Sponges have their wall covered
by cells called pinacocytes
having pores well-delimited special
cells called .The internal wall
is with choanocytes, flagellate
specialized in phagocytosis food
brought to central cavity; the
flagella also maintains
water flux inside sponge.

Between the and the inner
of the poriferan there are
cells amoeboid movement (by
), the amoebocytes; since
are embedded in
matrix, amoebocytes move
distribute nutrients to cells and
they produce spicules that a
primitive skeleton the tissue and
the body structure. (
poriferans have an skeleton, an
endoskeleton, of spicules and
fibers.)