A collection of hexactinellids (Porifera) from the deep South Atlantic and North Pacific: new genus, new species and new records Author Castello-Branco, Cristiana Author Collins, Allen G. Author Hajdu, Eduardo text PeerJ 2020 2020-07-09 8 e 9431 e 9431 http://dx.doi.org/10.7717/peerj.9431 journal article 10.7717/peerj.9431 6dd87e4c-4425-49d4-939e-265b2759830f PMC7354842 32714660 4624210 Advhena magnifica sp. nov. ( Figs. 8–10 ) Type Material Holotype . USNM 1424107 . Pigafetta Guyot , E of the Marianas’ Trench, Paci fi c Ocean (Deepwater Exploration of the Marianas, ‘Deep Discovery’ ROV; Cruise EX1605L1 ; 15 56 ′ 31.383 6 ″ N / 148 36 ′ 53.355 6 ″ E ), coll. R/V ‘ Okeanos Explorer ’, 2,028 m depth, 04.V.2016 . EZID : http://n 2t .net/ark:/65665/31f4b11ee-5685-4b5b-befb-58efb94b3c6c LSID: urn:lsid:zoobank.org:act:52622D46-619E-432B-9D80-77795C5FD8A7 Table 1 Comparative data for habit, anatomy, spicules and occurrence for Bolosoma spp. Data for new species presently generated. Data for previously known species gathered from the literature. All morphometric data are in micrometers (µm). n.o., not observed.

Body	Basalia	Choanosoma/Dermalia/	Microscleres	Distribution/Depth (m)
Atrialia
B. perezi sp. nov.	Fragment of	Diactines,	Diactines, 1,710–2,370 × 5–8	Discoxactines, absent	Rio Grande Rise, South Atlantic
(holotype,	sponge, massive	40–80 diam.	Hexactines, 270–830 × 5–8	Discohexasters, 70–80	Ocean/936
MNRJ 21955)	without a regular	Occasionally free	Rare pentactines	Discostauractines, 42–50
shape	diactines,	Codonhexasters, 155–175
15–20 diam.	(primary rosettes 27–43
diam.)
B. biocalum	Two fragments	Diactines,	Diactines, 900–5,000 × 6–15	Discohexactines, absent	New Caledonia/1,395–1,620
Tabachnick &	19–23 diam.	Hexactines (uncommon	Discohexasters, 61–108
Lévi (2004)	pentactines), distal actin	(primary rosettes, 7–14
(orig. descr.)	68–258 µm long, tangential	diam.)
actin 106–274 µm long,
proximal actin 258–775 µm
long; all actines 6–11 diam.
B. cavum Ijima	Vase–like shape	Diactines, up to	Hexactines, short ray 55–88	Discohexactines, absent	Sulawesi Sea, Makassar Strait/
(1927) (orig.	standing on a	50 µm thick, up	long, 7.5–11 thick near base;	Spherical holodiscohexasters,	918–1,613
descr.)	compact basal	to 7,000‒8,000	paratangential rays 180–266	113–133 diam.
disc	long	long	Hexactinoid
Occasionally	microdiscohexaster
hexactines or	(occasionally hemidisco.),
pentactines	23–38 (axial lenght), in one
case 50.
Hexactinoid codonhexaster,
152–180 diam.
B. charcoti	Holotype	Not reported	Diactines, 14–53 diam.	Toothed discohexactins,	New Caledonia/1,300–1,475
Tabachnick &	composed by a	Tauactins, uncommon	32–86 diam.
Lévi (2004)	fragment of the	Hexactines (dermal or atrial),	Discohexactines with anchors
(orig. descr.)	apical region,	distal actines 30–167 long;	(less common), 68–144
paratype	tangential actines 106–380	diam.
fragmented and	long; proximal actines,
attached to a	460–532 long
peduncle	Atrial hexactines, distal actines
30–547 long; tangential
actines 61–365; proximal
actines, 30–106; all with 7–9
diam.
B. cyanae	Pedunculated	Diactines , 8–46	Diactines, 1,200–3,800 × 8–15	Microdiscohexactines, 20–47	Loyauté Basin (New
Tabachnick &	champignon	diam.	Hexactines (dermal region),	diam.	Caledonia)/2,697–2,380
Lévi (2004)	Hexactines, distal	distal actine 65–250 long;	Macrodiscohexasters, 65–195
(orig. descr.)	actine with	tangential actines 95–470;	diam. (primary rosette,
400–600;	proximal actine 220–710 long;	10–23 diam.
tangential actine	10–17 diam.	Microdiscohexasters, 72–145
500–1,100;	Hexactines (atrial region), distal	diam.
proximal actine	actines, 110–680 long.;	Rare hemidiscohexasters,
400–1,400;	tangential actines 190–700;	same diam. of
all actines	proximal actine 40–210 long;	microdiscohexasters.
30–53 diam.	10–17 diam.

