Halichondria (Halichondria) cristata Sarà, 1978

Cóndor-Luján, Báslavi, Arteaga, Alvaro, Polo, Christian, Arroyo, Yessenia, Willenz, Philippe & Hajdu, Eduardo, 2023, Shallow Suberitida (Porifera, Demospongiae) from Peru, Zootaxa 5264 (4), pp. 451-489 : 456-458

Halichondria (Halichondria) cristata Sarà, 1978

( Figure 2 , Table 2)

Synonyms: Halichondria cristata Sarà (1978) : 23, Fig. 8 , 9A, B ; Genzano et al. (1991): 68.

Type locality. Cape Domingo near Rio Grande, Tierra del Fuego, Patagonian Shelf, Argentina .

Material examined. Twelve specimens. MNRJ 11386 , MNRJ 11387 and MNRJ 11388 , San Cristobal, Lobos de Afuera Islands , Lambayeque (06°54′52.50′′S 80°42′55.90′′W), 12 m depth, coll. K.L. Aguirre, E. Hajdu, Y. Hooker & Ph. Willenz. 07.X.2007 . MNRJ 11389 , Cristo Salva , Lobos de Afuera Islands, Lambayeque (06°55′21.70′′S 80°42′30.70′′W), 30.9 m, coll. K.L. Aguirre, E. Hajdu, Y. Hooker & Ph. Willenz, 08.X.2007 . MNRJ 12208 and MNRJ 12821 , La Vieja Island , Independencia Bay , Paracas, Ica (14°16′08.20″S 76°11′25.00″W), 2.8 m depth, coll. Y. Hooker, Ph. Willenz & F. Azevedo, 09.XII.2008 . UCSUR 07-000041 , Sensor Station , Asia Island , Cañete, Lima (12°46′57.05′′S 76°37′12.19′′W), 8 m depth, coll. B. Moreno, 15.VIII.2018 . UCSUR 07-000045 , Playa Sur , San Bartolo, Lima (12°24′32.40″S 76°46′46.42″W), 17. VI.2013. UCSUR 07-000046 and UCSUR 07-000047 , Sensor Station , Asia Island , Cañete, Lima, (12°46′57.05′′S 76°37′12.19′′W), 4 m depth, coll. B. Moreno, 10.XI.2018 . UCSUR 07-000048 , Embajadores Beach , Santa María, Lima (12°24′40.87″S 76°46′39.21″W), coll. M.J. Sanchez, 14.VII.2018 . UCSUR 07-000085 , Sensor Station , Asia Island , Cañete, Lima (12°46′57.05′′S 76°37′12.19′′W), 5 m depth, coll. B. Cóndor-Luján, 17.VIII.2019 .

Description. Specimens either encrusting, thin or thick cushion-shaped, irregularly spreading, or bearing irregular projections (lobate, digitiform, volcaniform). Specimens over 10 cm in largest diameter. Oscula common or uncommon, small (diam. = 1–3 mm), apical on short projections, or nearly flat, sometimes with prominent thin dermal membrane. Surface reticulated to the naked eye in MNRJ 12821. Consistency compressible and surface smooth.

Colour. Light yellow alive ( Fig. 2A, B ) and beige in ethanol.

Skeleton. Variously cavernous, with abundant canals and subectosomal lacunae ( Fig. 2C ). Ectosomal, a loose reticulation intersected by many obliquely placed oxeas forming denser nodes ( Fig. 2D ). Choanosomal, with only rarely any sign of tracts (MNRJ 12821), or presenting loose, paucispicular radiating tracts (MNRJ 11388) more visible in the subectosomal area. Mostly, oxeas appear strewn at random.

Spicules. Megascleres.Oxeas, slightly bent at centre, tapering gradually (205–544 x 5–19 µm, Fig.2F, H , Table 2).

