Baeria Miklucho-Maclay, 1870

Borojevic, Radovan, Boury-Esnault, Nicole & Vacelet, Jean, 2000, A revision of the supraspecific classification of the subclass Calcaronea (Porifera, class Calcarea), Zoosystema 22 (2), pp. 203-263 : 252-253

Genus Baeria Miklucho-Maclay, 1870

TYPE SPECIES. — Baeria ochotensis Miklucho-Maclay, 1870 by monotypy.

DIAGNOSIS. — Baeriidae in which the choanoskeleton consists of giant triactines and/or tetractines, lying without apparent order, and of very numerous microdiactines. A cavity equivalent to the atrium, localized only under the oscula, has a skeleton supported by tangential triactines. All the other exhalant canals have a skeleton composed of harpoon-shaped pugioles.

DESCRIPTION

In the genus Baeria we include the hitherto described species B. nivea (Grant, 1826) , B. johnstoni (Carter, 1871) , B. ochotensis Miklucho- Maclay, 1870, B. gladiator (Dendy, 1892) and B. prava (Breitfuss, 1898) , which bear a number

A B

of similarities. They all have a choanoskeleton containing numerous microdiactines (“mortar spicules”), and very large triactines or tetractines that lie scattered without any apparent order. The cortical skeleton consists of triactines and microdiactines, which are different in size and form from those in the choanosome. The atrium is always limited to the space immediately below the osculum, and the oscular area contains a dense layer of sagittal triactines. However, the exhalant canals of all sizes are devoid of a tangential skeleton and contain only pugioles ( Fig. 44 ). In Baeria johnstoni an additional type of very small tetractine is found in the choanosome.

Although Haeckel (1872) has represented the microdiactines of all these species as smooth and equally acerate on both ends, we have observed that in B. nivea and B. johnstoni the microdiactines are clearly hastate in form, with one long and one short actine, the shorter one having an angular twist close to the centre of the spicule. Dendy & Row (1913) reported that after reexamination of Haeckel’s preparations of B. ochotensis , many of microdiactines were found to have a “needle-eye” form. These correspond to tiny triactines, with two very much reduced paired actines bent to lie approximately parallel, which can be slightly swollen and fused at the end ( Fig. 45 ); such spicules can be observed in the Lithonida . Some of these spicules have their distal ends free, thus corresponding exactly to diapasons. Similar spicules are found in Kuarraphis Dendy & Row, 1913, which we place also in the Baeriida . In the original description of Kuarraphis (Leucyssa) cretacea, Haeckel (1872) indicated that the “needle-eye” spicules were found in Baeria ochotensis although they were not figured in its description.

B. johnstoni and B. nivea have previously been included in the genera Spongia , Grantia , Leucandra and Leuconia . The first three genera are now used in a different context, and the last one has been shown to be invalid (Dendy 1893; Dendy & Row 1913). The genus Baeria has been proposed previously by Dendy & Row (1913) for B. ochotensis , and the present definition of the genus is quite close to the one proposed by those authors.

Figures

FIG. 44. — Pugioles (p) in an exhalant canal (ex) of Baeria nivea (Johnston, 1842). Scale bar: 90 µm.

FIG. 45.— Diagram of pugioles and microdiactines;A, Baeria gladiator; B, Lamontia zona; C, Baeria nivea; D, Baeria ochotensis.