Dragmacidon alvarezae, Zea, Sven & Pulido, Alejandra, 2016

Zea, Sven & Pulido, Alejandra, 2016, Taxonomy of the Caribbean sponge Dragmacidon reticulatum (Ridley & Dendy, 1886) (Porifera, Demospongiae, Axinellida), with the description of a new species, Zootaxa 4114 (4), pp. 393-408 : 397-402

Dragmacidon alvarezae n. sp.

Fig. 1 B, 2B, 3B, 4; plate 1 figs. E–I, Tables 1–2

Pseudaxinella lunaecharta ; Wiedenmayer 1977: 155, pl. 31 figs. 7–10; pl. 32 figs. 1–3, textfig. 156 (Bimini, Bahamas; Florida Keys) (in part; some specimens could be Dragmacidon reticulatum ); Gómez López & Green 1984: 81, fig. 20 (Quintana Roo, Mexico); Pulitzer-Finali 1986: 102 (Bimini, Bahamas; Boca Chica and Boca de Yuma, Dominican Republic); Zea 1987: 195, fig. 70, pl 12 figs. 3–4 (Continental coast of Colombia; Old Providence Island); Gammill 1997: 5, photo 5 (Florida Keys; Bahamas; Caribbean); Gómez 2002: 73, fig. (Gulf of Mexico; Yucatán; Quintana Roo).

Dragmacidon “ lunaecharta ”; Zea et al. 2014 ( Bahamas; Florida Keys; continental coast of Colombia).

[Non: Axinella (?) lunaecharta Ridley & Dendy, 1886: 481 ( Cape Verde Islands); Ridley & Dendy, 1887: 186, pl. 37, figs. 1, 1a, 2 (= Dragmacidon lunaecharta , valid species from the eastern Atlantic, see Alvarez et al. 1998).]

Pseudaxinella reticulata ; Alvarez et al. 1998: 15, figs. 8, 9, table 8 [in part, apparently all specimens but USNM 32847 ( Bermuda) and USNM 42787 (Gulf of Mexico); North Carolina, South Carolina and Georgia shelves; east coast of Florida; Gulf of Mexico; Belize; Nicaragua; Puerto Rico; US Virgin Islands; Curaçao, Tobago, Venezuela].

Dragmacidon reticulata ; Díaz 2007: 47; Mora-Cristancho et al. 2007: 170, Table 1 (Santa Marta, Colombia, antifouling properties); Díaz & Zea 2008: 34 (Guajira, Colombia).

Dragmacidon reticulatus ; Valderrama & Zea 2013: 358 (Gulf of Urabá, Colombia; annotated list citing material from Zea 1987).

Dragmacidon reticulatum ; Zea et al. 2009 ( Bahamas, Florida Keys); Rützler et al. 2014: 70 (Carrie Bow Cay, Belize).

[Non: Dragmacidon reticulatum ( Ridley & Dendy, 1886) (original under Axinella ; a valid species).]

Type material and type locality. Continental coast of Colombia, Santa Marta, Holotype: INV-POR 0 525, Bahía de Santa Marta, Morro, SW side (11°14’57.77” N, 74°13’48.66” W), 15–23 m, coll. Sven Zea, 2 September 1997 (voucher for Castellanos et al. 2003, as Pseudaxinella reticulata ). Paratypes (coll. Sven Zea): INV-POR 0 330, Ensenada Granate, canal de la Aguja (11°18’28.40” N, 74°11’31.93" W), 6 m, 23 June 1981 (described by Zea, 1987 as Pseudaxinella lunaecharta ); ICN-MHN(Po) 0 140, Bahía de Nenguange, in front of Playa Brava (11°19’43.96” W, 74° 5’55.24” W), 12 m, 20 April 1982 (described by Zea, 1987 as Pseudaxinella lunaecharta ); INV-POR 1259, Bahía de Santa Marta, Morro, SW side (11°14’57.77” N, 74°13’48.66” W), 20 m, 9 July 1993.

