Crella (Pytheas) chiloensis Fernandez, Gastaldi, Pardo & Hajdu 2021, sp. nov.
Creators: name: Fernandez, Julio C. C.
name: Gastaldi, Marianela
name: Zapata-Hernández, Germán
name: Pardo, Luis M.
name: Thompson, Fabiano L.
name: Hajdu, Eduardo
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Porifera
Demospongiae
Poecilosclerida
Crellidae
Crella
Crella chiloensis

description: Crella (Pytheas) chiloensis Fernandez, Gastaldi, Pardo & Hajdu, sp. nov.
(Tables 1–2; Figures 2–3)
Type locality. Isla Metalqui, Chile (- 42.19499194 S, - 74.14436500 W).
Material examined. Holotype — IZUA-POR 170, Isla Metalqui, Western Chiloé Island, Chile (- 42.19499194 S, - 74.14436500 W), 15 m depth, coll. L.M. Pardo, 15 th November 2012. Fragment of holotype under MNRJ 16993. Paratypes — MNRJ 16989, Puñihuil, Cocotue bay, Chiloé Island, Chile (- 41.92085694 S, - 74.04113500 W), 15 m depth, coll. L.M. Pardo, 10 th November 2012; MNRJ 16996, Duhatao, Chiloé Island, Chile (- 41.98800306 S, - 74.05453000 W), 15 m depth, coll. L.M. Pardo, 16 th November 2012; MNRJ 17002, Isla Metalqui, Western Chiloé Island, Chile (- 41.19499194 S, - 74.14436500 W), 15 m depth, coll. L.M. Pardo, 15 th November 2012.
Diagnosis. Only Crella (Pytheas) in the Pacific being thickly encrusting to massive, reddish orange in life, with tornotes (120–188/3.2–7.5 µm), three categories of acanthostyles (choanosomal, I. 120–165/6–14 µm and II. 88–118/5.5–11 µm; ectosomal, 52–95/4–9 µm) and arcuate isochelae (13–19.5 µm).
Description. Habit thickly encrusting or irregularly massive and lobate (Figs. 2A–C); holotype in life, 14 (L) x 8 (W) x 3 cm (H), paratype in life (MNRJ 16989), 14 (L) x 11 (W) x 3.7 cm (H) and holotype preserved, 10 (L) x 6 (W) x 3 cm (H). Surface irregular, slightly corrugated (Fig. 2C), with thin, strongly adhered membrane (Fig. 2D). Oscula small, scattered (Fig. 2E). Pores very small and grouped in pore sieves, ca. 0.5 mm in diameter, in preservative (Fig. 2F). Subectosomal channels very slender, scarce. Consistency firm, but compressible. Texture slightly rough. Color reddish-orange in life and beige in preserved specimens.
Skeleton. Plumoreticulate architecture (Fig. 3A). Ectosomal region with several tornotes in vertical arrangement and in bouquets (Fig. 3B), usually protruding up to 80 µm above the surface. Beneath the surface (subectosomal region) thick tracts of tornotes (ca. 100–150 µm thick) run towards spongin fibers coring them at the choanosome (Fig. 3B). Acanthostyles (ectosomal category) in tangential to paratangential arrangement at the ectosome and subectosome (Fig. 3C). Choanosomal region with spongin fibers (up to 180 µm thick) strongly echinated by two categories of choanosomal acanthostyles (Figs. 3B, 3D). Some choanosomal acanthostyles occurring into the fibers too. Spongin fibers are more frequent in the choanosomal region than the ectosomal and subectosomal regions (Fig. 3B). A basal layer of erect choanosomal acanthostyles echinates the substrate (Fig. 3D). All categories of acanthostyles (ectosomal and choanosomal) are distinguished by size (length and width) and patterns of spination. Several tornotes, choanossomal acanthostyles and arcuate isochelae occur scattered throughout the choanosomal region. Furthermore, arcuate isochelae and a few ectosomal acanthostyles occur around channels as well. In spongin there are rounded subectosomal (ca. 250 µm longer length) and choanosomal channels (up to 2000 µm longer length).
