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Cephalic appendages of prawn
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- 2. Appendages • Each bodysegments 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 appendagesof 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 remainattached 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
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- 6. • They arefive 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 aremasticatory Structure used for cutting the food into pieces • First and second maxillae serves feeding jaws
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- 9. • Antennules (alsocalled 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 processarising from the basis • Thay are not truly the exopodote or endopodite But are tactile orngans
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- 12. • Antennae (Orsecond 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 poditesare three basal segments • And many jointed filamentarel process • Endopodite is a tactile orngan
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- 15. • Mandibles areuniramous 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
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- 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.
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- 19. • Second maxillaeare 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 isvery 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 1st Bsczoology Gvt college ,kasaaragod
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