Hymeniacidon perlevis (Montagu, 1814)

(Figure 4, Figure 5, Table 4)

Synonyms: (East Pacific, only) Hymeniacidon sinapium de Laubenfels, 1930: 26, Desqueyroux-Faúndez and van Soest 1997: 432, Hofknecht 1978: 54. Hymeniacidon perlevis (Montagu, 1814): Turner 2020: 542; Harbo et al. 2021: 280, Fig. 3.

Material examined. Twenty-two specimens. MNRJ 11252, Chilca Islet, Pucusana, Lima (12°28′42.13″S 76°47′55.26″W), 1 m depth, coll. E. Hajdu, Y. Hooker & Ph. Willenz, 20.IX.2007 . MNRJ 11288, North of Colorada Inlet, Samanco Bay, Chimbote, Ancash (09°11′40.80′′S 78°23′21.00′′W), 2.7 m depth, coll. E. Hajdu, Y. Hooker & Ph. Willenz, 24.IX.2007 . MNRJ 11430, Mancora Beach “El Point”, Piura (04°06′21.00″S 81°03′31.30″W), intertidal, coll. Y. Hooker & M. Ríos, 14.X.2007 . MNRJ 12084, Hotel de Turistas Beach, Ilo, Moquegua (17°38′11.63″S 71°20′28.99″W), intertidal, coll M. Ríos, 09.XI.2008 . MNRJ 12205 and MNRJ 12206, La Vieja Island, Independencia Bay, Paracas, Ica (14°16′08.20″S 76°11′25.00″W), 4.2 and 4.4 m depth, Y. Hooker, Ph. Willenz & F. Azevedo, 09.XII.2008 . MNRJ 12181 and MNRJ 12183, Punta San Juan, San Juan de Marcona, Ica (15°22′03.23″S 75°11′18.41″W), intertidal, coll. Y. Hooker, M. Vichez, Ph. Willenz, G. Lobo-Hajdu, F. Azevedo, 05.XII.2008 . MNRJ 12859, Roquedal, Laguna Grande, Paracas, Ica (14°09′11.80″S 76°15′51.30″W), 1.3 m depth, coll. E. Hajdu, Y. Hooker & Ph. Willenz, 12.XII.2008 . MNRJ 12886, Islote, Atenas Beach, Paracas, Ica (13°49′38.71″S 76°18′07.41″W), 1.6 m depth, coll. Y. Hooker, Ph. Willenz & N. Mostajo, 13.XII.2008 . UCSUR 07-000007, San Lorenzo Island 1, El Callao, Lima (12°05′46.71″S 77°11′29.46″W), 7 m depth, coll. L. Aguirre, XII. II.2010 . UCSUR 07-000013, Las Ninfas Beach, Pucusana, Lima (12°28′49″S 76°48′3″W), intertidal, coll. B. Moreno & A. Cuba, 27. VI.2010. UCSUR 07-000040, Playa Hermosa, San Juan de Marcona, Ica (15°21′20″S 75°10′16″W), intertidal, coll. J. Francia, 06.VIII.2018 . UCSUR 07-000043, north side of Santa Rosa Island, Independencia Bay, Paracas, Ica (14°15′24″S 76°13′9″W), subtidal, coll . R. Canales & B. Cóndor-Luján, 14.XI.2010 . UCSUR 07-000051, Atenas Beach, Paracas, Ica (13°49′13.16″S 76°18′2.81″W), 7 m depth, coll. K. Farfán, 01.II.2019 . UCSUR 07-000053, Las Ninfas Beach, Pucusana, Lima (12°28′49″S 76°48′3″W), intertidal, coll. A. Arteaga, Y.Arroyo & B. Cóndor-Luján, 19.II.2019 . UCSUR 07-000059, Las Ninfas Beach, Pucusana, Lima (12°28′49″S 76°48′3″W), intertidal, coll. M. Pita, 13.IV.2019 . UCSUR 07-000069, UCSUR 07-000070, UCSUR 07-000071, UCSUR 07-000072 and UCSUR 07-000073, Las Ninfas Beach, Pucusana, Lima (12°28′49″S 76°48′3″W), intertidal, coll. C. Polo, 23.X.2019 .

