Amphimedon estelae Santos, Docio & Pinheiro, 2014, sp. nov.
Creators: name: Santos, George Garcia
name: Docio, Loyana
name: Pinheiro, Ulisses
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Porifera
Demospongiae
Haplosclerida
Niphatidae
Amphimedon
Amphimedon estelae

description: Amphimedon estelae sp. nov.
(Figures 1–3; Tables 1–2)
Type Locality: Brazil, Bahia State, Maraú, Taípus de Fora (near Camamu Bay).
Type Specimens: Holotype— UFPEPOR 695, Taípus de Fora (13º53’49”S, 38º55’45”W), Maraú (near Camamu Bay), Bahia State, Brazil, intertidal 0.5 m depth, col. U. Pinheiro, 25.XI.2007. Paratype—UFPEPOR 689, Taípus de Fora (13º53’49”S, 38º55’45”W) Maraú (near Camamu Bay), Bahia State, Brazil, intertidal 0.5 m depth, col. U. Pinheiro, 20.V.2007.
Diagnosis. Amphimedon estelae sp. nov. is the only Amphimedon in the Atlantic with strongyles, styles or oxeas covered by lumped swellings.
External morphology of holotype (Fig. 2 A). Massive with volcano-shaped oscular projections, 2 x 1.6 cm (height x length). Surface punctate due to regularly distributed subdermal cavities, microconulose. Oscules circular, 5 mm in diameter. Ectosome a translucent membrane, not easily detachable. Consistency firm and relatively compressible, but difficult to tear. Color in life is dark green, turning beige after preservation in ethanol 80%.
Paratype. Massive, 3.5 x 1 cm (height x length). Consistency firm. Color in life is dark green, turning beige after preservation in ethanol 80%.
Specimens Color in life Spicules Skeleton. The ectosomal skeleton consists of an irregular paratangential reticulation of uni-paucispicular (Fig. 2 B). Producing rounded meshes (150–500 Μm in diameter), covered by a fine membrane, which is lost in preserved specimens. Rounded meshes (240–750 µm in diameter) parallels to the surface (subectosomal), which may be poorly defined or masked by abundant free spicules (Fig. 2 C–D). Choanosomal skeleton is isotropic in some parts with multispicular tracts (36–100 µm in diameter), these being regularly distributed and cored by 6–20 spicules. Spongin not abundant, but always present cementing tracts and joining free spicules (Fig. 2 D).
Spicules (Figure 3; Table 1–2). Three categories of spicules were observed: (1) Strongyles (89%) can also vary in styles (7%) and oxeas (4%) with just one category of size (115–154 / 6–9 µm). Theses spicules show surfaces lumped swellings, generally in the middle region, but sometimes occur near the tips (Fig. 3 A–B). Few spicules do not have surface with lumped swellings. (2) Oxeas smooth, robust, straight to slightly curved (158–184 / 7–11 µm) were observed. Tips short and sharp (Fig. 3 C).
(3) Thin oxeas smooth, slender, slightly curved and pointed at both tips were observed (100–153 / 1–1.6 µm). The finest oxeas are raphidiform (Fig. 3 D).
References: (1) Pulitzer-Finali (1986); (2) Verrill (1907); (3) van Soest (1980); (4) Hartman (1955); (5) Duchassaing & Michelotti (1864); (6) Cuartas (1988); (7) Wilson (1902);
) Dendy (1887); (9) Muricy & Hajdu (2006); (10) Muricy et al. (2011); (11) Hechtel (1965); (12) Campos et al. (2005); (13) Goodwin et al. (2011). * In Amphimedon estelae
. nov. the strongyle can vary also in styles and oxeas.
Ecology. The species is sciophilous and was collected at 0.5–1 m deep.
Distribution (Fig. 1). Northeastern coast of Brazil, Bahia State, Brazil. The distributions of others species of Amphimedon from Brazilian coast are available in Muricy et al (2011)
Etymology. The chosen specific name honors the senior author’s wife Maria Estela de Souza Alagão.
