Class chondrichthyes zoorepowt(1)

CLASS CHONDRICHTHYES

1. Class ChondrichthyesClass Chondrichthyes
Mirabel, Camille Joyce Mercado,
Pia Alyssa
Rivera, John David

2. E T Y M O L O
G Y
“Chondros’’ - Cartilages
“Ichthyos’’ - Fish

3. Class Chondrichthyes
Characteristics:Characteristics:
Cartilaginous fishes
Streamlined form with heterocercal tail
Cartilaginous skeleton
Leathery skin
With placoid scales ( dermal denticles )
Restricted notochord
Mouth and two nostrils ventral
Jaws and paired appendages
Male claspers
Eggs with large yolk

4. M O R P H O L O
G Y

5. Taxonomical HierarchyTaxonomical Hierarchy
Kingdom Animalia
Phylum Chordata
Subphylum Vertebrata
Infraphylum Gnathostomata
Class Chondrichthyes
Subclass Elasmobranchii
Orders Cladoselachii,
Pleuracanthodii ( extinct sharks )
Orders Squaliformes
Order Rajiformes
Subclass Holocephali

6. Subclass
Elasmobranchii
 Sharks (Selachii) and the rays & skates 
(Batoidea)
 lives in most oceans in the world

7. Circulatory SystemCirculatory System
Four chamber heart: sinus venosus,
atrium, ventricle, and conus
arteriosus.
One direction of flow: Heart Gills
Body
Ectotherms/Endotherms

8. Reproductive System Reproductive System
(Male)(Male)
Both testes
functional
 Seasonal
reproduction
cycle
 Sperm
stored in
seminal
vesicles
 Both
claspers
functional

9. Reproductive System (Female)Reproductive System (Female)
One functional ovary in most
viviparous species
 Seasonal reproductive cycle
 Fertilization in nidamental gland

10. Shark MatingShark Mating
One clasper will rotate 90º and
will be inserted into the female’s
cloaca
Clasper will expand cartilaginous
spurs to anchor in the female

11. Subclass Elasmobranchii:
Orders Cladoselachii,
Pleuracanthodii


extinct sharks

12. Order Squaliformes
sharks, body spindle-shaped; 5-7 pairs of
lateral gills not covered by operculum,
pectoral fins not enlarged example:
Squalus

13. Order Rajiformes
skates, rays and sawfishes, body
spreadout, pectoral fins enlarged and
attached to head and body; five pairs of
gill slits on ventral side, spiracles large

14. Subclass Holocephali
• chimaeras or ghost fish , gill slits covered with
operculum;
•spirally closed; aberrant shaped; jaws with tooth
plates;
• single nasal opening without scales; accessory
clasping organs in male ;
•lateral line an open groove, Chimaera

15. Nervous SystemNervous System
Cerebellum is small
Medulla Oblongata is produced laterally
into restiform bodies

16. Digestive SystemDigestive System
The mouth in holocephali is small as
compared to the wide mouth of
Elasmobranch
It is bounded by three lips-like fold and
equipped with the tooth plate having
irregular surface and sharp cutting Edges

17. Urogenital SystemUrogenital System
The kidney of holocephalians is
opisthonepric having a large number of
uriniferous tubules and built upon the
basic pattern other fishes.

18. Circulatory SystemCirculatory System
Heart is Built upon the pattern similar to
other fishes.
The Heart is consists of a sinus venosus,
artrium, ventricle and conus with three
rows of valves.

19. Respiratory SystemRespiratory System
A Mandibular pseudobranch is absent and
hyoid bear only a Posterior Hemibranch.
The first,second and the third branchial
arches have Holobranch but the forth Has
a hemibranch.