Favosthimosia milleporoides (Calvet)

Hayward, Peter J. & Winston, Judith E., 2011, Bryozoa collected by the United States Antarctic Research Program: new taxa and new records, Journal of Natural History 45 (37 - 38), pp. 2259-2338 : 2330-2331

Favosthimosia milleporoides (Calvet)

( Figure 33 )

Cellepora milleporoides Calvet, 1909: 38 , pl. 3, figs 11–13

Osthimosia milleporoides: Rogick, 1959: 26 , pl. 4, figs 43–55; Moyano, 1966: 118; Hayward, 1995: 308, fig. 179B,C.

Material

Hero cruise 721, station 775, 62 ◦ 55.4’ to 62 ◦ 56’ S, 60 ◦ 48.2’ to 60 ◦ 48.8’ W, 91–109 m, 8 January 1972: fragment of cylindrical colony, evidently from organic substratum (hydroid stem).

Description

This distinctive species is readily recognized by its striking ovicells, which are globular with an often extensive area of entooecium exposed frontally; the distal edge of the ovicell aperture forms a flared lip, abutting the peristome proximo-laterally to define a narrow tube. A moderately large avicularium, with semicircular mandible, is situated medio-proximally, just within the peristomial tube. Typically, ovicelled zooids crowd the frontal surface of the colony and non-brooding zooids are not readily apparent. In the present material only a minority of zooids bore, or were developing, ovicells and SEM demonstrates the striking difference between the two primary orifice types, those of brooding zooids ( Figure 33C ) being half as long and half as wide as those of non-brooding zooids ( Figure 33B ).

Osthimosia chaotica López Gappa and Liuzzi was distinguished from O. milleporoides by the primary orifice, which is scarcely wider than long in ovicelled zooids, and in a curious tubercular peristome complex associated with the peristomial avicularium, and present in both brooding and non-brooding zooids

Figures

Figure 33. Favosthimosia milleporoides. (A) Primary orifice of an autozooid; (B) primary orifice of a brooding female zooid; (C) primary orifice of a brooding female zooid. Scale bars: 0.25 mm (A), 0.05 mm (B, C).