Phylum - ChordateGeneral Characteristics and Classification

Mr. Narendra Kumar Lal, Assistant Professor (Zoology), C. M. Science College, LNMU, Darbhanga, Bihar

B.Sc. Zoology Subsidiary Degree 1

Chordate

•The name of this phylum is derived from two Greek words -• the chorde - meaning a string or cord, and •ata - meaning bearing, group or forms.

•Thus chordates are animals having a cord, i.e., notochord.

Mr. Narendra Kumar Lal, Assistant Professor (Zoology), C. M. Science College, LNMU, Darbhanga, Bihar

Fundamental Characteristics of Chordates

• All chordates shows all the following three(four) fundamental characteristics at least few of them for the some time in the life cycle:

• Notochord: in higher chordate called vertebrata, it is replaced by vertebral column

• Nerve cord: dorsal hollow nerve cord• Pharyngeal gill slits - Pharyngeal slits are

openings in the pharynx that develop into gill arches in bony fish and into the jaw and inner ear in terrestrial animals.

• Postanal tail also considered as a fundamental characteristic

Mr. Narendra Kumar Lal, Assistant Professor (Zoology), C. M. Science College, LNMU, Darbhanga, Bihar

https://courses.lumenlearning.com/wm-biology2/chapter/characteristics-of-chordates/

General Characteristics of Chordates

• Bilateral Symmetry• Triploblastic• Deuterostome• Complete digestive tract• Coelomate - Well developed coelom• Internal organs are suspended in the coelomic

cavity by a thin membranous tissue called mesentery

• Sexual reproduction• Post anal tail

Mr. Narendra Kumar Lal, Assistant Professor (Zoology), C. M. Science College, LNMU, Darbhanga, Bihar

• Endostyle: An endostyle is a longitudinal ciliated groove on the ventral wall of the pharynx which produces mucus to gather food particles. It is found in urochordates and cephalochordates, and in the larvae of lampreys.

Mr. Narendra Kumar Lal, Assistant Professor (Zoology), C. M. Science College, LNMU, Darbhanga, Bihar

Phylum Chordate Classification

•Phylum - P

•Subphylum - SubP

•Class - C

Mr. Narendra Kumar Lal, Assistant Professor (Zoology), C. M. Science College, LNMU, Darbhanga, Bihar

Chordata: Classification

• Phylum Chordata• Subphylum: Hemichordata• Subphylum: Urochordata• Subphylum: Cephalochordate• Subphylum: Vertebrata

• Protochordata (Hemichordate, Urochordata, Cephalochordate)

• Vertebrata (Pisces, Amphibia, Reptilia, Aves, Mammalia) • Cyclostomata• Pisces- Osmoregulation, Migration of Fishes• Amphibia- Origin of tetrapods• Reptilia- Amniotes; Origin and evolutionary radiation of reptiles• Aves- The origin of birds; Flight adaptations• Mammalia- Early evolution of mammals; Primates; Evolution of Man.

non-vertebrate chordate

Mr. Narendra Kumar Lal, Assistant Professor (Zoology), C. M. Science College, LNMU, Darbhanga, Bihar

CHORDATAP

HemichordataSubP CephalochordataSubP

(= Acrania)UrochordataSubP

(= Tunicata)VertebrataSubP

(= Craniata)

EnteropneustaC

PterobranchiaC

e.g. Balanoglossus

e.g. Cephalodiscus

AscidiaceaC

ThaliaceaC

Larvacea C

(= Appendicularia)

e.g. Brachiostoma(Amphioxus)

e.g. Herdmania, Ciona, Botryllus

e.g. Salpa, Doliolum, Pyrosoma

e.g. Oikopleura

AGNATHASupC

GNATHOSTOMATASupC

ChondrichthyesC

CyclostomataC

e.g. Petromyzon, Lampetra, Myxine

OsteichthyesC AmphibiaC ReptiliaC AvesC MammaliaC

e.g. Sphyrna, Pristis, Torpedo

e.g. Labeo, Anguilla, Exocetous, Propterus (Lung Fishe)

e.g. Ichthyophis, Ureotyphlus, Salamndera, Bufo, Hyla

e.g. Chelone, Hemidactylus, Chamaeleon, Draco, Vipera, Naja, GrvialisCrocodylus

e.g. Pavo (Peacock), Corvus (Crow), Psittacula (Parrot), Tytoor Bubo (Owl), Columba (Pigeon), Dinopium(Woodpecker)

e.g. Sorex, Bat, Funambulus, Loris

@narendra // Reference: Young, J. Z. (2004). The Life of Vertebrates. III Edition. Oxford university press.Pisces

Mr. Narendra Kumar Lal, Assistant Professor (Zoology), C. M. Science College, LNMU, Darbhanga, Bihar

Notochord absent Notochord present

NON-CHORDATES CHORDATES

INVERTEBRATES

Vertebral Column absent Vertebral Column present

INVERTEBRATES

PROTOCHORDATES(Invertebrate chordata)

VERTEBRATES

Mr. Narendra Kumar Lal, Assistant Professor (Zoology), C. M. Science College, LNMU, Darbhanga, Bihar

Vertebrata

•Agnatha/Cyclostome – without jaw

•Anamniotes/Lower Vertebrates (Fish and Amphibians) - lay their eggs in water

•Amniotes/Higher Vertebrates (Reptile, Birds & Mammals) - lay their eggs on land or retain the fertilized egg within the mother.

Mr. Narendra Kumar Lal, Assistant Professor (Zoology), C. M. Science College, LNMU, Darbhanga, Bihar

Amniotes- Terrestrial

• The amniotes are a group of tetrapod whose extant members are the reptiles (including birds) and mammals.

• During their evolution, amniotes acquired a number of new adaptations to life on land.

• The characteristic amniotic egg contains four specialized membranes: the amnion, the chorion, the yolk sac, and the allantois. Called extraembryonic membranesbecause they are not part of the body of the embryo itself, these membranes develop from tissue layers that grow out from the embryo.

Mr. Narendra Kumar Lal, Assistant Professor (Zoology), C. M. Science College, LNMU, Darbhanga, Bihar

Phylum ChordataSubphylum Class

Hemichordata Protochordata(non-

vertebratechordate;

Lower chordate)

Urochordata

Cephalochordata

Acraniata

Vertebrata Cyclostomata Agnatha Craniata Euchordata(Vertebrates;

Higherchordate)

Pieces Amniotes/Higher Vertebrates

Gnathostomata

Amphibia Tetrapoda

Reptilia Amniotes/Higher Vertebrates

Aves

Mammalia

Mr. Narendra Kumar Lal, Assistant Professor (Zoology), C. M. Science College, LNMU, Darbhanga, Bihar

• Thank you

Mr. Narendra Kumar Lal, Assistant Professor (Zoology), C. M. Science College, LNMU, Darbhanga, Bihar