Fenestrulina juani, Souto, Javier, Reverter-Gil, Oscar & Fernández-Pulpeiro, Eugenio, 2010

Souto, Javier, Reverter-Gil, Oscar & Fernández-Pulpeiro, Eugenio, 2010, Bryozoa from detritic bottoms in the Menorca Channel (Balearic Islands, western Mediterranean), with notes on the genus Cribellopora, Zootaxa 2536, pp. 36-52 : 43-45

Fenestrulina juani n. sp.

( Figs 13–19 ; Table 4)

Material examined. Holotype: MNCN-25.03/3822: Stn P2, 39.77571º N, 3.49746º E, 01/03/2009, 57.4 m. Paratypes: MNCN-25.03/3821, 3823, 3824: Stn P2, 39.77571º N, 3.49746º E, 01/03/2009, 57.4 m (4 colonies). MNHN-10382: Gautier Collection: Stn B10, “Prof Lac Duth”, June 1952, Îles Baléares, 2 ancestrulae and first autozooid, with the holotype of Cribellopora simplex ( Gautier, 1957) .

Diagnosis. Colony encrusting. Zooids with pseudostellate pores in one marginal row and about 20 in a triangular area between orifice and ascopore. Articulated oral spines present, the proximolateral pair bifurcate. Ascopore with a proximal well-developed ligula. Ovicell covered with thick, rounded nodules.

Etymology. This species is dedicated to Mr Juan Fernández Taboada, son of E.F.-P.

Description. Colony encrusting, unilaminar, forming irregular crusts, whitish-grey in preserved material. Autozooids hexagonal to rounded-rhomboidal, in alternating series separated by distinct grooves. Frontal shield convex, rough, covered by fine ridges, giving the aspect of “hammered metal”. Primary orifice Dshaped, wider than long. Articulated oral spines 3 in the zone of astogenetic repetition, the middle one simple, the proximolateral pair bifurcate, the distal tine slightly longer than the proximal one; post-ancestrula zooid with 6 oral spines, the proximal pair bifurcate. Ascopore in centre of zooid, surrounded by a rim with raised edge, especially proximally; opening crescentic, with delicate denticulations. Pseudopores pseudostellate, with 3–5 (often 4) radii, these not joined in the centre; deeply immersed, comprising 1 marginal row and 2 rows in the distal half, these sometimes occluded by secondary calcification; about 20 pores in a triangular area between the orifice and the ascopore. Two distolateral depressions separated by a mid-distal spine, each one with 2–3 pores; the depressions more separated in ovicellate zooids. Large basal pore-chambers present. Ovicell globular, prominent, surrounded by a single series of marginal pores; initially smooth, but soon covered by thick, rounded nodules, irregularly arranged. Ancestrula tatiform, with 9 peripheral spines. Daughter zooid budded mid-distally, small.

Mean SD Minimum Maximum N Autozooid length 0.589 0.0686 0.469 0.765 20 Autozooid width 0.360 0.0403 0.306 0.439 20 Primary orifice height 0.087 0.0116 0.071 0.112 20 Primary orifice width 0.137 0.0112 0.122 0.163 20 Distance Asc–Orif 0.167 0.0141 0.143 0.194 20 Ovicell length 0.285 0.0234 0.255 0.316 6 Ovicell width 0.303 0.0187 0.286 0.337 6

SD, Standard deviation; N, number of measurements.

Remarks. No ancestrula was found in the material collected; however, in the lectotype of Cribellopora simplex Gautier , also from the Balearic Islands (see below), we found two ancestrulae with one zooid of F. juani ( Figs 18, 19 ).

Fenestrulina is a speciose genus with 60 named taxa ( Bock 2010). The majority exhibit a relatively uniform morphology, with relatively few having extremes of variability. Fenestrulina juani , however, exhibits a combination of distinctive features that are not widely distributed in the genus. For example, whereas many species have pseudopores that are either simple or stellate, those in F. juani are “pseudostellate” in that they have radii that fail to joint in the centre. Bifurcate spines are also distinctive, though not uncommon in the genus, being found in species such as Fenestrulina cervicornis Hayward & Ryland, 1990 and F. d i c t y o t a Hayward & Ryland, 1990 from the Antarctic and F. disjuncta ( Hincks, 1885) and F. littoralis Gordon, 2009 from New Zealand. A South Atlantic species attributed to F. m a l u s i i ( Audouin, 1826) by Hayward (1980) also has bifurcated proximolateral spines.

On the other hand, the ovicell of F. juani is exceptional in its verrucosity. Generally, the ovicell in Fenestrulina species globular and smooth; in some cases there are ridges, as in F. reticulata Powell, 1967 from New Zealand and especially F. rugula Hayward & Ryland, 1990 from Antarctica. The ovicell of F. juani , however, is exceptionally rugose.

Finally, Fenestrulina malusii , the type species of the genus, has subcleithral ovicells ( Ostrovsky 2008). In F. juani , however, it appears that ovicells may not be closed by the operculum, unless this is an artefact of preservation (cf. Figs 15, 16 ).

At present, six Recent and one fossil species of Fenestrulina are known in Europe, but there seems to be no obvious relationship between F. juani and any of the other species.

Figures

FIGURES 13 – 19. Fenestrulina juani n. sp. 13, view of colony (holotype); 14, young colony showing bifurcate spines (MNCN – 25.03 / 3821); 15, ovicellate and non ovicellate zooids (holotype); 16, different degrees of calcification of the ovicell (MNCN – 25.03 / 3821); 17, autozooid showing development of ascopore rim (MNCN – 25.03 / 3821); 18, 19, ancestrula and daughter zooid (MNHN – 10382).