Lissodendoryx (Ectyodoryx) ballena Fernandez, Cárdenas, Bravo, Lôbo-Hajdu, Willenz & Hajdu, 2016, sp. nov.

Lissodendoryx (Ectyodoryx) ballena sp. nov.

(Tabs 1–2; Figs 2–3)

Holotype. IZUA–POR 166, Islote Ballena, Gulf of Ancud, southern Chile (42º09’25.00”S / 72º34’46.50”W), 14 m depth, coll. E. Hajdu, Ph. Willenz & G. Lôbo-Hajdu, 24 February 2005. Fragments from holotype deposited under MNRJ 8807, RBINSc–IG 32232–POR 8807 and MHNG 89960. Paratype. MNRJ 8813, same data as holotype. Fragments from paratype deposited under, RBINSc–IG 32232–POR 8813 and MHNG 89962.

Diagnosis. Thickly encrusting Lissodendoryx (Ectyodoryx), with numerous oscules (<0.5 mm across) over all its surface, with orange colour in life, smooth tornotes (108–135/2.5–4.8), acanthostyles (I. 180–232/8–16.8, II.77 – 95/4.8–8), arcuate isochelae (I. 31–47, II. 23–29, III. 12.5–18), and sigmas (19–26).

Description. Thickly encrusting (Fig. 2A), up to 0.7 cm thick. The holotype covered an area of approximately 10 x 5 cm (in life). Surface slightly rugose, with a few grooves. Oscules spread, few, smaller than 0.5 cm in diameter. Numerous other small openings occur all over the surface of the sponge (Fig. 2B). Colour in vivo orange, turning to dark beige in ethanol. Consistency moderately compressible. Texture velvety.

Skeletal architecture. Plumoreticulate (Figs 3 A–B). Acanthostyles form echinated tracts from the substrate to near the surface (Figs 3 C–D). Acanthostyles I (larger) core the tracts, while acanthostyles II (smaller) echinate those tracts. Tornotes are spread at random or slightly obliquely at the surface. These spicules, as well as acanthostyles and every microsclere category can be seen scattered in the choanosome too. Nevertheless, isochelae occur in larger quantities closer to the surface. Subectosomal lacunae were not seen, but numerous roundish canals (up to 700 µm in largest diameter) occur in the choanosome. Both the holotype and paratypes have their choanosome traversed by polychaete tubes. Spongin will envelop some of these choanosomal cavities and support erect acanthostyles I and II (Fig. 3 G). Larvae were observed in both specimens, up to 220 µm in diameter.

Spicules. Megascleres (Tabs 1–2): Tornotes (Figs 3 H–I), straight, smooth, slightly aniso-tylote, 108– 123.5 (8.4)–135/2.5– 3.5 (0.8)–4.8. Acanthostyles I (Figs 3 J–K), straight or slightly curved; base roundish, narrow or slightly swollen; sharp apex, thinning gradually; spines in large numbers, up to 5 µm high, straight or slightly curved, distributed over the entire shaft and base, 180– 202.5 (16)–232/8– 13 (2.6)–16. Acanthostyles II (Figs 3 L– M), morphology similar to that of category I, but with smaller spines, 77– 84.2 (4.4)–95/4.8– 7 (0.9)–8. Microscleres (Tabs 1–2): Arcuate isochelae I (Figs 3 E, F, N), shaft arched, smooth and relatively stout; Alae slightly elongate and bent backwards; Young forms with markedly reduced alae, 31– 39 (4)–47. Arcuate isochelae II (Figs 3 E, F, O), morphology similar to that of category I, but smaller, 23– 25.3 (1.2)–29. Arcuate isochelae III (Fig. 3 P), more slender and smaller than both preceding categories; alae slightly elongate, but not bent backwards, 12.5– 15.3 (1.8)–18. Sigmas (Fig. 3 Q), contorted, smooth and pointy, 19– 23.3 (1.5)–26.

Observation. Acanthostyles I (main choanosomal), acanthostyles II (echinating choanosomal), acanthostyles III (echinating choanosomal).

Ecology. Grows over barnacles, bivalves and rock covered by coralline algae, in a community dominated by mytilids and Crepidula gastropods. A few bryozoans and corallimorpharians occurred over its surface.

Distribution. Provisionally endemic from its type locality in the Gulf of Ancud (Islote Ballena), Chile.

Etymology. The specific epithet ‘ballena’ is used as a noun in apposition and refers to the species’ type locality. The word means whale in Spanish.

Remarks. The Sturges algorithm (Sturges, 1926) confirmed the occurrence of two size classes of isochelae; i.e. 34–46.8 and 12.5–29.5. The smaller size class can be easily distinguished in two morphological categories, thus indisputably raising the number of categories in this proposed new species to three.

As introduced above for the genus Lissodendoryx, the subgenus Ectyodoryx currently comprises 32 species recognized as valid according to van Soest et al. (2015), ten of which occur either in Chilean waters, or in neighboring biogeographic provinces, and demand a closer comparison. None of these, nevertheless, has three categories of isochelae as observed in L. (Ectyodoryx) ballena sp. nov. (Tab. 2). Furthermore, only four of these ten species possess ectosomal tornotes; viz. L. (E.) antartica, L. (E.) collinsi, L. (E.) jasonensis and L. (E.) minuta. However, these are quite larger than the tornotes of the new species.

Even though van Soest et al. (2015) assign Lissodendoryx diversichela Lundbeck, 1905 in the N Atlantic to subgenus Ectyodoryx, we propose its transfer to subgenus Lissodendoryx on the basis of its original description with a single category of acanthostyles. To the best of our knowledge there has never been a subsequent taxonomic account of this species where a second category of acanthostyles had been found. We would like to highlight the fact that L. (L.) diversichela has three categories of isochelae, as found in the new species described above.