Atlantisina lionensis Berning & Harmelin & Bader & Cibio 2017, gen. et sp. nov.
Creators: name: Berning, Björn
name: Harmelin, Jean-Georges
name: Bader, Beate
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Bryozoa
Gymnolaemata
Cheilostomatida
Atlantisinidae
Atlantisina
Atlantisina lionensis

description: Atlantisina lionensis gen. et sp. nov.
urn:lsid:zoobank.org:act: 54D46F97-6F57-41D2-9417-51DA064B3DF5
Figs 1A, 7 A–D, 8, Table 8
Diagnosis
Frontal shield with a reticulate pattern of raised ridges around polygonal depressions; orifice suborbicular, condyles short and without thickened tip; suboral region with a broad band of gymnocystal calcification forming a tall, relatively planar or slightly arched crest carrying three to five pointed mucrones of variable size and shape, the central ones shorter and vertically oriented, the two lateral ones longer and directing distolaterally; lateral walls moderately well developed, septular pores transversely oval to very elongate, area surrounding the pores reduced to absent, distal pore comparatively large, suborbicular, slightly raised relative to lateral ones; orifice margin with six oral spines. Ooecium slightly longer than wide; ectooecium relatively broad, covering about two-thirds of ooecium; exposed endooecium relatively small, imperforate, surface topography similar to that of frontal shield but with elongated depressions and steeper ridges; ooecial peristome relatively short. Ancestrula with 11 spines (four oral, seven mural).
Etymology
Named after its type locality, Lion Smt.
Material examined
Holotype
LION SMT: the ovicellate colony marked ‘H’, plus 3 smaller colonies, on a pebble of volcanic rock, Stn 36 (MNHN-IB-2014-66).
Paratypes
LION SMT: 1 coated colony, Stn 36 (MNHN-IB- 2014-67); 2 colonies on a pebble, Stn 36 (MNHN- IB- 2014-68); 7 colonies and 1 ancestrula on a pebble, Stn 36 (MNHN-IB- 2014-69).
Other material examined
LION SMT: ca 20 colonies on rocks, Stn 36 (unregistered MNHN material); 10 colonies on two pebbles, Stn 36 (OLL 2016/146).
SEINE SMT: 1 colony on limestone, Stn 43 (unregistered MNHN material).
Description
Colony encrusting, unilaminar, forming small patches and/or bi- to triserial ribbons (Fig. 7A). Zooecia roughly oval, with tapering proximal end(s) wedged in between proximal zooecia, separated by deep grooves. Frontal shield convex, surface with a reticulate pattern of raised ridges around polygonal depressions, imperforate except for a few small (although comparatively conspicuous) marginal pores faintly visible in frontal view (Fig. 1A); a tall, broad and moderately curved or planar suboral crest is formed predominantly by smooth gymnocystal calcification, sloping distolaterally and abutting proximal pair of spines, generally with two long, pointed lateral mucrones directing distolaterally that may occasionally bear tiny secondary mucrones, and one to three smaller central mucrones pointing vertically (Figs 1A, 7 B–D); lateral walls moderately well developed laterally, more extensive in distal part, lateral septular pores transversely oval to extremely elongate, area surrounding pores reduced to absent (Figs 1A, 7 B–D); distal pore comparatively large, suborbicular and slightly raised relative to lateral ones.
Orifice orbicular, widest at about mid-distance, proximal border fairly straight to slightly concave, proximal third delimited by a pair of short, blunt condyles, tips usually not thickened (Fig. 7B); distolateral margins with six thick spines arranged in two groups of three with a distinct distal gap; all six spines present in ovicellate zooids with distal pair abutting proximolateral ooecial wall and flanking ooecial aperture on both sides.
Ovicell hyperstomial, ooecium barely resting on frontal shield of distal zooid, globular, slightly longer than wide, with a very short tubular peristome opening at distal orifice margin (Figs 1A, 7 B–D); ectooecium relatively broad, covering about two-thirds of ooecium; exposed endooecium relatively small, surface topography similar to that of frontal shield but with steeper ridges delimiting smaller elongated concavities; ooecial aperture slightly taller than wide, acleithral.
Only ancestrula observed has 11 long and thin spines with four oral ones that are oriented vertically and seven mural ones that bend over opesia.
Remarks
The high morphological plasticity of the suboral crest in Atlantisina lionensis gen. et sp. nov., with a great variability in the number and shape of the mucrones occurring even within the same colony (Fig. 8), is a typical feature of this species. However, with two prominent lateral mucrones pointing in distal directions and shorter intermediate ones, the shape of the suboral crest of A. lionensis gen. et sp. nov. is in general similar to that of A. tricornis gen. et sp. nov., and also to the even larger ones in A. gorringensis gen. et sp. nov. and A. acantha gen. et sp. nov. (see below).
Ecology
The bi- to triserial colonies of Atlantisina lionensis gen. et sp. nov. were recovered from depths between 320 and 630 m, encrusting small rocks.
Distribution
The species occurs on the Lion and Seine seamounts.
description: Published as part of 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, pp. 1-51 in European Journal of Taxonomy 347 on pages 23-25, DOI: 10.5852/ejt.2017.347, http://zenodo.org/record/3832630