DIATOMS AND DINOFLAGELLATES BP221508.pdf

DIATOMS AND DAINOFLAGELLATES

1. DIATOMSANDDINOFLAGELLATES
P.VISHNUPRIYA
BP221508
I M.Sc Applied Microbiology
Sacred Heart College
(Autonomous)
Tirupattur.

2. Diatoms:
➢Diatoms,alsocalledasBacillariophyta,areamajortypeof
phytoplankton.
➢Theyincludemainlymarinespecies.
➢Theyaresingle-celled,eukaryoticalgae.
➢Thediatomscanbeclassifiedmainlybasedontheirshape.
➢Therearetwocategoriesnamelycentricdiatomsand
pennatediatoms.
1.Centricdiatomshavearadialsymmetrical
shape.
2.Incontrast,pennatediatomsshowbilateral
symmetry.

3. ➢Diatomsaregoodindicatorsofwaterquality
➢Theuniquefeatureofdiatomsisthepresenceofatheca.
➢Thecaisanexternalcellwallcoveringthecell.Itconsistsof
silicondioxideandisahardenedshell-likestructure.
➢Thethecahastwopartsthatfitnicelywitheachother.
➢Theyaretheepithecaandthehypotheca.Thethecaalso
containsmanypores.Theyappearlikethinlinesonthe
externalcellwall.
➢Diatomshavepigmentssuchaschlorophylland
fucoxanthin.
➢Thesepigmentsprovidecharacteristiccolourstodiatoms.
➢Thereareover10,000speciesofidentifieddiatomssuchas
Coscinodiscus,DitylumandLauderia,etc..

4. What are Din
Diatoms

5. DINOFLAGELLATES:
➢Dinoflagellatesbelongtothephylumpyrrhophyta.
➢Theyaremarine,single-celled,eukaryoticalgaewhichare
phytoplankton.
➢Theyhaveabiflagellatedstructure.Thepresenceoftwo
flagellalimitsthemobilityoftheseorganisms.Therefore,they
arelessmotileinnature.
➢Thecellwallofdinoflagellatescontainscellulose.
➢Therearespecialfeaturesofdinoflagellatessuchasthe
abilityforbioluminescenceandtheabilitytoproduce
neurotoxins.
➢Dinoflagellatescanresultinalgalbloomswhenpresentin
highnumbers.
➢TherearemanyspeciesofdinoflagellatessuchasCeratium,
PeridiniumandDinophysis,etc.

6. Dinoflagellates

7. WhataretheSimilaritiesBetweenDiatoms
andDinoflagellates:
➢DiatomsandDinoflagellatesaresingle-celled,eukaryotic
algae.
➢Bothresideinmarineenvironments.
➢Theyaretypesofphytoplankton.
➢Bothcontainchlorophyllandotherpigments.
➢Theydophotosynthesistoproducefoods.
➢DiatomsandDinoflagellatesgenerateoxygen.
➢Theyareabletoindicatethewaterquality.

9. THANK YOU