Table 1 (continued)

Body	Basalia	Choanosoma/Dermalia/ Atrialia	Microscleres	Distribution/Depth (m)
B. meridionale Tabachnick & Lévi (2004) (orig. descr.)	Pedunculated sponge with apical part in funnel form	Diactines, 8–61 diam.	Diactines , 1,300–1,900 × 7–9 Hexactines (dermal region), distal actines 53–114 long, tangential actines 99–205, proximal actine 296–486 µm; 10–17 diam. Hexactines (atrial region), distal actines 68–433; tangential actines 137–319; proximal actines 46–106; 10–17 diam.	Discohexactines, 50–72 diam. Hemidiscohexasters, 47–79 diam. (primary rosette, 7–9 diam.) Discohexactine derivates, 50–72 diam.	S–E New Caledonia/995–1,010
B. musorstomum Tabachnick & Lévi (2004) (orig. descr.)	A fragment of peduncle with an apical part	Diactines, smooth, cemented	Diactines, 1,400–1,900 × 6–8 Hexactines (dermal region), distal actine 30–190 long, tangential actines 38–410, proximal actine 46–471; 19–22 diam. Hexactines (atrial region), distal actines 68–411; tangential actines 152–274; proximal actine 30–137; 19–22 diam.	Discohexactines, 15–36 diam. Discostauractines, discotauactines and discodiactines (“amphidiscs”)	Wallis Island, New Caledonia/ 775–730
B. paradictyum ( Ijima, 1903 ) (orig. descr.)	Fungus–like body with everted atrial cavity	Diactines fused into a rigid skeleton by synapticulars.	Diactines, 2,000–8,000 × 15 Hexactines (dermal region), distal ray 45–100 long; tangential rays 150–300 long; 8–9 diam. at base Hexactines (dermal region), tangential rays 200–260 long; proximal ray 600–800 long; 8–9 diam. at base	Microdiscohexactines, 30–60 diam. Toothed microhemidiscohexasters, 30–100 diam. Toothed macrodiscohexasters, 100–240 diam. Toothed microdiscohexasters, 30–100 diam. Anchorate macrodiscohexasters, 132 diam. Anchorate macrodiscohexactines, 110–176 diam.	Sagami Bay, (Japan)/501–572
B. volsmarum Tabachnick & Lévi, 2004 (orig. descr.)	Fragment of peduncle, which carries an apical, incomplete part.	Diactines, smooth, cemented	Diactines, 1500–3200 x 8–15 µm Hexactines (dermal region), distal actines 91–228 µm long; tangential actines 182–418 µm; proximal actines 365–874 µm; 15–19 µm diam. Hexactines (atrial region), distal actines 593–737 µm; tangential actines 236–692 µm; proximal actine 38–160 µm; 15–19 µm diam.	Discohexactines, 32–65 diam. Discohexasters, 54–126 diam. (primary rosette, 11–22 diam.)	S–E New Caledonia / 825–850

Table 2 Comparative data for habit, anatomy, spicules and occurrence for Bolosominae genera. Data for new genus presently generated. Data for previously known genera gathered from the literature. n.o., not observed.

