Cradoscrupocellaria arisaigensis, VIEIRA & JONES & WINSTON, 2013

VIEIRA, LEANDRO M., JONES, MARY E. SPENCER & WINSTON, JUDITH E., 2013, <p class = " HeadingRunIn " align = " left "> <strong> <em> Cradoscrupocellaria </ em>, a new bryozoan genus for <em> Scrupocellaria bertholletii </ em> (Audouin) and related species (Cheilostomata, Candidae): taxonomy, biodiversity and distribution </ strong> </ p>, Zootaxa 3707 (1), pp. 1-63 : 47-48

Cradoscrupocellaria arisaigensis n. sp.

( Fig. 24 , Table 5)

Material examined. Holotype. NHMUK 2010.12 .6.1 ( Fig. 24 ), Scrupocellaria reptans, O’Donoghue det., C.H. O’Donoghue Collection, Arisaig, Scotland, British Isles.

Type locality. Arisaig , Scotland .

Etymology. Pertaining to the locality (Arisaig).

Diagnosis. Chitinous joints passing across gymnocyst in zooids C and D at bifurcation; zooids with 6 distal spines; distalmost spine slender and shorter than outer and inner ones; scutum stout and flattened, branched 3–4 times, covering almost entire frontal membrane; no distolateral avicularia; frontal avicularia monomorphic, variable in size, with rostrum directed proximomedially; rhizoids with short-spaced retroussé hooks.

Description. Colony erect, with branches of 5–9 zooids. Internodes with alternating zooids, slightly curved; chitinous joints passing across gymnocyst in both outer (zooids C and D) and inner zooids (F and G) at bifurcation. Autozooids almost cylindrical, tapering proximally, with slightly curved outline in basal view. Oval opesia occupying half to three fifths of zooidal length; cryptocyst very narrow and inconspicuous, forming a double band of calcification around opesia. Large, stout, flattened scutum, branched 3–4 four times, inserted at midline of inner opesial border and covering almost entire frontal membrane. Distal spines long, unbranched; 6 equally spaced distal spines, with second outer spine longer and stouter than others; distalmost spine shorter than outer and inner spines; proximalmost spines directed slightly forward; axial zooid with 6 spines. Lateral avicularium absent. Frontal avicularia monomorphic with acute and slightly curved rostrum of variable size, serrated laterally, with a hooked tip; mandible triangular, hooked distally and directed forward. Vibracular chamber slightly lateral on basal surface of each zooid, sometimes conspicuous in frontal view; chamber of vibraculum almost trapezoidal, with proximal rhizoidal foramen; setal groove transverse to internode axis, straight, with smooth seta longer than one autozooid. Single axial vibraculum without rhizoidal foramen. Rhizoids tubular, with several short-spaced retroussé hooks. Ovicells not observed.

Remarks. Cradoscrupocellaria arisaigensis n. sp. resembles C. reptans in the shape of scutum and the presence of rhizoids with retroussé hooks, but differs in having longer spines, stouter frontal scuta, no distolateral avicularia and a smaller distance between rhizoidal hooks. Cradoscrupocellaria aegyptiana n. sp. is also characterized by absence of lateral avicularia, but differs from C. arisaigensis n. sp. in the shape of the frontal avicularia.

Distribution. British Isles: west coast of Scotland (Arisaig).

Figures

FIGURE 24. Cradoscrupocellaria arisaigensis n. sp. A–F, NHMUK 2010.12.6.1, holotype, Scotland. A, Frontal surface of colony; note the rhizoids with retroussé hooks. B, Frontal surface of branch bifurcation; note the well-developed frontal scutum. C, Lateral view of branch; note the absence of a lateral avicularium. D, Close-up of axial zooid; note the position of the joints in the gymnocyst of inner and outer zooids at the bifurcation. E, Abfrontal surface of colony. F, Abfrontal surface of branch bifurcation; note the rhizoids with several short-spaced retroussé hooks.