Verrucocoeloidea undetermined

Reiswig, Henry M. & Dohrmann, Martin, 2014, Three new species of glass sponges (Porifera: Hexactinellida) from the West Indies, and molecular phylogenetics of Euretidae and Auloplacidae (Sceptrulophora), Zoological Journal of the Linnean Society 171 (2), pp. 233-253 : 240-244

VERRUCOCOELOIDEA LIBERATORII SP. NOV.

( FIGS 4 , 5 ; TABLE 2)

Type material: Holotype: USNM 1231336 , MOV ‘ Johnson SeaLink II ’, dive 3210, 11 May 2000, Seamount , off Porto Mari Baai, south-central coast, Curacao, 12°12.853′ N, 69°05.837′ W, 220 m. Paratypes: HBOM 002 : 00027, same data ; USNM 1231337 , same data ; USNM 22339 , Johnson-Smithsonian Deep Sea Expedition, MV Caroline , stn 49, 14 Feb. 1933, north of Puerto Rico, 18°14′18″ N, 67°35′30″ W, 329 m (misidentified by M.W. de Laubenfels as Cyrtaulon sigsbeei ) ; USNM 00985 , Caribbean Islands Expedition, 1878–1879, USFS Blake, stn 158, 17 Jan. 1879, off Montserrat, 16°30′ N, 62°00′ W, 271 m (misidentified by unknown as Volvulina sigsbeei ) ; USNM 00986 , United States Coast Survey , USFS Blake, stn 22, May 1880, east of Cape Cruz, Cuba, 19°48′47″ N, 77°23′00″ W, 457 m (two specimens, misidentified by O. Schmidt as Volvulina sigsbeei ) ; MCZ 25428 , Caribbean Islands Exploration Expedition, 1878–1879, USFS Blake, stn 210, 12 Feb 1879, off Martinique, 14°29′10″ N, 61°05′47″ W, 349 m (misidentified by unknown as Volvulina sigsbeei ) ; MCZ 25429 , Caribbean Islands Exploration Expedition, 1878–1879, USFS Blake, stn 166, 21 Jan 1879, off Guadeloupe, 15°55′50″ N, 61°37′05″ W, 274 m, three specimens, unidentified ; MCZ 25436 , Caribbean Islands Exploration Expedition, 1878–1879, USFS Blake, stn 139, 17 Jan 1879, off St Croix, US Virgin Islands, 17°46′45″ N, 64°48′50″ W, 399 m, unidentified ; UWI GSN564 , RV Gosnold , stn 112/88, 26 Feb. 1968, Pedro Channel, Jamaica, 17°45.8′ N, 76°45.0′ W, 1500 m (misidentified by H.M. Reiswig as Dactylocalyx crispus ) ; UWI GSN062 & GSN1277 B, RV Gosnold , stn 97/35, 18 Mar. 1967, Morant Ridge, Jamaica, 17°54.9′ N, 76°05′ W, 420 m (misidentified by H.M. Reiswig as Dactylocalyx crispus ) .

Diagnosis: Recent Verrucocoeloidea of plicate funnel form, with external nodes markedly swollen and spined; lateral oscula distributed without order or on longitudinal ridges. Atrial ingrowths end in simple ridges with digitate upper ends or occasionally fuse with other ridges, but not forming a secondary lining of the atrium. Loose spicules include pentactine dermalia and atrialia, tyloscopules, strongyloscopules, uncinates, oxyhexasters, and discohexasters.

Description: Body form of all known specimens is basically consistent with that of the four specimens imaged in the type collection ( Fig. 4A ) and that of the holotype ( Fig. 4B ). The holotype is a small upright globular funnel or cup borne on a short stalk with tubular lateral extensions uniformly scattered and ending distally as small openings: the lateral oscula. The large terminal osculum is strongly plicate in shape ( Fig. 4B right), as distal growth conforms to the formation of lateral tubules at its margin. Some specimens are longitudinally pleated with between two and five external ridges extending from the upper end of the stalk to the osculum, separated by deep grooves almost meeting axially. In some specimens the external tubules are restricted to the ridges, and thus occur only in longitudinal series; in others, the tubules are distributed evenly on ridges and in grooves. The holotype is 46.5 mm tall, 29.9 and 32.0 mm in greatest lateral diameters, with greatest diameters of the main osculum of 15.1 and 16.8 mm; other specimens range from 15 to 60 mm in height. Lateral tubules of the holotype are 4.0– 5.5–6.5 mm (n = 23) in external diameter, 2.3–4.9– 7.5 mm (n = 14) in length, and 1.1–1.9– 2.9 mm (n = 28) in diameter of their distal oscula opening; external tubule diameters may be as small as 2.0 mm in other smaller specimens. Wall thickness is 0.55–0.92– 1.93 mm (n = 41) where ingrowth does not occur. In many areas of the atrial surface, without a clear pattern, the inner wall is extended several millimetres into the atrium as longitudinal ridges and upright stalagmite-like digital pillars ( Fig. 4B right, C), occasionally fusing, subdividing the atrial cavity, and strengthening the thin outer body wall. Both dermal and atrial surfaces are covered by a loose lattice of pentactins and occasional hexactins arranged in fairly regular quadrate meshwork. Colour of freshly collected specimens is white; after preservation, they are light orange. Symbionts of the holotype and probably all specimens include small orange to darkbrown cnidarian polyps, probably zoanthids, scattered across the external surface ( Fig. 4B and strong reflective spots in Fig. 4A ), which do not seem to be connected through the sponge by internal stolons, but a histological search for them has not been carried out. A large syllid polychaete occupies a pocket of the holotype atrial cavity. The species is widely distribut- ed throughout the Greater and Lesser Antilles ( Fig. 1 ) at depths of 271–1500 m.

