PETROMYZON

PETROMYZON (Lamprey)

P= Chordata
C= Cyclostomata
O= Petromyzonta
G= Petromyzon

- These animal have both type marione or fresh water living habitat
- These animal are sanguivours animal ( Blood sucking)
- There respiration occur by gill
- These animal by lateral undulation of body
- These animal larva called "ammocoetus larva"
- These animal larva feed on microphagous particles so have filter feeder feeding
- Fertilization is external in this animal
- Colur of this animal is greenish brown color
- Their body divisible into head, trunk and tail
- their head consist buccal funnel for adhese on other animal ,
- there mouth also consist tongue in which teeth are present and anticoagulant agents for prevent coagulant of blood when animal feed or such blood
- 7 pair of gill slits are present
- Two eyes and one naris also present in head region
- Ther trunk is cylindrical type having dorsal fin which are supported by fin ray
- fin ray are the catilagenous structure which are help ful to keep fin on that place and give them some what rigidity
- Tail pf this animal are pointed having caudal fin which help this animal for moving one place to another
- Sexes are separate in this animal
- These animal skin consist of epidermis and dermis layer after that a musculature and one peritoneum layer found
- locomotion in this are typically swimming type
- skull of this animal are primitive and peculiar type
- There last long nerve cord are covered by notochord sheath
- Digestive system is complete in this animal
- These animal having S-shaped heart having four chamber as
* Sinus venous
* Auricle
* Ventricle
* Conus Arteriosus
- There arterial system system consist ventral aorta , dorsal aorta and carotid arteries
- There blodd consist RBC and WBC as circulatory fluid
- These animal having well developed nervous system with forebrain , mid brain and hind brain
- There central canal having only grey matter no white matter present
- Having 10 pair of cranial nerve
- These animal having two epiphysial eye which covered by conjuctiva
- These animal also have internal eye  which act as auditory organ
- These animal have a apir of opisthonephric kidney for excretion
- Sexes are separate in this animal
- No genital duct is present
- Female one have only single ovary and male have single testis
- These animal show unequal cleavage due to Telolecithal egg
- Cleavage is Holoblastic
- These animal show anadromous migration before breeding
- Female lay egg in under pebble nest and male release their sperms
- After breeding these animal die because there alimentary canal dimished during migration