Ptilocaulis cf. spiculifer ( Lamarck, 1814 )

Alvarez, Belinda, De Voogd, Nicole J. & Soest, Van, 2016, Sponges of the family Axinellidae (Porifera: Demospongiae) in Indonesia, Zootaxa 4137 (4), pp. 451-477 : 469-473

Ptilocaulis cf. spiculifer ( Lamarck, 1814)

( Figs 2 , 10–11 )

Spongia spiculifera Lamarck, 1813 –1814:449

Axinella spiculifera .— Ridley 1884: 617; Dendy 1922: 115.

Ptilocaulis spiculifer . — Topsent 1932: 111; Burton 1959: 266. Pulitzer-Finali 1993: 289

Material examined. Palawan/ North Borneo: NTM Z5850, Malaysia, Sabah, N Gaya I., off Kota Kinabalu, 6.0345°N, 116.0064°E, 10–18 m depth, 23 October 2005, coll. B. Alvarez. NTM Z5851, Malaysia, Sabah, N Gaya I., off Kota Kinabalu, 6.0345°N, 116.0064°E, 10–18 m depth, 23 October 2005, coll. B. Alvarez; NTM Z852, Malaysia, Sabah, North Bay, off Kota Kinabalu, 6.0783°N., 116.0791°E, 10–20 m depth, 29 October 2005, coll. N. Plitcher; RMNH POR. 2389, Indonesia, Berau, East Kalimantan, SE Kakaban island, 15 m depth, 21 October 2003, # BER 36/ 211003 /215 coll. W, Renema; RMNH POR. 4280, Indonesia, Berau, East Kalimantan, Sangalaki island, 2.0855°N 118.3911°E, 5 m depth, 15 August 2008, # BER 108/ 150808 /079, coll. N.J. de Voogd; RMNH POR. 4342, Indonesia, Derawan Islands, Maratua island, ‘midnight’, 2.2386°N, 118.6538°E, 10 m depth, 20 August 2008, #Ber114/ 200808 /141, coll. N.J. de Voogd. Sulawesi Sea/Makassar Strait: ZMA POR.17369, Indonesia, North Sulawesi, North Bunaken I., Sachiko Point, 1.6303°N, 124.7706°E., 12 m depth, 9 May 2002, #MD01/ 090502 /005, coll. N.J. de Voogd, RMNH POR. 2373, Indonesia, N Sulawesi, Bunaken Island, Alung banua, 1.6303°N, 124.7706°E, 5 m depth, #MD07/ 150502 /043, coll. N.J. de Voogd; RMNH POR. 2622, Indonesia, South Sulawesi, 5.8289°S, 120.7036°E, Tanjung Bira, Pulau Liukan, 25 m depth, #BIR05/ 230501 /246, 23 May 2001, coll. N.J. de Voogd; RMNH POR. 2650, Indonesia, Sulawesi SW, Bira, Pulau Liukan, 5.6509°S, 120.4473°E, 14 m depth, 5 July 2002, # BIRA / 050702 /324, coll. N.J. de Voogd; ZMA Por. 0 0 468, Indonesia, N Bay, Biaru Island, Sulawesi, 2.1295ºS, 125.385ºE, 27 m depth, 17 July 1899, coll. Siboga Expedition Sta. 123, dredge; ZMA Por. 13198, Indonesia, Kudingareng Keke, SW Sulawesi, 5.102°S, 119.286°E, 15 m depth, 2 June 1997, coll. N.J. de Voogd; ZMA Por. 13310, Indonesia, SW Sulawesi, Langkai island, 5.019°S, 119.063°E, 9 m depth, 10 May 1997, coll. N.J. de Voogd. Banda Sea: ZMA Por. 17687, Indonesia, South Sulawesi, Tanjung Bira, Pulau Liukan, 25 m depth, 5.8289°S, 120.7036°E, 23 m depth, 23 May 2001, #BIR05/ 230501 /246, coll. D. Erpenbeck & N.J.de Voogd. Lesser Sunda: RMNH POR. 2328, Indonesia, Bali, SE-end Tulamben beach, 8.2778°S, 115.5958°E., 10 m depth, #Bal22/NV/ 100101 /124, 10 April 2001, coll. N.J. de Voogd; RMNH POR. 3613, Indonesia, Bali, Tulamben beach, 'Liberty wreck', 8.2738°S 115.5911°E., 30 m depth, 10 April 2001, #Bal21/NV/ 100401 /116, coll. N.J. de Voogd. ZMA Por. 0 0 896, Timor Leste, anchorage between Nusa Besi and NE Timor, 8.42°S, 127.3066°E, 27–54 m depth, 15 November 1900, coll. Siboga expedition, Sta 282, dredge. ZMA Por. 0 8394, Indonesia, of Komodo, Selat Linta, Nusa Tenggara, 8.5833°S, 119.57°E, 4–11 m depth, 18 September 1984, coll. R.W.M. van Soest on Snellius II Expedition, Sta.079/ III/19. Sunda Shelf: RMNH POR.2090, Indonesia, NE Java, Thousand Island, Lancang Island, 5.9269°S, 106.5914°E, 6 m depth, 21 September, 2005, #SER13/ 210905 /128, coll. N.J. de Voogd.

