Ernstia KLAUTAU ET AL. 2013
Creators: name: Azevedo, Fernanda
name: Cóndor-Luján, Báslavi
name: Willenz, Philippe
name: Hajdu, Eduardo
name: Hooker, Yuri
name: Klautau, Michelle
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Porifera
Calcarea
Clathrinida
Clathrinidae
Ernstia

description: GENUS ERNSTIA KLAUTAU ET AL., 2013   
 Diagnosis: Calcinea in which the cormus comprises a typical clathroid body. A stalk may be present. The skeleton contains regular (equiangular and equiradiate) and/ or sagittal triactines and tetractines. Tetractines are the most abundant spicules or occur at least in the same proportion as the triactines. Tetractines frequently have very thin (needle-like) apical actines. Diactines may be present. Asconoid aquiferous system.   
 ERNSTIA TETRACTINA (KLAUTAU & BOROJEVIC, 2001)   
(FIG. 9; TABLE 9)  
 Material examined: Two specimens. MNRJ 11344 (fragments: RBINSc-IG 32239-POR 11344, CZA 11344, and MHNG 85343); Ladrón Bay, Lobos de Afuera Islands, Guano Islands and Capes National Reserve System (06°56′00.59′′S, 80°42′58.70′′W); collected by Ph. Willenz and Y. Hooker; 11 m depth; 04.x.2007. MNRJ 11347 (fragments: RBINSc-IG 32239-POR 11347, CZA 11347, and MHNG 85346); Santo Domingo Islet, Lobos de Afuera Islands, Guano Islands and Capes National Reserve System (06°55′09.80′′S, 80°44′09.40′′W); collected by Ph. Willenz and Y. Hooker; 20 m depth; 05.x.2007.   
 Colour: White in life and light beige in ethanol.   
 Description: Thinly encrusting sponge (2.5 × 1.0 × 0.2 cm). Consistency is soft and fragile. Cormus is formed by irregular and loosely anastomosed tubes (0.2–0.5 mm) (Fig. 9A–C). Water-collecting tubes are present (1.5 mm, diameter). Granular cells are absent. Aquiferous system is asconoid.   
 Skeleton: Without any special organization, composed of abundant tetractines and few triactines (Fig. 9E).   
 Spicules (Table 9):   
1. Triactines: regular (equiangular and equiradiate). Actines are conical, straight, with sharp tips.  
2. Tetractines: regular (equiangular and equiradiate). Actines are conical, straight, with sharp tips (Fig. 9F). Apical actine is straight, smooth, very thin, and frequently longer than the basal ones (Fig. 9F).  
 Reproduction: Unknown   
 Ecology: Lives in habitats with low amounts of sediment. Individuals were found underneath boulders, protected from sunlight. A low diversity of fauna was found near this species. Chitons and serpulid polychaetes as well as a finely incrusting yellow demosponge were found sharing the same substrate; however, these were fairly distant from E. tetractina. Some sea urchin spines were also found nearby. Bathymetrical distribution varies from 11 to 20 m depth.   
Geographical distribution: South-eastern coast of Brazil (23°S) and Lobos de Afuera Islands in Peru (6°S) (Fig. 9H).  
 Remarks: The genus Ernstia was recently proposed (Klautau et al., 2013). It comprises five species: Ernstia adusta (Wörheide & Hooper, 1999) (Australia), Ernstia quadriradiata (Klautau & Borojevic, 2001) (Brazil), Ernstia sagamiana (Hôzawa, 1929) (Japan), Ernstia septentrionalis (Rapp et al., 2001) (Norway), and Ernstia tetractina (Klautau & Borojevic, 2001) (Brazil). Ernstia tetractina was originally described from and considered endemic to the coast of Brazil, where its distribution is restricted to the south-east coast (Klautau & Borojevic, 2001). Its first report outside Brazil raises the need for a population genetics study.
description: Published as part of Azevedo, Fernanda, Cóndor-Luján, Báslavi, Willenz, Philippe, Hajdu, Eduardo, Hooker, Yuri & Klautau, Michelle, 2015, Integrative taxonomy of calcareous sponges (subclass Calcinea) from the Peruvian coast: morphology, molecules, and biogeography, pp. 787-817 in Zoological Journal of the Linnean Society 173 (4) on page 806, DOI: 10.1111/zoj.12213, http://zenodo.org/record/4890637