Answer 1:
This is a tough question, because there is so
much about marine life that we
still don’t know. Scientists recently discovered a
new relationship between
Octopus vulgaris and Heteromysis octopodis,
a type of shrimp. Scientists
Charles Griffiths and Karl Wittman recently filmed
the shrimp living in the den of
an octopus off the coast of South Africa and
published their results in ZooKeys.
However, not all symbiotic relationships are
happy, like the octopus letting the
shrimp live in her den. The protozoan Aggregata
octopiana is a type of parasite
which can infect the digestive system of the
Octopus vulgaris and cause it
various health problems. Another example of a
parasite which infects the
Octopus vulgaris is a dicyemid mesozoan
which is a type of worm that lives in
the nephrid tracts of its hosts. | 
