Zoogeography is a branch of biogeography concerned with the geographic distribution of animals and especially with the determination of the areas characterized by specific groups of animals and the study of the causes and significance of such groups. Holoplankton are organisms that are planktic (they live in the water column and cannot swim against a current) for their entire life cycle. So, zoogeography of holoplankton generally discusses the distribution and causes of the distribution of zooplankton.

1. Ramkrishno Paul Partho
Zoogeography of the
Holoplankton

2. Zoogeography
Geographic
distribution of
animals
Branch of
biogeography
Determines
areas
characterized
by specific
groups
Causes and
significance of
such groups
*According to Merriam-Webster

3. Quality
Phytoplankton
Zooplankton
Size*
Netplankton
• Megaloplankton
• Mesoplankton
• Microplankton
Nanoplankton
• Nanoplankton
• Ultraplankton
Local
Environmental
Expansion
Limnoplankton
Rioplankton
Helioplankton
Helioplankton
Hypalmyroplankton
Origin
Autogenic plankton
Allogeneic
plankton
Structural
elements
Euplankton
Pseudoplankton
Life history
Holoplankton
Meroplankton
Planktonic classification
*Dussart proposed the classification in 1985

4. Holoplankton
• Remains planktonic during
their whole life time
• Known as permanent
zooplankton
• Examples : Krill, Copepods,
Jellyfish
Meroplankton
• Spent part of life cycle
( larval stage ) in planktonic
state
• Known as temporary
zooplankton
• Examples : Sea stars,
Urchins
Holoplankton
Vs
Meroplankton

6. Zoogeography of the Holoplankton
• Noise
• Climate
• Wrong medium
• Time and
distance
Physical barriers Hydrographic barriers
• Temperature
• Salinity
• Pressure
• Density
• Face less physical barriers compared to terrestrial organisms in case of gene flow

8. Zoogeography of the Holoplankton
Longitudinal Hydrographic Barrier
0
Longitudinal
distribution •50% of all epipelagic
zooplankton extend from
tropical and sub tropical to
temperate zone
•1/3 restricted to warm waters of
tropics and sub tropics
Fewer species restricted to cold
and/or temperate waters with
some of bipolar habitat species

9. Zoogeography of the Holoplankton
Latitudinal Hydrographic Barrier
0
Latitudinal
distribution •Number of epipelagic
species decreases from low
to high latitude
•Reverse tendency has been
seen for cold water
epipelagic species with
greater number of individuals
Reason behind latitudinal
differences and abundance
remains debated

10. Do humans influence the distribution of zooplankton ?
Suez Canal
140 species from
Red sea to
Mediterranean
01
Accidental
transport
Through ballast
water in black
Sea
02

11. Summary
Large seasonal fluctuations in
temperate and polar regions
Conversely, zooplankton biomass
tends to be low in the tropics and
increase with latitude
On a global scale, zooplankton
diversity is higher at the equator
and decreases towards the
poles
02
03
01
Drago L, Panaïotis T, Irisson J-O, Babin M, Biard
T, Carlotti F, Coppola L, Guidi L, Hauss H, Karp-
Boss L, Lombard F, McDonnell AMP, Picheral M,
Rogge A, Waite AM, Stemmann L and Kiko R
(2022) Global Distribution of Zooplankton
Biomass Estimated by In Situ Imaging and
Machine Learning