AnimaliaNot EvaluatedacceptedspeciesAccepted

Calyssopora volcano

Grischenko, Gordon & Melnik, 2018

GBIF:9855463

0year

PROFILE

Species Profile

Habitat

Marine

Characteristics

Extant

ABOUT

Descriptions(5)

Description. Colony erect, thickly pedunculate, with autozooidal peristomes radiating outwards around periphery of capitulum (Fig. 28), up to maximum of 22 peristomes in single irregular whorl. Skeletal surface of column with weakly defined ridges and furrows, granular-tubercular (Fig. 29 A – C), with sparse pores; surface ultrastructure with irregularly arranged crystallites lacking obvious preferred growth direction (Fig. 29 H). Capitulum of submature colony infundibuliform (Fig. 30 L), bottom of funnel comprising deep alveolar chambers delimited by trabeculae (Fig. 30 O). Additional thin walls cross gaps between adjacent peristomes at colony periphery where additional autozooidal chambers develop to fill vacancies in whorl as colony expands (Figs 29 J, 30 A, I, O); some of these openings seem to represent adjacent extrazooidal spaces, their openings narrowed in mature colony (Fig. 29 B). Increasing calcification reduces openings in calyx center to expanding porous platform that serves as irregular open ‘ floor’ to gonozooid (s) (Fig. 30 O). Autozooidal peristomes in single subregular series, skeletal surface like that of column, with sparse, simple pores (Fig. 29 G) having irregular outline, tending to be in single longitudinal series on lower side (Fig. 29 L). Developing apertures slightly irregular, subrounded (Fig. 29 A, K) or having bilateral symmetry, opening obliquely outwards and downwards (Fig. 29 L). No spinules or prickles on inner surface of peristome tubes (Fig. 29 K, L). Gonozooid large and capacious (Fig. 28 A, B), 1 – 2 per mature colony (Fig. 28 C, D). Floor of gonozooid not discrete and continuous. If solo, gonozooid in center of calyx or to one side, chamber roof sloping upwards to ooeciostome (Fig. 29 A – D), resembling volcanic cone in profile, with lateral ridges and furrows and porous cancelli that are mostly on periphery of gonozooid (Fig. 29 D); ooeciopore variably elevated, subcircular to suboval (Fig. 28 A, C, E). Surface microstructure of gonozooid like that of column and zooidal peristomes, with weak imbrication of irregular crystallites (Fig. 29 H). Ancestrula not seen in isolation, but evidently erect judging from smallest (four-zooid) colony stages seen (Fig. 30 A, B). Trabeculae form in center of developing colony to support colony elevation and expansion, with extrazooidal alveolar spaces between trabeculae (Fig. 30 A, C, I, K, M, O). Measurements (mm). Holotype, ZIRAS 1 / 50714 (Fig. 28 A, B): Colony height 1.78; capitulum 2.07 × 1.98; base at substratum 0.85 × 0.93 with narrowest cross-section 0.60 × 0.64; ZL 0.591 – 0.980 (0.809 ± 0.122); PeL 0.372 – 0.597 (0.492 ± 0.069); PeD 0.137 – 0.177 (0.155 ± 0.013); ApL 0.152 – 0.185 (0.172 ± 0.011); ApW 0.128 – 0.153 (0.138 ± 0.009). Gonozooid (n = 1): GZL 0.644; GZW 0.817; OsL 0.155; OsW 0.127; OsH 0.138; OpL 0.133; OpW 0.119.