Lycopodina nikitawimandi, Ekins & Erpenbeck & Hooper, 2020

Ekins, Merrick, Erpenbeck, Dirk & Hooper, John N. A., 2020, Carnivorous sponges from the Australian Bathyal and Abyssal zones collected during the RV Investigator 2017 Expedition, Zootaxa 4774 (1), pp. 1-159 : 141-144

Lycopodina nikitawimandi sp. nov.

Figures 27 & 28 , Tables 14 & 16

urn:lsid:zoobank.org:act:F5AAEA15-DBAF-4A21-A2B9-E336733E613D

Material examined: Holotype QM G337534 off Freycinet Peninsular , Tasman Sea, Station 11, Tasmania, Australia, 41° 43’ 14.5”S, 149° 7’ 30.7” E, 2793 m, Box Corer, Coll. Merrick Ekins on RV Investigator, Cruise IN2017_ V03 , Sample 11-110.2, 19/v/2017, growing on a skeleton of a hexactinellid.

Paratypes: QM G337510 same collection details and hexactinellid skeleton as for holotype, Sample 11-110.1 ; QM G337537 same collection details and hexactinellid skeleton as holotype, Sample 11-110.3 ; QM G337549 same collection details and hexactinellid skeleton as holotype, Sample 11-110.4 ; QM G337197 same collection details as holotype but on a different hexactinellid skeleton, Sample 11-120.1 ; QM G337514 off Central New South Wales, Tasman Sea, Station 89, New South Wales, Australia, 30° 15’ 47.9”– 30° 17’ 21.5” S, 153° 51’ 31.3”– 153° 50’ 37.7” E, 4436– 4414 m, Brenke Epibenthic Sledge, Coll. Merrick Ekins on RV Investigator, Cruise IN2017_ V03 , Sample 89-129, 6/vi/2017, growing on worm tubes .

Etymology: Named for the son of the first author, Nikita Wimandi Ekins.

Distribution. Central East coast and central Tasmania, Tasman Sea, Australia, at bathyal to abyssal depths.

Description:

Growth form: This sponge is an erect stipitate sponge with filaments radiating in all directions projecting from the cylindrical stalk ( Figures 27 A , 28 C ). The body is 28 mm in length and 1–2 mm in width. The filaments are 2–3 mm in length and between 50–250 µm in width, and cover approximately 80% of the upper stem. The sponge has a spherical basal region of 3 mm diameter, with protruding smaller mycalostyles ( Figure 28 F ). This basal holdfast region grows within a hard or consolidated substrate. Many specimens appear to be a 2 dimensional feather due to damage sustained during collection.

Colour: Pale cream on deck and in ethanol.

Ectosomal skeleton: The ectosomal skeleton is thin and membranous and contains the anisochelae ( Figure 28 E ).

Endosomal skeleton: The axis of the peduncle and the filaments consist of bundles of mycalostyles longitudinally arranged ( Figure 28 D ).

Megascleres: Large mycalostyles only occurring in the main axis (1040–1910 x 12–37 µm, n=132) ( Figure 27 C–D). Smaller mycalostyles consistent throughout the sponge including the filaments and basal holdfast (209–992 x 3–19 µm, n=250) ( Figure 27 E–F) (see Table 16 )

Microscleres: Palmate anisochelae with the frontal upper alae nearly fully detached from the two lateral alae, and the three lower alae nearly completely fused to each other and the fimbria, with the frontal lower alae bearing three terminal spines and each of the lateral alae with two terminal spines (9–18 µm (length) x 2–6 µm (large alae width), 3–4 µm (small alae width), n=258) ( Figure 27 B ) (see Table 16 ).

Molecular data: The 28S sequences of QM G337197 and QM G337534 are provided in the Sponge Barcoding Database under accession numbers SBD#2304, SBD#2305 respectively and the molecular difference to other congenerics displayed in Figure 3 .

