hammerhead flatworm

animal arrowhead biodiversity bipalium broad china close coloration connecticut conservation cosmopolitan dangerous destructive distribution diversibipalium earthworm economy england environment environmental flat flatworm found fragmentation france garden giant global hammerhead head hermaphroditic immobilize insect invading invasive kewense land moss multilineatum natural nature neurotoxin new pattern planarian poison predatory preservation research science soil tetrodotoxin toxin trade worm york