174
Fig. 2.16 Ovicell anatomy in Tegella unicornis (decalcifi ed specimens). Longitudinal section of hyperstomial acleithral ovicell with
early embryo ( A ), and ovicell without an embryo, the ooecium
slightly folded ( B ). Arrows indicate ooecial communication pore
plugged by non-specialized epithelial cells ( A , B ) and coelomic cavity
of ooecium ( A ) (From Ostrovsky et al. 2009a , courtesy of Springer
Verlag, http://link.springer.com/article/10.1007/s00435-008-0070-8 ).
Abbreviations: av avicularium, bc brood cavity, cr cryptocyst, dz
distal zooid, е embryo, ес ectooecium, en entooecium, fm frontal
membranous wall, m muscle strands of ooecial vesicle, mz maternal
zooid, oc ooecial coelom, of ovicell fl oor, op operculum, sc sclerite of
ooecial vesicle, tw transverse wall, v ooecial vesicle, vw vertical wall
between coelomic cavities of ooecium and avicularium. Scale bars:
A , B , 20 μm
2 Cheilostome Brood Chambers: Structure, Formation, Evolution
Fig. 2.16 Ovicell anatomy in Tegella unicornis (decalcifi ed specimens). Longitudinal section of hyperstomial acleithral ovicell with
early embryo ( A ), and ovicell without an embryo, the ooecium
slightly folded ( B ). Arrows indicate ooecial communication pore
plugged by non-specialized epithelial cells ( A , B ) and coelomic cavity
of ooecium ( A ) (From Ostrovsky et al. 2009a , courtesy of Springer
Verlag, http://link.springer.com/article/10.1007/s00435-008-0070-8 ).
Abbreviations: av avicularium, bc brood cavity, cr cryptocyst, dz
distal zooid, е embryo, ес ectooecium, en entooecium, fm frontal
membranous wall, m muscle strands of ooecial vesicle, mz maternal
zooid, oc ooecial coelom, of ovicell fl oor, op operculum, sc sclerite of
ooecial vesicle, tw transverse wall, v ooecial vesicle, vw vertical wall
between coelomic cavities of ooecium and avicularium. Scale bars:
A , B , 20 μm
2 Cheilostome Brood Chambers: Structure, Formation, Evolution