Elsevier

Toxicon

Volume 45, Issue 2, February 2005, Pages 163-169
Toxicon

Accumulation and depuration rates of paralytic shellfish poisoning toxins in the shore crab Telmessus acutidens by feeding toxic mussels under laboratory controlled conditions

https://doi.org/10.1016/j.toxicon.2004.10.004Get rights and content

Abstract

Accumulation and depuration rates of paralytic shellfish poisoning toxins (PSP) in the crab Telmessus acutidens were investigated by feeding toxic and non-toxic mussels under laboratory controlled conditions. The crab accumulated toxins in the hepatopancreas in proportion to the amount of toxic mussels they ingested, and the toxicity in the crab hepatopancreas became 3.2 fold of that in the prey mussels after 20 days of feeding. During depuration, a fast reduction of the total toxicity was observed in the crab, and the retention rate of the toxicity after 5 days depuration with feeding of non-toxic mussels was 45.8±18.7%. The reduction of the toxicity was moderated in the later period of depuration, and the retention rates of the total toxicity after 10 and 20 days were 54.1±29.8% and 14.5±9.0%, respectively. The toxin profiles in the crab and mussel were investigated by high performance liquid chromatography, and reductive conversions of the toxins were observed when the toxins were transferred from the mussel to the crab. Consequently, high concentrations of GTX2 and GTX3, and STX that were not detected in the prey mussels, were found in the crab.

Introduction

Carnivorous or scavenging shellfishes have recently been considered as possible vector species of paralytic shellfish poisoning (PSP) toxins (Shumway, 1995, Compagnon et al., 1998). Along the Atlantic coast of Canada, the American lobster, Homarus americanus, has been found to be contaminated by PSP toxins (Watson-Wright et al., 1991, Desbiens and Cembella, 1995), and thus periodically included in the monitoring program of the toxin (Cembella and Todd, 1993). We also reported that two species of shore crabs, Telmessus acutidens and Charybdis japonica, which are commercially harvested species in Japan, accumulate the PSP toxins mainly in the hepatopancreas (Oikawa et al., 2002, Oikawa et al., 2004). The level of the toxicity in T. acutidens was as high as that reported in the American lobster (Desbiens and Cembella, 1995, Oikawa et al., 2002). In April 2004, the Ministry of Health, Labour and Welfare in Japan set the regulation limit for carnivorous and scavenging species, taking into consideration of our monitoring results in 2003 (unpublished data). Consequently, dealing in crabs over 4 MU/g in hepatopancreas was prohibited by the Food Sanitation Law in Japan. Actually, the harvesting of the crab T. acutidens was prohibited in two prefectures in Japan from April to June, 2004. In our previous study, the crabs became highly toxic when the prey bivalves showed a high toxicity, therefore the bivalves could be regarded as one of the potential origins of the toxins for the crab (Oikawa et al., 2002). However, as the toxicities of the crabs were variable among the specimens even collected in the same place on the same date (Oikawa et al., 2004), it seemed difficult to investigate the accumulation kinetics of the toxins by field studies. In addition, as T. acutidens moves away from the shore at the end of the blooming season of toxic dinoflagellates, we could not follow the toxin discharge from the crab until the toxicity in the crab reached safe levels. We also compared the toxin profiles between the mussel and crab by high performance liquid chromatography with fluorescence detection (HPLC-FLD), and this suggested that reductive conversions of the toxin occurred in the crab. However, reductive conversions could not be directly demonstrated, because it was impossible to determine what amounts and what kinds of toxic prey the crab actually ingested in the natural environment.

In this study the crab T. acutidens was fed on toxic mussels to investigate the toxin accumulation in laboratory aquaria, and the toxicity and toxin profiles of the crabs and mussels were analyzed by mouse bioassay and by HPLC-FLD. In addition, crabs which had accumulated toxins by being fed toxic mussels were maintained with and without feeding of non-toxic mussels in order to investigate the depuration of the toxin in T. acutidens.

