Scrupocellaria curvata Harmer, 1926

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 : 35-37

Scrupocellaria curvata Harmer, 1926

( Figure 5 )

Scrupocellaria curvata Harmer, 1926: 380 , pl. 26, figs 11–15; Canu & Bassler, 1929: 207, pl. 8, figs 12–13. Scrupocellaria ulrichi Canu & Bassler, 1929: 208 , pl. 9, figs 1–3.

Material examined. Holotype: NHMUK 1928.3.6.187 (part, mounted in Canada Balsam), [remainder of holotype at the Zoological Museum Amsterdam ( ZMA 01063aq)] Siboga Stn 273 (299.D2), Anchorage off Pulau Djedan (Pulu Jedan), east coast of Aru Islands (Pearl Banks), Indonesia, 5.3852° S, 134.6058° E, 23–26 December 1899, 13 m. Paratypes: NHMUK 1928.3.6.186, Siboga Stn 77 (037Q), Borneo Bank, Strait of Makassar, 3.45° S, 117.60° E, 10 June 1899, 59 m; NHMUK 1928.9.13.105, Singapore, from a submarine cable, C. Stewart, Reg. 26 April 1899; NHMUK 1882.2.23.396–400, Thursday Island. Other material examined: NMNH 7889 (syntype of Scrupocellaria ulrichi ), Albatross Stn 5147, off Sulade Island, Sulu Archipelago, Philippines, 5.6944° N, 120.7861° E, 38 m (21 fms); NMNH 7890 and NHMUK 1932.9.16.22 (syntypes of Scrupocellaria ulrichi ), Albatross Stn 5478, off Tacbuc Point, E. Leyte, Philippines, 10.7733° N, 125.2750° E, 104 m (57 fms); MTQ G25340, Site 1973, Sample Id 0 31244, SBD 0 25165, Great Barrier Reef, 10.855° S, 143.125° E, 2 February 2005, 16 m; 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, 0.343–0.413 mm (0.367±0.021) long and 0.191–0.238 mm (0.229±0.017) wide, with smooth, proximal gymnocyst, approximately one quarter area of oval opesia (partially occluded by frontal avicularian cystid), cryptocyst smooth and very narrow. Scutum originating from just distal of midway along inner lateral margin of opesia, very large, oval, symmetric, convex, shield-shaped, the distal edge truncated, flaring out frontally, and sloping laterally. Orificial spines seen only in newly budded autozooids, a single spine at each distal angle of the orifice, a median spine rarely seen. Lateral avicularia very small, 0.036–0.056 mm (0.0.46±0.006) 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, hooked tip. Frontal avicularium originating proximal to cryptocystal rim, its cystid raised, developing proximolaterally around both sides of opesia, with the outer end (i.e. away from the branch midline) forming a point and the inner end developing into the avicularian rostrum; rostrum triangular, directed distolaterally, similar in shape to lateral avicularia but twice the size, the mandible triangular, curved basally with an acuminate, hooked tip. Ovicells smooth, 0.160–0.192 mm (0.178±0.011) long, 0.170–0.210 mm (0.181±0.014) wide, with approximately six circular or elongate oval pores around the distal end; ovicelled zooids sometimes with 1 outer spine. Single axial vibraculum; other very large vibracula 0.224–0.274 mm (0.240±0.017) 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.

Remarks. Scrupocellaria curvata is characterised by presence of 2–3 oral spines (1 inner, 1 outer and rarely one distal spine), its large scutum and the two types of avicularia that produce discernible cystids that curve around the zooidal opesia.

Canu & Bassler (1929) described a new species, Scrupocellaria ulrichi , from the Philippines, characterised by long vibracular chambers and short scuta. The morphology of the autozooids, avicularia and vibracular chamber of the S. ulrichi syntypes deposited in NHMUK ( Figure 5 B) and NMNH are identical to those of S. curvata ( Figure 5 A), however the scuta are not seen in these specimens, only their broken bases on the inner edge of the opesia. Their absence notwithstanding, Scrupocellaria ulrichi is here considered to be a junior synonym of S. curvata .

A new species very similar species to Scrupocellaria curvata also occurs on the Great Barrier Reef. This species is here described as Scrupocellaria peltata n. sp. ( Figure 11 ); it differs from S. curvata in having larger scuta, 4 oral spines and different avicularian cystids.

Distribution. Originally described from Indonesia, Scrupocellaria curvata has been recorded in the East Philippines ( Canu & Bassler 1929) and the Beagle Gulf, northwest of Darwin, Northern Territory, Australia ( Gordon 2009) in the Timor Sea. This species is found on both the northwestern and eastern coasts of Queensland, i.e. in the Gulf of Carpentaria and on the Great Barrier Reef.

Figures

FIGURE 5. Scrupocellaria curvata Harmer, 1926. A, NHMUK 1928.9. 13.105, part of Holotype of Scrupocellaria curvata. B, NHMUK 1932.9. 16.22, syntype of Scrupocellaria ulrichi Canu & Bassler, 1929. C – F, MTQ G 25340. A, frontal surface of brooding colony. B, frontal surface of branch; note the broken bases of scuta on the inner edge of the opesia. C, frontal surface of brooding colony. D, frontal surface of zooids showing details of scuta and lateral and frontal avicularia. E, frontal surface showing curving frontal avicularia in relation to adjacent other features. F, basal surface at branch bifurcation. Scale bars: 200 µm (A, B); 500 µm (C, E); 100 µm (D, F).

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).