Membranicellaria balanyai, Figuerola & Gordon & Cristobo, 2018

Figuerola, Blanca, Gordon, Dennis P. & Cristobo, Javier, 2018, New deep Cheilostomata (Bryozoa) species from the Southwestern Atlantic: shedding light in the dark, Zootaxa 4375 (2), pp. 211-249 : 214-216

Membranicellaria balanyai n. sp.

( FIg. 2A–F ; TAbLE 3)

Etymology. NAMED AFTER THE gENETICIST DR JOAN BALANYà, UNCLE OF THE FIRST AUTHOR, IN RECOgNITION OF HIS SCIENTIFIC CONTRIbUTIONS.

Material examined. HΟlΟtype: CRBA-58264, STN PAT0209DR04 (SAMPLE COATED WITH gOLD), FRAgMENT 10 MM LONg, 7 MM WIDE. Paratypes: CRBA-58265, STN PAT1108DR06 (SAMPLE COATED WITH gOLD), FRAgMENT 10 MM LONg, 9 MM WIDE, CRBA-58246, STN PAT1208DR05, FRAgMENT 45 MM LONg, 14 MM WIDE. CRBA-58247, STN PAT1108DR05, FRAgMENT 15 MM LONg, 8 MM WIDE. ALL TYPE SPECIMENS LACKINg DISTAL COLONY PORTIONS. Other: SEM MICROgRAPHS OF NHMUK 1887.12.9.438, LECTOTYPE OF Membranicellaria dubia (BUSK, 1884).

Description. COLONY ERECT, bILAMINAR, bRANCHINg IRREgULARLY, DEVELOPINg bROAD, FLAT LObES, ATTACHED bY CUTICULAR RHIZOIDS; OVERALL SIZE NOT KNOWN. AUTOZOOIDS qUADRANgULAR TO HEXAgONAL, SEPARATED bY RAISED MARgINS; MEMbRANOUS FRONTAL WALL UNDERLAIN bY A THICKLY CALCIFIED CONCAVE CRYPTOCYST; OPESIA OVAL, SITUATED IN THE CENTRE OF THE CRYPTOCYST AND EqUIVALENT TO HALF TOTAL LENgTH OF A ZOOID OR MORE; VERTICAL WALLS WITH LARgE MULTIPOROUS SEPTULA. SMALL KENOZOOIDS WITH REDUCED OPESIAE. ELONgATE AVICULARIA WITH ELONgATED ROUNDED ROSTRUM, DISTRIbUTED ALONg COLONY EDgES; PALATE WITH AN ELONgATE OVAL OPESIA AND STOUT MANDIbULAR PIVOTS. OVICELLS AbSENT IN THE AVAILAbLE MATERIAL.

n, number of measurements made; SD, standard deviation Remarks. Membranicellaria balanyai n. sp. REPRESENTS THE THIRD KNOWN SPECIES OF THE gENUS. SCANNINg ELECTRON MICROgRAPHS OF THE LECTOTYPE OF M. dubia (BUSK, 1884), PROVIDED bY MARY SPENCER JONES (NATURAL HISTORY MUSEUM, LONDON, NHMUK) CLARIFIES THE DISTINCTNESS OF OUR NEW SPECIES ( FIg. 2G–H , TAbLE 4).

BUSK'S LECTOTYPE SPECIMEN OF M. dubia WAS COLLECTED FROM A DEEP-SEA STATION OFF THE PATAgONIAN SHELF AT 37°S. BOTH LEVINSEN (1909) AND HAYWARD & WINSTON (2011) ILLUSTRATED OVICELLATE ZOOIDS OF THE LECTOTYPE bY LINE DRAWINgS, SHOWINg THE OPENINg OF THE OVICELL TO bE ‘TRIFOLIATE’. THIS SHAPE IS NOT EVIDENT IN FIg. 2G AND WE ASSUME THAT A SLIgHTLY DISTAL TILTINg MIgHT bETTER SHOW OR ENHANCE IT. M. balanyai n. sp. DIFFERS FROM M. dubia IN LACKINg THE DISTINCTLY RAISED RIMS DEFININg ZOOIDAL AND OPESIAL MARgINS, AND THE AVICULARIUM HAS A LONgER, SUbHASTATE ROSTRUM AND SHORTER MANDIbULAR PIVOTS, COMPARED TO THE LINgULATE ROSTRUM WITH LONgER PIVOTS OF M. dubia . MEAN ZOOIDAL AND OPESIAL SIZES ARE ALSO gREATER IN M. balanyai THAN IN M. dubia . M. pellucens DE BLAUWE & GORDON, 2014 FROM EASTERN WEDDELL SEA HAS HYALINE ZOOIDS THAT ARE PROPORTIONATELY LONgER THAN IN THE OTHER TWO SPECIES AND THE CRYPTOCYST OF M. dubia IS MUCH MORE DENSELY gRANULAR THAN IN M. pellucens .

Figures

FIGURE 2. A–F, Membranicellaria balanyai n. sp., HOLOTYPE. A, PORTION OF A COLONY EDGED WITH KENOZOOIDS; B, GROUP OF AUTOZOOIDS; C, GROUP OF AUTOZOOIDS WITH AN AVICULARIUM; D, DETAIL OF THE MARGINAL AVICULARIUM; E, DETAIL OF A MARGINAL AVICULARIUM WITH SEMI-ELLIPTICAL ROSTRUM;F, VERTICAL WALL OF ZOOID WITH A LARGE MULTIPOROUS SEPTULUM.G–H, Membranicellaria dubia (BUSK, 1884), LECTOTYPE NHMUK 1887.12.9.438. G, OVICELLS; H, DETAIL OF AN AVICULARIUM WITH SEMI-ELLIPTICAL ROSTRUM. SCALE bARS:A, 1 MM; B–F, 500 ΜM;G–H, 100 ΜM.