Scrupocellaria peltata, Tilbrook, Kevin J. & Vieira, Leandro M., 2012

Tilbrook, Kevin J. & Vieira, Leandro M., 2012, Scrupocellaria (Bryozoa: Cheilostomata) from the Queensland coast, with the description of three new species, Zootaxa 3528, pp. 29-48 : 45-46

Scrupocellaria peltata n. sp.

( Figure 11 )

Material examined. Holotype: MTQ G25998, HI10–040, North Heron Island—Tenements 1, 23.43309° S, 151.8843° E, 21 November 2010, 16 m, coll. KJT. Other material examined: MTQ G25342, Site 813, Sample Id 0 0 0 125, SBD 0 0 1593, Great Barrier Reef, 18.635° S, 147.275° E, 18 September 2003; MTQ G26001, Gulf of Carpentaria, 15.9988° S, 139.65332° E, 4 May 2005.

Description. Autozooids at slight angle to each other, partially back to back; robust-looking, 0.503–0.642 mm (0.562±0.044) long and 0.191–0.245 mm (0.221±0.023) wide, with smooth, proximal gymnocyst, approximately one third area of opesia or longer, cryptocyst smooth, very narrow. Scutum originating from just distal of midway along inner lateral margin of opesia, very large, oval, asymmetric, convex, shield-shaped, the distal edge truncated, flaring out frontally and sloping laterally, occupying entire opesia. Orificial spines present on all zooids, 2 outer and 1 inner, a median spine often present. Lateral avicularium small, 0.055–0.075 mm (0.0.63±0.007) long, on distolateral corner of opesia in front of vibracular chamber, frontolaterally directed, the long tubular cystid originating proximolateral to opesia and hugging the opesial margin, with triangular rostrum, mandible with acuminate, slightly hooked tip. Frontal avicularium originating proximal to cryptocystal rim, its cystid slightly raised, directed distolaterally, similar in shape to lateral avicularium, the mandible triangular, curved basally with an acuminate, hooked tip. Ovicell smooth, 0.229–0.254 mm (0.241±0.010) long, 0.162–0.189 mm (0.181±0.011) wide, with several irregularly spaced circular pores; ovicelled zooids with 1 inner and 2 outer spines. Single axial vibraculum; other very large vibracula, about 0.350 mm long, triangular, projecting laterally, visible frontally, long slit-shaped setal groove directed proximomedially, seta long, exceeding four autozooids in length; a rhizoid foramen present in proximolateral wall of all lateral vibracula except for the axial vibraculum, rhizoids usually only present at base of branch.

Etymology. Latin, peltatus, armed with a shield, alluding to the large scutum.

Remarks. Scrupocellaria peltata n. sp. has up to four oral spines (typically one inner, two outer and one middistal spine) and a very large scutum that arches over the entire opesia. It is easily distinguished from Scrupocellaria curvata by its larger zooid size.

Distribution. Scrupocellaria peltata n. sp. has been found on both the west coast (southeastern Gulf of Carpentaria) and east coast (offshore of Townsville to Heron Island) of Queensland.

S. peltata n. sp. has also recently been found from Lizard Island, GBR (Tilbrook pers. obs.).

Figures

FIGURE 11. Scrupocellaria peltata n. sp. A – D, MTQ G 25998. A, frontal surface of brooding colony. B, frontal surface of zooids showing details of scuta and presence of four oral spines. C, frontal surface at branch bifurcation. D, basal surface at branch bifurcation. Scale bars: 500 µm (A, C); 100 µm (B) 200 µm (D).