Cyamon vickersii (Bowerbank, 1864)

Soest, Rob van, Carballo, Jose Luis & Hooper, John, 2012, Polyaxone monaxonids: revision of raspailiid sponges with polyactine megascleres (Cyamon and Trikentrion), ZooKeys 239, pp. 1-70 : 6-12

Cyamon vickersii (Bowerbank, 1864) Figs 1 A–D, 2 A–D

Unnamed spicule; Bowerbank 1862: 831, pl. 36 fig. 15 (West Indies?).

Dictyocylindrus vickersii Bowerbank 1864: 267, figure 234 (West Indies?); Carter 1879: 292, pl. 27 figs 5-8 (West Indies); Carter 1880 b: 42.

Cyamon vickersii ; Gray 1867: 546 (West Indies); Dendy 1922: 108, pl. 4 fig. 4, pl. 16 fig. 5 (Seychelles).

Cyamon vickersi ; Thomas 1973: 26, pl. 1 fig. 14 (Seychelles); Van Soest 1994a: 71 (Seychelles); Hooper 2002: 498, Fig. 17.

Cyamon dendyi de Laubenfels 1936: 80.

Not: Trikentrion wickersi (sic); Topsent 1889: 4, figure 2A (Campeche Bank, Gulf of Mexico); Topsent 1894: 35 (corrected to Trikentrion vickersi ) = Cyamon agnani .

Nec: Cyamon vickersi var. toxifera Arndt 1927: 149, pl. 2 fig. 9, text figure 10 ( Curaçao) = mixture of Cyamon agnani and Clathria (Microciona) ferrea .

Nec: Cyamon vickersii ; Burton and Rao 1932: 355 (S India) = Cyamon hamatum sp. n.

Nec: Cyamon toxifera ; de Laubenfels 1936: 80 = Cyamon agnani .

Nec: Cyamon vickersi ; De Laubenfels 1936: 80 (Florida); Little 1963: 48 (Gulf of Mexico); Hooper 2002: 498, Fig. 17 = Cyamon agnani .

Nec: Cyamon vickersi ; De Laubenfels 1950 (Bermuda) = Timea sp.

Material examined.

HolotypeBMNH 1877.5.21.1887, dry condition, labeled from Mr Vickers, Dublin, West Indies?

The holotype was extensively described by Carter (1879) (his illustrations are reproduced in Fig. 1B), and redescribed by Hooper (2002). The specimen is now (2012, see Fig. 1A) a dry, macerated, wedge-shaped sponge, glued to a label containing the text Bk. 1887, Dictyocylindrus vickersii, lodged in a round box. There are five microscopic slides: three thick sections (one is reproduced in Fig. 1C), and two spicule mounts. A photo was made (Fig. 1D) of the contents of one of the spicule slides showing characteristic polyactines and one centrotylote strongylostyle. All microscopic slides are labeled with texts in Bowerbank’s and Carter’s handwritings.

Description.

The specimen consists of a barely coherent mass of columns, fragile, crumbly. Size approx. 3 × 2.5 × 0.6 cm. Colour now dark red-brown.

Skeleton: a branched columnar structure built by bundles of short thick styles supported at the base and along the column by masses of polyactines. The remaining spicules are not readily visible in the sections, so their positions are derived from Carter’s drawings (Fig. 1B): the columns are echinated by long and short styles and wavy strongylostyles.

Spicules (Fig. 2): long thin styles, short thin (strongylo-)styles, short thick styles, polyactines.

Long thin styles (Fig. 2A, A1) curved, usually broken, rounded end faintly constricted subterminally, 1785-2200 × 14-22 µm.

Short, thin, crooked or wavy, centrotylote styles (Fig. 2B, B1), sometimes strongylote, with the pointed end often swollen or mucronate, and faintly to markedly spined, 355 –408.8– 490 × 3.5 –4.4– 6 µm.

Short thick styles (Fig. 2C, C1), smooth, curved subterminally at the rounded end, 470 –537.7– 662 × 15 –22.3– 32 µm.

