Alyonushka echinata, 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: 41-43

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/521587E4-561A-552D-09EE-F8FA884FF82C

treatment provided by

Plazi

scientific name

Alyonushka echinata
status

n. sp.

Alyonushka echinata   n. sp.

( Figs 26 View FIGURE 26 , 27 View FIGURE 27 )

Material examined. Holotype: ZIRAS 1/50712, colony attached to nodule particle, YMG R.V. Yuzhmorgeologiya

cruise YMG4–13, Stn 288, 26 July 2014, 12.94712° N, 132.54418° W, 5056 m. Paratype: ZIRAS 2/50713, colony attached to particle of nodule, YMG R.V. Gelendzhik cruise GLD4–11, Stn 206, 18 April 2012, 13.47733° N, 133.02290° W, 4824 m. Total specimens examined two.

Etymology. Latin, echinatus, spiny, prickly, alluding to the minutely prickled colony surface.

Description. Colony erect, pedunculate and subcalyciform, with outwardly flaring capitulum of seven short autozooidal peristomes ( Fig. 26 View FIGURE 26 ), in single whorl. Column of more or less equal diameter to base or broadening somewhat at base, thickened, with small, shallow alveolar chambers at surface ( Fig. 26A View FIGURE 26 ). Entire external skeletal surface of colony covered by tiny minutely branching prickles ( Fig. 27K View FIGURE 27 ), except for distal part of peristomial surface where prickles are a little less complex ( Fig. 27H View FIGURE 27 ). Pores simple, most evident on outer surface of peristomial tubes ( Fig. 26C, F View FIGURE 26 ).

Surface of autozooidal peristomes with crystallites aligned into coarse, upwardly directed micro-nodules ( Fig. 27E View FIGURE 27 ); skeletal ultrastructure of generally narrow, irregular imbricated crystallites. Aperture subrounded, rim granulated or prickled, inner surface of peristomes also with simple and minutely branching prickles/spinules ( Fig. 27I, J View FIGURE 27 ).

Gonozooid ( Figs 26A –F View FIGURE 26 , 27A –D View FIGURE 27 ) occupying calyx center, large, slightly convex, with sparsely distributed tiny openings of alveoli, centrally imperforate, surrounded by irregular alveoli around periphery. Ooeciostome(s) difficult to discriminate from larger alveoli; one broken, one more evident ( Fig. 27B, F, G View FIGURE 27 ), very short with thin prickled rim, inner surface with sparse low irregularities. Ooeciopore much smaller than autozooidal apertures.

Ancestrula and very small colonies not seen.

Measurements (mm). Holotype, ZIRAS 1/50712 ( Fig 26A –C View FIGURE 26 ): Colony height 1.54; capitulum 1.02 × 0.66; base at substratum 0.41 × 0.51; ZL 0.331–0.478 (0.386 ± 0.049) (n = 7); PeL 0.144–0.303 (0.204 ± 0.059) (n = 7); PeD 0.153–0.178 (0.163 ± 0.009) (n = 7); ApL 0.121–0.153 (0.135 ± 0.013) (n = 7); ApW 0.098–0.133 (0.114 ± 0.014) (n = 7); OpD 0.044 (n = 1).

Remarks. Alyonushka echinata   n. sp. is most readily distinguished from the type species by its short peristomes with a less-barbed lineated surface texture, and the form of the gonozooid and its openings. It differs most obviously from A. hystricosa   n. sp. in that the interior walls of zooidal peristomes are prickled, not smooth.

Distribution. Recorded from two stations within coordinates 12.94712– 13.47733° N, 132.54418– 133.02290° W, at depth range 4824–5056 m.