Cradoscrupocellaria galapagensis, 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 : 23-26

Cradoscrupocellaria galapagensis n. sp.

( Fig. 10 , Table 3)

Scrupocellaria bertholletii (Audouin) : Hastings 1930: 703 (in part), pl. 1, fig. 3 (non figs 1, 2, 4, 5). [Galapagos Islands]

Not Acamarchis Bertholletii Audouin, 1826: 241 . [ Egypt]

Material examined. Holotype. NHMUK 2010.12 .6.3 ( Fig. 10 ), Scrupocellaria bertholletii, A.B. Hastings det., 25 July1924, St George Collection , Galapagos 1, Specimen 42S, James Island , James Bay, Galapagos . Paratypes. NHMUK 1924.4 .26.243, Scrupocellaria bertholletii, A.B. Hastings det., St George Collection, Galapagos 8, Specimen 3H . NHMUK 1924.4 .26.17, same data as the holotype . NHMUK 1924.4 .26.286, same data as the holotype . NHMUK 1924.4 .26.20, Scrupocellaria bertholletii, A.B. Hastings det., St George Collection, Galapagos 11, Specimen 36D 1 (figured by Hastings 1930, pl. 1, fig. 3) and Specimen 36D 2, Tagus Cove, 12 fms (22 m) .

Type locality. Galapagos Islands .

Etymology. Alluding to the type locality.

1 NHMUK 2010.12 .6.3, Galapagos. 2 NHMUK 2010.12 .6.4, Gorgona , Colombia . 3 NHMUK 1929.4 .26.25, Galapagos. 4 NHMUK 2010.12 .6.16, Cape Verde . 5 AMNH (Unregistered specimens), same data as holotype, Jamaica .

Diagnosis. Chitinous joints passing across proximal end of opesia in both outer zooids at bifurcation (zooids C and D); zooids with 3 inner and 4 outer distal spines; scutum slender, branched 3 times and with 8–15 acute points; large distolateral avicularium on each zooid; dimorphic frontal avicularium with triangular mandible, obliquely directed along axis of internode; ooecium globular, with deep proximal border and several rounded pseudopores.

Description. Colony erect, highly branched, with branches of 7–11 zooids. Internodes robust with curved outlines, zooids alternating slightly back to back; acute bifurcating pattern with new branches directed slightly inwards; chitinous joints passing across proximal end of opesia and cryptocyst in outer zooids at bifurcation (zooids C and D), and across proximal gymnocyst of inner zooids (F and G). Autozooids elongate, subrectangular, slightly narrower proximally than distally. Oval opesia occupying almost entire zooid length; cryptocyst smooth, deep, forming a wide and conspicuous strip around opesia. Scutum slender, inserted at midline of inner opesial border, branched 3–4 times with 8–15 (often 8–10) acute points, covering almost entire frontal membrane. Distal spines straight and long, unbranched; 3 inner and 4 outer distal spines; axial zooid with 7 spines. One conspicuous distolateral avicularium present in each zooid, laterally directed, rostrum triangular, 0.060 –0.077 mm long, with serrated lateral edge and slightly hooked tip. Frontal avicularia dimorphic: a small frontal avicularium with triangular rostrum; a large frontal avicularium with triangular serrated rostrum, oblique to axis. A vibracular chamber present on basal surface of each zooid, inconspicuous in frontal view; vibraculum trapezoidal, occupying a third of basal surface, with rhizoidal foramen on its proximal outer corner; setal groove transverse to internode axis, with smooth seta twice autozooidal length. Single axial vibraculum, almost triangular, without rhizoidal foramen. Rhizoids tubular and smooth. Ovicells globular, deeper proximally than distally, with ectooecium perforated by several rounded pores; ovicelled zooids with 2 inner and 3 outer spines.

Remarks. Hastings (1930) reported Scrupocellaria bertholletii from the Pacific (Gorgona Island and Galapagos) and noted variable morphology among the specimens. Despite the differences noted by her—scuta, frontal avicularia and zooid shape—the Pacific specimens have shared characteristics, such as the shape and size of the basal vibraculum, lateral avicularium and ovicells. Among Hastings’s specimens deposited at NHMUK were three distinct species: specimens with highly branched scuta (specimen 36D, from Galapagos, see Hastings 1930, p. 703) are described as Cradoscrupocellaria galapagensis n. sp. ( Fig. 10 ), while specimens with slender zooids and less-branched scuta, from Gorgona and Galapagos, comprise two distinct species, Cradoscrupocellaria gorgonensis n. sp. (see below, Fig. 11 ), with the scutum bifurcated twice, and Cradoscrupocellaria hastingsae n. sp. (see below, Fig. 12 ), with forked scutum (sometimes absent) and robust dimorphic avicularia.

Distribution. Pacific Ocean: James Island and Tagus Cove, Galapagos Islands.

Figures

FIGURE 10. Cradoscrupocellaria galapagensis n. sp. A–F, NHMUK 2010.12.6.3, holotype, Galapagos. A, Frontal surface of colony. B, Frontal surface of branch bifurcation with ovicelled zooids. C, Close-up of a branch; note two ovicelled zooids at left. D, Close-up of ovicelled zooids; note the wide periopesial cryptocyst and dimorphic frontal avicularia. E, Abfrontal surface of colony. F, Abfrontal surface of branch bifurcation.

FIGURE 11. Cradoscrupocellaria gorgonensis n. sp. A–F, NHMUK 2010.12.6.4, holotype, Gorgona. A, Frontal surface of colony. B, Frontal surface of two branches with ovicelled zooids. C, Close-up of a branch; note the frontal avicularium with curved rostrum. D, Close-up of frontal avicularium; note the serrated rostrum, hooked distally. E, Abfrontal surface of colony. F, Abfrontal surface of branch bifurcation.

FIGURE 12. Cradoscrupocellaria hastingsae n. sp. A–F, NHMUK 2010.12.6.8, holotype, Galapagos. A, Frontal surface of colony. B, Frontal surface of branch bifurcation; note the joints passing across opesia in outer zooids at bifurcation. C, Close-up of a branch; note one zooid without scutum and three distalmost zooids with forked scutum. D, Close-up of zooid; note the absence of a scutum and the gigantic frontal avicularium. E, Abfrontal surface of colony. F, Abfrontal surface of branch bifurcation.