The fused skeleton ( Fig. 4D ) consists of a thin primary framework overlain on all dermal surfaces and most of the atrial surface by irregular secondary cortex. Channellization is not present. The primary framework is euretoid in having dictyonalia linearly fused to form longitudinal strands with nodes aligned and beams outlining rectangular meshes ( Fig. 4E ); it is between two and four dictyonalia in thickness, and is not layered. Nodes are simple, not swollen, and most surfaces are smooth, with occasional spination on both beams and nodes (see measurements in Table 2). On some internal patches of particularly thin body wall, the primary framework is not covered by an atrial cortex. The secondary cortical layers on dermal and atrial sides are composed of dictyonalia fused irregularly forming triangular to occasional polygonal meshes ( Fig. 4F, G ). All superficial cortical nodes are conspicuously swollen and ornamented with either small spines in groups ( Fig. 4H ) or evenly distributed single conical spines ( Fig. 4I ). Subsurface cortical nodes may be only slightly swollen, but they always exhibit spined ornamentation. Beams of the cortical layers are ornament- ed with simple spines scattered over their centres, but areas adjacent to nodes are smooth. Node diameter and beam thickness of the dermal cortex are greater than those of the atrial cortex, which are, in turn, greater than those of the primary layer. Spurs are uncommon and often broken on both surfaces, but where present they are short and digitate with rounded tips ( Fig. 4H ). No oxyhexactins are appended to the framework.

Megascleres are mostly pentactins, a few hexactins, two types of scopules, and uncinates. Dermalia are pentactins ( Fig. 5A ), entirely thickly spined with nearly cylindrical tangential rays ending in slightly inflated rounded tips; a small nub is present in place of the sixth distal ray. Atrialia are mostly (99%) similar pentactins and a few (1%) hexactins with short distal rays ( Fig. 5B ); the hexactins are often less densely spined and rays are often tapered to abruptly sharp tips. Mean lengths and widths of pentactine dermalia and atrialia are 152 × 7.2 μm for tangential rays and 125 × 7.4 μm for proximal rays. Tyloscopules, 315 μm in mean total length ( Fig. 5C ), are the most abundant scopule form, particularly on the dermal side; their necks are smoothly tapered from the shaft and carry between two and six tines ending in spherical tyles with bare tops; they are entirely and densely covered with fine reclined spines. On the atrial side the tyloscopules are relatively uncommon, and those present have smaller terminal tyles. Strongylo- to subtyloscopules ( Fig. 5D ) are larger, with mean length 603 μm, uncommon, and occur in small patches, projecting from both dermal and atrial surfaces; their necks arise abruptly from the shaft heads and bear four stout tines ending as either simply rounded or slightly inflated tips with small bare apices. Reclined spines densely cover the head and tines, but spination on the shaft is sparse. Uncinates ( Fig. 5E ) are moderate in size, length 1323 μm, with welldeveloped brackets and barbs; a central swelling occurs in about half of these. All megasclere types have been found in all listed specimens, except strongylo/ subtyloscopules, which have not been found in MCZ 25436.

Microscleres consist of oxyhexasters (91.5%), discohexasters (5.5%), hemioxyhexasters (2%), onychohexasters (1%), and oxy/onychodiasters (<1%). Oxyhexasters, mean diameter 63.5 μm ( Fig. 5F ), and hemioxyhexasters are distinctive in form, being stellate and having between one and five sigmoid terminal rays curving strongly outwards; they bear fine reclined spines on all surfaces except the hooked terminal tips, and spination is less dense on primary rays. The smaller discohexasters, mean diameter 41.0 μm ( Fig. 5G ), are stellate, with between three and five similarly sigmoid terminals ending in discs with between four and eight strong marginal spines; reclined spines are very dense on terminals and sparse on primary rays. Onychohexasters ( Fig. 5H ) grade smoothly into discohexasters, and individual spicules have some terminals clearly onychoid and some clearly discoid; they are most likely to be young discohexasters that have not yet been fully developed. Diasters ( Fig. 5I ) occur with between three and six terminals either all bearing oxyoid tips or with some bearing onychoid tips, as illustrated. Special distributions have not been detected for any of these microsclere types. The complete set of microscleres have been found in all of the listed specimens.

