Cradoscrupocellaria tenuirostris ( Osburn, 1950 ) 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 : 15-18

Cradoscrupocellaria tenuirostris ( Osburn, 1950) n. comb.

( Fig. 6 , Table 2)

Scrupocellaria bertholetii var. tenuirostris Osburn, 1950: 134 , pl. 18, fig. 8, pl. 21, fig. 6. [California and Costa Rica] Material examined. Paratype. SBMNH 96148, balsam slide, Scrupocellaria bertholleti var. tenuirostris, Allan Hancock Foundation n. 32.2, R.C. Osburn Collection, Allan Hancock Pacific Expedition Station 255, 520-35, 25°31’0” N, 111°1’45” W, Gulf of California, 27 February 1936. Additional material. AMNH 1506.1, Santa Clara Point, Missin Bay, California, 18 February 1991. NHMUK 2010.10.5.1 ( Fig. 6 ), L.M. Vieira det., B. Okamura & P. Taylor leg., August 2010, San Diego, California. USNM 10344, Gulf Lower California, Angelus Bay, Mexico. USNM 10350, Gulf Lower California, San Francisquito Bay, Mexico. USNM 559191, Scrupocellaria bertholleti var. tenuirostris, R.C. Osburn Collection, University of Southern California, Corona del Mar, California, 30 December 1944, low tide. USNM 559192, balsam slide, Scrupocellaria bertholleti var. tenuirostris, R.C. Osburn Collection, University of Southern California, Allan Hancock Pacific Expedition Station 253-34. USNM 559193, balsam slide, Scrupocellaria bertholleti var. tenuirostris, R.C. Osburn Collection, Allan Hancock Pacific Expedition, Station 775-38. USNM 559194, balsam slide, Scrupocellaria bertholleti var. tenuirostris, R.C. Osburn Collection, Newport Harbor, California. USNM 10343, Scrupocellaria sp. , Gulf Lower California, Angelus Bay, Mexico. VMNH 13105, Scrupocellaria tenuirostris, Judith E. Winston det., SERC 07750, San Diego, California, 2000, L. McCann col., intertidal.

1 NHMUK 2010.10 .6.1, California, USA . 2 MZUSP 532 , São Paulo, Brazil . 3 VMNH 10403.0000, Florida, USA .

4 MNHN 15979, Recife, Brazil. 5 NHMUK 2010.12.6.2, Tortugas, USA.

Diagnosis. Chitinous joints passing across proximal opesia in zooids C and D at bifurcation; zooids with 2 inner and 2–3 outer distal spines; scutum slender, branched 3–4 times, with 8–16 acute tips; large distolateral avicularium in each zooid; dimorphic frontal avicularia with lanceolate mandibles; rhizoids with some retroussé hooks; ooecium wider than long, with several rounded pores.

Redescription. Colony erect, highly branched, branches comprising 5–9 zooids. Internodes almost straight, acute bifurcating pattern with new branches directed slightly inward; chitinous joints passing across proximal end of opesia 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 more than three-fifths of zooidal length; smooth cryptocyst reduced to very narrow strip around opesia. Slender scutum inserted at midline of inner opesial border, branched 3–4 times, with 8–16 (often 10) acute tips and covering most of frontal membrane. Distal spines slightly curved and long, unbranched; 2 inner and 2–3 outer spines, often 1 median spine; axial zooid with 5–6 distal spines. Conspicuous distolateral avicularium present in each zooid, directed laterally; rostrum triangular, 0.051 –0.070 mm long, with serrated lateral edge and slightly hooked tip. Frontal avicularia dimorphic: a small frontal avicularium with triangular rostrum; large frontal avicularium with elongate rostrum, 0.213 –0.286 mm long, raised and compressed laterally, with deep curved groove directed downward at axis of internode, between adjacent series of autozooids; mandible very long and narrow, lanceolate and curved laterally. Vibracular chamber present on basal surface of each zooid, inconspicuous in frontal view; chamber trapezoidal, with rhizoidal foramen on its proximal outer corner; setal groove transverse to internodal axis, with smooth seta longer than one autozooid length. Single axial vibraculum without rhizoidal foramen. Rhizoids tubular, with some retroussé hooks. Ovicells subglobose with abruptly deep edge, with ectooecium perforated by 15–22 medium-sized rounded pores; ovicelled zooids with 2 inner and 3 outer spines.

Remarks. Cradoscrupocellaria tenuirostris is distinguished from congeners by its unique frontal avicularia having an elongate rostrum with a lanceolate mandible directed downward along the axis. Osburn’s (1950) original description and illustration of this species differ slightly from the specimens described and figured here, including those in the R.C. Osburn Collection at USNM and SBMNH, in having wider vibracular chambers than figured by Osburn (1950, plate 21, fig. 6).

Distribution. Eastern Pacific Ocean: California to Costa Rica.

Descriptions of new taxa

Figures

FIGURE 6. Cradoscrupocellaria tenuirostris (Osburn, 1950) n. comb. A–F, NHMUK 2010.10.5.1, California. A, Frontal surface of colony. B, Frontal surface of branches; note the ovicelled zooid and lanceolate frontal avicularia in right branch. C, Frontal surface of branch; note two ovicelled zooid and two lanceolate frontal avicularia, characteristic of this species. D, Close-up of lanceolate frontal avicularium. E, Abfrontal surface of colony. F, Abfrontal surface of branch bifurcation.