Body	Peduncle/Basalia	Choanosoma/	Microscleres	Graphiocomes/
Dermalia/Atrialia	Floricomes/
Plumicomes
Advhena gen. et	Champignon–like	Long peduncle	Diactins	Discohexasters (type	Graphiocomes
sp. nov.	inverted with	Fused diactins	Hexactins	species with two
lateral openings	Short hexactines	Rare pentactins	types of)
concentrated on	Codonhexasters
one side	Calycodiscohexasters
Amphidiscella	Cup-like	Rigid tubular	Diactins	Amphidiscs	Floricomes
Tabachnick &	peduncle	Hexactins	Staurodiscs
Lévi (1997)	Fused diactins	Paratetractins	Hexadiscs
Discohexasters
Hemidiscohexasters
Sigmatocomes
(sometimes)
Amphoreus	Thick-walled,	Short thick	Diactins	Discohexasters	n.o.
Reiswig &	funnel-shape	peduncle	Sword hexactins	Stellate- fl oricoid
Kelly (2018)	Fused diactins	(dermalia)	discohexasters
Hexactins (atrialia)	Hexasters
Oxystauraster
Bolosoma Ijima	Fungus–like body	Pedunculate	Diactins	Discohexactines	n.o.
(1904)	with a more-or-	Fused diactins	Hexactins	Hemidiscohexasters
less everted atrial	Pentactins	Discohexasters and
cavity	derivates
Caulocalyx	Cup-like	Pedunculate	Diactins	Discohexasters	Plumicomes
Schulze (1886)	Fused diactins	Pentactins
(dermalia)
Hexactins (atrialia)
Hyalostylus	Bell-like or	Long peduncle	Diactins	Sigmatomes	Floricomes
Schulze (1886)	discoidal upper	Fused diactins	Hexactins	Discohexasters
part and vast	(spherical and
atrial cavity	stellate)
Hexasters
Neocaledoniella	Fungus-like with	Long tubular	Diactins	Calycodiscohexasters	Graphiocomes
Tabachnick &	completely	peduncle	Pinular hexactins	(calycocomes)
Lévi (2004)	everted atrial	Fused diactins
cavity
Rhizophyta	Fungus-like with	Long, root-like	Diactins	Stellate discohexasters	n.o.
Shen et al.	completely	outgrowths	Pinular hexactins
(2019)	everted, laterally	peduncle	Rare pentactins
directed atrial	Fused diactins
cavity	Pentactins

Table 2 (continued)

Body	Peduncle/Basalia	Choanosoma/ Dermalia/Atrialia	Microscleres	Graphiocomes/ Floricomes/ Plumicomes
Saccocalyx Schulze (1896)	Cup-like with large atrial cavity and thin walls	Long tubular peduncle Fused diactins	Diactins Hexactins Pinular hexactins	Spirodiscohexasters Codonhexasters Drepanocomes Acanthose microxyhexactins	Plumicomes
Trachycaulus Schulze (1886)	Spherical body	Long, rigid peduncle Fused diactins	Diactins Pinular hexactins	Drepanocomes	Graphiocomes
Trychella Reiswig & Kelly (2018)	Cowbell-shape	Short hard peduncle	Diactins Hexactins Sword Hexactins (dermalia)	Amphidiscs Tetradiscs and derivates Dicasters Discohexasters Microxy diactins	Graphiocomes with helicoid terminal rays (spiroxyhexasters)
Vityaziella Tabachnick & Lévi (1997)	Cup-like	Long peduncle Fused diactins	Diactins Hexactins	Amphidiscs	Graphiocomes