Spicules. Megascleres (Tables 1–2). Tornotes (Figs. 3E–F, 3K–L) straight and usually smooth, some formed as aniso-tornotes or with a few small spines, tips mucronate, lanceolate, conical to asymmetrical; juvenile forms slender and smooth: 120– 155 (11.6)–188/3.2– 5.7 (0.9)–7.5 µm. Choanosomal acanthostyles I (Figs. 3G, 3M), largest category of acanthostyles, straight to slightly curved, not fully spined, blunt bases (no tyle), tips usually acerate; spines small (up to 3 µm high), concentrated at the bases; spines from the axis slightly bent towards the base and usually absent on the apical fourth; juvenile forms slender, with smaller and straight spines: 120– 152.3 (14) –195/6– 10 (1.4)–14 µm. Choanosomal acanthostyles II (Figs. 3H, 3N), intermediate category of acanthostyles, almost fully spined; spines also more concentrated at the bases; juvenile forms, slender, with smaller and straighter spines: 88– 102 (7.4)–118/5.5– 8.8 (1)–11 µm. Ectosomal acanthostyles (Figs. 3I, 3O), the smallest category of acanthostyles, slightly curved to slightly sinuous, axis with regular diameter and fully spined, blunt bases (no tyle), tips conical to acerate; spines small (up to 3 µm high), straight and uniformly distributed; juvenile forms, slender with several smaller and thinner spines: 52– 75.6 (7)–95/4– 6.3 (1.1)–9 µm. Acanthoxeas (Fig. 3I, in the right), rare, patter of spination (fully spined) closer to the ectosomal acanthostyles: average of 85/8 µm (n = 3). Microscleres (Tables 1–2). Arcuate isochelae (Figs. 3J, 3P) in one size category, axis curved in the middle, alae slightly elongated and rounded; relatively short distance between opposite alae, less than 1/3 of maximum chelae length; juvenile forms with slender axis and smaller alae (reduced alae): 13– 16 (1.3)–19.5 µm.
Ecology. Specimens grew over hard bottom covered by calcareous algae and barnacle. Holotype and paratypes with polychaete tubes.
Distribution. Provisionally endemic to western Chiloé Island (Southern Chile, Fig. 1).
Etymology. The name ‘chiloensis’ is a reference to Chiloé Island, where the type locality of the new species is located.
Remarks. Five species of Crella (Pytheas) occur in the Pacific Ocean, four of them from New Zealand and one from Hawaii (Table 2). Crella (P.) chiloensis Fernandez, Gastaldi, Pardo & Hajdu, sp. nov. is set apart from these Pacific species as well as from all other known species of Crella (P.) due to the combination of three categories of acanthostyles (two choanosomal and one ectosomal) and small size of megascleres (tornotes up to 188/7.5 µm, larger choanosomal acanthostyles up to 195/14 µm, smaller choanosomal acanthostyles up to 118/11 µm and ectosomal acanthostyles up to 95/9 µm). Three categories of acanthose megascleres are also present in other Crella (P.) species, but the tangential layer of acanthose megascleres of them is composed by acanthoxeas rather than acanthostyles, that separates them from the new species (Table 2). Although a few acanthoxeas were observed in Crella (P.) chiloensis Fernandez, Gastaldi, Pardo & Hajdu, sp. nov., they are interpreted as a variation of ectosomal acanthostyles due to the similar dimensions, pattern of spination and position in the skeleton. A few acanthoxeas are also present in C. (P.) jaegerskioeldi Alander, 1937 and have been mentioned in its original description as a variation of ectosomal acanthostyles as well, since such acanthoxeas occur among the ectosomal acanthostyles in the tangential layer (Alander 1937: 72; Fig. 2).
description: Published as part of Fernandez, Julio C. C., Gastaldi, Marianela, Zapata-Hernández, Germán, Pardo, Luis M., Thompson, Fabiano L. & Hajdu, Eduardo, 2021, New species of Crella (Pytheas) Topsent, 1890 and Crellomima Rezvoi, 1925 (Crellidae, Poecilosclerida, Demospongiae) from Chilean shallow and Argentinean deep waters, with a synthesis on the known phylogenetic relationships of crellid sponges, pp. 353-379 in Zootaxa 5052 (3) on pages 356-357, DOI: 10.11646/zootaxa.5052.3.3, http://zenodo.org/record/5572169