Ecology. This species occurred as an abundant epibiont on seagrass at Lobos de Afuera Islands (northern Peru), with several individuals forming patches over 50 cm in diameter, but also encrusting on cirripeds and densely intermingled to abundant erect, ramified bryozoans. At La Vieja and Asia islands (southern and central Peru), specimens occurred amidst anemones [Anthotoe chilensis ( Lesson, 1830)] and red-algae or associated to the holdfast of the kelp Eisenia cockeri (UCSUR 07-000041). Previously, it was found associated to mytillids and Macrocystis ( Sarà 1978) .

Geographic and bathymetrical distributions. SW Atlantic: Tierra del Fuego ( Sarà, 1978). SE Pacific: along the coasts of Peru, including Lobos de Afuera (06° S), Asia (12° S) and La Vieja islands (14° S, this study). Marine Ecoregions of the World (MEOW) in Peru: Central Peru and Humboldtian ecoregions ( Spalding et al. 2007). From intertidal ( Sarà 1978) to 31 m depth (this study).

Remarks. The only Halichondria known thus far from the SE Pacific is H. prostrata Thiele, 1905 , with oxeas only 300–320 µm long. Other seven species are known from the SW Atlantic. Among these, another two were reported with yellow(ish) colour in life, H. (Eumastia) attenuata ( Topsent, 1915) from Falklands Islands and H. (Halichondria) cristata from Tierra del Fuego. The former with a distinct densely fistular surface and oxeas that can be telescoped or mucronated, while the latter, aside its surface reported to bear abundant laminae and ridges, appears indistinguishable from the Peruvian specimens. In the original description of H. (H.) cristata, Sarà (1978) mentioned that the surface ornamentation was considerably less pronounced in encrusting specimens, which might explain the apparent absence in the encrusting Peruvian specimens studied.

Halichondria (H.) cristata has also been recorded from Mar del Plata ( Cuartas 1991) but has been tentatively assigned to Halichondria (H.) elenae Gastaldi, de Paula, Narvarte, Lôbo-Hajdu & Hajdu, 2018 from Bahia San Antonio (North Patagonian, Argentina) based on the similarity of their spicule dimensions (290–360 × 5–9 µm and 185–458 × 5–19 µm, respectively) and geographic proximity ( Gastaldi et al. 2018). Compared to H. (H.) cristata from Peru, Cuartas´ material possesses paucispicular tracts perpendicular to the surface joined transversely by one or two spicules ( Cuartas 1991), while the skeleton of the Peruvian specimens is composed of multispicular tracts and the spicules can attain larger dimensions (205–544 x 5–19 µm).

Figures

FIGURE 2. Halichondria (Halichondria) cristata Sarà, 1978. A–B, live specimens (MNRJ 11388 and MNRJ 12821, respectively); C, skeleton architecture in transverse ground section; D, skeleton architecture of the ectosome in tangential ground section; E–F, oxeas; G–H, details of E; Scale bars: A, 1 cm; B, approx. 1 cm; C–D, 500 µm; E–F, 100 µm; G–H, 20 µm; (C–H = MNRJ 11388).

FIGURE 8. Suberites aff. latus Lambe, 1893. A–B, live specimen (MNRJ 13698); C, tangential section of the ectosome in ground section (MNRJ 13698); D, skeleton architecture in transverse ground section (MNRJ 13698); E–F, tylostyles I & II, respectively; G–H, tylostyles heads of E–F. Scale bars: A, approx. 2 cm; B, 1 cm; C, 200 µm; D, 500 µm; E–F, 100 µm; G–H, 20 µm.

FIGURE 9. Suberites aff. latus Lambe, 1893. A–B, live specimen of the encrusting form (MNRJ 13688); C, skeleton architecture in transverse ground section (MNRJ 13688); D–E, tylostyles I & II respectively; F–G, tylostyles heads of D–E; H–K, centrotylotes. Scale bars: A, approx. 5 cm; B, 1 cm; C, 500 μm; D–E, 100 μm; F–G, 20 μm; H–K, 10 μm.