Etymology: The species name, ‘ liberatorii ’, is formed to recognize the extensive discoveries and collections of sponges and other benthic marine organisms made by Dominic Liberatore during his long career as a submersible pilot at HBOI: he and Dr Shirley Pomponi collected the holotype and two paratypes of this new species.

Remarks: The new species is unquestionably a member of the family Euretidae by virtue of its primary framework and lack of special channellization. In body form it is similar to several species of hexactinellids in the genera Anomochone Ijima, 1927 , Cyrtaulon Schulze, 1866 , Calyptorete Okada, 1925 , Dactylocalyx , and Verrucocoeloidea ; indeed, paratypes were often misidentified as species of the first four genera. The new form is excluded from the tretodictyid genera Anomochone and Cyrtaulon because of the lack of any indication of schizorhyses and absence of the distinctive scopule-like cyrtaulon spicule. The new form differs from the single species of Calyptorete , Calyptorete ijimai Okada, 1925 , in having much smaller dermalia/ atrialia, and in having oxyhexasters, swollen surface dictyonal nodes, and ingrowth of the atrial wall. The new form differs from Dactylocalyx crispus Schmidt, 1870 in that the type series of that species is a mixture, the main and illustrated specimen of which is identical to the tretodictyid Cyrtaulon sigsbeei ( Schmidt, 1880) (pers. observ., H.M.R.). We compared the new specimen with the original description of Verrucocoeloidea burtoni Reid, 1969 and its redescription in Systema Porifera ( Reiswig & Wheeler, 2002) and two of the co-type specimens. We consider the shared characters sufficiently strong to accept placement in the same genus. Shared characters by V. burtoni and the new species include body form, which is almost identical, extension of the atrial wall framework into the atrial cavity, and their formation of secondary longitudinal structures known nowhere else in Euretidae . They also share similarity of primary framework and oxyhexaster shape, among other features. The two species differ in that V. burtoni has all dictyonal nodes simple (not swollen), dermal epirhyses (absent in the new form), discohexasters as primary microsclere (versus oxyhexasters), and much larger uncinates (up to 3.6 mm, versus 1.8 mm). Examples of all of these differences can be found between species within other genera of Euretidae . Among all Euretidae , the genus Verrucocoeloidea is by far the best placement for the new form and preferable to the erection of another new monospecific genus. This previously monospecific genus has been known only from the tropical Indopacific region (Borneo); the addition of the new West Indian species expands the generic distribution and strengthens the systematic ties between the two tropical regions. The new species, V. liberatorii sp. nov. has been long known to one of us (H.M.R.) as a common but problematic species in many institution collections under the informal name ‘the sugar candy, pillow tube down sponge’; we suggest the retention of this awkward but descriptive designation as the common name of the species.

Figures

Figure 1. Map of collection sites of new hexactinellid species. 1, Conorete pourtalesi sp. nov. from Pourtales Terrace, Florida, USA. 2, Verrucocoeloidea liberatorii sp. nov. from the following sites, counter-clockwise from the lower centre: Curaçao; Martinique; Montserrat; Guadeloupe; St. Croix; Puerto Rico; Morant Ridge, Jamaica; Pedro Channel, Jamaica; Cape Cruz, Cuba. 3, Dictyoplax lecus gen. et sp. nov. from five closely spaced sites in the Bahamas, with overlapping symbols.

Figure 4. Verrucocoeloidea liberatorii sp. nov., body and framework: A, four specimens in situ (arrowheads) at type locality prior to collection, including the holotype and two paratypes, 5–6 cm in height; bright reflective spots are zoanthid symbionts; B, the preserved holotype in side (left) and top (right) view, orange-brown spots are zoanthid symbionts; C, fragments of two paratypes, USNM 1231337 (left) and HBOM 002:00027 (right), opened to view the atrial surfaces with ingrowths; D, thin wall area between tubules, showing the overall regularity of the dictyonal framework, with the growth direction upwards; E, primary framework dissected from wall fragment, showing longitudinal strands, aligned transverse connecting beams, and simple unswollen nodes; F, cleaned framework of tubule margin of lateral osculum, showing external cortical surface with swollen nodes and internal atrial surface (below) with smaller nodes, note general lack of spurs (SEM); G, clean external body surface framework with swollen nodes (SEM); H, close-up of external framework showing nodes ornamented with groups of small spines and a few spurs (SEM); I, a different area with nodes ornamented with single conical evenly spaced spines (SEM). All microscopic images are taken from the holotype.

Figure 5. Verrucocoeloidea liberatorii sp. nov., holotype spicules (SEM): A, dermal pentactin, whole and enlarged tangential and proximal ray ends; B, two atrial hexactins, same scale as (A); C, dermal tyloscopule, whole and enlarged head end; D, dermal subtyloscopule, whole and enlarged head end, same scales as (C); E, uncinate, whole and enlarged anterior and middle parts; F, oxyhexaster, whole and enlarged terminal ray end; G, discohexaster, whole and one enlarged ray cluster; H, onycho/discohexaster, with some terminal tips discoid and some onychoid; I, diaster, with oxyoid and onychoid ray tips; all whole microscleres at same scale as (F).