The animal that acts like a plant, but is an act
■ Robert Carter
WHO DOESN’T like to see photos of tropical coral reefs? They are colourful and teeming with life. But these wonderful ecosystems would not exist were it not for the efforts of a strange, gooey little animal called a ‘coral’.
Plant or animal?
God designed corals to be both hunters and farmers, and they do both
very well. They don’t have eyes, but they can detect light, and react to
passing shadows by retracting into their homes. Corals are active pred-
ators, snagging small floating food particles with their tentacles.1 There
is not much food in the clear tropical waters, but they are very good
at grabbing what is there. That food (tiny crustaceans and bits of other
debris) is protein-rich but has little in the way of carbohydrates (sugars).
To supplement their diet, they are also active farmers. Corals capture
algae from the water and provide a place for them to live inside their
cells. 2 Even though corals come in a rainbow of colours, the basic colour
of most corals is a dull brown. This is not the colour of the animal itself,
but of the millions of little algal cells that are being farmed inside it. 3
In a wonderful display of mutualism, the coral provides a nice sunny
place for the algae to live and provides them with nutrients. In turn
it receives lots of carbohydrates, which the algae produce in surplus.
They do this by combining dissolved carbon dioxide (CO2) and water
using the energy of sunlight through the amazing process of photo-
synthesis, just like land plants do using atmospheric CO2.
Jellyfish on the half shell
Corals, jellyfish, and the freshwater hydra all have stinging cells (called
cnidae, from Greek knidē, stinging nettle), and thus belong to the
phylum Cnidaria (here, the C is silent). The basic body plan of a
cnidarian is called a ‘polyp’ and consists of a mouth, tentacles, and
a digestive cavity. Unlike the free-swimming jellyfish, corals are
anchored to the sea bottom in homes they create themselves.
A coral is essentially an upside-down jellyfish that lives in a hole.
Most scientists divide the corals into seven major families, which
could well correspond to seven created kinds. Reef-building corals
belong to class Anthozoa (literally, ‘flower animals’, for obvious
reasons). Most of the anthozoans have a hard skeleton, and as they
grow they add to the coral reef structure.
CREATION.com 28 Creation 39( 3) 2017