If the manta ray gets 50 kcal of energy by eating the
starfish, how much energy does the clam get from
eating the plankton?
kcal
Tertiary Consumer
Secondary Consumer
Primary Consumer
) Intro
?

5000 Kcal of energy does clam get from  eating the plankton.

Explanation:

At each trophic level only 10 % of the existing energy of the organism is transferred to the other level or upper level in food pyramid. This is termed as 10% energy rule.

Information given:

Manta ray eats starfish and gets 50 Kcal of energy.

how much energy does clam get from eating planktons =?

planktons as zooplanktons are the primary consumer in the marine food web

so clam is secondary consumer manta ray is tertiary consumer.

50 Kcal is the net energy at tertiary level

so at secondary level the energy would have been

500 Kcal

50000 Kcal at primary consumer level (plankton)

so when plankton is eaten by clamp

10 % of 50000

x 50000

= 5000 Kcal of energy clam gets from plankton.