Commonly Seen Species The following 40 opisthobranch species are among the most commonly seen by divers. Some of them are seen "all the time" while others only occasionally. Also, we've selected them just based on their frequency in photo galleries and our experience--other choices are possible. Please remember that they represent only about 7% of the species in Hawaiian waters. So, if you can't find an exact match go here: http://seaslugsofhawaii.com/general/combined-family.html Aplustrum amplustre Micromelo scriptus Siphopteron quadrispinosum Chelidonura hirundinina Lamprohaminoea cymbalum Aplysia argus Aplysia elongata Stylocheilus striatus Plakobranchus ocellatus Thuridilla neona Umbraculum sp. #2 Berthellina delicata Asteronotus cespitosus Halgerda terramtuentis Hiatodoris fellowsi Platydoris formosa Ardeadoris poliahu Ardeadoris tomsmithi Ceratosoma tenue Diversidoris flava