Disporella calcitrapa, Winston, Judith E. & Vieira, Leandro M., 2013

Winston, Judith E. & Vieira, Leandro M., 2013, Systematics of interstitial encrusting bryozoans from southeastern Brazil, Zootaxa 3710 (2), pp. 101-146 : 104-105

Disporella calcitrapa sp. nov.

( Figs 3 , 25 B; Table 1 )

Material examined. Holotype: MZUSP 703 ( Fig. 3 ), measured specimen #3, BIOTA Stn 211. Paratypes: MZUSP 688, specimen #17, near BIOTA Stn 205, 15 m; MZUSP 689, #18 [7 colonies], near BIOTA Stn 205, 15 m; MZUSP 704, measured specimen #1, BIOTA Stn 211; VMNH 70000, measured specimen #2, BIOTA Stn 205; VMNH 70001, 1 colony, BIOTA Stn 211. Additional material: MZUSP 690, #19 [24 colonies], near BIOTA Stn 205, 15 m

Supplementary video. http://cifonauta.cebimar.usp.br/taxon/disporella-calcitrapa/ Etymology. From middle Latin, calcitrapa , caltrops, spiked weapons tossed on the ground to disable warhorses. Noun in apposition.

Diagnosis. Encrusting lichenoporid with a fan-shaped mature growth form. Distinguished from the one other interstitial species known by its different angle of branching, more densely pustulose surface and the presence of cancellae and minute spiked spinules inside zooids.

Description. Colony encrusts on interstitial sand or shell grains, sometimes curving over the edge of a grain. The settled larva metamorphoses into a primary zooid in the form of a bulb with a tubular opening. Additional tubular zooids follow, branching fanlike into several rows of zooids, the angle of branching about 90 degrees. The pustulose upper surface of the colony is reinforced by many irregular pointed tubercles. Zooid tube openings are oval to round with one to three projecting tubercles. Between zooid tubes are rounded cancellae of various sizes. Both cancellae and zooids have with internal mace-shaped calcified spinules, spiked balls of calcification raised on short pedestals. Polypides with about 8 translucent white tentacles. No colonies with gonozooids were found in our material.

Remarks. This species is similar in colony form to Disporella plumosa Winston & Håkansson, 1986 from the Florida interstitial bryozoan fauna. However, Disporella plumosa has smoother surface calcification, more fimbriate tube openings, and lacks the spikes of calcification found in the internal spaces of the Brazilian colonies. Ramalho et al. (2009) noted internal mace-shaped spinules in cancellae of Patinella tonica (Marcus, 1955) from Rio de Janeiro, but they are absent in zooid tubes as seen in Disporella calcitrapa sp. nov. ( Fig. 3 D). Disporella pila Marcus, 1955 has somewhat similar mural spinules (Ramalho et al. 2009, fig. 9D), but its circular colony form and irregularly oriented central autozooid tubes are distinct.

Distribution. São Paulo state, Brazil.

Figures

FIGURE 3. Disporella calcitrapa sp. nov.: A, colony attached to edge of sand grain. B, young colony, showing growth from primary disc and texture of calcification. C, openings of zooid tubes. D, close-up to show spiked projections (spinules) inside and between zooid tubes. Scale bars: A, C, 0.1 mm; B, D, 0.4 mm.

FIGURE 25. A, sample of sand from Stn 205; the small units on the ruler are millimeters. B, live colony of Disporella calcitrapa sp. nov. encrusting the edge of a quartz grain; tentacles are visible. C, live colony of Reptadeonella granulosa sp. nov. D – F, three frames from a digital video of Rosulapelta rosetta sp. nov., showing a lophophore tentacle curving in towards the mouth during feeding. Scale bars: B, 0.2 mm; C, 1 mm; D – F, 0.1 mm.

Tables

TABLE 1. Measurements (in mm) of Disporella calcitrapa sp. nov..

	Lz	Wz
N	16	16
Mean	0.307	0.099
SD	0.022	0.015
Min	0.270	0.072
Max	0.342	0.126