Cauloramphus spencerjonesae, Min, Bum Sik, Seo, Ji Eun, Grischenko, Andrei V. & Gordon, Dennis P., 2017

Min, Bum Sik, Seo, Ji Eun, Grischenko, Andrei V. & Gordon, Dennis P., 2017, Intertidal Bryozoa from Korea — new additions to the fauna and a new genus of Bitectiporidae (Cheilostomata) from Baengnyeong Island, Yellow Sea, Zootaxa 4226 (4), pp. 451-470 : 455-456

Cauloramphus spencerjonesae n. sp.

( Figs 6, 7 )

Cauloramphus ‘Korea Baeng. sp. 2’: Dick et al. 2013: 33, 40, 41.

Etymology. Honorific for Ms Mary Spencer Jones, Natural History Museum, London (NHMUK), in recognition of her unfailing helpfulness to bryozoologists in providing information and images of bryozoans in the NHMUK collection.

Material examined. Holotype: NIBRIV0000325932, Yeonhwa-ri , 37.9378° N, 124.6233° E, Baengnyeong Island, 27 November 2007, low tide, collected by B.S. Min and A.V. Grischenko . Paratypes: NIBRIV0000711263, same collection data as for holotype. Other material: Woosuk University collection—Baengnyeong Island: Hwadong (11 colonies), Junghwadong (65 colonies), Dumujin (110 colonies), Jinchon-ri (28 colonies), Gobongpo (1 colony), Yeonhwa-ri (173 colonies); mostly on rocky substrata, but also on plastic debris, shell and crustose coralline algae ( Clathromorphum ).

Description. Colony encrusting, unilaminar, up to 22 mm in diameter, brownish when dried. Zooids more or less elongate-oval, contiguous, arranged regularly in quincunx, the interzooidal boundaries well-defined by deep furrows. Gymnocyst confined to the steeply sloping sides and usually a slightly larger area proximally, smooth, often somewhat irregular in outline, bearing 12–20 periopesial spines; the distalmost 4–5 spines more or less erect, the remaining spines slightly curved, angled part way across opesia; bases dark. Cryptocystal rim coarsely granular inside and between the periopesial spine bases, of same width throughout. Opesia large, oval. Operculum comprising a transversely D-shaped flap at distal end of membranous frontal wall. Avicularia typically paired, fusiform in frontal view, clavate in lateral view, sometimes only one present, placed between the 2nd and 3rd, or 3rd and 4th periopesial spines on each side, the mandibular-opesial surface steeply slanted, facing laterally or proximolaterally; rostrum and mandible acute; short basal stalk of avicularium cuticular. Ooecium vestigial, comprising a small transversely arcuate structure at the distal end of maternal zooids, displacing the distal spines such that a distolateral pair is wider apart and a mid-distal one is obliterated or indents the distal margin. Communication pore areas in many small chamber-like recesses along the base of the lateral and distal walls.

Measurements. ZL, 398–569 (459) µm; ZW, 224–350 (283) µm; OpL, 300–407 (334) µm; OpW, 157–220 (191) µm.

Remarks. Cauloramphus spencerjonesae n. sp. is the second of two species from Baengnyeong Island analyzed genetically and morphologically by Dick et al. (2013). Initially, the identity of this species was unclear and it was compared with Cauloramphus variegatus ( Hincks, 1881) , which has been recorded from the northeastern Pacific from California to Alaska. Whereas Osburn (1950) considered C. variegatus probably to be synonymous with C. spinifer, Dick & Ross (1988) considered the two species to be distinct, and considered that while Osburn's description and illustration of C. spinifer appeared instead to represent C. variegatus , various previous northeastern Pacific records that Osburn listed in his synonymy of C. spinifer were either not C. spinifer or were questionably C. spinifer , but also were not C. variegatus . Dick and Ross (1988) noted that their own material from Kodiak Island , Alaska differed from Hincks’s (1881) description and illustration. Thanks to the courtesy of Mary Spencer Jones, we have been able to examine SEM images of unbleached C. variegatus from Santa Cruz , California, the type locality. Unlike both C. spinifer and the material from Baengnyeong Island here described as new, C. variegatus has a conspicuously pustulose cryptocyst and no gymnocyst, total spine number is 8–13, and the palate of the claviform avicularium is much less oblique, thus facing more frontally. Ooecia were not discernible in the images, in which skeletal details of most zooids were concealed by membranes. None of the three slides of specimens from Santa Cruz had been designated as the holotype, so we here select NHMUK 1899.5 . 1.666 from the Hincks Collection as the lectotype, and designate specimens NHMUK 1899.5 .1.665 and 667 as paralectotypes.

Distribution. Korea: Baengnyeong Island; low intertidal on hard substrata.

Figures

FIGURES 6, 7. Cauloramphus spencerjonesae n. sp., Yeonhwa-ri. 6, An unbleached zooid and neighbours with spines and avicularia (two visible); scale bar, 100 µm. 7, Bleached zooids showing bases of spines and (thin arrows) avicularia; the thick arrow indicates a vestigial ooecium with a flattened area of interior wall; scale bar, 200 µm.