Domosclerus

Matsuyama, Kei, Janssen, Annika, Arbizu, Pedro Martínez, Martha, Silviu O. & Freiwald, André, 2014, Bryozoans from RV Sonne deep-sea cruises SO 167 ‘ Louisville’ and SO 205 ‘ Mangan’, Zootaxa 3856 (1), pp. 100-116 : 108

Domosclerus sp.

( Fig. 5 , C–E)

Material examined. SMF 15004, SO 205 Stn 61, 13.174° N – 3.194° N, 118.106° W – 118.0953° W, Equatorial East Pacific, 3996–4007 m, collected 16 May 2010. Not bleached.

Description. Colony erect, only a single branch of 3.8 mm length in collection ( Fig. 5 , C). Zooids alternating, showing a bark-like surface. Lateral suture forming a curved zigzag line from avicularium to avicularium ( Fig. 5 , D). Proximolaterally, 2 pairs of large pores directly distal to orifice of proximal zooid ( Fig. 5 , D), opening in distolateral direction; a few tiny pores along the lateral suture. Proximal peristomial rim projecting, thick, concealing inner orifice. Median suture weakly carinate. Lateral-oral avicularia tiny, circular, at corners of orifice, with small mandibular pivots that do not touch. Fertile zooids not observed.

Measurements.

Zooid length 732–808 µm, σ = 36 µm, N = 6; width 422–428 µm, σ = 5 µm, N = 3

Avicularium length 42–56 µm, σ = 4 µm, N = 8; width 45–58 µm, σ = 4 µm, N = 8.

Remarks. This species is most similar to Domosclerus edulis Gordon, 1993 . Differences include the absence of lateral avicularia and narrower zooids. The bark-like surface might be the result of a granular, striated texturing of the frontal shield in more proximal, ephebic zooids. As this specimen is very small and lacks ooecia, a species attribution is not possible.

Figures

FIGURE 5. A – B, F – H, Bifaxaria submucronata Busk, 1884. A, frontal view of stem fragment. B, lateral view. F, orificial area, frontal view. G, close-up of oral avicularium. H, underside of concealed costal shield. C – E, Domosclerus sp. C, lateral view of stem fragment. D, single zooid and neighbours. E, orificial area. Scale bars: A – C, 1 mm; D, 300 Μm; E – F, H, 100 Μm; G, 30 Μm.