Additional material. Bahamas: voucher 189 (tissue slide, 10 m, 19 June 2004), voucher 286 (12 m, 26 June 200,), Stirrup Cays, N Berry Islands (25°49’39.2” N, 77°53’497.9” W), coll. Sven Zea. USA, East side of Florida: USNM 30384 (fragment INV-POR 1261), Florida Keys, Looe Key, west patch reef, coll. S. Pomponi, 14 June 1984 (originally identified as Pseudaxinella lunaecharta by K. Rützler and S. Pomponi, 1994). USA, Florida west coast, Gulf of Mexico: USNM 39859 (fragment INV-POR 1262), Florida west coast, Sta 0 7 (26°16’49” N, 82°44’01” W), 30.4 m, 19 July 1981 (originally identified as Pseudaxinella rosacea ). Southwestern Caribbean, Old Providence Island: INV-POR 0 331, Blue Hole (13°24’16.80” N, 81°23’37.11” W), 27 m, coll. Sven Zea, 8 December 1980 (material described by Zea 1987). Continental coast of Colombia, Gulf of Urabá: INV-POR 0 327, 328, Peñón Napú (08°25’10” N, 77°07’14” W), coll. INVEMAR Expedition, October 1977 (described by Zea 1987 as Pseudaxinella lunaecharta ; listed by Valderrama & Zea 2013 as Dragmacidon reticulatu s); Cartagena: INV-POR 0 329, Banco Salmedina (10°22’24.59” N, 75°39’58.59” W), 24 m, coll. Sven Zea, 19 July 1980 (described by Zea 1980); ICN-MHN(Po) 0 139, Islas del Rosario, Isla Tesoro, north side (10°14’3.93” N, 75°44’25.22” W), 15 m, coll. Sven Zea, 1 February 1983 (described by Zea, 1987 as Pseudaxinella lunaecharta ); Santa Marta: INV-POR 881, Bahía de Santa Marta, Morro, SW side (11°14’57.77” N, 74°13’48.66” W), 24 m, coll. Sven Zea & Marisol Santos-Acevedo, 18 November 2003 (voucher for Mora-Cristancho et al. 2007, as Dragmacidon reticulata ). Guajira: INV-POR1097, 10 m, coll. INVEMAR-CORPOGUAJIRA Expedition on board R/V Ancón, station 215, Bahía Honda (12°23’33” N, 71°45’40” W), 30 March-9 April 2005 (material described by Díaz 2007 as Dragmacidon reticulata ).

Description. Shape, color and consistency. Encrusting, massive, or erect with lobed, fan- or club-shaped projections; the latter sometimes divided; large specimens can be arborescent, with flattened branches thickened at the tips. Size from a few cm in height and thickness up to 25–30 cm or more in height when erect. At Santa Marta, continental coast of Colombia, it is always encrusting, up to 2–3 cm thick and up to 20–25 cm in maximum diameter. Surface smooth to slightly hispid, sometimes more so in elevated portions; oscules even or slightly elevated, scattered, or aligned on ridges or fanned projections, where these occur, 1–5 mm in diameter. Live color scarlet red to orange; interior orange; cream when preserved. Consistency toughly compressible; erect specimens more compressible and flexible. Abundant mucus is exuded upon handling.

Skeleton. Vertically elongated reticulation of ascending and diverging plumose spicule tracts, 100–500 µm thick, up to 300 µm apart, interconnected every 175–1225 µm by thinner, 50–350 µm tracts. At the surface, ascending tracts end in non-projecting spicule brushes. Spicules are: (1) Styles, slightly curved, with smooth heads and acute to slightly telescopic ends, 170–390 µm by 4.5–28 µm. (2) Oxeas, slightly curved, usually slightly asymmetric, with pointed to slightly telescopic ends, 210–420 µm by 5–17.5 µm. Specimen measurements are given in Table 1 .