Section snippets

Crab and mussel samples

Live specimens of the crab T. acutidens were purchased from a wholesale market in Miyagi Prefecture, in the north-eastern part of Honshu, Japan. The crab samples were transferred to the National Research Institute of Fisheries Science in Kanagawa Prefecture, and were maintained for over a month at 10 °C, almost the same temperature as that for the crab found to be toxic in our previous paper (Oikawa et al., 2004), and the crabs were fed on mussels, mackerel and squid twice a week. Prior to

Results

Relations between the total toxicity in the crab hepatopancreas and the amount of the toxic mussels ingested by the crab are shown in Fig. 1. The total toxicity in the crab hepatopancreas increased linearly along with the amount of mussels ingested, and the relation was expressed as y=1.33x−32.7 with a high correlation (R2=0.86). The toxicity per 1 g of hepatopancreas also increased with feeding, and the toxicity of the crab hepatopancreas after feeding for 20 consecutive days reached to 12.8±3.8

Discussion

The total toxicity in the crab hepatopancreas increased linearly with the amount of toxic mussels the crabs ingested. The toxicity of the crab per one gram of hepatopancreas became 3.2 times higher than that of the toxic mussels by 20 days feeding of toxic mussels. These results directly demonstrated that T. acutidens is able to accumulate PSP toxins from toxic mussels. In addition, we observed T. acutidens to prey on mussels during the blooming season of toxic dinoflagellates (Oikawa et al.,

Acknowledgements

We express our gratitude to Dr Oshima of Tohoku University, Dr Noguchi of Japan Frozen Foods Inspection Corporation, and the Fisheries Agency of Japan for providing the PSP toxin standards. We also thank Mr Fujita and Mr Saito of Fukushima Prefectural Fisheries Experimental Station for collecting the toxic mussels, and Ms Hatano of National Research Institute of Fisheries Science for the sample preparation.

References (19)

There are more references available in the full text version of this article.

Cited by (22)

  • Bioluminescence and toxicity as driving factors in harmful algal blooms: Ecological functions and genetic variability

    2020, Harmful Algae
    Citation Excerpt :

    Similar to bioluminescence, toxin production may aid in HAB initiation as it alleviates grazing pressure on the HAB species. Numerous studies have been conducted with organisms from multiple trophic levels – including micro- and mesozooplankton, fish, and macroinvertebrates - and results vary as to the effects on health and whether the organisms actively reject the toxic cells (Barreiro et al., 2006; da Costa et al., 2005; Frangoulos et al., 2000; Oikawa et al., 2005; Robineau et al., 1991; Teegarden, 1999; Zimmer and Ferrer, 2007). One of the most well-studied interactions is that of copepod grazing on dinoflagellates.

  • Geographical distribution and seasonal variation in paralytic shellfish toxins in the coastal water of the South China Sea

    2019, Toxicon
    Citation Excerpt :

    In the current study, large proportion of high–potency toxins GTX1/4 appeared in bloody clam Cl collected from ZJ in autumn 2006, the oyster Cg, Od and Ca (with high PST content > 2 nmol g−1) dominated by N–sulfocarbamoyl toxin C2, the same species (8 samples of hard clam Mm and 4 samples of mussel Pv) dominated by apparently different toxin profiles could be due to different sampling time and sites, the 3 scallop Cn samples dominated C1, NEO, GTX2 and GTX5 (Figs. 2 and 4). In addition, high content STX were not detected in prey mussels but in shore crab Telmessus acutidens (Oikawa et al., 2005). In the current study, STX appeared in 11 out of 18 crustacean samples (Fig. 4).

  • Experimental uptake and depuration of paralytic shellfish toxins in Southern Rock Lobster, Jasus edwardsii

    2018, Toxicon
    Citation Excerpt :

    The identification of PST in Southern Rock Lobster highlighted a number of uncertainties and data gaps for the Australian industry, including the mechanism by which lobsters accumulate toxins, the amount of time it would take for PST to depurate to compliant levels, and whether PST in lobster hepatopancreas pose a risk to human health. Studies conducted in various regions (principally in North America) have shown that trophic transfer of PST is an important exposure route, and is likely to represent the principal uptake mechanism for PST in crustaceans (Haya et al., 1994; Oikawa et al., 2005). However, this had not previously been demonstrated experimentally in Australian lobsters.

  • Accumulation and depuration of paralytic shellfish poisoning toxins in the oyster Ostrea rivularis Gould - Chitosan facilitates the toxin depuration

    2013, Food Control
    Citation Excerpt :

    Another reason was the fact that depurated PSP toxins can be reabsorbed by ORG. Various attempts have been made at detoxifying shellfish contaminated with PSP toxins in an effort to reduce the duration of off market times (Oikawa, Satomi, Watabe, & Yano, 2005). The most obvious method is to transfer shellfish to waters free of toxic organisms and allow them to self-depurate.

View all citing articles on Scopus
View full text