Description. Shape ( Figs 10 A–E). Very variable: bushy with short branches or projections, on short and broad peduncle; branching, digitate, erect, or creeping, with single or multiple branches, 1–2 cm diameter, sometimes fused near the tips in fan shape, or becoming broad or dividing towards tips, arising from common base or peduncle, thick, short or long up to 6 cm long, or arising from multiple points of attachment. Specimens up to 35 cm high by 15 cm wide

Colour. Red, orange or cream. Beige in alcohol; some specimens with pink tinge.

Oscula. Inconspicuous, irregularly distributed, few, flush, covered by transparent thin membrane, up to 5 mm diameter. In some specimens with thin exhalant channels radiating away or with other openings observed in the dermal membrane. Minute pores (ostia) evenly distributed between the conules and surface reticulation.

Specimen Locality Styles [Styles [[ Strongyles RMNH POR. 3613 Lesser Sunđa (Bali) 231.6/324.9μm (286.7±20.1) 405.2/500.1μm (452.6±67.1) [2] 151.5/236μm (204.3±29.6) [13] X 9.9/16.6μm (13.8±1.8) X 8.3/12.4μm (10.3±2.9) [2] X 6.7/23.1μm (17.6±4.5) [13] ZMA Por. 896 Lesser Sunđa ( Timor Leste) 245.5/282.1μm (258.4±11.3) 148/203.2μm (167.5±21.1) [5] X 4.4/16.3μm (13.1±2.4) X 13.3/18.5μm (16±2.2) [5] ZMA Por. 8394 Lesser Sunđa (E of Komođo) 314.1/426.8μm (365.9±25.5) 130.3/352μm (225.9±101.3) [6] X 11.2/22.5μm (16.4±2.6) X 14 /21.8μm (18.4±3.3) [6]

RMNH POR. 2389 Palawan/ North Borneo 242.3/301.9μm (266±15.6)

X 6.3/14μm (10.3±1.9)

RMNH POR. 2650 Sulawesi 249.2/335.8μm (284.4±20.8)

X 5.5/14.5μm (10.9±2.5)

RMNH POR. 2373 Manađo 240.4/300.4μm (270.3±18.3) 42.1/152.7μm (78.3±43.9) [5] X 6.3/11.9μm (9.3±1.4) X 4 /8.6μm (6.9±1.9) [5]

RMNH POR. 2090 Sunđa Shelf 281.3/368.4μm (325.2±24.2) 543.7/779.1μm (635.3±59.7) [20] X 7 /14.4μm (11.2±1.7) X 8.2/15μm (11.7±1.5) [20] ZMA Por. 17687 Banđa Sea 199.7/276.3μm (246.9±20)

MNHN DT3345 (Lectotype)* Bass Strait, Victoria 270/300μm 575/700μm

X 15/17 μm X 11 μm

X 3 /14.3μm (10.8±2.8)

Measurements from * Topsent (1932)

Consistency. Soft, slightly compressible, flexible, spongy.

Surface. Covered with spiky, blunt conules in short bushy specimens. Otherwise, uniformly covered with ‘scopiform’ or flattened, spatula-like conules, 1–5 mm long, closely spaced, fused laterally at base, projecting from longitudinal choanosomal fibres and forming a surface reticulation of round meshes or meandering channels. Transparent membrane, partially collapsed in preserved specimens, stretched over conules. Near peduncle of erect specimens is smooth, with short or no conules.

Skeleton ( Figs 11 A–B). Without ectosomal specialisation. Plumoreticulated, slightly compress in axis of branches; with ascending fascicles of primary tracts projecting from axial region, irregularly, loosely or tightly connected by secondary tracts or single spicules, or anastomosing, converging at subectosomal level and ending in small and ill-defined spicule brushes or longer plumose tracts corresponding with surface conules. Primary tracts multispicular, slightly embedded in clear spongin; secondary tracts uni-paucispicular, invested in clear spongin.

