5. ECOLOGICAL PYRAMID
• An ecological pyramid (or trophic pyramid) is the graphical
representation of the trophic structure such as number, biomass
and energy of an ecosystem.
6.
7. TYPES OF ECOLOGICAL PYRAMIDS
• Three types of ecological pyramids can be usually
disguished namely:
• Pyramid of numbers
• Pyramid of biomass
• Pyramid of energy
8. Pyramid of numbers -example
• Shape may vary from ecosystem to ecosystem.
• In aquatic ecosystem and grassland communities,autotraphs are
present in large number per unit area.
• They support a lesser number of herbivorus,which in turn support
fewer carnivores.
9. Example of inverted pyramid of biomass
• Phytoplankton are microscopic plants –like organisms that can make
food by photosynthesis.
• Zooplankton are microscopic primary consumers that feed on
phytoplankton.
11. CONT..
Grazing food chain
• The producers are the green plants, which prepare their own food in
the presence of sunlight. So, they are also called as Autotrophs. The
herbivorous animals eat the plants (autotrophs/ primary producers).
• The carnivores eat the herbivorous animals. Thus, the grazing food
chain starts with primary producers and ends with carnivores.
12. a) Predator food chain
• In this food chain one animal kills and eat the other animals.
• The animal which kills other animals for food is called a predator. This
act of hunting is called predation.
• Animals that are caught and eaten by a predator are called prey.
Predators that only eat the meat of prey are carnivores
13. b) Parasitic food chain
• The plants and animals of the grazing food chain are affected by
parasites. Parasites derive their energy from their hosts.
• Example: angular fish
14. • c) Detritus food chain:
dead organic matter
fungi n bacteria
decomposers
inorganic matter
• The organisms of detritus chain may serve as food for the organisms
of grazing food chains
15. Trophic Adoptability
• The ability to take advantage of the most profitable food source at a
particular time is called trophic adaptability
brown trout (Salmo trutta),
Phoxinus phoxinus (prior),
Eel (Anguilla anguilla)
18. • Nano plankton-contribute as nutrition of fish larvae
• Benthic algae-whether leafy or filamentous, grow attach to bottom
substrate
• Epilithic form- grow on rocks, corals
19. • Epiphytic- grow on leaves or thalli of plants
• Psammon-algae survive among the sand grains of beach or on wave
washed flats
20. Trophic level 2
Includes plant eaters and detritus feeders
a. Plant eaters
• Phytoplankton feeder- Tilapia esculenta
21. • Periphyton feeder- Hemitilapia oxyrhycus
• Macrophyte feeder- oreochromis rendalli
• Benthic algae feeder –pseudotrophius tropheos(rock
scrapper),pseudotrophius zibra (rock comber), gephyrochromis moori
(scoopers)
• Roughly 50% of herbivores are found in the coral reefs
22. Grazers and browsers
1. Browsers – bite off pieces of plants above the substrate
• Browsers point the head upward and use a bite – and –tear technique
• Examples: Giant gouramy, grass carp
•
23. 2. Grazers –crop algae very closely to the substrate along with the plant
growth
Example:-surgeonfish (acanthuridae)
24. Detritus feeder
• Biters –Oreochromis mosambica grazes on the bottom by biting into
the substrate and swallowing the detrital aggregate
• Suction feeders – mrigal sucks flocculant detritus from the bottom by
using its lips which is have fine short teeth.
25. • Scoopers – sarotheodon galilaea mouth breeder classed as detritus
feeder
• Filterers – detritus is also obtained by filtering organic particles from
the water. The best example is mullets
26. Trophic level 3
• Plankton feeders
• algal feeding –herring and plaice larvae are to feed in the mid- yolk
sac stage, taking diatoms, such as biddulphia and coscinodiscus, for
short period of time
• And switching to animal matter after yolk sac is absorbed
28. • Coral reef fish employ a wide variety of feeding strategies to exploit
benthic food
• Dominant feeding strategies are
1. Line in wait predators- moray and conger eels
29. Hunters of mobile benthos-feed either solitarily or in small groups by
day or by night
Ex: squirrelfish and snappers
30. 3.Crushers- have heavy dentine or pharyngeal armature for crushing
Ex:puffers, file fish and triggerfish
4.Grazers – butterfly fish
31. Trophic level 4
SWIMMING PREDATORS
Feeding strategies
1.Luring - sit and wait type of predatory behavior .
2. Prey are enticed to the predators location by being attracted to a lure
that resembles a source of food
eg., Frog fish, Deep sea angler fish
32. 3.Stalking – the unobtrusive pursuit of pray
eg., long nose gar, needle fish
33. Chasing – large teleost's, such as bill fish & some tuna (catch shoal fish
instead of single pray)
Ambush – this behavior typifies those species that live in small caverns
of coral reefs like morays (Muraenidae), pike fish.
34. Nutrient production
• The greatest benefits of wetlands to maintaining and improving water
quality are that they trap sediment, remove harmful amounts of
nutrients (mostly nitrogen and phosphorus), and remove pesticides
before they can enter streams
• For all these reasons, there should be a strong effort to maintain or
restore wetlands, especially adjacent to streams
36. • Generally, the nutrients from the River are tidally transported into
shallow areas of the wetland, where upon the water becomes clearer,
phytoplankton assimilate the nutrients as they grow, and then this new
phytoplankton is transported by the tides back into the deeper
channels where it is available to support the pelagic food web
37. • Wetlands help maintain and improve the water quality of our nation's
streams, rivers, lakes, and estuaries
• Since wetlands are located between uplands and water resources,
many can intercept runoff from the land before it reaches open water
• As runoff and surface water pass through, wetlands remove or
transform pollutants through physical, chemical, and biological
processes
38. Transportation or removal
• wetlands may remove between 70% and 90% of entering nitrogen
• Riparian forests can reduce nitrogen concentrations in runoff and
floodwater by up to 90%.
• The estimated mean retention of phosphorus by wetlands is 45%
• Wetlands with high soil concentrations of aluminium may remove up
to 80% of total phosphorus
39. Removal of Metals
• Certain wetlands play an important role in removing metals from
other water resources, runoff, and ground water
• Wetlands remove 20% - 100% of metals in the water, depending on
the specific metal and the individual wetland
• Forested wetlands play a critical role in removing metals downstream
of urbanized areas
40. Removal of Pathogens
• Faecal coliform bacteria and protozoans, which are indicators of
threats to human health, enter wetlands through municipal sewage,
urban storm water, leaking septic tanks, and agricultural runoff
41. • Bacteria attach to suspended solids that are then trapped by wetland
vegetation
• These organisms die: after remaining outside their host organisms,
through degradation by sunlight, from the low pH of wetlands, by
protozoan consumption, and from toxins excreted from the roots of
some wetland plants
• In this way wetlands have an important role in removing pathogens
from surface water
42. Conclusion
• It helps to understand the interaction between organisms of different
trophic levels
• There is an effective relationship in between the nutrient production,
transportation and trophic levels
• Any changes in lower trophic level effects the higher level organisms
43. Reference
1. North Carolina State University. (NCSU Water Quality Group)
2. ca.water.usgs.gov/projects/2013-33.html
3. www.water.ncsu.edu/watershedss/info/wetlands/values.html
4. Cofmelearn.org
