Creature of the week
Golf Ball Sponge
Tethya aurantium
Up to 60 mm
Sponges
love the
shaded
overhangs of
the platforms
at Long Bay.
Four
different
sponges are
seen on this
overhang
Photo David Gray@MERC
Golf Ball Sponge
Tethya aurantium
Up to 60 mm
Description:
Each sponge is a complete animal made up of 17 different cell types arranged around a
specific skeleton and all arising from a stem-cell that is able to differentiate into whatever duty –cell might be
required for its filter-feeding life style which requires huge volumes of water to be pumped in the pores,
screened of plankton and expelled. This, despite the animal having no heart, no central nervous system, no
gut – yet all the cells are nourished and coordinated!
Different sponges have different skeleton materials – some soft (bathing sponges), some firm
of silicon, and some calcified like coral. The Golf Ball sponge has radiating spicules. (diagram)
Habitat:
Shady places low tide – under the overhangs on Long Bay is where we see many different varieties
offtt sponges. They can be bright red, grey, blue, purple, bright yellow, or dull khaki. Different species have
different shapes – flat spreading, branched like antlers, round, pin-head, lobulated – all shapes and sizes.
Sponges have an autoimmune system, occur in both fresh and salt water , at the Poles or the tropics,
and live at any depth – even beside the fumaroles in deep sea trenches.
Diet:
Plankton filtered out of the water.
Reproduction:
. Reproduction may be internal-sexual, or asexual whereby lobes are pushed out and eventually
separated, or sections broken by accident can reform themselves into viable cloned individuals!
Reference:
Morton and Miller “The New Zealand Sea Shore”
Diagram from Fig 41, page 113
Also from lecture by Dr. Michelle Kelly at MERC
in 2011.