Baerida is an order of

sea sponges Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through ...

in the subclass of

Calcaronea Calcaronea is a Class (biology), subclass of sea sponges in the class Calcarea. They are Calcarea with the triactines and the basal system of tetractines sagittal (i.e. the rays of the spicule make unequal angles with each other), exceptionally r ...

, first described in 2000 by Radovan Borojevic, Nicole Boury-Esnault and

Jean Vacelet Jean Vacelet is a French marine biologist who specialises in the underwater fauna of the Mediterranean. After earning his licence at the Faculté des Sciences de Marseille and learning to dive in 1954, he specialised in the study of sponges at th ...

. Species of the order Baerida are leuconoid calcareous sponges with the skeleton either composed exclusively of micro-diactines, or in which microdiactines constitute exclusively or predominantly a specific sector of the skeleton, such as choano-skeleton or atrial skeleton. Large or giant spicules are frequently present in the cortical skeleton, from which they can partially or fully invade the choanoderm. In sponges with a reinforced cortex, the inhalant pores can be restricted to a sieve-like ostia-bearing region. Dagger-shaped small tetractines (pugioles) are frequently the sole skeleton of the exhalant aquiferous system. Although the skeleton may be highly reinforced by the presence of dense layers of microdiactines in a specific region, an aspicular calcareous skeleton is not.

References.

External links

* http://species-identification.org/species.php?species_group=sponges&id=12&menuentry=groepen Calcaronea Taxa named by Nicole Boury-Esnault Taxa named by Jean Vacelet {{calcarea-stub