http://www.conchology.uunethost.be/GENERAL/Cyberconchology/SuperConch/Gastropoda/HYDATINIDAE.html
http://www.seaslugforum.net/showall/hydazona
http://www.umiushi.info/photo_species/photo_splist_eng.php?sopt=0&loc=0000
http://www.ne.jp/asahi/kappa-kuri/miyamoto/OSEHOO/umiushi220.html
http://www.medslugs.de/E/Pac-NW/Hydatina_zonata/Selection.htm
http://www.Philippine-Sea-Slugs.com/Heterobranchia/Hydatina_zonata.htm
http://www.nudipixel.net/species/hydatina_zonata/
http://www.nmr-pics.nl/Aplustridae/album/index.html
http://www.medslugs.de/E/Pac-W/Hydatina_zonata/Selection.htm
http://www.umiushi-zukan.com/eng/list_pic.php?ssw=g&kind_id=508
http://www.vibrantsea.net/hydatina2686_anilao2013.htm
http://slugsite.us/bow2007/nudwk1202.htm