Remarks. Amphimedon estelae sp. nov. differs from all other species of the genus because it is the only that has one category of spicules with surfaces lumped swellings, varying among strongyles, styles and oxeas (see Table 2, Fig. 3). Among the five species recorded for the Brazilian coast, A. viridis is the most similar to A. estelae sp. nov. in the spicules size (see Table 2), color green and massive shape. The new species differs from A. viridis in the skeleton: A. estelae sp. nov. presents ectossomal skeleton with paratangential reticulation of uni-paucispicular tracts against the ectosomal skeleton with a tangential reticulation of multispicular tracts of A. viridis (Pinheiro et al. 2005). However, the principal difference between the species is the type of spicules. Despite A. viridis be one of the most known species of the Brazilian cost and Caribbean (Zea 1987; Muricy & Ribeiro 1999; Pinheiro et al., 2005; Muricy & Hajdu 2006; Moraes 2011; Muricy et al. 2011), it always had only oxeas and never was record strongyles and styles for this species or the presence of spicules with surface lumped swellings.
Other species whose oxeas have lumped swellings is Dendroxea adumbrata Corriero, Scarela Liace & Pronzato (1996) from Mediterranean Sea. The authors used this characteristic as main diagnostic character of this species. Despite ecophenotypic variation had seen in the spicules of marine sponges (e.g. Uriz 1983; Uriz et al. 2003), nobody indicated the spicules with surface lumped swellings as consequence of silica concentration ranges in the environment. Finally, other sponges collected in the same locality of A. estelae sp. nov. did not present modifications in its spicules. Thus, we believe that the spicule with surface lumped swellings is a reliable character. De Laubenfels (1956) recorded A. erina to São Paulo State (Brazil) without describing it. However, this species never been collected again, even after several studies carried out in this region (e.g. Muricy & Ribeiro 1999; Santos & Hajdu 2003; Pinheiro et al. 2005). We believe that the specimen reported by De Laubenfels is A. viridis, which is very common in the region, here synonymized. It is plausible that A. erina be a junior synonym of A. viridis requiring further studies for confirmation (Alcolado 1984; Zea 1987; Muricy & Ribeiro 1999; Muricy et al. 2011). Amphimedon caribica was recorded in Brazil by Campos et al. (2005) from Maranhão State. However, when we compared to the original description (Pulitzer-Finali 1986: 170) and this record differs in the shape of spicules, as well as the dimensions. Spicules vary between oxeas and styles with mucronate tips in Brazilian material, which are different from those present in Puerto Rican material, because the latter has only oxeas with simple tips. In addition, spicules of Caribbean material are larger and thicker (Tab. 2). Thus, we consider invalid the report A. caribica for Brazil, which requires a review to define the taxonomic status of these specimens.
Sarmento & Correia (2002) made the only record of Amphimedon complanata for Brazil (from Alagoas State), providing a list of species. This material was revised and identified as Halichondria sp. (Hajdu E. pers. com.) therefore we also invalidate this record.
Amphimedon compressa from Virgin Islands differs of new species by presents ramose to flabelliform shape, dark red color, surface smooth and, small oxeas (Tab. 2). In addition, A. compressa has skeleton like A. viridis with multispicular tracts against uni-paucispicular tracts of A. estelae sp. nov. According Moraes (2011), the skeleton characteristics of Brazilian specimens of A. compressa were not different from the Caribbean specimens. However, no ramose specimens were found in Brazil and the spicules size of Brazilian specimens was lower than Caribbean specimens. A systematic study with revision of Brazilian populations is necessary to confirm the co-specific status between both populations.
Thus, only three valid species are considered to occur in Brazil: Amphimedon estelae sp. nov., A. compressa and A. viridis.
description: Published as part of Santos, George Garcia, Docio, Loyana & Pinheiro, Ulisses, 2014, Two new species of the family Niphatidae van Soest, 1980 from Northeastern Brazil (Haplosclerida: Demospongiae: Porifera), pp. 265-274 in Zootaxa 3774 (3) on pages 266-270, DOI: 10.11646/zootaxa.3774.3.3, http://zenodo.org/record/225014