• Macrophthalmus latreillei Latreille's sentinel crab
  Konoha-òsagani
  
• Macrophthalmus milloti Crosnier-òsagani
  
• Macrophthalmus pacificus Taiyo-òsagani
  
• Macrophthalmus philippinensis Philippines-òsagani
  
• Macrophthalmus quadratus Newcaledonia-òsagani
  
• Macrophthalmus serenei Menaga-òsagani
  
• Macrophthalmus telescopicus Telescope-eyed ghost crab
  Owen-òsagani
  
• Macrophthalmus tomentosus Manila-òsagani
  
• Maja gibba Oh-keashigani
  
• Maja japonica Yamato-keashigani
  
• Maja kominatoensis Kobu-keashigani
  
• Maja miersii Kií-keashigani
  
• Maja nagashimaensis Nagashima-keashigani
  
• Maja sakaii Hime-keashigani
  
• Maja spinigera Keashigani
  
• Majella brevipes Kuwagata-keashigani
  
• Manella spinipes Ashibuto-ítoashigani
  
• Margelopsis haeckeli
• Margelopsis hartlaubi
• Mathildella serrata Nokogiri-énkougani
  
• Matuta planipes Amime-kinsengani
  
• Matuta victor Kinsengani
  
• Medaeops granulosus Suehirogani
  
• Medaeus serratus Nokoha-ohgigani
  
• Megaesthesius yokoyai Hige-mekuragani
  
• Megametope ogaensis Oga-himeohgigani
  
• Meganyctiphanes norvegica
• Melicertum octocostatum
• Menaethiops okai Oka-tsunogani
  
• Menaethius monoceros Itsukaku-gani
  
• Menaethius orientalis Gokaku-mogani
  
• Menippe rumphii Rumphius-iso-óhgigani
  
• Meriola corallina Kií-beniohgi
  
• Merocryptoides frontalis Hime-tsubasa-kobushi
  
• Merocryptus lambriformis Tsubasa-kobushi
  
• Mertonia lanka Merto-gani
  
• Mesopodopsis slabberi
• Metaconchoecia teretivalvata
• Metadynomene tanensis Yokoya-toge-kamuri
  
• Metaplax elegans Orange signaller crab
  Tanrei-áshihara-gani
  
• Metaplax longipes Hongkong-áshihara-gani
  
• Metaplax takahashii Tenaga-áshihara-gani
  
• Metasesarma aubryi Hama-benkeigani
  
• Metasesarma rousseauxi Akahama-benkeigani
  
• Metaxanthops acutus Nosy-be-ohgigani
  
• Meterythrops picta
• Metopograpsus latifrons Kuira-hashiri-ìwagani
  
• Metopograpsus messor Hashiri-ìwagani
  
• Metopograpsus quadridentatus Macao-hashiri-ìwagani
  
• Metopograpsus thukuhar Hashiri-ìwagani-modoki