Mohamad, Samsur

Osamu, Arakawa

Takefumi, Sagara

Tamao, Noguchi

Tomohiro, Takatani

Yasunaga, Yamaguchi

Unimas Institutional Repository

OriginalAccumulation and Elimination Profiles of Paralytic Shellfish Poisonin the Short-necked Clam Tapes japonica Fed with the ToxicDinoflagellate Gymnodinium catenatum(Received August 15, 2006)Mohamad S6BHJG1, Tomohiro T6@6I6C>2, Yasunaga Y6B6<J8=>3, Takefumi S6<6G64,Tamao ND<J8=>5 and Osamu AG6@6L62, 1 Graduate School of Science and Technology, Nagasaki University: 114, Bunkyo-machi,Nagasaki-shi, Nagasaki 8528521, Japan;2 Faculty of Fisheries, Nagasaki University: 114, Bunkyo-machi, Nagasaki-shi,Nagasaki 8528521, Japan;3 Maruzen Pharmaceuticals Corporation Ltd.: 1470310, Mukaihigashi-machi, Onomichi-shi,Hiroshima 7220062, Japan;4 Faculty of Junior College, Shikoku University: 1231, Ebisuno, Furukawa, Ohjin-cho,Tokushima-shi, Tokushima 7711192, Japan;5 Tokyo Health Care University: 3113, Setagaya, Setagaya-ku, Tokyo 1548568, Japan; Corresponding authorThe paralytic shellfish poison (PSP)-producing dinoflagellate Gymnodinium catenatum (Gc) wasfed to the short-necked clam Tapes japonica, and the accumulation, transformation and elimina-tion profiles of PSP were investigated by means of high-performance liquid chromatography withpostcolumn fluorescence derivatization (HPLC-FLD). The short-necked clams ingested most of theGc cells (4106 cells) supplied as a bolus at the beginning of the experiment, and accumulated amaximal amount of toxin (181 nmol/10 clams) after 12 hr. The rate of toxin accumulation at thattime was 16, which rapidly decreased thereafter. During the rearing period, a variation in toxincomposition, derived presumably from the transformation of toxin analogues in the clams, wasobserved, including a reversal of the ratio of C2 to C1, and the appearance of carbamate(gonyautoxin (GTX) 2, 3) and decarbamoyl (dc) derivatives (decarbamoylsaxitoxin (dcSTX) anddcGTX2, 3), which were undetectable in Gc cells. The total amount of toxin contained in clamsand residue (remaining Gc cells and/or excrement in the rearing tank) gradually declined, andonly about 1 of the supplied toxin was detected at the end of the experiment.Key words: paralytic shellfish poison; short-necked clam; Tapes japonica; dinoflagellate;Gymnodinium catenatumIntroductionAlong the coastal waters o# Kyushu in Japan, para-lytic shellfish poison (PSP)-producing dinoflagellates,Alexandrium catenella (designated Ac below) andGymnodinium catenatum (designated Gc below), occurevery year, and intoxicate many edible bivalves such asthe short-necked clam Tapes japonica, the musselMytilus galloprovincialis (formerly classified as M.edulis), the oyster Crassostrea gigas, and the scallopClamys nobilis, presenting a serious problem for thefisheries industriy1)4).Accumulation and elimination profiles of PSP in bi-valves di#er greatly depending on the bivalvespecies3), 5), 6). The mussel rapidly reaches a high level oftoxicity, which declines shortly (usually within severalweeks) after disappearance of the causative dino-flagellate. Scallops, such as Patinopecten yessoensis andChlamys nipponensis, are known to become much moretoxic than the mussel under the same environmentalconditions, and require several months until the toxici-ty drops below the regulation level. On the other hand,levels of intoxication of the short-necked clam and theoyster are generally low, and the toxicity quickly de-clines, as in the mussel.PSP compositions of bivalves are not necessarily thesame as those of the causative dinoflagellates, and inter-species di#erences are also observed among bivalvescollected from the same area at the same time. Forexample, the mussel and the oyster better reflect thecomposition of the causative plankton1), 7), 8), whereasclams such as Meretrix lamarckii, Pseudocardiumsachalinensis and Protothaca staminea often show verydi#erent compositions9), 10). The di#erence of toxin pro-files between the bivalves and the causative planktonis considered to arise mainly from the enzymatic and/or chemical transformation of toxins in bivalvetissues9), 11)14), and possible participation of selectiveFebruary 2007 13

Accumulation and Elimination Profiles of Paralytic Shellfish Poison in the Short-necked Clam Tapes japonica Fed with the Toxic Dinoflagellate Gymnodinium catenatum

Accumulation and Elimination Profiles of Paralytic Shellfish Poison in the Short-necked Clam Tapes japonica Fed with the Toxic Dinoflagellate Gymnodinium catenatum

Abstract

Similar works

Full text

Available Versions

Unimas Institutional Repository