One in a Krillion +100DesmanSnorkel-nosed aquatic mole of Pyrenean and Russian streams.Water OpossumOnly aquatic marsupial; its pouch seals watertight when diving.Deep Cut +85AcrophocaAegicetusAegyptocetusAetiocetusAfrican Clawless OtterAfrican ManateeAfrican Marsh RatAllodesmusAmazonian ManateeAmbulocetusAmerican MinkAmerican Water ShrewAncalecetusAndrews' Beaked WhaleAndrewsiphiusAntaecetusAntarctic Fur SealAntarctic Minke WhaleAquatic GenetAraguaian River DolphinArchaeoparadoxiaArnoux's Beaked WhaleArtiocetusAshoroaAsian Small-Clawed OtterAtlantic Humpback DolphinAtlantic Spotted DolphinAtlantic White-Sided DolphinAttockicetusAustralian Humpback DolphinAustralian Sea LionAustralian Snubfin DolphinBabiacetusBaijiBaikal SealBaird's Beaked WhaleBaird's TapirBarasinghaBasilosaurusBasiloterusBasilotritusBeaked WhaleBearded SealBehemotopsBlainville's Beaked WhaleBottlenose WhaleBowhead WhaleBrown Fur SealBryde's WhaleBurmeister's PorpoiseBurrunan DolphinBush DogCalifornia Sea LionCaribbean Monk SealCarolinacetusCaspian SealCetotheriumChilean DolphinChinese Water ShrewChrysocetusClymene DolphinCommerson's DolphinCommon DolphinCongo Clawless OtterCornwalliusCrab-Eating MongooseCrab-Eating RaccoonCrabeater SealCrenatocetusCuvier's Beaked WhaleCynthiacetusDalanistesDall's PorpoiseDeraniyagala's Beaked WhaleDesmostylusDhedacetusDorudonDusky DolphinDwarf Sperm WhaleEarless Water RatEast African Wading RatElegant Water ShrewEnaliarctosEnhydriodonEocetusEthiopian Amphibious RatEurasian BeaverEurasian OtterEurasian Water ShrewEuropean MinkFalse Killer WhaleFin WhaleFinless PorpoiseFish-Eating RatFishing CatFlat-Headed CatFlorida ManateeFranciscanaFraser's DolphinGalapagos Fur SealGalapagos Sea LionGandakasiaGanges River DolphinGaviacetusGeorgiacetusGervais' Beaked WhaleGiant Beaked WhaleGiant BeaverGiant OtterGiant Otter ShrewGiant TapirGinkgo-Toothed Beaked WhaleGlacier Bay Water ShrewGray's Beaked WhaleGreater Cane RatGrey SealGuadalupe Fur SealGuiana DolphinHairy-Nosed OtterHarbor porpoiseHawaiian Monk SealHeaviside's DolphinHector's Beaked WhaleHector's DolphinHimalayacetusHimalayan Water ShrewHooded SealHourglass DolphinHubbs' Beaked WhaleHumpback DolphinIchthyolestesIndian Ocean Humpback DolphinIndian RhinocerosWallows for hours a day to keep cool.Indo-Pacific Bottlenose DolphinIndo-Pacific Finless PorpoiseIndo-Pacific Humpback DolphinIndocetusIndohyusIndus River DolphinIrrawaddy DolphinJamaican Rice RatJanjucetusJapanese OtterJapanese Sea LionJapanese Water ShrewJuan Fernandez Fur SealKalakocetusKekenodonKobKolponomosKronokotheriumKutchicetusLechweLesser CapybaraLivyatanLong-Beaked Common DolphinLong-Finned Pilot WhaleLongman's Beaked WhaleLowland TapirLutrine OpossumMaiacetusMakaracetusMalayan TapirMalayan Water ShrewMammalodonMarine OtterMarsh DeerMarsh MongooseMarsh RabbitMarsh Rice RatMasracetusMassoia's Lutrine OpossumMaui DolphinMediterranean Monk SealMediterranean Water ShrewMelon-Headed WhaleMetaxytheriumMinke whaleMonk SealMountain TapirMountain Water RatNalacetusNarrow-Ridged Finless PorpoiseNatchitochiaNeoparadoxiaNeotropical OtterNew Britain Water RatNew Guinea Water RatNew Zealand Fur SealNew Zealand Sea LionNile LechweNimba Otter ShrewNorth American BeaverNorth American River OtterNorth American Water VoleNorth Atlantic Right WhaleNorth Pacific Right WhaleNorthern Bottlenose WhaleNorthern Elephant SealNorthern Fur SealNorthern Right Whale DolphinOcucajeaOdobenocetopsOmura's WhaleOtter CivetOtter ShrewOunalashkastylusPachycetusPacific Water ShrewPacific White-Sided DolphinPakicetusPaleoparadoxiaPantropical Spotted DolphinPappocetusPeale's DolphinPere David's DeerPeregocetusPerrin's Beaked WhalePerucetusPezosirenPhiomicetusPiscophocaPontobasileusPontogeneusPotamotheriumProrastomusProtocetusPuijilaPygmy Beaked WhalePygmy Killer WhalePygmy Right WhalePygmy Sperm WhaleQaisracetusRakaliRamari's Beaked WhaleRayanistesRemingtonocetusRibbon SealRice RatRice's WhaleRinged SealRisso's DolphinRodhocetusRorqualRoss SealRough-Toothed DolphinRound-Tailed MuskratRuwenzori Otter ShrewSaghacetusSaimaa Ringed SealSato's Beaked WhaleSea MinkSei WhaleShaw Mayer's Water RatShepherd's Beaked WhaleShort-Finned Pilot WhaleSiamogaleSitatungaSmooth-Coated OtterSouth American Fur SealSouth American Sea LionSouthern Bottlenose WhaleSouthern Elephant SealSouthern Right WhaleSouthern Right Whale DolphinSouthern River OtterSouthwestern Water VoleSowerby's Beaked WhaleSpade-Toothed WhaleSpectacled PorpoiseSpinner DolphinSpotted SealSpotted-Necked OtterSqualodonStejneger's Beaked WhaleSteller Sea LionSteller's Sea CowStrap-Toothed WhaleStriped DolphinStromeriusSubantarctic Fur SealSumatran Water ShrewSunda Water ShrewSupayacetusSwamp RabbitTakracetusTamanend's Bottlenose DolphinThalassocnusTogocetusTranscaucasian Water ShrewTrogontheriumTrue's Beaked WhaleTucuxiTutcetusWater ChevrotainWater DeerWater MouseWater RatWater shrewWater voleWaterbuckWeb-Footed TenrecWeddell SealWest Indian ManateeWestern Water RatWhite-Beaked DolphinYangtze Finless PorpoiseZiegler's Water RatZygorhizaRare +60Amazon river dolphinBaleen WhaleBelugaBottlenose DolphinCapybaraDugongElephant sealFur SealGray whaleHarbor sealHarp SealHumpback whaleLeopard sealMinkMooseDives to feed on pondweed, eyes open underwater.MuskratNarwhalNutriaPilot whalePlatypusPorpoisePygmy HippopotamusRight whaleRiver DolphinSperm whaleStar-Nosed MoleTapirVaquitaRarest marine mammal alive, under ten left in 2026.Water buffaloSpends its afternoons submerged to the nostrils.Schooler +30BeaverBlue whaleHippopotamusManateeOrcaPolar bearOfficially a marine mammal; it hunts from sea ice.Sea lionSea otterWalrusPlankton +10DolphinOtterSealWhale