Distribution. Bahamas, Florida, Gulf of Mexico, Antilles, Central America, north coast of South America. Its presence in Bermuda and Brazil is possible, but needs to be confirmed.

Ecology. It inhabits rocky littorals and reefs, from shallow to deep, generally exposed to light, but sometimes cryptic ( Rützler et al. 2014). Depth range 1– 31 m.

Etymology. Named in honor of Venezuelan spongologist Belinda Alvarez, now at Lund University, Sweden, for her contributions to systematics and taxonomy of sponges, especially of the order Halichondrida sensu lato.

Remarks. Although D. reticulatum and D. alvarezae n. sp. share many characteristics such as both being encrusting, exudating mucus, having the same color, same spicule types, and overlapping size range of spicules and skeletal tracts, they can also be distinguished as different species from a combination of characteristics ( Table 2 ). We confirmed these differences by detailed examination of co-occurring specimens from the Bahamas and from Santa Marta, Colombia (see also Plate 1). While D. reticulatum is predominantly encrusting and massive, D.

alvarezae n. sp. can grow fan or club shaped projections, sometimes even becoming arborescent (excepting at Santa Marta, where both species are always thickly encrusting); erect specimens of D. alvarezae n. sp. can be more flexible and compressible than encrusting forms of both species. The surface of D. reticulatum is rugose, often with hispid projections, while D. alvarezae n. sp. has a more even and smoother surface, usually without or with fewer and lower hispid projections. The skeletal architecture is also distinctive. In D. reticulatum the ascending tracts are usually thicker, more widely spaced, and protrude above the surface to form the hispid projections, while in D. alvarezae n. sp. the reticulation is elongated vertically, more compact and uniform, and although at the surface there are dense bouquets of spicules, these do not project as much to form spines. Although spicule sizes overlap in the two species and oxeas always reach larger sizes than styles in both species, maximum sizes are always smaller in D. alvarezae n. sp. than in D. reticulatum ( Tables 1 and 2 , Fig. 4 ); in D. alvarezae only rarely a specimen may have a few spicules that surpass 400 µm in length (max measured 420), while in D. reticulatum many spicules within a specimen reach larger sizes ( Fig. 4 ). Statistical comparison of spicule length (mean per specimen) in localities where there was available data for both species ( Bahamas, Florida Keys, Gulf of Mexico, Santa Marta) confirmed that D. reticulatum styles and oxea are significantly larger (p<0.05) than those of D. alvarezae n. sp. (two-way ANOVA with factors being species, locality and species*locality).

Figures

FIGURE 1. Light micrographs of spicules. A) Dragmacidon reticulatum (voucher PBH- 04, Bahamas). B) Dragmacidon alvarezae n. sp. (voucher 286, Bahamas). Upper panels show styles, lower panels oxeas. Scale bars for full spicules 100 µm, for endings 20 µm.

FIGURE 4. Boxplot of spicule length (styles, oxeas) for the localities where measurements of the two species were available (Bahamas, Florida Keys, Gulf of Mexico, Santa Marta). Data were combined for all specimens within localities. Notice overlap for spicule sizes in both species, but only one spicule (outlier marked as asterisk) surpassing 400 µm in D. alvarezae.

Tables

TABLE 1. Spicule sizes, length x width in μm. values are minimum- mean - maximum οf 25 - 50 spicules. St = st " les # Οx = οxeas.

Locality̸Specimen	Dragmacidonreticulatum	Dragmacidon alvarezae n. sp.
Bermuda USNM 32847(INv-PΟR 1260)2	St∶ 280 -364.9 -450 x 7.5- 11.2 -15 Οx∶ 320- 373.2 -490 x 7.5- 10 -12.5
BMNH1948.8.6.37	St∶ 250- 330.8 -400 x 7.5- 11.5 -15 Οx∶ 320- 351.3 -460 x 7.5- 11.2 -15