Polyactines (2D), robust, mostly equiangular, predominantly four-claded, three-claded forms also rather common, five-claded spicules rare and much smaller than the other; juvenile spicules almost entirely smooth, mature spicules with all cladi spined at the ends, which are also lightly swollen; only sparingly spined near the centre; all cladi approximately equal in length, basal cladi barely distinct from lateral cladi: basal cladi 55 –62.5– 69 × 10 –12.6– 16 µm, lateral cladi 50 –65.6– 78 × 9 –12.4– 15 µm.

Remarks.

Contrary to most other authors referring to Cyamon vickersii , we have become convinced that this species does not occur in the Western Atlantic. The evidence for this is two-fold.

(1) There is considerable uncertainty about the origin of the type specimen. Bowerbank (1862: 831), when he first drew attention to the polyactine spicule, described it as follows:

Spiculated inequi-angulated triradiate, with cylindrical entirely spined radii (Plate XXXVI. fig. 15). - From a fragment of a sponge presented to me by Mr. Vickers of Dublin, who thinks it probably came from the West Indies. This spiculum is an external defensive one. The triradiate rays are imbedded immediately beneath the dermal membrane, and the spicular ray is projected through it at right angles to its plane; they are very numerous.

The part of the sentence we placed in roman lettering contains the only factual information on the origin of the specimen, which was subsequently named Dictyocylindrus vickersii by Bowerbank (1864: 267) with the same sentence and figure repeated. Bowerbank’s slides of the type material in BMNH marked as Bk 1887 were labeled prudently "West Indies?" (see Fig. 1C), but first Gray (1867: 546) and later Carter (1879: 292) omitted the question mark. Carter did an extensive redescription of the Bowerbank material (see Fig. 1B), which properly established the characters of the species. Shortly before that ( Carter 1876: 391) he alluded to a specimen with quadriradiate spicules obtained from Thomas Higgin from Grenada (Caribbean Sea), which he thought to belong to the same species. Higgin (1877: Pl. 14 Fig. 9) figured the spicule. However, both authors mentioned only long styles in addition to the polyactines, which is, as we know now, insufficient to characterize Cyamon species. As we described above, and was also clearly pictured by Carter himself (1879: Pl. 27 Fig. 6c, see also our Fig. 1B), Cyamon vickersii should possess undulated or crooked centrotylote thin styles or strongylostyles. We will demonstrate below that none of the Western Atlantic specimens of Cyamon we examined possess such spicules, in stead of which they have straight thin styles without centrotylote swelling or undulations. Nevertheless, from the time of Carter onwards it was assumed, that Bowerbank’s type came from the West Indies. Subsequent reports of Cyamon from Western Atlantic localities all employed the name Cyamon vickersii , and ignored the peculiar shape of the short thin styles.

(2) Dendy (1922) and Thomas (1973) reported Cyamon vickersii from the Seychelles. Their descriptions exactly match the properties of Bowerbank’s type specimen, including the undulating short thin centrotylote styles. They especially mention the spination on the pointed ends of many of the undulating styles, precisely as we found in the type (see Fig. 2B, B1). De Laubenfels (1936: 80) also was of the opinion that the Seychelles material differed specifically from the Western Atlantic material. Because he believed that Cyamon vickersii was West Indian, he proposed the name Cyamon dendyi for the Seychelles material. Below, we describe and illustrate (Fig. 3) material obtained from the Seychelles, in which we demonstrate beyond doubt that it belongs to Cyamon vickersii .

To conclude: specimens identical or similar to the type of Cyamon vickersii are reported from the Seychelles. Specimens recorded from the Western Atlantic are dissimilar to the type of Cyamon vickersii , a.o. by lacking the characteristic undulating spicules. For the Atlantic representatives, the name Cyamon agnani (Boury-Esnault, 1973) is available (see below).

Description of ZMA material of Cyamon vickersii .

Figs 3 A–F

Material examined.

Three samples, ZMA Por. 11729, preserved in alcohol, Seychelles, Amirante Islands, N of Poivre Island, 5.7333°S, 53.3333°E, Netherlands Indian Ocean Programme, Leg E, stat. 776/05, rectangular dredge, depth 43-48 m, coll. R.W.M. van Soest, 29 –12– 1992.

ZMA Por. 10660, preserved in alcohol, Seychelles, Amirante Islands, NE of D’Arros Island, 5.4S, 53.3167E, Netherlands Indian Ocean Programme, Leg E, stat. 750/09, rectangular dredge, depth 48-53 m, coll. R.W.M. van Soest, 26 –12– 1992.

