Smittina isabelae, Souto, Javier, Berning, Björn & Ostrovsky, Andrew N., 2016

Souto, Javier, Berning, Björn & Ostrovsky, Andrew N., 2016, Systematics and diversity of deep-water Cheilostomata (Bryozoa) from Galicia Bank (NE Atlantic), Zootaxa 4067 (4), pp. 401-459 : 438-439

Smittina isabelae n. sp.

( Figs 91–94 , Table 16 )

Material examined. Holotype: MNCN 25.03/3963, locality DR09. Paratypes: MNHN IB- 2013-630, locality DW111.

Etymology. Honorific for the first author's mother, Maria Isabel Derungs-Cachaza.

Description. Colony encrusting, unilaminar, forming small whitish patch. Autozooids oval to rhomboidal, frontal shield slightly convex and granular, with evenly distributed small round pseudopores except for central suboral area, surface between pseudopores a meshwork of low loose ridges; lateral zooidal walls well developed with 2–3 uniporous septula per lateral wall. Primary orifice oval, longer than wide, broadest at mid-distance; lyrula anvil-shaped, one quarter of total orifice length, condyles acicular, proximomedially directed. Peristome thin- or thick-walled depending on age of zooid, developed around proximolateral orificial margin, incomplete distally where 4–6 oral-spine bases occur.

Ovicell hyperstomial, ooecium formed by distal zooid, globular, about as wide as long, ectooecium with numerous small round pseudopores, each with slightly raised rim, proximal margin overarching distal part of orifice, proximolateral edges abutting lateral peristomial margins.

Avicularia absent. Ancestrula not observed.

SD, standard deviation; N, number of measurements

Remarks. Although the globally occurring genus Smittina is extremely speciose, few species have been described from deep waters in the Lusitanian Province (sensu Spalding et al. 2007). Smittina crystallina (Norman, 1867) was recovered from the edge of the continental shelf from the Bay of Biscay (Hayward & Ryland 1978), Galicia (Soto-García et al. 2002) and Portugal (Hayward 1979) to about 800 m depth. Smittina jordii Reverter-Gil & Fernández-Pulpeiro, 1999 a was described from the NW Iberian peninsula at 594 m and was later recorded from Portugal at 450–1050 m by Souto et al. (2014). Both species are clearly different from Smittina isabelae n. sp. in having, among other distinctive features, a suboral avicularium, fewer oral spines (two if present at all) and a more uniform distribution of pseudopores on the frontal shield.

Species in the genus Prenantia Gautier, 1962 , which are occasionally treated as synonymous with Smittina , also lack the suboral avicularium. These Atlantic-Mediterranean species [ P. cheilostoma (Manzoni, 1870) , P. inerma (Calvet, 1906) ] are, however, also characterised by the absence of oral spines.

Only two colonies were recorded from two different localities at 685 and 779 m depth, both encrusting a rock.

Figures

FIGURES 91 – 94. Smittina isabelae n. sp. (holotype): 91, general view of colony fragment; 92, general view of several autozooids; 93, autozooidal orifice; 94, distal part of autozooid with ovicell.

Tables

TABLE 16. Measurements (in mm) of Smittina isabelae n. sp.

	Mean	SD	Minimum	Maximum	N
Avicularium frontal area length	0.714	0.0515	0.573	0.772	12
Avicularium frontal area width	0.519	0.0653	0.411	0.618	12
Orifice length	0.159	0.0168	0.132	0.176	6
Orifice width	0.138	0.0118	0.119	0.153	6
Ooecium length	0.242	0.0066	0.235	0.248	3
Ooecium width	0.271	0.0055	0.267	0.277	3