Calvetopora, Berning & Harmelin & Bader & Cibio, 2017

Berning, Björn, Harmelin, Jean-Georges & Bader, Beate, 2017, New Cheilostomata (Bryozoa) from NE Atlantic seamounts, islands, and the continental slope: evidence for deep-sea endemism, European Journal of Taxonomy 347, pp. 1-51 : 37-38

Genus Calvetopora gen. nov.

urn:lsid:zoobank.org:act:95E74E9B-013C-4E02-8E66-E71E4CD93B34

Type species

Lepralia inflata Calvet, 1906 .

Diagnosis

Colony encrusting, unilaminar, multiserial, budding intrazooidal. Zooidal frontal shield umbonuloid, perforated by several central pseudopores and a single series of pores at the zooecial margin; lateral walls moderately developed, mostly gymnocystal, two or more basal pore chambers per neighbouring zooid, septular pores relatively large, elongated oval, surrounded by cryptocystal-type calcification. Orifice D-shaped, condyles present but extremely small and invisible in perpendicular view, oral spines present. Maternal zooids slightly dimorphic, with a gap between distal pair of spines, ooecium either produced by the zooid distal to the maternal one, or formed by a kenozooid budded from the distal septular pore of the maternal zooid, hyperstomial, recumbent on the distal zooid’s frontal shield; ectooecium partially calcified or entirely membranous; endooecium entirely calcified, imperforate; not closed by operculum (acleithral). Adventitious avicularia present. Ancestrula tatiform, opesia extensive, with a constriction in distal (oral) part; gymnocyst narrow all around, cryptocyst absent.

Etymology

Named in honour of Louis Calvet, who discovered and introduced the type species, in conjunction with - pora, a common ending of bryozoan genera, alluding to their perforate frontal shields.

Remarks

Calvetopora gen. nov. shares its paired, distolateral adventitious avicularia and also its large zooids with Bathycyclopora gen. nov., the main differences being the perforated frontal shield and the absence of interzooidal avicularia in Calvetopora gen. nov. On the other hand, with most of the outer surface formed by gymnocystal calcification, and septular pores that are surrounded by cryptocyst, the lateral walls in Calvetopora gen. nov. are rather similar to those of Atlantisina gen. nov., albeit not as well developed.

Interestingly, the mode of ooecium formation differs between species of Calvetopora gen. nov. Whereas the ooecium in Calvetopora inflata gen. et comb. nov. ( Calvet, 1906) is produced by a kenozooid that is budded from the distal pore chamber of the maternal zooid, in Calvetopora otapostasis gen. et sp. nov. the ooecium is produced by the zooid distal to the maternal one (see below). Thus, Calvetopora gen. nov. combines characteristics of both Bathycyclopora gen. nov., in which the zooid distal to the maternal one produces the ooecium, and Atlantisina gen. nov., in which the maternal zooid forms a kenozooidal ooecium.

The ooecium itself may also vary between species in Calvetopora gen. nov.: while the ectooecium is entirely membranous in C. inflata gen. et comb. nov., it is partially calcified around the lower part of the ooecium in C. otapostasis gen. et sp. nov., just as in species of Atlantisina gen. nov. and Bathycyclopora gen. nov.

Interzooidal communication in species of Calvetopora gen. nov. takes place via one or two septular pores. They thus differ from species of Atlantisina gen. nov. and Bathycyclopora gen. nov., which have

a single septular pore per neighbouring zooid, whereas certain Romancheinidae (e.g., Escharoides ) also communicate via two pores with neighbouring zooids.

There is a large gap in geographic distribution between species of Calvetopora gen. nov., with C. inflata gen. et comb. nov. being reported from the Gulf of Cádiz and C. otapostasis gen. et sp. nov. from Atlantis Smt and the Great Meteor Bank. Moreover, the individual species have been recorded from a single or a few sites only. The species occur at depths of 400 to over 700 m. Owing to their large size of about one millimetre, the zooids can easily be detected even with the naked eye.