Abyssoecia elevata, Grischenko & Gordon & Melnik, 2018

Grischenko, Andrei V., Gordon, Dennis P. & Melnik, Viacheslav P., 2018, Bryozoa (Cyclostomata and Ctenostomata) from polymetallic nodules in the Russian exploration area, Clarion - Clipperton Fracture Zone, eastern Pacific Ocean-taxon novelty and implications of mining, Zootaxa 4484 (1), pp. 1-91: 25-29

publication ID

https://doi.org/10.11646/zootaxa.4484.1.1

publication LSID

lsid:zoobank.org:pub:D66524CF-9C6D-4DF4-8CA2-B2C9708CF5FD

persistent identifier

http://treatment.plazi.org/id/521587E4-562A-551B-09EE-F88F884FFBFB

treatment provided by

Plazi

scientific name

Abyssoecia elevata
status

n. sp.

Abyssoecia elevata   n. sp.

( Figs 2G, H View FIGURE 2 , 13–15 View FIGURE 13 View FIGURE 14 View FIGURE 15 )

Material examined. Holotype: ZIRAS 1/50703, colony detached from nodule, YMG R.V. Yuzhmorgeologiya cruise YMG4–13, Stn 302, 30 July 2014, 13.16460° N, 132.52885° W, 4934 m. Paratype 1: ZIRAS 2/50704, colony detached from nodule, YMG R.V. Yuzhmorgeologiya cruise YMG4–06, Stn 106, 2 September 2006, 13.26750° N, 134.51797° W, 4805 m. Paratype 2: ZIRAS 3/50705, colony attached to particle of nodule, YMG R.V. Gelendzhik cruise GLD4–09, Stn 191, 3 January 2011, 13.40957° N, 133.47513° W, 4897 m. Paratype 3: ZIRAS 4/50706, colony fragment (with gonozooid) detached from nodule, YMG R.V. Yuzhmorgeologiya cruise YMG4–13, Stn 282, 12 July 2014, 13.41580° N, 132.28818° W, 4946 m. Additional material: YMG4–04, Stn 44; YMG4–06, Stn 99; YMG4–07, Stns 129, 135; GLD4–09, Stn 196; YMG4–13, Stn 313. Total specimens examined 11.

Etymology. Latin, elevatus, raised, alluding to the elevation of colony above the substratum.

Description. Colony suberect to erect, flabellate ( Fig. 13 View FIGURE 13 ), pale lemon yellow ( Fig. 2G, H View FIGURE 2 ), supported by founding zooids and additional pillars derived from autozooids ( Figs 13B, F View FIGURE 13 , 15C –I View FIGURE 15 ); up to 5.77 mm long and 9.09 mm wide. Arcuate lateral margins of large colonies tending to curve proximad, occasionally meeting around a space or spaces, creating open calyciform shape ( Figs 2G View FIGURE 2 , 13A View FIGURE 13 ). Supportive pillars of about 4–8 connate zooids, each budded in such a way as to be bent, with proximal portion subvertical, descending towards substratum (e.g. Fig. 15F View FIGURE 15 ), and frontodistal part forming peristomial tubes (e.g. Fig. 15I View FIGURE 15 ). No kenozooids. Surface calcification of colony forming sinuous concentric striae ( Figs 13D View FIGURE 13 , 14A, E –J View FIGURE 14 ) and having fibrous (planar-spherulitic) microstructure ( Fig. 14K View FIGURE 14 ); pseudopores small, simple, sparse, evenly distributed.

Frontal surface with evenly distributed autozooidal peristomes, all obliquely inclined in direction of colony growth, generally longer towards colony margin, fully formed apertures mostly circular ( Fig.14J View FIGURE 14 ), calcified terminal diaphragms rare. New zooids budded from part of distobasal wall of preceding zooid ( Fig. 14G, H View FIGURE 14 ), hence zooids partly overlapping. Interior wall surface of imbricated foliated fabric of wedge-shaped crystallites; no spinules ( Fig. 14K View FIGURE 14 ).

Gonozooid simple, transversely reniform ( Fig. 14A View FIGURE 14 ), wedged in among autozooidal peristomes at colony margin, moderately densely pseudoporous, narrow ooeciostome directed outwards, with more or less circular ooeciopore ( Fig. 14B –E View FIGURE 14 ).

Ancestrula ( Figs 14L –N View FIGURE 14 , 15D –I, K View FIGURE 15 ), suberect, inclined at 50–60° angle to substratum. Protoecium typically flared at base, narrowing at base of peristome but no distinction in surface calcification of needle-like crystallites; peristome tending to be angled to one side ( Figs 14L View FIGURE 14 , 15H, I View FIGURE 15 ). Later daughter zooids tending to form descending outgrowths to substratum, helping to support ancestrula as colony grows; no basal kenozooids.

Measurements (mm). Holotype, ZIRAS 1/50703 ( Fig. 13A –B View FIGURE 13 ): Colony length 3.28, width 4.88, height 2.79; ZL 0.597–0.802 (0.711 ± 0.074); PeL 0.062–0.191 (0.108 ± 0.037); PeD 0.148–0.185 (0.171 ± 0.012); ApL 0.136–0.165 (0.149 ± 0.008); ApW 0.124–0.143 (0.133 ± 0.006).

Paratype 3, ZIRAS 4/50706 ( Fig. 14A –E View FIGURE 14 ): Gonozooid (n = 1): GZL 0.703; GZW 0.880; GZH 0.383; OsL 0.155; OsD 0.133; OpD 0.111.

Non-type specimen YMG4–04, Stn 44 ( Figs 14L –M View FIGURE 14 , 15G –K View FIGURE 15 ): Ancestrula (n = 1): AnH 0.903; AnPeD 0.221; AnPrL 0.247; AnPrW 0.234.

Remarks. Eleven colonies, representing a range of sizes, were isolated from the nodule samples; only one was fertile. The elevated, flabellate form of the colony is consistent, with the pillar-like supports providing stability as the colony expands.

Distribution. Recorded from 10 stations within coordinates 13.09421– 13.49873° N, 130.80695– 134.72239° W, at depth range 4787–5050 m.