Abyssocladia glomeris (Castello-Branco & Hajdu, 2024)

Echinostylinos gorgonopsis Lévi, 1993 View in CoL ( Fig. 7 View Fig )

Abyssocladia mucronata Vacelet, 2020: 269 ; Figs. 7 View Fig –8.

Material examined: Holotype. Echinostylinos gorgonopsis Lévi, 1993 MNHN DCL 3612, New Caledonia, SW Pacific ( BIOCAL 74 ; st. CP 45, ‘l'ORSTOM’ campaign; -23.1717 / 167.7163), 950– 1000 m depth, coll. R / V 'Jean Charcot'. GoogleMaps

Diagnosis: The only species of Abyssocladia with anisoxeas (525–650 × 4–5 µm) and tornotes (250–370 × 4–5 µm) as megascleres, and abyssochelae as its sole microscleres (30–50 µm).

Brief redescription (based on the holotype and Lévi (1993) description): Sponge, erect, arborescent, 14 cm long × 12 cm wide, with a short and cylindrical stalk (ca. 2 cm, broken). Most branches at the same plane, with 3–7 successive dichotomies. Irregular surface, rough to the touch, with small projections (lobes), giving the impression of a slight annealing, and with numerous circular openings at the apical branches. Sponge yellow to ocre in ethanol (modified from Lévi 1993; Fig. 6A View Fig ).

Skeleton: Dense, with ascendant multispicular tracts of megascleres, and microscleres abundant especially on the surface.

Spicules (presently remeasured): Megascleres anisoxeas and tornotes (both as tornostyles in Lévi, 1993). Anisoxeas smooth, straight to slightly curved, with acerate and conical or mucronate ends; 440–513.9– 620 × 15–16.8–18 µm. Tornotes smooth and straight, with acerate ends; 280–318.3–350 × 5–7.4–8 µm. Microscleres cleistochelae with 35–38.6–50 µm.

Distribution: Known from SW Pacific, New Caledonia, depth 950–1019 m ( Lévi 1993; Vacelet 2020).

Remarks: Lévi chose to name E. gorgonopsis megascleres of tornostyles. However, after better detailed analysis through SEM images, we prefer to name the larger ones as anisoxeas, and the smaller ones, tornotes, according to the thesaurus of nomenclature for sponges ( Boury-Esnault and Rützler 1997). The anisoxeas of E. gorgonopsis have acerate and conical or mucronate ends. The tornotes are straight and have acerate ends.

W h e n w e f i r s t a n a l y z e d t h e t y p e, w e h a d decided to propose the transfer of Echinostylinos gorgonopsis to Abyssocladia Lévi, 1964 on account of its habit, skeleton and spicules, which appear more related to the latter genus, than to Echinostylinos or Phelloderma . The arbuscular shape (gorgonian-like) of E. gorgonopsis , with a short stalk, its two categories of basally mucronated styles, and twisted cleistochelae (abyssochelae-like), concentrated at the surface of the sponge ( Fig. 6 View Fig ) are easily correlated to the habit of a typical carnivorous sponge, such as Abyssocladia spp. (sensu Vacelet 2006). However, after discovered of new samples with redescriptions of the former, plus a synomymization of an Abyssocladia species from the same region ( Abyssocladia mucronata Vacelet, 2020 ) in Echinostylinos ( Vacelet & Kelly, 2022) , we have decided to keep this species as valid. The authors ( Vacelet and Kelly 2022) highlighted the similarities of both species, equating the lobes with openings observed on video records with the channels reported by Lévi (1993), choosing to synonymize both species. Evolution is made of several reversions and convergences, and there are cases reported in the literature, of channels in Chondrocladia (although none has ever been recorded in an Abyssocladia ). With the evidence of possible channels suggesting a filter feeding habit we prefer to keep E. gorgonopsis as Echinostylinos (including Vacelet’s synonymized species). In a future study, this and other hypotheses about Echinostylinos and Abyssocladia can be tested by DNA sequencing.

Identification key for the species of Echinostylinos View in CoL

1. Unguiferate isochelae ................................................................. 2

- Spatulate isochelae ..................................................................... 7

- Abyssochelae-like isochelae .............. E. gorgonopsis Lévi, 1993 View in CoL

2. Isochelae tridentate ..................................................................... 3

- Isochelae tetradentate .................................................................... ............... E. brasiliensis Carvalho, Lopes, Cosme & Hajdu, 2016 View in CoL

3. Only one category of megascleres ................................................ ......................................................... E. schmidtii ( Arnesen, 1903) View in CoL

- Two categories of megascleres ................................................... 4

- Two categories of megascleres ......... E. mycaloides Koltun, 1970 View in CoL

4. Sigmas present ............................................................................ 5

- Sigmas absent ............................................... E. abyssalis sp. nov.

5. More than one category of chelae and sigmas ........................... 6

- Only one category of chelae and sigmas ....................................... ................................................................ E. hirsutus Koltun, 1970 View in CoL

6. Only one category of chelae and two of sigmas ............................ ................... E. patriciae Carvalho, Lopes, Cosme & Hajdu, 2016 View in CoL

- Two categories of chelae and only one of sigmas ......................... ................................................ E. stylophora ( Lévi & Lévi, 1983) View in CoL

7. A single category of megascleres ............................................... 8

- More than a single category of megascleres .............................. 9

8. Only one category of chelae and sigmas ..... E. iatapiuna sp. nov.

- Two categories of chelae and only one of sigmas ......................... ................................................................ E. lingua ( Koltun, 1970) View in CoL

9. (Largest megascleres up to 600 µm, occurrence in the Atlantic Ocean ............................................... E. reticulatus Topsent, 1927 View in CoL

- Largest megascleres>1000 µm, occurrence in the Pacific Ocean ................................................................................................... 10

10. Body massive narrowed basally with low conules; smaller category of sigmas u-shaped (flagellate condition) ....................... ..................................................... E. shimushirensis Koltun, 1970 View in CoL

- Erect sponge gradually widening away from the base; smaller category of sigmas c-shaped .............. E. tubiformis ( Lévi, 1993) View in CoL