Life cycle of mud crab

Examples of Mud crap
Types of Mud crabs
The life cycle of mud crab

1. LIFE CYCLE OF MUD CRAB
Presented by
IPSITA SAHOO
Reg. No -200705180160
Guided by
Dr. SITARAM SWAIN
Assistant Professor, School of Applied Sciences
Centurion University of Technology and Management,
Bhubaneswar, Odisha

2. Review Literature
METHODOLOGY
Introduction
Examples of Mud crap
Types of Mud crabs
Life cycle of mud crab
References
Presentation
Outline
Conclusion

3. CrabsofthegenusScyllaarecommonlyknownasmud
crabsormangrovecrabs.Theyarefoundinintertidaland
sub-tidalzonesofestuariesandinmangrovesystemsin
tropicaltowarmtemperatezonesofthePacificandIndian
oceans.
Mudcrabshaveacomplexlifecycle,wherethelarvaego
throughfivezoealstages(3-5dayseach)andonemegalopal
stage(8-10days)beforefinallymetamorphosingintothe
benthicfirstjuvenilecrabstage.
INTRODUCTION
Image source-http://advancefishery.com/crab/

4. Examples of Mud crap
Image source-Keenan, C., Davie, P. J., & Mann, D. L. (1998).

5. Types of Mud crabs
MudcrabsinthegenusScyllainhabitcoastalareas,estuariesandbackwaters.
i.Largerspecies:
Thelargerspeciesislocallyknownas`greenmudcrab'.
Itgrowstoamaximumsizeof22cmcarapacewidthand2kginweight.
Thesearefreelivinganddistinguishedbythepolygonalmarkingspresentonall
appendages.
ii.Smallerspecies:
Thesmallerspeciesisknownas`redclaw'.
Thisgrowstoamaximumsizeof12.7cmcarapacewidthand1.2kginweight.
Itiswithoutpolygonalmarkingsandhasaburrowinghabit.
Bothspecieshavegooddemandinthedomesticaswellasintheforeignmarket.

6. Life cycle of
mud crab

8. ZOEA
Amudcrabbeginslifeasalarvacalleda‘zoea’,whichhatchesfromanegg.Itisaboutone
millimetrelongwithundevelopedlimbsandlooksalittlelikeatadpole.Thezoeafloatsinthewater
withplankton–microscopicorganismsthatdriftinclusters.
Thezoealarvaundergoes5successivemoultstobecomethemegalopalarva.Thusthereare5
zoealstages.Foreachmoult,ittakes3-4days.
Image source-http://ecoursesonline.iasri.res.in/mod/page/view.php?id=51482

9. MEGALOPA
Azoeagrowsby‘moulting’(sheddingitsshell)fourtimesover12to
15days.
Duringthefifthmoult,ittransformsintoa‘megalopa’,whichhas
functionalclaws.Afteraweekorso,itmovesinshoreandsettlestothe
seabed.
Afterafewdays,itmoultsintoastageonejuvenilecrab.
Importantmorphologicalcharacters
Carapacelongerthanwider;abdomenwith5pairsofpleopods;a
pairofcheliped;4pairsoflegs.
Image source-http://ecoursesonline.iasri.res.in/mod/page/view.php?id=51482

10. JUVENILE CRAB & YOUNG ADULT
Aminiatureversionoftheadult,itisabout4mm
wide.
Aboutamonthafterhatching,when10–20mm
wide,itmovestoanestuaryandsettlesinasheltered
area.
Juvenile Crab
Thecrabreachessexualmaturityat18to24months.A
greenmudcrabmaturesatabout110millimetres
(carapacewidth)andabrownatabout90millimetres.
JuvenileCrab
Youngadult
Image source-http://ecoursesonline.iasri.res.in/mod/page/view.php?id=51482

11. Mating
Inthewarmermonths,maturefemalesreleasea‘pheromone’
(chemicalattractant)intothewatertoattractmales.
Oncepaired,themaleclimbsontopofthefemale,claspsher
withhishindlegs,picksherupandcarriesheraroundforupto
fourdays.
Hereleasesherwhenshebeginstomoult,andaftershehas
shedhershell,heturnsherupsidedowntomate.
Hedepositsacapsuleofsperminsideherreproductive
opening,whereit’sstoredformonthsuntilherdeveloping‘ova’
(eggs)arereadytobefertilised.
Aftermating,themaleflipsthefemaleuprightandholdsher
underhimforafewmoredayswhilehershellhardens.
Precopulatorycaging
Male guarding over newly
molted female prior to
copulation
Male flipping female over,
with female’s abdomen
readily opened
Copulation between male
and female
Insertion of male’s
gonopodsinto female’s
gonopores Postcopulatoryguarding
Image source-https://doi.org/10.1016/j.aqrep.2015.08.004

12. Spawning and hatching
Thefemalemigratesoffshoretospawn.
Thefertilizedeggsarereleasedin
batchesoftwotofivemillion.
Afterdiggingaholeinthesandormud
withherabdominalflap,thefemale
releaseshereggsintoit.
Usingherswimminglegs,shegathersthe
eggsuptocarrythemunderherabdomen.
Theeggshatchintwotofourweeks.
Thelifecyclethenbeginsagain.
Image source-https://doi.org/10.1093/icesjms/fst181
Life cycle of S. serratashowing ontogenetic shift
between the inshore (estuarine) and the offshore
(oceanic)

13. Mudcrabsarehighlyfecund:afemalecanproduceseveralmillioneggsperspawningand
canspawnmultipletimesperyear.
Inthetropics,spawningofmudcrabsoccursyearround,butinsubtropicalandwarm
temperateareas,spawningisrestrictedtolatespringtomid-autumn.
Anunderstandingofontogeneticchangesindigestivephysiologyandfeedingbehaviourof
variouslarvaestagesisimportantforthedevelopmentofanappropriatehatcheryprotocoland
thedesignofformulatedfeedsforcrablarvae.
CONCLUSION

14. Fushimi,H.,&Watanabe,S.(1999).Problemsinspeciesidentificationofthemudcrabgenus
Scylla(Brachyura:Portunidae).UJNRTechRep,28,9-13.
Australia,W.(2013).MudCrab.
Phelan,M.,&Grubert,M.(2007).Thelifecycleofthemudcrab.FishnoteNo.11,Department
ofPrimaryIndustry.FisheriesandMines,Darwin,Australia.
Australia,W.(2020).ResourceAssessmentReport.
Keenan,C.,Davie,P.J.,&Mann,D.L.(1998).ArevisionofthegenusScylladeHaan,1833
(Crustacea:Decapoda:Brachyura:portunidae).TheRafflesBulletinofZoology,46,217-245.
Websites: http://www.fish.wa.gov.au/species/mud-
crabs/pages/default.aspx#:~:text=Lifecycle,over%2012%20to%2015%20days.
http://advancefishery.com/crab/
REFERENCES