Triops spp.

Basic information
Scientific name	Triops spp.	(No picture)
Common names	tadpole shrimp
Higher taxon	Triopsidae, Notostraca, Branchiopoda, Arthropoda
Natural range	Arid region of N America (T. longicaudatus), Europe (T. cancriformis), and E Asia (T. granarius)
Habitat	rice field

Invasion information
Range in Japan	Triops longicaudatus and T. granarius are widely distributed in central to western Japan. Triops cancriformis is recorded from Yamagata, Nagano, Tochigi, and Miyagi Prefs.
Origin	Unknown.
Date	The first records of T. longicaudatus, T. cancriformis, and T. granarius are 1916, 1948, and 1966, respectively.
Route	Accidental: Hitchhiking on some transport such as crops. Spread within Japan is possibly due to captive breeding as pet and/or deliberate introduction to rice field for weed eradication.
Impact	This species inhibit growth of sprout and harmful to rice cropping in USA. But, it is not harmful to Japanese style rice cropping.
Regulation in Japan	No action for prevention, mitigation, control, or eradication.
Introduced range in other countries	Unknown.

Reference	Notes
Ecol Soc Japan (ed) (2002) Handbook of Alien Species in Japan. Chijin-Shokan. (in Jpn) Nakai et al. (eds) (2003) Alien Species: Their Biology, Impact and Control. Lake Biwa Museum. (in Jpn) Takahashi (1977) High Water Temperature Prevents Egg Hatching in Triops granarius (Notostraca : Triopsidae). App Entomol Zool. 12(2):196-197