Description. Sponge with variable growth. Encrusting or cushion-shaped (up to 1 cm thick, Fig. 4A, B, 5A). Bearing massive lobes (over 5 cm in height) or short digitiform fistules (up to 1 cm high, Fig. 5B). Specimens reaching over 50 cm in maximum diameter, but more often up to 10 cm. Oscula (diam. = 1–4 mm) on top of small elevations (average height = 6.5 mm), with one or multiple openings (Fig. 4A, 5B). Surface rough, consistency slightly compressible.

Colour. Orange (Fig. 4A–B) or yellow with a slightly orange tint (Fig. 5A–B) in life and dark mustard to beige in ethanol.

Skeleton. Ectosomal,architecture tangential or paratangential,reticulated or resembling a parchment arrangement in tangential view (Fig. 4C and 5C), with subectosomal cavities (average diameter = 430 µm). Choanosomal architecture confused, with ascending tracts ending in bouquets when reaching the surface (Fig. 4D and 5D).

Spicules. Megascleres. Styles to subtylostyles, smooth, straight or slightly curved, tyles small subterminal (102–443 x 2–13 µm, Fig. 4E–H and 5E–H, Table 4).

Ecology. This species is very frequent in intertidal and shallow subtidal habitats and it can attain considerable coverage and biomass in certain localities (e.g Pucusana and northern Peru). Specimens live attached to rocky substrates, near algae (e.g. Ulva lactuca) and invertebrates such as anemones, gastropods, mussels, ophiuroids and cirripeds (Gastaldi et al. 2016; this study).

Geographic and bathymetrical distributions. Cosmopolitan. N Atlantic and Mediterranean Sea (Montagu 1814; Topsent 1934). SW Atlantic: Argentina (Cuartas 1985; Gastaldi et al. 2018). SE Atlantic: Namibia and South Africa (Samaai et al. 2022). SW Indian: South Africa (Samaai et al. 2022). NW Pacific: Japan and Korea (Sim & Lee 2003; Hoshino et al. 2008). E Pacific: Canada, USA, Mexico and Galapagos Islands (Laubenfels 1932; Hofknecht 1978; Desqueyroux-Faúndez & van Soest 1997; Turner 2020; Harbo et al. 2021). Along the Peruvian coast: from Mancora (Piura, 04° S) to Ilo (Moquegua, 17° S, this study). MEOW in Peru: Guayaquil, Central Peru and Humboldtian ecoregions (Spalding et al. 2007). Intertidal to subtidal (25 m depth, Samaai et al. 2022).

Remarks. In the Eastern Pacific, eight valid Hymeniacidon species are known (de Voogd et al. 2022): H. actites (Ristau, 1978), H. adreissiformis Dickinson, 1945, H. calva (Ridley, 1881), H. corticata (Thiele, 1905), H. fernandezi Thiele, 1905, H. longistylus Desqueyroux, 1972, H. rubiginosa (Thiele, 1905) and H. perlevis (Montagu, 1814) . The Peruvian specimens match the descriptions of H. fernandezi, H. perlevis and H. rubiginosa (see Table 5 for details) but differ from the Chilean H. fernandezi and H. rubiginosa in the presence of subtylostyles, only described for H. perlevis (Erpenbeck & van Soest 2002) . Considering this, we rather identify the Peruvian material as H. perlevis, which has been found in the NE Pacific (e.g. Turner 2020, Harbo et al. 2021).

......continued on the next page

It is important to mention that due to their high morphological similarities in colour (red to yellowish), encrusting growth form with oscula frequently located on small elevations, confused choanosomal skeleton arrangement, and styles measuring 200–400 µm x 3–16 µm, H. fernandezi and H. rubiginosa have been suggested as synonyms of H. perlevis (de Laubenfels 1932; Erpenbeck & van Soest 2002; Burton 1932; Desqueyroux-Faúndez & van Soest 1997; Turner 2020, Table 5) and it would not be surprising to confirm the synonymy of these three species in future studies.