Figure 8 Advhena magnifica gen. et sp. nov. holotype (USNM 1424107). (A‒D) specimen in situ; (E and F) details of specimen in ethanol (1 cm). Full-size DOI: 10.7717/peerj.9431/ fi g-8 Diagnosis Advhena magnifica sp. nov. is the only representative of Bolosominae with microscleres as discasters (480–570 m m diam.), discohexasters (55–60 m m diam.), codonstaurasters (103–160 m m diam.), discohexasters with calycocomes (138–255 m m diam.) and graphiocomes (150 m m ( N = 1); 20–33 m m primary rays’ diam.). EXTERNAL MORPHOLOGY. Pedunculate sponge characterized by mushroom-like shape (136 mm in diameter and 75 mm thick) with lateral openings concentrated on one side of the body, each one with 50 and 18 mm in diameter, and peduncle longer than 154 mm in length (broken) and 16 mm in diameter (at least four times the body size). Figure 9 Advhena magnifica sp. nov. (A) diactin; (B) detail of hexactin extremity; (C and D) pentactines; (E) discasters (discohexaster); (F and G) discohexaster; (H and I) codonhexasters (J) calydiscohexasters (partially broken); (K) graphiocome (primary rays with one of the secondary rays). Scales: (A) 250 m m; (B, H, I and J) 20 m m; (C–E) 100 m m; (F, G, J and K) 10 m m. Full-size DOI: 10.7717/peerj.9431/ fi g-9 SKELETON AND SPICULES. Peduncle with cemented diactins (1,310–2,825 × 20–60 m m) and a few short hexactins and pentactins with distal ray reduced (195–250 × 2–5 m m). Choanosomal diactins with rough ends and sometimes rudiments of actins in the middle region; 1,075–2,575 × 15–18 m m. Dermal and atrial hexactins smooth with rough ends and shorter distal ray; 300–789 × 10–18 m m, and distal ray 80–110 × 12–25 m m; rare pentactins as dermalia/atrialia (450–680 × 15–18 m m). Microscleres discasters (480–570 m m diameter); discohexasters (50–75 m m diameter); codonstaurasters (103–160 m m diameter) usually with four to six central axis and fi ve to seven secondary rays (sometimes bent over), discs with eleven teeth; calycocomes (138–255 m m diameter), and graphiocomes (150 m m ( N = 1); 20–33 m m primary rays’ diameter) with six central rays and straight and short secondary rays (maximum found 65 m m length). Figure 10 Illustration of Advhena magnifica gen. et sp. nov. microscleres. (A) Codonstauraster; (B) graphiocome (Illustrations by Nicholas Bezio). Full-size DOI: 10.7717/peerj.9431/ fi g-10 DISTRIBUTION AND ECOLOGY. Known from its type locality in the Pigafetta Guyot, east of the Mariana Trench (Paci fi c Ocean), 2028 m depth. Some video footage of likely Advhena specimens was obtained by NOAA ‘Okeanos’ expedition a year later (25 July 2017) at a locality rich in sponge diversity, dubbed the “Forest of the Weird”, as part of the Laulima O Ka Moana: Exploring Deep Monument Waters Around Johnston Atoll expedition (EX1706; on https://oceanexplorer.noaa.gov/ okeanos /explorations/ex1706/ dailyupdates/media/video/dive11-forest/forest.html). ETYMOLOGY. The speci fi c epithet is used as a noun in apposition, and refers to the species’ magni fi cent, beautiful appearance. Remarks Considering all genera of Bolosominae (see table 2), Advhena gen. nov. appears most similar to Neocaledoniella Tabachnick & Lévi (2004) , the only other bolosomine with calycocomes and graphiocomes. However, the new species has discaster, discohexaster and codonstauraster microscleres. In addition, Neocaledoniella presents heavily spined pinular hexactins, missing here. Thus, we propose a new monospeci fi c genus within Bolosominae to include Advhena magnifica gen. et sp. nov.