Life of Sea | Pygmy Killer Whale (Feresa attenuata) | ThePygmykiller whaleis a tiny, rarely seencetaceanofthe oceanicdolphin family(Delphinidae). It derives itsname fromcommon parts ofanumber of physicalcharacteristics of theOrca. Itis the smallestspecies"whale" in the commonly knownname.Infact,"killer" aremoreappropriate in thecase of thepygmykiller whalethan itslarger cousin. Pygmykiller whalesarein the vicinityof Japan, Hawaii andthewarmerareas inthe easternNorth PacificOcean.They are primarilyakindof tropicalwaters,butitwasspotted incoolerwaters off thecoast of SouthAfricaand Peru. Itpreferssub-tropical and tropicalwaters,usually indeep water inthe openoceanand is veryrare inclosed water. Pygmykiller whalesis believedthat non-migratory, but little isknown about theirmigratoryhabits.
Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Cetacea Family: Delphinidae Genus: Feresa Species: F. attenuata
Pygmykiller whalesare verysimilar in appearance toMelon-headedwhales and young Falsekiller whales.The head ofPygmykiller whalesis completedand lacks abeak.Theyhaveanunderslungjawandlipswhite,and usuallyawhite spot onthe tipof the mandible.The skullis asymmetrical andtheright jawis smaller andusually hasonelesstooththan the leftjaw.The teethare large andconical.Pygmykiller whalesarea sub-triangular,long-based,highdorsal finwithatip thatpointsbackward.Thefins ofthePygmykiller whalesare moderatein lengthandhaverounded tips.
The body ofPygmykiller whaleis slim,but thebellyforwardslightlymore robust thanthe bellyback.Pygmykiller whalesarenot awhale-sizedatall,but rather,theyare medium in sizeand part ofthedolphinfamilyDelphinidae.Inboth men andwomen,thisslotcontainsthe navel,the anusand genitals.Lifetime of thesespecies ispoorly known.
Pygmykiller whalesaredescribed asaggressiveanimals that wereseensnappingtheir jaws,beating theirflippersandflukeson the surfaceof the water,andgrowling.They will oftenkillothercetaceansin the tankwith them.Althoughaggressivetoward otheranimals,Pygmykiller whalesareshyofboats.On the surface ofthe water,pygmykiller whalesare veryacrobatic.Theyareoftenseenjumping,spyhopping, tailstrike,and occasionallybowriding.Social groupsof this kind areusually composed ofabout 25individu.
The dietconsistsofPygmykiller whales aresquid, octopus,andlarge fishsuch astunaand dolphin fish.Pygmykiller whalesare also knownto occasionallyattackgroupsof smallcetaceanssuch asotherdolphins. Little isknown aboutthe predatorsofthepygmykiller whales.Theirlarge sizeandaggressivenessmakes theminvulnerableto manypredators,butperhaps notlargesharksor largercetaceanssuch asOrca.
Pygmykiller whalesis included in Convention onInternational Trade inEndangered Species of WildFauna andFlora (CITES).As a non-endangeredspecies to besubject toregulation in ordertospecies.Reportsendangeredsmall cetaceanfisheryof St.Vincent andLameleracontrolsuggest thatPygmykiller whalesareavery smallpart of the catchandthecatchmayhavelittle effectthepopulation inthose areas.
The numbers ofanimals thatare slainincidentallyin netfisheries, asin SriLanka,can be much higherthan previouslydocumented, as the verificationofthis widespreadactivityis incomplete.In the longterm,such astakingasignificant impact onthelivingresourcesin areas wherePygmykiller whale(andother smallcetaceans) and extensiveoverlapgillnetting.Smallincidentalcatchesare known infisheriesin other areas,such asthe Philippines.