 |
| Advhena magnifica
Castello-Branco, Collins & Hajdu, 2020
DOI: 10.7717/peerj.9431
|
Abstract
This article describes or redescribes four hexactinellid sponges, namely Poliopogon amadou, Euplectella sanctipauli sp. nov., Bolosoma perezi sp. nov. and Advhena magnifica gen. et sp. nov. P. amadou, E. sanctipauli sp. nov. and B. perezi sp. nov. represent new findings for the South Atlantic deep-sea fauna, including the first record of Bolosoma for this ocean. Advhena magnifica gen. et sp. nov., on the other hand, was collected by NOAA oceanographic expeditions in the North Pacific (Pigafetta Guyot).
 |
| Figure 8: Advhena magnifica gen. et sp. nov. holotype (USNM 1424107). (A‒D) specimen in situ; (E and F) details of specimen in ethanol (1 cm). |
Genus Advhena gen. nov.
Type species: Advhena magnifica gen. et sp. nov.
Diagnosis: Bolosominae with a globular body slightly flattened, with big lateral opening and long stalk (at least four times the body size). Choanosomal spicules are diactins. Dermalia and atrialia are hexactins and pentactins. Microscleres are discohexasters, codonhexasters, calycodiscohexasters and graphiocomes.
Etymology: Feminine gender. Modified from the latin, ‘Advena’, meaning stranger, foreigner, alien, newcomer, guest, in reference to the sponge shape, which calls to mind aliens from various movies. An ‘h’ was added in ‘Advena’ (Advhena) to distinguish the name from that of the helicarionid gastropod Advena Gude, 1913, in order to make sure there will be no overlapping with valid names.
Remarks: The new specimen cannot be accommodated in any of the currently accepted genera in the subfamily (Table 2). It is clearly a long stalked Bolosominae individuum, with diactins as the main spicules, plus hexactins and pentactins. It is distinguished from other Bolosominae by the set of microscleres present, namely discasters, discohexasters, codonhexasters and derivatives, calycocomes, and graphiocomes, which render it unique among bolosomines, and justifies the proposal of a new genus.
Advhena magnifica sp. nov.
Diagnosis: Advhena magnifica sp. nov. is the only representative of Bolosominae with microscleres as discasters (480–570 μm diam.), discohexasters (55–60 μm diam.), codonstaurasters (103–160 μm diam.), discohexasters with calycocomes (138–255 μm diam.) and graphiocomes (150 μm (N = 1); 20–33 μm primary rays’ diam.).
DISTRIBUTION AND ECOLOGY. Known from its type locality in the Pigafetta Guyot, east of the Mariana Trench (Pacific Ocean), 2028 m depth. Some video footage of likely Advhena specimens was obtained by NOAA ‘Okeanos’ expedition a year later (25 July 2017) at a locality rich in sponge diversity, dubbed the “Forest of the Weird”, as part of the Laulima O Ka Moana: Exploring Deep Monument Waters Around Johnston Atoll expedition (EX1706; on https://oceanexplorer.noaa.gov/okeanos/explorations/ex1706/dailyupdates/media/video/dive11-forest/forest.html).
ETYMOLOGY. The specific epithet is used as a noun in apposition, and refers to the species’ magnificent, beautiful appearance.
 |
| Figure 10: Illustration of Advhena magnifica gen. et sp. nov. microscleres. (A) Codonstauraster; (B) graphiocome (Illustrations by Nicholas Bezio). |
Cristiana Castello-Branco, Allen G. Collins and Eduardo Hajdu. 2020. A Collection of Hexactinellids (Porifera) from the deep South Atlantic and North Pacific: New Genus, New Species and New Records. PeerJ. 8:e9431 DOI: 10.7717/peerj.9431
A Magnificent New Sponge from the Deep Gets a Name
