Kingdom AnimaliaKingdom Animalia

Phylum ChordataPhylum Chordata

Chapter 14 - 1Chapter 14 - 1The Tunicates, Lancelets and The Tunicates, Lancelets and

Vertebrates, Vertebrates,

What are Chordates?What are Chordates?

All chordates possess All chordates possess these 4 characteristics these 4 characteristics during sometime of its life during sometime of its life cycle:cycle:– Dorsal nerve cordDorsal nerve cord– NotochordNotochord– Gill slitsGill slits– tailtail

Chordate CharacteristicsChordate CharacteristicsDorsal Nerve CordDorsal Nerve Cord – tubular in shape, main nerve cord runs along the back – tubular in shape, main nerve cord runs along the back of the animalof the animalNotocordNotocord – rigid yet flexible supporting rod. Most chordates have notocords – rigid yet flexible supporting rod. Most chordates have notocords during embryonic stage only. Most are replaced by boney vertebral column.during embryonic stage only. Most are replaced by boney vertebral column.Gill slitsGill slits – aka. pharyngeal pouches – paired structures in the throat region. – aka. pharyngeal pouches – paired structures in the throat region. In fish & amphibians these structures develop into gills In fish & amphibians these structures develop into gills TailTail – Muscle/boney structure extends past ventral anus. – Muscle/boney structure extends past ventral anus. 3 subphyla3 subphyla: : – UrochordataUrochordata – the Tunicates – the Tunicates– CephalochordataCephalochordata – Lancelets – Lancelets– VertebrataVertebrata – the backboned animals – – the backboned animals –

– AgnathisAgnathis – jawless fishes – jawless fishes– ChondrichthyesChondrichthyes - Cartilaginous fish - Cartilaginous fish– OsteichthyesOsteichthyes – boney fish – boney fish– AmphibiaAmphibia – Amphibians – Amphibians– ReptiliaReptilia - Reptiles - Reptiles– AvesAves – Birds – Birds– MammaliaMammalia - mammals - mammals

Urochordata – The TunicatesUrochordata – The Tunicates

CharacteristicsCharacteristics– Soft-bodied –Soft-bodied – marine & sessile marine & sessile

– Filter feederFilter feederGill slits trap foodGill slits trap food

Gill slits absorb OGill slits absorb O22

– AdultsAdults With gill slits, without nerve cord or notochordWith gill slits, without nerve cord or notochord

– Larval formLarval form – – look like a tadpolelook like a tadpole

Mobile w/ all three chordate characteristicsMobile w/ all three chordate characteristics

Common name of the group : Sea Squirts

Cephalochordata – The LanceletsCephalochordata – The LanceletsCharacteristicsCharacteristics– All are marineAll are marine– Filter feederFilter feeder

Gill slits trap foodGill slits trap food

Gill slits absorb OGill slits absorb O22

– Mobile Mobile – Adults w/ all three chordate characteristicsAdults w/ all three chordate characteristics

Example of the group : Example of the group : Amphioxius sp. sp.

Vertebrata– Vertebrata– The Backboned AnimalsThe Backboned AnimalsCharacteristicsCharacteristics– Most numerous & complex of ChordatesMost numerous & complex of Chordates– NTK 7 ClassesNTK 7 Classes

Agnathis, Chondrichthyes, Osteichthyes, Agnathis, Chondrichthyes, Osteichthyes, Amphibia, Reptilia, Aves, MammaliaAmphibia, Reptilia, Aves, Mammalia

– Spinal column replaces notochordSpinal column replaces notochord– Anterior end of nerve cord modified into brainAnterior end of nerve cord modified into brain– Body usually divided into head, neck & trunkBody usually divided into head, neck & trunk– Two pair of appendages (arms & legs)Two pair of appendages (arms & legs)– Heart w/ 2, 3 or 4 chambersHeart w/ 2, 3 or 4 chambers– Respiration – gills & lungsRespiration – gills & lungs– Closed circulatory systemClosed circulatory system– Endothermic or exothermicEndothermic or exothermic

That’s all Folks!!That’s all Folks!!

Keep an eye out for part 2Keep an eye out for part 2Fishes, Amphibians & ReptilesFishes, Amphibians & Reptiles