 ml by volume and sterilized for 75 minutes at $110^{\circ}C$. The canned products were stored for one year at room temperature. The EDTA treatment of surf clam meat appeared effective on color preservation during processing. After three month storage, the samples showed little color change comparing with those right after processing. After one year storage, EDTA or BHA treated samples showed better color preservation as compared with control.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.3 no.1
• /
• pp.27-32
• /
• 1970

A study on the purification of the surf clam Mactra Sulcataria REEVE for the remove of sand and fecal piles was conducted in the laboratory. The sand was mostly distributed around the inhalent and exhalent siphon, mantle and gill, and were also distributed in the digestive tract including the mid-gut gland. The sand particles in the digestive tract were extremely small and their sizes were about $180\times10\mu\;to\;550\times200\mu$. It could be seen that there was little, if any, difference in the rate of sand removal when either the hanging Purification method was used or the method of laying the surf clams in thick or thin layers on the bottom of the experimental vessel was used. The surf clam removed about $50\%$ of its sand during the first hour of purification. The weight of the removed sand and fecal piles on a dry basis reached a constant value after 22 to 26 hours of purification. After 42 hours of Purification, no sand could be seen in the fecal piles. The surf clam removed the sand in its body more rapidly when it was in sea water with the pH of 8.75 than when it was in natural sea water. Also high temperature had a much greater depressing effect upon the removal of sand In the surf clam than did natural sea water. Also low salinity had greater accelerating effect upon the removal of sand in the body than did natural sea water. However the surf clam died when the salinity was $8.19\%_{\circ}$.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.23 no.2
• /
• pp.15-24
• /
• 2021

For the aquaculture industrialization of surf clam (Tresus keenae), it is important to basic data on the marine environment of the habitat of surf clam (T. keenae). In this study, we investigated the marine environment of habitat of surf clam (T. keenae) and sought to basic data for the preparation of surf clam (T. keenae) for artificial seed production. The water temperature of the habitat of surf clam (T. keenae) was the lowest in winter and appeared high in summer. The salt concentration showed it range from 31.2 to 33.9 psu. The pH showed it range from 7.69 to 8.70, with high pH in winter and low pH in summer. The dissolved oxygen(DO) was showed it range from 6.20 to 10.24 mg / L and the autumn was relatively higher than the spring and winter. The species composition of phytoplankton was about 30 to 40 species, and most of them were diatoms. The abundance of seasonal phytoplankton showed it range from 23.5 to 61.3 cells / ml, showing seasonal differences. The expression of dominant species also showed a difference depending on the season. As for the particle size composition of the sediment, sandy silt was the most distributed. Flow velocities appeared at 50-80 cm / s in the southeast direction at ebb tide and at 60-100 cm / s in the northwest direction at flood tide. The results of this study can be used as basic data for providing knowledge about the habitat and marine environment of surf clam (T. keenae) and for studying shellfish that inhabit the sedimentary layer.

• Journal of fish pathology
• /
• v.22 no.3
• /
• pp.305-316
• /
• 2009

Haemocyte characterization in the surf clam, Mectra veneriformis was carried out based on morphological, cytochemical, and phagocytic characteristics. The haemocytes were classified into two cell types, granulocytes and agranulocytes on the basis of presence of cytoplasmic granules. Granulocytes were then classified again into 2 types, large eosinophilic granulocytes and small eosinophilic granulocytes after staining with May-Grünwald Giemsa. In electron microscopy, both types of granulocytes contained electron-dense and electron-lucent cytoplasmic granules. Agranulocytes (hyalinocytes) were also divided into two cell types, large agranulocytes and small agranulocytes based on their sizes. Both cell types did not have granules in cytoplasm. Granulocyte and agranulocyte were negative for the enzyme activities of alkaline phosphatase, peroxidase, and $\beta$-glucuronidase but positive for phenoloxidase and acid phosphatase activities. Both types of haemocytes have phagocytic activity, with the exception of small agranulocyte, and granulocytes seemed more active in this respect than agranulocytes. This present study is the first study to characterize haemocytes of M. veneriformis.