Stephanotheca barrosoi, Reverter-Gil, Oscar, Souto, Javier & Fernández-Pulpeiro, Eugenio, 2012

Reverter-Gil, Oscar, Souto, Javier & Fernández-Pulpeiro, Eugenio, 2012, A new genus of Lanceoporidae (Bryozoa, Cheilostomata), Zootaxa 3339, pp. 1-29 : 7-11

Stephanotheca barrosoi n. sp.

( Figs 1, 6 , 9, 10 , 13–23 ; Table 1)

Metroperiella lepralioides (Calvet) : Barroso 1923: 251, fig. 1.

Schizomavella ambita (Waters) : Barroso 1935: 376, figs 4, 5.

Schizoporella ambita (Waters) : Gautier 1957: 210 (part or whole).

Schizomavella rudis (Manzoni) : Gautier 1962: 145 (in part: records from the Balearics). Schizomavella ochracea (Hincks) : Hayward & Thorpe 1995: 674 (in part).

Material examined. Holotype: MNCN 3829: Menorca Channel, 39º45’40’’ N, 3º32’16’’ E, 59 m, 16/03/2009. Paratype #1: MNCN 3831, Menorca Channel, Patín 25, 39.9815º N, 03.7295º E, 06/09/ 2011, 60 m. Paratype #2: MNCN 3832, Menorca Channel, Patín 37, 39.9410º N, 03.6803º E, 09/09/ 2011, 63 m. Paratype #3: MNCN 3833: Menorca Channel, Patín 40, 39.9290º N, 03.7088º E, 10/09/ 2011, 66 m. Paratype #4: NHMUK 2012.4.23.1: Menorca Channel, Patín 27, 39.8528º N, 04.0885º E, 07/09/ 2011, 50 m. Paratype #5: MNHN IB- 2009-1564: Menorca Channel, Patín 38, 39.9392º N, 03.6790º E, 10/09/ 2011, 64 m. Other Material Examined: MNHN 11152: Menorca, Coll. Gautier; MNHN 11189: Balearics, Coll. Gautier; MNHN 11191: Balearics, Coll. Gautier; NHMUK 1899.7.1.2343, 2345: Mediterranean, Coll. McAndrew. Numerous colonies collected in the Menorca Channel, 39.9822– 39.7245º N, 03.4722– 04.1055º E, 53–76 m, 02–12/09/2011.

Etymology. The species is dedicated to Mr Manuel Gerónimo Barroso, who first studied it.

Description. Colony forming irregular crusts, multilaminar. Autozooids of polygonal irregular shape, in irregularly arranged series, separated by a fine suture on raised ridges. Frontal shield slightly convex; initially smooth, but soon covered by small blunt conical nodules. Surface evenly perforated by small, circular pseudopores; marginal areolar pores only obvious in older zooids. Nodules near the orifice form a weak lateral and proximal peristomial thickening. Primary orifice elliptical, slightly wider than long. Poster a wide, rounded V shape occupying about half width of proximal border, flanked by a pair of large condyles with serrate edges. Oral spines absent. Polypide with about 12 tentacles. One suboral avicularium, inconstant, with slender, complete crossbar, and large oval palatal foramen; mandible semi-elliptical, proximally directed. Distance to proximal border of the orifice equal to avicularium length. Vicarious avicularia infrequent, similar to autozooids in shape but slightly wider, with a presumably functional polypide with about 6 tentacles, rarely with a frontal suboral avicularium similar to that in autozooids. Orifice extremely elongated; poster a wide, rounded sinus occupying nearly all the proximal border, flanked by a pair of projecting condyles with serrated edges, larger than in autozooids. Ovicell globular, from prominent to subimmersed depending on thickness of overgrowing secondary calcification, closed by zooidal operculum; central flat circular area of ectooecium with rounded, elongate or irregular pseudopores, these larger at periphery; secondary calcification of distal zooid forming a corona of prominent conical nodules almost encircling the exposed ectooecial area, incomplete and flattened proximally; proximal ovicell rim with a fine longitudinal suture of entooecium visible through ectooecium in light microscope. Primary orifice of ovicelled zooids wider than in non-ovicelled ones, with smaller sinus; concealed by inclined ovicell opening, the lateral margins of which overarch the primary orifice, extending to its proximolateral corners. Embryos orange. Uniporous septula. Ancestrula unknown.

SD, Standard deviation; N, number of measurements.

Remarks. Stephanotheca barrosoi n. sp. was first reported from the Balearic Islands by Barroso (1923, 1935), initially as Metroperiella lepralioides (Calvet in Jullien & Calvet, 1903) and later as Schizomavella ambita ( Waters, 1889) . Although Barroso’s material does not exist anymore, his descriptions and figures are clear enough as to assure it matches the present description. This species was also reported from the Balearics by Gautier (1957 as S. ambita ; 1962 as S. rudis ), the original samples of which we examined.

Stephanotheca barrosoi n. sp. is the only species of the genus that has zooids with hypertrophied orifices, here considered to be ‘primitive’ or less-derived vicarious avicularia.

Two colonies reported by Hayward & Thorpe (1995) in their redescription of S. ochracea are reported here as S. barrosoi n. sp. Both colonies come from the Mediterranean, whereas their exact location is unknown. The sample NHMUK 1899.7.1.2345 ( Figs 14, 15 ) exhibits an orifice similar to the one in the type species as well as vicarious avicularia of the same type, but there are also slight differences — the avicularia tend to form clusters, their orifice does not have parallel lateral rims but are more slender and distally converging, and constantly show a suboral avicularium; in contrast, in the type specimen of S. barrosoi only a single vicarious avicularium with a suboral avicularium was seen. This sample is provisionally labelled as S. barrosoi owing to the limited amount of material available at present.

Stephanotheca barrosoi n. sp. is known only from several stations off the Balearic Islands (Western Mediterranean).

Figures

FIGURES 1 – 8. Ovicell development in Stephanotheca. 1, communication pore between the ooecium-producing zooid and the coelomic cavity of the ooecium (arrow) (S. barrosoi n. sp.). 2, calcification of ectooecium and beginning of the calcification of entooecium (S. watersi n. sp.). 3, calcified ooecial floor (S. ochracea n. comb.). 4, developing ooecia (S. watersi n. sp.). 5, developing ooecium (S. monoecensis n. comb.). 6, central suture of the ectooecium (arrow) (S. barrosoi n. sp.). 7, complete ovicell, ooecial floor, and a partially broken ovicell showing ectooecial pseudopores (S. watersi n. sp.). 8, secondary calcification growing over the central porous area (S. monoecensis n. comb.).

FIGURES 9 – 10. Ovicell in Stephanotheca (S. barrosoi n. sp.). More information in the text. nc: nodular crown; oa: ovicell opening; pa: pseudoporous area; po: primary orifice.

FIGURES 13 – 19. Stephanotheca barrosoi n. sp. (holotype: MNCN 3829). 13, general view, with ovicells and a vicarious avicularium; 14, primary orifice. 15, autozooid with a suboral avicularium; 16, maternal zooid and ovicell; 17, vicarious avicularium; 18, vicarious avicularium with operculum. 19, vicarious avicularium with suboral avicularium.

FIGURES 20 – 23. Stephanotheca barrosoi n. sp. 20, autozooid and vicarious avicularium (MNHN 11152); 21, primary orifice and suboral avicularium (NHMUK 1899.7.1.2343); 22, primary orifice and suboral avicularium (NHMUK 1899.7.1.2345); 23, same, autozooids and vicarious avicularia with opercula.