(Figure 5–7; Table 2)
Original description. Chondrocladia verticillata Topsent, 1920:12.
Synonoms and citations. Cladorhiza concrescens in part (Schmidt, 1880:83); Chondrocladia verticillata (Topsent, 1930:430)
Material examined. U.S. Coast Survey, str. “ Blake ”, st. 162 Ag, ZMBN 39 (Guadeloupe, 1879–01–19, 16°02.67’N, 061°50.47’W, 1342 m). This specimen, probably sent to the Bergen Museum by Schmidt, is most likely part of the material given as “ Grenada, 533 bis 734 Faden” in the original description of Chondrocladia (C.) concrescens (Schmidt, 1880). The closest matches to this information in the Blake station list are the stations 161 Ag and 162 Ag, given as off Guadeloupe, at 583 and 734 fathoms respectively (Smith & Rathbun, 1888), and presumably there has been a misattribution to Grenada as well as a transcription error in the depth of station 161. This is corroborated by the label of specimen ZMBN 39, which states the collection locality as Guadeloupe. U.S. Coast Survey, str. “ Blake ”, st. 163 Ag, USNM 975 (Guadeloupe, 1879–01–20, 16°03'10"N, 061°52'20"W, 1406 m). R/V “ Alaminos ” 65A, st. 65A9–2, USNM 31180 (Between Florida and Cuba, 1965–07–02, 24°00'N, 081°00'W, 1000 m). Kraken 2 ROV, specimen HBOM 003:01095 (Florida, south of Pulley Ridge, 2011–09–19, 24°39.71'N, 083°55.08'W, 779 m).
Comparative material examined. Chondrocladia (C.) gigantea (Hansen, 1885); C. (C.) grandis (Verrill, 1879); C. (C.) michaelsarsi Arnesen, 1920; C. (C.) robertballardi Cristobo, Rios, Pomponi & Xavier, 2015; C. (C.) virgata Thomson, 1873.
Diagnosis. Erect Chondrocladia consisting of a single straight stem. The upper part of the stem contains nodelike enlargements at regular intervals from which branches issue in each direction from the stem, typically in groups of four per node. Branches have terminal swellings. Megascleres are two categories of mycalostyles and acanthostyles; microscleres are larger anchorate anisochelae in the range of 41–(65)–78 µm, smaller anchorate anisochelae in the range of 13–(18)–34 µm and sigmas in the range of 16–(20)–27 µm.
Description. The examined specimens all have a similar morphology consisting of an erect, single, and straight cylindrical stem carrying lateral projections except for a short lower portion at the base. Specimens are all fragments, lacking either the basal or top part. The largest and best preserved specimen (HBOM 003:01095) is 19.5 cm long (25 cm at time of collection before removal of part of the specimen for subsampling). The smallest fragment is 4 cm long. The lower part of the stem, up to 6 cm long in fragment USNM 975, is 2–4 mm in diameter and without projections. The main part of the stem is slightly wider, 3–6 mm in diameter, and has numerous nodular swellings at regular intervals spaced 5–10 mm apart serving as attachment for the projections. The projections are up to 40 mm long, but more typically 20 to 25 mm in length, and are 1 mm in diameter. There are four projections per node equally distributed every 90° around the stem, with the projections of adjacent nodes offset about 45°. The projections terminate in swellings that are inflated in situ, but are deflated in preserved specimens. The main stem is mostly covered in a soft outer layer coated with fine sediment particles also present at the base of the processes, creating a sleeve-like transition. Specimen USNM 31180 retains a partial base, showing that the sponge is connected to the substrate by splitting off the basal stem into several root-like processes. Color in ethanol ranges from white to light brown (Fig. 5 A–H).
Skeleton. The core skeleton of the main stem is made up of easily visible fibers of mycalostyles in a slightly spiraling pattern reminiscent of a rope, though this torsion is less pronounced than in other Chondrocladia species such as C. (C.) gigantea. The outer layer of the lower stem is soft, easily detaches from the central stem, and contains subtly spined acanthostyles. The outer layer of the upper stem is firmer. Between the core stem and the outer layer there is a less dense lacunose layer containing only small amounts of megascleres and containing longitudinal canals, parts of the modified aquiferous system present in the sponge. The skeleton of the branch processes is made up of tightly packed mycalostyles and originates in the central part of the main stem (Fig. 6 A– D). Microscleres are found throughout the outer layer of the stem and branches.
Spicules. Mycalostyles 1, straight, fusiform, 728–(1606)–2815 µm long, 13–(27)–38 µm wide. Most common in the branch processes rather than the central stem, but present in both locations (Fig. 6 E).