Spicules ( Fig. 11 E, Table 9). Styles, slightly curved or less often bent, with pointed ends or less often round ends some with subtylote bases, in one size category, thinner forms common in some specimens, 199.7–426.8 x 3 – 24.2 µm. Larger styles, in very low frequency only in some specimens 405.2–779.1 x 8.2–15 µm. Short straight strongyles, in low frequency, 42.1–352 x 4 –23.1 µm, only in some specimens; some with a pointy end (observed in ZMA Por. 0 0 896 and ZMA Por. 08394). Broken spicules are common in preparations suggesting spicules might be fragile relatively to homologous ones find in another species.

Remarks. The material examined is assigned to the allegedly wide distributed Ptilocaulis spiculifer . The type specimen (Lectotype MNHN DT3345, JNA Hooper pers.comm.) was re-described by Topsent (1932) under Ptilocaulis , noticing the similarities with Ptilocaulis digitatus Topsent, 1928 described from Cape Verde.

The external morphology and the spicule composition of Ptilocaulis spiculifer seems to be variable at the intraspecific level. The second and larger category of styles is absent or in very low frequencies in many of the specimens examined ( Table 9). This was also noticed by Topsent (1932) and Pulitzer Finalli (1993). Short and thick strongyles, often with modifications were found in very low frequency as well only in some specimens ( Table 9).

The specimen ZMA Por. 0 0 896, is assigned to this species with some doubt. The surface is covered by conules as in other specimens but only in the tips of the branches, while the rest is smooth and have an Axinella- like appearance and star-shape oscules also common in that genus; the skeleton agrees with the rest of the material.

It is quite remarkable that the material examined here is also very similar to the one described under Ptilocaulis walpersi by Alvarez et al (1998). The CW Atlantic populations are characterised also by a great diversity of growth forms, and have nearly identical skeletons, and spicule composition and size.

Other species of Ptilocaulis recorded by the WPD, for adjacent areas are: Ptilocaulis arbora ( Sim, Kim & Byeon, 1990) described originally under Homaxinella , is transferred here to Phakettia arbora ( Sim, Kim & Byeon, 1990) , based on the description provided by the authors (comb. nov. here established). Ptilocaulis echidnaeus ( Lamarck, 1814) [fragment of holotype, MNHN DT 640, examined] is a dubious Ptilocaulis and might be related to Trikentrion (Van Soest et al. 2015) ; Ptilocaulis trachys ( De Laubenfels, 1954) from the Marshall Is (Eastern Indo-Pacific) is transferred here to Phakettia (comb. nov.; type specimen USNM 22990; examined).

Phylogenetic analyses based on molecular data have shown consistently that Ptilocaulis spiculifer and other species of Ptilocaulis including the type species P. gracilis Carter, 1883 and its junior synonym of P. walpersii (Duchassaing & Michelotti, 1864) are genetically related to Reniochalina stalagmites Lendenfeld, 1888 , and to the raspailiid Axechina raspailioides Hentschel, 1912 ( Redmond et al. 2013 and references within). As discussed in Alvarez and Hooper (2009) neither Ptilocaulis and Reniochalina , have the typical raspailiid ectosomal skeleton which is clearly present in Axechina and a synapomorphy of the family Raspailiidae (Hooper 2002) , which leaves these relationships unresolved (but see discussion below).

Distribution. The species is common throughout a great number of ecoregions of the Western Triangle Province (i.e, Banda Sea, Lesser Sunda, Palawan/ North Borneo, Southern Java, Sulawesi Sea/Makassar Strait) ( Fig.2 ). Also known from adjacent provinces (Java Transitional, (Naturalis collections), Tropical Western Pacific (Coral Reef Research Foundation collections), Northeast Australian Shelf (Queensland Museum collections). The species type locality is King Island, Tasmania, Australia and it was recorded for the Indian Ocean by previous authors (see under list of synonyms). It is found from 4–30 m depth.

Figures

FIGURE 2. Map showing the geographical location of the described species.

FIGURE 10. Different growth forms of Ptilocaulis cf. spiculifer: A, ZMA POR. 17369, in situ at N Sulawesi. B, NTM Z 5851 in situ at Kota Kinabalu. C, RMNH POR. 2622, S Sulawesi, preserved specimen. D, ZMA Por. 13310, SW Sulawesi, preserved specimen. Scale bars: C – D, 4 cm. Photos A, Nicole de Voogd; B, Belinda Alvarez.

FIGURE 11. Ptilocaulis cf. spiculifer: A – B, RMNH POR. 2622: light microphotograph of skeleton; C, diagram of spicules. * indicates that spicule is not found in all examined specimens. Scale bars: A, 500 µm; B, 200 µm, C, 50 µm.