Galiciapora unica, 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 : 448-449

Galiciapora unica n. sp.

( Figs 114–118 , Table 20 )

Material examined. Holotype: MNCN 25.03/3976, locality DR04. Paratypes: MNCN 25.03/3977, locality DR01; MNCN 25.03/3978, locality DR02; MNCN 25.03/3979, 3980, locality DR03; OLL 2015/919, locality DR03; OLL 2015/920, locality DR01.

Etymology. Latin unicus, only, single, alluding to the single zooids in uniserial chains.

Description. Colony encrusting, uniserial, branching at an angle of c. 40–50°. Zooids oval, large, frontal shield convex with smooth surface texture, entirely covered by about 150 pseudopores right up to prominent, widely flaring peristome, distal part of peristome not formed in ovicellate zooids; vertical walls not developed laterally, but 2 distolateral basal pore-chambers present, well-marked by raised borders, each with paired communication pores from which 1–2 zooids may be budded on either or both sides; central distal area in between has single pore through which communication with ooecium-producing distal kenozooid is established when budded. Orifice a little longer than wide, widest in distal third, anter roughly horseshoe-shaped, proximal margin with broad, shallow U-shaped sinus, condyles rather small, smooth. Peristome thick-walled, flared, with paired lateral adventitious avicularia.

Avicularia adventitious, small, paired, incorporated into lateral rim of peristome, oval in outline, rostrum semielliptical, directed distolaterally, crossbar complete, without columella, palatal foramen and postmandibular opesia rounded, the latter smaller, both with cryptocystal shelf.

Ovicell terminal, prominent; ooecium formed by flat distal kenozooid budded from distal uniporous pore chamber of maternal zooid, longer than wide; ectooecium smooth, frontally flattened with 25–30 pseudopores of variable shape and size, proximal area concave, paralleling margin of zooidal orifice, lateral margins abutting peristome.

An ancestrula not observed.

SD, standard deviation; N, number of measurements

Remarks. This species is yet another uniserial encrusting ascophoran cheilostome described from bathyal depths. As in many of the other uniserial species, and in contrast to multiserial species from shallow waters, the zooids are relatively large, the lateral walls are greatly reduced and the ooecium is formed by a distal kenozooid, not by a distal autozooid. These characters have seemingly evolved as adaptations for bathyal conditions independently in numerous clades as the uniserial growing species are distributed over different superfamilies. It is also possible that many have a long evolutionary history as it is often difficult or impossible to determine sister taxa. The systematic position of uniserial ascophorans is therefore often fairly isolated, leading to the existence of several monspecific genera [e.g. Nimbella with N. limbata Jullien & Calvet, 1903 ; Sertulipora with S. guttata Harmelin & d'Hondt, 1992 ; Cheilonellopsis with C. inflata Gordon, 2014 ; Placidoporella n. gen. with P. insperata (Jullien, 1882) ].

Sertulipora guttata was described from the Gibraltar Strait region based on four specimens designated as a holotype and three paratypes (Harmelin & d’Hondt 1992). Later, Tricart & d’Hondt (2009) indicated another paratype with the number MNHN-19792 from the Bay of Biscay. This designation is invalid because the location and specimen were not included in the original description; further, examination of the specimen showed that it is not S. guttata and could belong to the genus Galiciapora . A detailed study of the specimen is required, however, to come to a definite conclusion about its specific identity.

Galiciapora unica was found at five stations between 1138 and 1697 m depth, encrusting corals and rocks.

Figures

FIGURES 114 – 118. Galiciapora unica n. sp.: 114, general view of holotype colony; 115, autozooids and ovicellate zooids (holotype), 116, 117, general view of autozooids (respectively holotype and MNCN 25.03 / 3977); 118, distal part of autozooid with ovicell and lateral avicularia (holotype).

Tables

TABLE 20. Measurements (in mm) of Galiciapora unica n. sp.

	Mean	SD	Minimum	Maximum	N
Autozooid length	1.152	0.1372	1.024	1.349	7
Autozooid width	0.766	0.0664	0.682	0.845	7
Orifice length	0.183	0.0141	0.161	0.200	6
Orifice width	0.158	0.0158	0.138	0.182	6
Avicularium length	0.076	0.0100	0.067	0.093	5
Avicularium width	0.060	0.0069	0.053	0.070	5
Ooecium length	0.331	0.0174	0.311	0.343	3
Ooecium width	0.373	0.0078	0.368	0.382	3