Table 1. List of species included in this study with information on the largest known individuals.

Phylum/ Class/ Order	Species	Common name	Record	Largest known confirmed individual
Porifera Demospongiae Haplosclerida	Xestospongia muta	Caribbean Giant Barrel Sponge	Largest poriferan	Base diameter: 2.5 m; Volume: 7.24 m3
Cnidaria Scyphozoa Semaeostomeae	Cyanea capillata	Lion’s Mane Jellyfish	Longest medusozoa	Tentacle length: 36.6 m (note this estimate may not be accurate, see text for discussion)
Cnidaria Scyphozoa Rhizostomae	Nemopilema nomurai	Nomura’s Jellyfish	Heaviest medusozoa	Bell diameter: 2 m; Mass: 200 kg
Arthropoda Malacostraca Isopoda	Bathynomus giganteus	Giant Isopod	Largest isopod	Total length: 50 cm
Arthropoda Malacostraca Decapoda	Macrocheira kaempferi	Japanese Spider Crab	Largest arthropod legspan	Leg span: 3.7 m; Mass: >13.6 kg
Annelida Polychaeta Canalipalpata	Riftia pachyptila	Giant Tube Worm	Largest annelid	Tube length: 3 m; Tube diameter: 5 cm; Wet weight: 650 g
Mollusca Bivalvia Veneroida	Tridacna gigas	Giant Clam	Largest bivalve	Shell length: 137 cm; Soft tissue mass: 333 kg
Mollusca Gastropoda Caenogastropoda	Syrinx aruanus	Australian Trumpet	Largest extant gastropod	Shell length: 72.2 cm
Mollusca Cephalopoda Octopoda	Enteroctopus dofleini	Giant Pacific Octopus	Largest octopod	Radial spread: 9.8 m; Mass: 198.2 kg
Mollusca Cephalopoda Teuthida	Mesonychoteuthis hamiltoni	Colossal Squid	Heaviest cephalopod and invertebrate	Total length: 4.2 m; Mantle length 2.5 m; Mass: 495 kg
Mollusca Cephalopoda Teuthida	Architeuthis dux	Giant Squid	Longest cephalopod	Total length: 12 m
Chordata Chondrichthyes Orectolobiformes	Rhincodon typus	Whale Shark	Largest chondrichthyian	Total length: 18.8 m
Chordata Chondrichthyes Lamniformes	Cetorhinus maximus	Basking Shark	Largest temperate selachimorphan, second largest chondrichthyian	Total length: 12.27 m
Chordata Chondrichthyes Lamniformes	Carcharodon carcharias	Great White Shark	Largest macropredatory selachimorphan	Total length: 7 m (but see text)
Chordata Chondrichthyes Squaliformes	Somniosus microcephalus	Greenland Shark	Largest arctic selachimorphan	Total length: 6.4 m
Chordata Chondrichthyes Hexanchiformes	Hexanchus griseus	Bluntnose Sixgill Shark	Largest hexanchoid selachimorphan	Total length: 5.5 m
Chordata Chondrichthyes Myliobatiformes	Manta birostris	Giant Ocean Manta Ray	Largest batoidean	Disc width: 7 m (but see text)
Chordata Actinopterygii Lampriformes	Regalecus glesne	Oarfish	Longest osteichthyan	Total length: 8 m
Chordata Actinopterygii Tetraodontiformes	Mola mola	Ocean Sunfish	Heaviest osteichthyan	Total length: 3.3 m; Total height: 3.2 m; Mass: 2,300 kg
Chordata Reptilia Testudines	Dermochelys coriacea	Leatherback Turtle	Largest testudines	Curved carapace length: 2.13 m; Mass: 650 kg
Chordata Mammalia Carnivora	Mirounga leonina	Southern Elephant Seal	Largest pinniped and carnivoran	Total length: 6.85 m; Mass: 5,000 kg
Chordata Mammalia Carnivora	Odobenus rosmarus	Walrus	Third largest pinniped	Total length: 3.8 m; Mass: 1,883 kg
Chordata Mammalia Cetacea	Physeter macrocephalus	Sperm Whale	Largest odontocete	Total length: 24 m
Chordata Mammalia Cetacea	Balaenoptera musculus	Blue Whale	Largest mysticete, largest cetacean, largest mammal, largest metazoan	Total length: 33 m