Cephalic appendages of prawn

They are five pair in numbers

They includes
paired Antennules
Antennae
Mandibles
First maxillae
second maxillae
They are five pair in numbers

They includes
paired Antennules
Antennae
Mandibles
First maxillae
second maxillae

1. Cephalic appendages of prawn

2. Appendages Each body segments bears a pair of appendages on its ventral side There are nineteen pairs of appendages Five pair in cephalic ,eight pair in thoracic ,six pair in abdominal Each appendage remains attached to the sternum of the exoskeleton.

3. The appendages of the successive segments closely correspond in Structure and development The appendages of prawn Are biramous (Each of them has two process Or rami arising basal portion called protapodite ) and Segmentented The two process are outer exopodite and inner endopodite Their segments are called podomeres Protopodite is typically 2 segmented Its two segments are Coxa (basal segment ) and basis (terminal segment)

4. Coxa remain attached to the body walll Basis bear exopodite and endopodite Exopodite is unsegmented in all appendages But endopodites is segmented in some appendages , and unsegmented in others

5. Cephalic appendages

6. They are five pair in numbers They includes paired Antennules Antennae Mandibles First maxillae second maxillae In this mandible and first maxillae are uniramous and other are biramous Antennules and antenae are tactile structure

7. Mandible are masticatory Structure used for cutting the food into pieces First and second maxillae serves feeding jaws

8. 1. Antennules

9. Antennules (also called first Antennae) are the first pair of cephalic appendage Each of them consist of protopodite and two flagellar processes Protopodite consist of three segments Or Podomeres namely pre-coxa,coxa, Basis Pre coxa having concavity on one side Whiich lodge a compound eye and a balancing organ called statocyst

10. Flagellar process arising from the basis Thay are not truly the exopodote or endopodite But are tactile orngans

11. 2. Antennae

12. Antennae (Or second antennae) are second pair of cephalic appendages. Each of thenm has a two segmente protopodite Formed coxa and basis Coxa carries the excretary Organ green gland or antennury gland Basis bears An expanded and un segmentedExopodite or squam and many Jointed exopodite or feeler

13. Endo podites are three basal segments And many jointed filamentarel process Endopodite is a tactile orngan

14. 3.Mandibles

15. Mandibles are uniramous appendages Modified as mastagatory orngan for cuttying the food into small piecs They lie one on each side of mouth Each mandible has a Stout,toothed and calcified Base and two joined Palp The Base doesn’t represent protpodite The toothe base Serves as masticatory Organ forcutting and geindind the food

16. 4 . First maxillae

17. First maxilae (or maxillulae) are the smallest of all appendages They are thin, leafe like and umiramous Each of themm consist of bilobed protopodite and an unsegmented Flat and leafe like endopodite .ExopoditE is absent Protopodite has Flat and lobular coxa and basis. First maxillae of two sides Project inwarda and act together as Jaws hence they are called Gnathobases. they are used to pushing the food Into mouth.

18. 5.Second maxillae

19. Second maxillae are the last pair of appendages They are thin , leafe like and biramous Each of them has three parts,protopodite ,exopodite, endo podite Protopod is a four lobed structure Formed of a bilobed coxa and a bilobed basis Exopodite and endopodite are Flat and unsegmented

20. Endopodit is very small , But exopodite is broad And fan like It is often called Scaphognathite Or baler Because it vibrate All time to maintain constant flow of water Over the gills (Scaphe-boat, gnatho-jaws) It also drive away the rejected Food particles Thus second maxillae are feeding as well as respiratory in function

21. By Fathimath Thanzeela 1 st Bsc zoology Gvt college ,kasaaragod

22. The end