presentation on plankton research

1. Plankton
COLLECTION OF ORGANISMS THAT ARE UNABLE TO PROPEL THEMSELVES AGAINST CURRENT.

2. Plankton are primarily divided into broad functional groups:
 Phytoplankton: are autotrophic prokaryotic or eukaryotic algae that live near the
water surface where there is sufficient light to support photosynthesis.
 Zooplankton: are small protozoans or metazoans that feed on other plankton.
Some of the eggs and larvae of larger nektonic animals, such as fish, crustaceans,
and annelids, are included here.
 Mycoplankton: include fungi and fungus-like organisms, which, like
bacterioplankton, are also significant in remineralisation and nutrient cycling.
 Bacterioplankton: include bacteria and archaea, which play an important role
in remineralising organic material down the water column
 Virioplankton: are viruses. Viruses are more abundant in the plankton than
bacteria and archaea, though much smaller

3. Zooplankton
 Zooplankton are the animal component of the planktonic community
Based on size
• Picozooplankton (< 2um)
• Nanozooplankton (2-20um)
2μm

4. Zooplankton
 Holoplankton - organisms that are planktic for their entire life cycle.
 Meroplankton – only a part of their life cycle, they exists as planktonic. Much
of the meroplankton consists of larval stages of larger organism.
 Ichthyoplankton - are the eggs and larvae of fish. They are mostly found in
the sunlit zone of the water column,
2μm

5. Phylum Sarcomastigophora
1. Radiolaria
Protozoa distinguished by segregation of their soft body into the
central capsule containing endoplasm, and the surrounding
ectoplasm and by the siliceous skeletons
2. Acantharia
Protozoa with skeleton of celestite formed by a set of spicules
which, unlike radiolaria, always meet at centre of protoplasmic
body.
3. Foraminifera
Range from 30 um to few mm in size. Skeleton arranged in series
of chambers of increasing size.

6. Phylum Ciliophora
Tintinnida
 Main body is enclosed in a flask shaped lorica composed of gelatinous
material.
 In live animals a crown of cilia emerges from the flask

7. Phylum Cnidaria
• Possess Cnidobalst.
• Three classes separated by distintive features in their bottom living
polypoid or free-swimming jellyfish phases:
 Class Anthozoa- includes sea anemones and corals
 Class Scyphozoa- the large jellyfish
 Class Hydrozoa- five subclasses but only two are planktonic:
1) Hydroidomedusae 2) Siphonophora

8. Phylum Ctenophora
 Composed of jelly.
 Swim by cilia, which are joined together in rows like comb(comb jellies)
 Delicate and breaks in plankton net

9. Phylum Platyhelminthes
Order Turbellaria
 Called flat worms,
 Few species are planktonic and less than 5 mm in length

10. Phylum Nemertina
 Worm like organisms, looks like flatworm, but tend to be larger, thicker
bodied and longer.
 Most species are less than 20 cm
 Free-swimming, ciliated pilidium larvae can be common in plankton
sample

11. Phylum Rotifera
 Flask shaped organisms with cilia surrounding the mouth area.
 Eats phytoplankton, bacteria and detritus.
 Commonly feeded to larval fishes as their first food

12. Phylum Mollusca
 Soft bodies partly or entirely covered by a mantle, a sheet of tissue
exclusive to molluscs
 Have a protective shell excreted by mantle
 Class Monoplacophora
 Class Aplacophora
 Class Polyplacophora
 Class Scaphopoda- tusk shells
 Class Gastropoda- snails, sea slugs
 Class Pelecypoda- bivalves
 Class Cephalopoda- squid, cuttlefish

13. Phylum Arthropoda
 Subphylum Crustacea

15. Crustaceans
 External chitin skeleton
 Paired jointed appendages
 Antennae, mandibles and maxillae as
head appendages
 Includes copepods, krills, amphipods

16. Copepods
 Size - <1mm to few mm long
 Planktonic forms belong to order calanoida
 Long pair of antennae
 Swim mainly with aid of 5 pairs of thoracic
appendages
 Feeds on phytoplankton or small zooplankton
depending on species

17. Process that control 10 productivity
 The rate of primary production of a parcel of a marine environment
depends on light and on the chemical conditions provided by the physics
of water masses.
 Nutrient availability, is widely known as a crucial component in
phytoplankton biomass regulation.

18. Process that control 20 productivity AS
 In Summer – Upwelling
 Winter- Convective mixing due to winter cooling
 Inter-monsoon-Microbial loop
Other regulating factors
 Mesoscale eddies
 Regional scale process Lakshadweep low
 Cyclones
 Ocean currents

19. Process that influence 20 productivity
in BoB
 Upwelling
 Mesoscale eddies
 Cyclones
 River-plume fronts