Mycalostyles 2, straight or curved, making up the main part of the central stem, 420–(589)–1240 µm long, 9– (15)–27 µm wide (Fig. 6 F).
Acanthostyles, curved, with very fine knobs or spines that might be difficult to see properly in some specimens, 192–(310)–500 µm. Associated with the soft outer layer of the lower stem and basal part of branches (Fig. 6 G).
Anchorate isochelae 1, numerous, with a curved shaft, usually six, sometimes seven teeth in each end and fimbriae. Teeth less than 20% of total spicule length, fimbriae around twice the length of the teeth, 41–(65)–78 µm (Fig. 6 H).
Anchorate isochelae 2, less numerous than the larger kind, but not uncommon, with a strongly curved shaft, usually six, sometimes five teeth in each end. The points of the teeth are modified into claw-like structures. Fimbriae are rudimentary. Teeth around 25% of total spicule length, 13–(18)–34 µm (Fig. 6 I).
Sigmas, common, stout, with a somewhat uneven curvature and terminal points bent slightly inwards, 16– (20)–27 µm (Fig. 6 J). In specimen ZMBN 39 a small number of a second type of sigma was also encountered: 47– (58)–68 µm, possibly contamination.
Molecular sequence. A COI extended barcode (1215 bp) and partial 28S rDNA (C1–D2, 771 bp) of specimen HBOM 003:01095 has been uploaded to GenBank with accession numbers KU950333 (COI) and KU950334 (28S rDNA).
Remarks. From its general morphology, Chondrocladia (C.) verticillata is a close relative to C. (C.) concrescens Schmidt, 1880, also originally described from the Caribbean. As they are mentioned specifically by Schmidt, specimens from “Blake” stations 41, 130, 161 and 162 Ag should be considered syntypes of C. (C.) concrescens, however, the specimen from station 162 Ag examined here (as well as a specimen from 163 Ag not mentioned by Schmidt) is C. (C.) verticillata. As it is, the only specimen certain to be C. (C.) concrescens is the specimen or specimens actually used by Schmidt for his spicule measurements (clearly not including all listed syntypes) and the subsample examined by Topsent (1920), which lacks collection information. The status of the remaining three syntype locations is unknown, and the specific distributions of C. (C.) concrescens and C. (C.) verticillata are thus not known, though it can be established that the material mentioned by Schmidt contains both species. The identification of “ concrescens - type ” Chondrocladia is difficult owing to the uncertainties in the amount of variation of the spicules of this species (Vacelet, 2006), and several Pacific specimens have been attributed to C. (C.) concrescens (Koltun, 1970; Lévi, 1993; Ridley & Dendy, 1886, 1887), probably incorrectly (cf. Topsent, 1930; Vacelet, 2006).
While all specimens examined here proved to be C. (C.) verticillata, there are clear differences between the characters across these specimens and C. (C.) concrescens as described by both Schmidt (1880) and Topsent (1920), and there is no reason to doubt that Topsent did a thorough investigation on the differences between C. (C.) concrescens and C. (C.) verticillata when erecting the latter species: In both the original description by Schmidt and the following re-examination by Topsent, the larger category of isochela is significantly larger in C. (C.)
concrescens compared to C. (C.) verticillata, as are the sigmas. Another clear difference regards the morphology of the smaller type of isochela: Both Schmidt and Topsent emphasize long, fine teeth, where the upper teeth almost touch the lower in C. (C.) concrescens (Fig. 7), while this character is not present at all in the specimens identified as C. (C.) verticillata. Thus C. (C.) verticillata is by all appearances a valid species distinct from C. (C.) concrescens. It should be noted that of the two specimens illustrated by Schmidt (1880) (reproduced here, Fig. 7), the spacing of the projections is quite different, which could indicate that one of them (Fig. 7 A) is C. (C.) concrescens while the other (Fig. 7 B) is C. (C.) verticillata.
The results of the phylogenetic analysis of specimen HBOM 003:01095 shows that C. (C.) verticillata is most closely related to two as of yet undescribed species of Chondrocladia from Patagonia (species “A”, SW Atlantic) and the New Zealand EEZ (species “C”) (Fig. 8). More distant relatives within the same clade include the Northern Atlantic and Arctic species C. (C.) gigantea (Hansen, 1885) and C. (C.) robertballardi Cristobo, Rios, Pomponi & Xavier, 2015. These results are in general agreement with morphological characters, as all the related species have a roughly similar habit consisting of a single or branching stem with numerous branches along the upper part of the axis, as opposed to other members of subgenus Chondrocladia which typically have a pedunculate, spherical morphology.
