Hippomonavella brasiliensis Ramalho et al., 2009

Ramalho, Laís V. & Calliari, Lauro, 2015, Bryozoans from Rio Grande do Sul Continental Shelf, Southern Brazil, Zootaxa 3955 (4), pp. 569-587 : 580

Hippomonavella brasiliensis Ramalho et al., 2009

( Fig. 7 A–C)

Hippomonavella brasiliensis Ramalho et al., 2009: 236 , fig. 2.

Material examined. Parcel do Carpinteiro, MNRJ-1178, (fertile), MNRJ-1179, (unfertile): am24 station2, 32°09.406’S, 51°28.318’W, 31 July 2009; MNRJ-1217, am30 station 0 1, 32°14.300’S, 51°46.630’W, 25 meters depth; MNRJ-1218, am05, 32°16.894’S, 51°48.454’W, 24 meters depth, 28 March 2007.

Description. Colony unilamellar ( Fig. 7 A). Autozooids disposed in quincunx, rectangular, longer than wide (473–923 (705) µm long x 255–423 (348) µm wide). Frontal wall crenulated, imperforate except for rounded areolar pores (13-17). Orifice aproximately quadrate (109–154 (133) µm long x 127–192 (162) µm wide) with poster almost even with a pair of prominent downward condyles ( Figs. 7 A–B).

Suboral avicularium (73–91 (81) µm long) directed downwards and slightly to the side; mandible triangular, rounded at the tip; crossbar complete; two small rounded pores, one at each side of the avicularium ( Fig. 7 C).

Oecium large (182–218 (200) µm long x 254–327 (285) µm wide) almost submersed, not prominent, frontal wall perforated with small rounded pores forming one marginal line and others spread on the surface ( Fig. 7 C); opening dependent of maternal zooid orifice.

Geographic distribution. Rio de Janeiro ( Ramalho et al. 2009) and Rio Grande do Sul States (Parcel do Carpinteiro - present study).

Remarks. Comparing RS material with type material (MNRJ-073, Rio de Janeiro), the latter one has smaller autozooids (510–637 (586) µm long x 245–353 (295) µm wide), prominent and smaller oecia (127–147 (140) µm long x 157–186 (171) µm wide). Therefore, it is believed these specimens are H. brasiliensis and its distribution is expanded from Southeast to South Brazil.

Figures

FIGURE 7. Hippomonavella brasiliensis Ramalho et al. 2009 (A, B: MNRJ- 1178; C: (MNRJ- 1179). A, colony fragment with infertile zooids; B, close-up of an entire zooid; note the form of the intact orifice with condyles and an eroded suboral avicularium, and the marginal areolar-septular pores; C, close-up of a fertile zooid showing the perforate ooecium (broken), intact suboral avicularium and orifice with condyles. Scalebars: A, 500 µm; B, 100 µm; C, 50 µm.