Systematics and diversity of deep-water Cheilostomata (Bryozoa) from Galicia Bank (NE Atlantic)
Author
Souto, Javier
Author
Berning, Björn
Author
Ostrovsky, Andrew N.
text
Zootaxa
2016
4067
4
401
459
journal article
46900
10.11646/zootaxa.4067.4.1
4d2bf7a6-415a-4fb2-8c8f-12b79f8a400a
1175-5326
257945
1CC5D0E7-0B60-4E62-BACD-9775931ED7F9
Porella
sp.
(
Figs 74, 75
)
Material examined.
MNCN
25.03/3955, locality DR04;
MNCN
25.03/3956, locality DR05.
FIGURES 74, 75.
Porella
sp., respectively showing part of fractured colony and zooidal orifice (MNCN 25.03/3955, 3956).
Description.
Colony encrusting, unilaminar, pluri- to multiserial, forming small patches. Zooids elongate-oval to hexagonal, often widest midlength, separated by shallow grooves or narrow ridges. Frontal shield slightly convex, producing a peristome of 2 low flaps lateral to orifice and incorporating suboral avicularium; surface nodular, imperforate except for single row of large areolar pores along zooecial margins and communication pore(s) on avicularian cystid. Orifice suborbicular, distal margin with 2 oral spines; condyles not visible, lyrula very short but almost as broad as proximal orificial margin, anvil-shaped.
Avicularium adventitious, single, suboral, small, oval, situated within peristome and directly abutting lyrula, oriented perpendicular to it.
Ovicells and ancestrula not observed.
Remarks.
Although general zooidal morphology suggests that these specimens belong to the genus
Porella
, the absence of important characters such as the ovicell compels us to leave the species in open nomenclature. Vague similarities in autozooidal morphology exist between the encrusting
Porella concinna
(Busk, 1854)
, nominally ranging from the western Mediterranean to
Norway
(Hayward & Ryland 1999, p. 160), although we cannot rule out the possibility that the encrusting colonies from Galicia Bank develop an erect colony part during astogeny. A distinctive character in the present specimens is certainly the short but extremely broad lyrula.
Porella
sp. was recovered from two stations at
1099 and
1288
m depth.