ZMA Por. 12558, preserved in alcohol, Seychelles, N of Aride Island, 4.1833S, 55.6667E, Netherlands Indian Ocean Programme, Leg E, stat. 716/09, rectangular dredge, depth 40 m, coll. R.W.M. van Soest, 19 –12– 1992.

N.B.: Dendy’s (1922) specimen labeled and described as Cyamon vickersii, BMNH 1931.1.1.19, Amirante, Sea Lark Expedition, 60 m, was examined and photographed by J.H. (Hooper, 2002: Fig. 17) but could not be found in the collection of the Natural History Museum in 2011 (Ms Emma Sherlock, in litteris).

Description.

Strawberry-shaped sponge (Fig. 3A), forming a single semiglobular mass with microlobate surface. Color red or orange-red (alive), dark brown-red in alcohol. Consistency firm, barely compressible. Specimens now looking clathrate due to loss of thin surface membrane, still present in places. Size of largest specimen 3 × 2 × 2 cm.

Skeleton: condition described as columnar, consisting of hillock-like masses of polyactines, variable in thickness up to 2 mm, supporting thick plumose bundles of thick styles, which in turn are peripherally surrounded by short thin strongylostyles. Rare long thin styles are not present in all slides.

Spicules (Figs 3 B–F): long thin styles, short thick styles, strongylostyles, polyactines, overview presented in Fig. 3F.

Long thin styles (Fig. 3B), very rare, invariably broken in small pieces, largest piece found in our slides 300 × 12 µm; according to Dendy they can reach 1700 × 14 µm. We reconstructed a long style from several pieces found on the SEM stub (Fig. 3B).

Strongylostyles (Figs 3D, D1), angulated, often faintly centrotylote, with unequal endings, smoothly rounded at one end, spined-mucronate at the other, 294 –347.1– 402 × 4 –5.6– 7 µm.

Short thick styles (Fig. 3C), characteristically curved in the upper half and provided with a faint tyle, shape of spicule fusiform, smooth, occasionally strongylote, 361 –538.9– 678 × 16 –24.1– 31 µm.

Polyactines (Fig. 3E), three- or four-claded in approximately equal proportions, a single five-claded form was observed in the slides (Dendy shows a reduced two-claded form). Basal cladi bluntly pointed, heavily spined apically, lightly spined along the shaft, lateral cladi ending rounded, equally heavily spined apically, less so along the shaft. In the center of the spicule there are usually no spines. Young growth stages are frequently entirely smooth. Basal cladi usually longer, 54 –77.5– 102 × 9 –14.4– 18 µm, than the lateral cladi, 39 –58.9– 78 × 7 –13.1– 16 µm, regardless of the number of cladi.

Distribution.

So far known with certainty from several localities throughout the Seychelles ( Mahé and the Amirante Islands).

Ecology.

Sandy bottoms at 30-50 m surrounding reefs and atolls.

Discussion.

The ectosomal strongylostyles in Cyamon vickersii are reminiscent of those found in the type species of the Axinellidae genus Reniochalina ( Reniochalina stalagmitis Lendenfeld, 1888), which Alvarez and Hooper (2009) suggested were indicative of a possible close relationship between Reniochalina and the Raspailiidae . This close relationship was further confirmed from molecular evidence ( Erpenbeck et al. 2007b) showing affinities of Reniochalina stalagmitis with the raspaillid species Axechina raspailioides Hentschel (1912), indicating the strong morphological apomorphy of these ectosomal spicules for the Raspailiidae.

Burton and Rao (1932) reported Cyamon vickersii from South India (21 miles WSW from Mangalore), stating their specimen answered to Dendy’s (1922) material. We were able to examine a slide made by Burton (BMNH 1931.1.1.19a, the specimen is presumably in the collections of the Indian Museum), and found it to be close but nevertheless distinct from Cyamon vickersii proper. See below for a description and illustration, as Cyamon hamatum sp. n.

Gray’s (1867: 546) suggestion that the unnamed spicule without locality pictured in Bowerbank, 1864: figure 88 also belongs to Cyamon vickersii is debatable as the spicule with its single cladus spined conforms more likely to Trikentrion .