Post on 19-Jan-2023
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