Biological impacts caused by the release of the imported manila clam, Ruditapes philippinarum, in Japan

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1 Tidal flat in Japan Biological impacts caused by the release of the imported manila clam, Ruditapes philippinarum, in Japan Naoaki TEZUKA and Masami HAMAGUCHI(FEIS) P-1 Sea grass bed in Japan

2 Changes in landings and amount of the imported clam in Japan t he import ed clam Landings in J apan year Amount of the clam(met ric t on) P-2

3 Import origin of the clam ot hers 2005 Korea China North Korea 0 5,000 10,000 15,000 20,000 25,000 30,000 P-3 Amount of the imported clam(ton)

4 Biological impacts caused by the imported manila clam Is the imported clam genetically identical to the native clam? Does nonindigenous species (NIS) introduce with the imported clam? Does pathogens introduce with the imported clam? P-4

5 Construction of the mitochondrial DNA of the clam unknown NC- 3 CO2 t-rna Cyt B ND4 ATPFO ND5 ND6 CO3 CO1 ND1 NC- 1 NC- 2 16SrRNA t-rna ND3 t-rna t-rna 12SrRNA t-rna ND2 ND4L t-rna P-5 Total length was 22.7Kbp. The mitochondrial DNA of manila clam was longer than human!

6 Phylogenetic relationship among 8 populations collected from China, Korea and Japan China form-1 China Hokkaido Japan Hokkaido Japan Akkeshi Venerupis 1.00 Southern Korea Korea China form-2 Yoshitomi 0.01 Hiroshima Japan Miyajima Eastern Korea Wonsan Hamfun Eastern Korea P-6

7 Rapid identification of genetic form of the clam by PCR and real-time PCR genetic form China Preparation PCR-RFLP 国産 中国産 M A B C M (A)genetic form China-1 (B)genetic form China-2 (C)genetic form Japansouthern Korea Of DNA P-7 Genetic form Japan-southern Korea Real-time PCR React to genetic form Japansouthern Korea form only!

8 Japan-Korea forms Chinese forms coexistence P-8 Genetic form of the clam collected from China to Japan, revealed by the rapid identification method.

9 Microsatellite marker of the clam 170bp 160bp 150bp Individuals Yasuda et al. Molecular Ecology Notes (2006) P-9

10 Biological impacts caused by the imported manila clam Is the imported clam genetically identical to the native clam? Does nonindigenous species (NIS) introduce with the imported clam? Does pathogens introduce with the imported clam? P-10

11 P-11 What is NIS? Nonindigenous species (NIS): a species introduced to areas beyond its native range by human activity Many human activities, such as agriculture, aquaculture, recreation and transportation, promote both the intentional and accidental spread of species across their natural dispersal barriers. Although most organisms die in transit, or soon after release, those that persist can have grave effects on human health, devastating economic impacts, and can threaten native biodiversity and ecosystem function. Annually, NIS cause environmental damage and economic losses in excess of US $137 billion in the USA alone. Invasion of marine NIS is wide spread phenomenon in the world. Marine organisms have been moved around the world accidentally or intentionally. Aquaculture is now considered one of the major gateways for introduction of Marine NIS.

12 Survey of NIS with the imported clam Transporting route from china to Miyagi Prefecture Prof. Okoshi surveyed NIS with imported manila clam from China to Miyagi Prefecture, Japan. from Okoshi, 2005 P-12 Sacks filled with the clam imported from China Ship freighted with clams and NIS just before relaese

13 NIS collected from the clam sacks. a, Euspira fortunei; b, Glossaulax didyma; c, Glossaulax reiniana; d, Varichinassa varicifera; e, Trigonostoma scalariformis.; f, Meretrix petechialis; g, Crassostrea gigas. d g a c b f e P-13

14 No found Miyako Mangoku-ura inlet Nakatsu Native habitat Matsushima Bay Torinoumi inlet Matsukawa-ura Inlet Ariake Sound Kushida River Lake Hamana Mikawa Bay Obitsu River Distribution of the mollusk-eating snail Euspira fortunei in Japanese waters. P-14

15 Biological impacts caused by the imported manila clam Is the imported clam genetically identical to the native clam? Does nonindigenous species (NIS) introduce with the imported clam? Does pathogens introduce with the imported clam? P-15

16 Perkinsus spp. in the imported clam Histological observation of gill Hamaguchi et al,(1999) reported high prevalence rate of perkinsus protozoan in imported clam. P-16

17 No found the clam production areas (over 1000 tons) Mangoku-ura inlet Nakatsu Infection area of Perkinsus protozoan Ariake Sound Hiroshima Kushida River Lake Hamana Mikawa Bay Matsushima Bay Torinoumi inlet Matsukawa-ura Inlet Obitsu River P-17 Distribution of the Perkinus protozoan, which is parasite of the clam, in Japanese waters.

18 Prevalence of Perkinsus protozoan in recreational shellfish gathering grounds, fishing grounds of the clam and undisturbed or no fishing grounds Prevalence of Perkinsus protozoan(%) * Recreational shellfish gathering grounds release of the imported clam by fisherman s cooperative * Fishing ground of the clam no fishing ground P-18

19 Does Perkinsus protozoan infect in fishing ground in Japan? We released the non-infected clam to the aquaculture ground of the imported clam P-19 Prevalence of Perkinsus protozoan(%) Days after release St.1 St.2 Waterborne infection in Japanese water!

20 Biological impacts caused by the imported manila clam Is the imported clam genetically identical to the native clam? No it is not! The naive clam is genetically different from the almost imported clam. P-20 So the imported clam itself is also NIS.

21 P-21 Biological impacts caused by the imported manila clam in Japan Does nonindigenous species (NIS) introduce with the imported clam? Yes it is! Euspira fortunei is becoming a new, strong predator of the native clam stocks in Japan. The effect of NIS with the imported clam on preexisting population is also important problem to be solved.

22 Biological impacts caused by the imported manila clam Does pathogens introduce with the imported clam? Yes or No But, We need to attention to NIS problems P-22

23 Biological impacts caused by the imported manila clam In the case of the clam, imported clam can have negative effect to the clam production in Japan. Resource enhancing project of the native clam is necessary, and it is starting now in Japan. P-22

24 Thank you! Dr. Hamaguchi will correspond.