Remarks: Of the 29 described species of Lycopodina six have stipitate growth form, numerous large filaments along most of the stem, an enlarged basal attachment (where known), and only simple spiculation of styles or mycalostyles as structural megascleres, and palmate anisochelae as microscleres ( Table 14 ). Lycopodina drakensis Goodwin, Berman, Downey & Hendry, 2017 , also has forceps microscleres, and the shorter mycalostyles occur in the stem and the longest ones in the filaments, the opposite of those in L. nikitawimandi sp. nov. Lycopodina lycopodium ( Levinsen, 1887) and L. occidentalis ( Lambe, 1893) have a similar distribution of short and long styles in the stem, body, filaments and basal attachment, but these are generally smaller than those of the new species, and both species also have forceps microscleres. Lycopodina robusta ( Levinsen, 1887) has significantly smaller styles and also possesses forceps, L. tendali Hestetun et al., 2017 has larger styles that are uniformly distributed and forceps, and L. vaceleti ( Van Soest & Baker, 2011) has similar mycalostyles in the stem as L. nikitawimandi sp. nov., but also has a second category of smaller styles in the filaments and body, two categories of anisochelae, one of which has a unique sigma-like shape, and forceps microscleres ( Table 14 ).

Figures

FIGURE 3. Maximum-likelihood phylogram of the DNA sequences of this study in comparison with other, published cornivorous sponges. Sequences from taxa of this study are in bold. Number at the branches are RAxML rapid bootstrap values. Numbers following the taxa are either QM registration numbers (QM G3xxxxx) or NCBI Genbank accession numbers. Scale bare are substitutions per site. Please note that the reconstruction does not represent a phylogeny as due to the variability of the 28SrRNA gene C-Region barcoding marker no unambiguous alignment is possible and clipping ambiguous sites would remove diagnostic characters for taxon distinction. The tree therefore indicates molecular differences rather than a robust phylogeny.

FIGURE 27. Lycopodina nikitawimandi sp. nov. QM G337534. A. Holotype QM G337534. B. Palmate anisochelae. C. Large mycalostyle 1. D. Magnified ends of the mycalostyle 1 illustrated in C. E. Small mycalostyle 2. F. Magnified ends of the smaller mycalostyle 2 illustrated in E.

FIGURE 28. Lycopodina nikitawimandi sp. nov. A. Preserved specimens of paratypes QM G337510 and QM G337534 still attached to the hexactinellid skeleton substrate.Arrows pointing to carnivorous sponges. B. Copepod trapped in isochelae, arrow pointing to the copepod. C. Bottlebrush body of the holotype QM G337534, showing the many filaments and the anisochelae in the ectosome. D. Close-up of the filaments branching from the stem. E. Filaments showing the ectosomal clusters of anisochelae and the underlying mycalostyles. F. Root ball and stem showing the hispid surface from the small mycalostyles.

Tables

TABLE 16. A comparison of spicule measurements (µm) between the different specimens of Lycopodina nikitawimandi sp. nov.

Specimen	Anisochelae	Large mycalostyles	Small mycalostyles
Holotype QM G337534	12.5-(15.6)-17.8 x 3.3-(4.0)-4.8, n=65	1080-(1400)-1660 x 11.9-(20.1)-33.3, n=54	476-(615)-824 x 4.4-(9.6)-17.9, n=92
Paratype QM G337510	11.0-(14.1)-16.5 x 2.8-(3.9)-4.9, n=63	1040-(1482)-1910 x 15.2-(24.4)-36.6, n=38	209-(557)-777 x 6.7-(12.3)-18.6, n=34
Paratype QM G337537	11.9-(13.7)-15.7 x 2.8-(3.7)-4.9, n=26	1130-(1387)-1650 x 14.9-(20.3)-35.7, n=15	340-(555)-650 x 7.3-(10.7)-14.9, n=37
Paratype QM G337549	10.4-(12.8)-15.6 x 2.8-(3.6)-4.9, n=29	1070-(1235)-1400 x 13.5-(21.9)-37.2, n=5	376-(512)-667 x 4.7-(10.7)-16.5, n=29
Paratype QM G337197	12.4-(14.4)-17.6 x 3.2-(4.1)-6.0, n=33	1120-(1487)-1770 x 17.9-(21.8)-28.3, n=20	331-(583)-992 x 5.0-(12.1)-17.5, n=56
Paratype QM G337514	9.3-(11.4)-13.0 x 2.1-(3.2)-3.9, n=42	-*	378-(508)-638 x 3.1-(6.8)-9.7, n=2

* Most of the specimen disappeared off the SEM stub before the measurements of the large styles, which were present, could be made.