Related species. Chondrocladia (Chondrocladia) concrescens Schmidt, 1880; C. (C.) concrescens sensu Ridley & Dendy, 1886 (= C (C.) “ challengeri ”, cf. Topsent, 1920; 1930); C. (C.) gigantea Hansen, 1885; C. (C.) grandis (Verrill, 1879); C. (C.) michaelsarsi Arnesen, 1920; C. (C.) robertballardi Cristobo, Rios, Pomponi & Xavier, 2015; C. (C.) virgata Thomson, 1873; C. (C.) yatsui Topsent, 1930.
TABLE ³. List of recorđs of Clađorhiziđae from the Caribbean Sea anđ ađjacent Atlantic Ocean. Spicule measurements are an aggregation of those reporteđ by the listeđ sources.
Area Depth Morphology Spicules Source(s) Abyssocladia Mycalostyles Mycalostyles Strongyles Arcuate Sigmancistras
/ subtylostyles isochelae
Abyssocladia Muir 2829 m Central stem 720((933)(430((686)(380((568)(780 x 28 ((43)(50 9((10)(11 This article polycephalus Seamount, anđ branches 1070 x 14 (960 x 5 ((10)(15((18)(22
. nov. NE of each with a (17)(22 13
Bermuđa. đisc(shapeđ
bođy.
Asbestopluma Mycalostyles Subtylostyles Acantho – Anisocercichelae Palmate Sigmancistras
tylostyles anisochelae
Asbestopluma Beata Riđge, 4007 m Erect single 990((1194)(320((550)(74((114)(194 52((64)(74 8((10)(12 19((26)(34 This article. ) caribica Caribbean stem with two 1426 x 18 (660 x 8 ((12)(
. nov. Sea. opposite rows (23)(33 14
of filaments.
Asbestopluma Probably 585(Peđunculate 900(1400 x 300(600 x 2 (4 90(120 x 1 (3 10(12 20(25 (Hajđu &. ) gracilior between 640 m with ovate 20(25 Vacelet, 2002; Schmiđt, Floriđa anđ main bođy. Schmiđt, 1870) 1870) Cuba.
Chondrocladia Mycalostyles Mycalostyles Acanthostyles Anchorate Anchorate Sigmas
isochelae isochelae
Chondrocladia East of 527 m Peđunculate 665(1075 x 50 (55, 3 teeth 46 (Schmiđt, 1880;. ) amphactis Barbađos. spherical boy 6(25 Topsent, 1930) Schmiđt, 1880 with lateral
branches
Chondrocladia Guađeloupe? 825(Erect single Present Unknown 71(130, 6 teeth 27(40, 4(6 69(97 (Schmiđt, 1880;. ) St. Croix? 1573 m? stem with long teeth Topsent, 1920, concrescens Between branches. 1930) Schmiđt, 1880 Floriđa anđ
Cuba?
Chondrocladia Guađeloupe, 1000(Erect single 728((1606)(420((589)(192((315)(680 41((65)(78, 6 (7) 13((18)(34, 6 16 ((20)(27 (Topsent, 1920,. ) verticillata between 1472 m stem with 2815 x 13 (1240 x 9 (teeth (5) teeth 1930); this Topsent, 1920 Floriđa anđ branches. (27)(38 (15)(27 article
Cuba.
……continued on the next page TABLE ³. (Continueđ)
Area Depth Morphology Spicules Source(s) Cladorhiza Mycalostyles Anchorate Sigmas Sigman –
anisochelae cistras
Cladorhiza East of 1447(Arbuscular. 310(680 x 20 (25, 5 teeth 100(140 35(48 (Vacelet & methanophila Barbađos. 4943 m 5(20 Boury-Esnault, Vacelet & 2002), Boury-Esnault, unpublisheđ
material
Euchelipluma Subtylostyles Placochelae Sigmancistras Euchelipluma Between Dry 1047 m Stem 553(1004 x 13 (15 18(21 (đe Laubenfels, congeri đe Tortugas anđ expanđing 9(13 1936) Laubenfels, Cuba. into conical
apex with
filaments.
Lycopodina Styles / Subtylostyles Tapering Arcuate Forceps
subtylostyles subtylostyles anisochelae spicules
Lycopodina South of 1947 m Peđunculateđ 280(570 x 5 (132(274 x 3 (6 450(910 x 3 (6 16((18.5)(20 Present in (Hestetun et al., infundibulum Barbađos. cup. 8 species, not 2015) Levinsen, present in)* specimen
This species is also founđ in the North Atlantic anđ Arctic. Data given is for the Barbađos specimen only.