Sponges of the New Caledonian lagoon - IRD

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Sponges
of the New
Caledonian
Lagoon
Apopyle
An aperture through which water leaves
a choanocyte chamber (cL prosopyl).
Aquiferous system
The water 'circulatory' system extending
from the inhalant pores (ostia) to
exhalant pores (oscula).
Aragonite
A crystalline form of calcium carbonate.
Arborescent
Branching, tree-like.
Archaeocyte
A motile amoeboid or phagocytic cell
within the mesohyl of the sponge, with
at least one nucleolus and many phagosomes;
it is able to develop into any
other sponge cell type and is also
known as a nucleolate cell.
Arcuate chela
Microsclere where the teeth are formed
as one to three curved plates.
Arenaceous
Condition of skeletal architecture in
which sand and/or foreign spicule
debris partly or completely replace native
spicules within the sponge skeleton.
Areolate
The surface has many circular ectosomal
features, e.g. Hamigera.
Ascending fibre
A synonym for a primary fibre.
Asconoid
Simple tubular body-plan, without folding
of the body wall, and with the central
cavity (atrium) lined by choanocyte
chambers: a single osculum at the apex
(characteristic of primitive Calcarea,
also seen in a few homoscleromorph
demosponges), (et. syconoid, leuconoid).
Aspicular
No spicules.
Aster
Star-like microsclere with more than
two rays radiating from a central point.
Asterose
Star-like.
Astrorhizae
Refers to surface excurrent canal pattems
seen in sclerosponges: appear as
radiating or star-shaped grooves.
Atrium
Central exhalant water cavity leading to
one or more exhalant canals (oscula):
also known incorrectly as cloaca.
Autotrophic
Self-sustaining (cL heterotrophic).
Auxiliary spicules
Referring to second and third categories
of megascleres, other than the structural
or 'principal' megascleres, usually
found outside the fibres, dispersed
between tracts or on the surface: