Latrunculia (Biannulata) gotzi, Samaai, Toufiek, Janson, Liesl & Kelly, Michelle, 2012

Samaai, Toufiek, Janson, Liesl & Kelly, Michelle, 2012, New species of Latrunculia from the Agulhas shelf, South Africa, with designation of a type species for subgenus Biannulata (Demospongiae, Poecilosclerida, Latrunculiidae), Zootaxa 3395, pp. 33-45 : 37-40

Latrunculia (Biannulata) gotzi sp. nov.

( Fig. 3 A–F; Fig. 6 Y; Table 1 )

Material examined. Holotype SAM-A24718: Alphard Banks, Agulhas continental shelf, about 60 km from Cape Agulhas, Western Cape, South Africa, 35.054° S, 20.919° E, RV Ellen Khuzwayo, collected on SCUBA, 25 March 2009, 41 m [cross reference numbers TS 1482 (3557/03)].

Type locality. Alphard Banks, South Africa.

Description. Hemispherical sponge, 2.5 cm long x 6 cm wide x 4.5 cm high ( Fig. 3 A), oscules with slightly raised margins, 4–7 mm wide, 1 mm high, areolate porefields forming broad swathes that meander and cover a majority of the surface. Surface smooth, velvety to the touch, texture firm, compressible, interior feels fibrous. Colour in life mahogany brown, areolate porefields cork brown, dark mahogany brown in preservative.

Skeleton. Choanosome an irregular polygonal reticulation of wispy tracts of megascleres ( Fig. 3 B), ranging in width from 48 to 86 μm, and forming meshes that range in width from 160 to 240 μm. Tracts within the deeper choanosome diverge towards the surface and are 65 to 86 μm wide. A single layer of anisodiscorhabds forms a palisade in the ectosome, below which is a paratangential layer of megascleres 144 μm thick, becoming vertical to support the edges of the porefields. Numerous anisodiscorhabds are scattered between the megascleres in the ectosome and choanosome.

Megascleres. Styles ( Tab. 1 ; Fig. 3 F): Smooth, straight, centrally thickened, hastate, irregularly and sparsely spined along the proximal end of the shaft: 319 (288–346) x 10 (7–12) μm, n=20.

Microscleres. Anisodiscorhabds ( Tab. 1 ; Fig. 3 C–E): Shaft occasionally spined, 8 μm wide. Basal whorl and manubrium undifferentiated, forming a cuff of irregularly distributed acanthose spines. Median whorl, 27.6 μm in diameter, divided into four segments, each segment possessing acanthose spearhead-shaped spines, subsidiary whorl with spines slanted slightly upwards, also divided into four segments, each segment possessing acanthose spearhead-shaped spines ( Fig. 3 E). Apical whorl and apex form a tuft of smooth to acanthose spines: 49 (48–53) μm, n=20.

Ecology. Sponge associated with the coral Allopora nobilis , various anemone species, bushy hydroids ( Eudendrium sp.), various bryozoan species, and other sponges, on a horizontal rock platform at 41 m.

Etymology. Named after Dr Albrech Götz, South African Environmental Observation Network, for assistance on the Agulhas Shelf survey.

Remarks. Latrunculia (Biannulata) gotzi sp. nov. differs from other South African species in having meandering areolate porefields rather than discrete raised structures. In life, these porefields are a lighter colour than the body which is mahogany brown ( Tab. 1 ; Fig. 3 A). Latrunculia (B.) lunaviridis is pale olive green and has thicklipped, irregular, crater-shaped areolate porefields, with a distinctive shallow poral membrane, while L. (B.) microacanthoxea Samaai et al. 2003 , is dark green mottled with brown patches and has short thick-lipped crater-shaped areolate porefields with a deep, barely visible, poral membrane. The megascleres and microscleres in L. (B.) gotzi sp. nov. are somewhat smaller than in other South African species ( Tab. 1 ) and lack the curved polytylote styles found in L. (B.) lunaviridis and the microacanthoxeas of L. (B.) microacanthoxea .

Subtle differences in the ornamentation of the anisodiscorhabds also differentiate these South African species. The microspines on the median, subsidiary and apical whorls of L. (B.) lunaviridis and L. (B.) microacanthoxea anisodiscorhabds form rough serial serrations that are smaller and less obvious than the larger irregular spines on the various whorls of L. (B.) gotzi sp. nov. In the former species the apical whorl and apex are quite uniform, forming a tuft, whereas in L. (B.) gotzi sp. nov. the apical region is spinose and the apex formed from several large spines. Also in the former species the basal tuft of spines are only occasionally spinose, whereas the basal tuft in L. (B.) gotzi sp. nov. is comparatively heavily spined. Finally, the median and subsidiary whorls of L. (B.) gotzi sp. nov. form quite distinctive spearhead-shaped spines, that at least in the median whorl are vertically orientated.

Species Styles (µm) Anisodis- Additional characters Location corhabds (µm)

L. (B.) lunaviridis Samaai 357 (336–384) x 12 54 (53–60) Ouderkraal, 17–32 m et al. 2003

Material examined. Holotype SAM-A24719: 45-Mile Banks, Agulhas continental shelf, about 40 km from Agulhas Point, Western Cape, South Africa, 35.349° S, 20.608° E, RV Ellen Khuzwayo, dredge, 22 March 2009, 85 m [cross reference number TS 1420 (3526/6)].

Type locality. 45-Mile Banks, South Africa.

Description. Small, thin encrusting sponge, elongate to meandering, 1.5 cm long x 1 cm wide x 0.8 cm high ( Fig. 4 A), with numerous low conical, volcano-shaped oscules, 1 mm wide, 0.2 mm high, barely visible in the preserved specimen. Areolate porefields crater-shaped, about 1 mm wide. Texture firm, leathery, and slightly granular to the touch. Colour in life dark greenish brown, lighter in preservative.

Skeleton. Choanosome a highly cavernous array of irregular polygonal wispy tracts of megascleres ( Fig. 4 B) ranging in width from 77 to 192 μm, forming meshes about 144 to 480 μm wide. Tracts diverge from the inner choanosome towards the surface and are 144 to 192 μm wide. A single layer of anisodiscorhabds forms a palisade in the ectosome, below which is a paratangential layer of megascleres, 144–288 μm thick, becoming vertical near the porefields. Numerous anisodiscorhabds and megascleres are scattered throughout the choanosome between tracts.

Megascleres. Styles ( Tab. 1 ; Fig. 4 D): Smooth, slightly sinuous, centrally thickened, sparsely and finely spined along the proximal end of the shaft, often polytylote; 367 (346–394) x 11 (10–12) μm, n=20.

Microscleres. Anisodiscorhabds ( Tab. 1 ; Fig. 4 C): Shaft smooth, 6 μm wide. Basal whorl and manubrium undifferentiated, forming a cuff of irregularly distributed smooth spines. Median whorl, 36 μm in diameter, and subsidiary whorl are brackets of irregularly serially serrated spearhead-shaped spines, divided into four segments resembling a ‘hand’. The apical whorl and apex form a tuft of acanthose spines, the apex is composed of well separated spines; 53 (48–55) μm, n=20.

Ecology. Sponge encrusting igneous rock with numerous other encrusting sponges, bryozoans and hydroids, 85 m.

Etymology. Named after Dr Sven Kerwath, South African Department of Agriculture, Forestry and Fisheries, in recognition of efforts since 2008 to coordinate an integrated biomonitoring programme in the Cape region of South Africa.

Remarks. Latrunculia (Biannulata) kerwathi sp. nov. is unusual in the genus Latrunculia in that it forms a small, thin, meandering encrustation. This species is dark greenish brown, differing from L. (B.) gotzi sp. nov. which is mahogany brown with lighter porefields. The microscleres and megascleres of L. (B.) kerwathi sp. nov. are larger than in L. (B.) gotzi sp. nov. ( Tab. 1 ), and the former has a much thicker ectosome and cavernous interior than the latter. The anisodiscorhabds of L. (B.) kerwathi sp. nov. have whorls that form quite distinctive brackets, or ‘hands’ of acanthose spines in which the margins are serrated.

Latrunculia (B.) kerwathi sp. nov. differs from known South African species L. (B.) microacanthoxea , and L. (B.) lunaviridis in that the latter are both massive olive green sponges, and L. (B.) microacanthoxea has microacanthoxeas. The anisodiscorhabds of L. (B.) lunaviridis have well-spaced spines compared to the rather dense arrangement in L. (B.) kerwathi sp. nov.

Figures

FIGURE 3. Latrunculia (Biannulata) gotzi sp. nov.: A. Holotype SAM-A 2418, in situ, scale = 15 mm; B. Transverse histological section of the body showing loose wispy tracts and relatively cavernous interior, scale = 144 µm; C. Protodiscorhabd showing undifferentiated basal and apical whorls, scale = 12 µm; D. Mature anisodiscorhabds with incised whorls of spines and undifferentiated basal whorl and manubrium, scale = 12 µm; E. Ornamentation of the subsidiary and median whorls showing spear-head morphology, scale = 8 µm; F. Lightly spined styles, scale = 5 µm.

FIGURE 4. Latrunculia (Biannulata) kerwathi sp. nov.: A. Holotype SAM-A 27419, preserved specimen, scale = 5 mm; B. Transverse histological section of the body showing the cavernous interior and thick tangential ectosome, scale = 24 µm; C. Anisodiscorhabd, scale = 10 µm; D. Style with light spinning, scale = 8 µm.

FIGURE 6. A comparison of anisodiscorhabds and other microscleres of species presently considered valid within subgenera Latrunculia (L.) du Bocage, 1869 (A – N), L. (Biannulata) Samaai et al., 2006 (O – AA), and L. (B.) incertae sedis (AB – AD): A. L. (L.) triverticillata Alvarez et al., 2002; B. L. (L.) fiordensis Alvarez et al., 2002; C. L. (L.) oxydiscorhabda Alvarez et al., 2002; D. L. (L.) cratera du Bocage, 1869; E. L. (L.) bocagei Ridley & Dendy, 1886; F. aciculodiscorhabd of L. (L.) apicalis Ridley & Dendy, 1886; G. aciculodiscorhabd of L. (L.) biformis Kirkpatrick, 1908; H. L. (L.) basilis Kirkpatrick, 1908; I. L. (L.) brevis Ridley & Dendy, 1886; J. L. (L.) palmata Lévi, 1964; K. L. (L.) multirotalis Topsent, 1905; L. L. (L.) ikematsui Tanita, 1968; M. L. (L.) novaecaledoniae Samaai et al., 2006; N. L. (L.) crenulata Lévi, 1993; O. L. (B.) kaakaariki Alvarez et al., 2002; P. L. (B.) duckworthi Alvarez et al., 2002; Q. L. (B.) procumbens Alvarez et al., 2002; R. L. (B.) wellingtonensis Alvarez et al., 2002; S. L. (B.) kaikoura Alvarez et al., 2002; T. L. (B.) millerae Alvarez et al., 2002; U. L. (B.) spinispiraefera Brøndsted, 1924; V. L. (B.) purpurea Carter, 1881; W. L. (B.) lunaviridis Samaai & Kelly, 2003; X. L. (B.) microacanthoxea Samaai & Kelly, 2003; Y. L. (B.) gotzi sp. nov.; Z. L. (B.) kerwathi sp. nov.; AA. L. (B.) algoaensis sp. nov.; AB. L. austini Samaai et al., 2006; AC. L. citharistae Vacelet, 1969; AD. L. oparinae Samaai & Krasokhin, 2002. Reproduced or redrawn from du Bocage (1869), Ridley & Dendy (1886), Topsent (1905), Brøndsted (1924), Lévi (1964, 1993), Alvarez et al. (2002), Samaai & Krasokhin (2002), Samaai & Kelly (2003), Samaai et al. (2006), (not to scale).

Tables

TABLE 1. Morphological characters of species of South African Latrunculia (Biannulata) Samaai et al. 2006.

Species	Morphology	Colouration
L. (B.) lunaviridis Samaai et al. 2003	hemispherical with thick-rimmed oscules and crater-shaped porefields	pale olive green
L. (B.) microacanthoxea Samaai et al. 2003	hemispherical with thick-rimmed oscules and crater-shaped porefields	olive green
L. (B.) gotzi sp. nov.	hemispherical with broad meandering areolate porefields and simple membranous oscules	mahogany brown (porefields light cork brown)
L. (B.) kerwathi sp. nov.	Thin encrusting with tiny raised aquiferous structures	dark greenish brown
L. (B.) algoaensis sp. nov.	hemispherical with thick-lipped, circular areolate porefields	green
continued.