Othilia brasiliensis ( Müller & Troschel, 1842 )

Cunha, Rosana, Martins, Luciana, Menegola, Carla & Souto, Camilla, 2021, Taxonomy of the sea stars (Echinodermata: Asteroidea) from Bahia State, including ontogenetic variation and an illustrated key to the Brazilian species, Zootaxa 4955 (1), pp. 1-78 : 27-28

Othilia brasiliensis ( Müller & Troschel, 1842)

Figures 13–14

Echinaster brasiliensis Müller & Troschel, 1842: 22 , pl. 1, fig. 2.

Echinaster brasiliensis — Nunes 1975: 183; Tommasi & Aron 1987: 3; Tommasi et al. 1988: 6; Fernandes et al. 2002: 422; Netto 2006: 30–32, pl. 5a; Alves et al. 2012: 758; Miranda et al. 2012: 144.

Echinaster (Othilia) brasiliensis — Clark & Downey 1992: 363–367, fig. 57a, pl. 87A–F; Hopkins et al. 2003: 98–100, figs. 2–6; Brites et al. 2008: 182–183; Lima & Fernandes 2009: 59; Xavier 2010: 75; Benavides-Serrato et al. 2011: 192; Gondim et al. 2014: 37 , fig. 11a–e; Alitto et al. 2016: 10, figs. 7g –h; Bumbeer et al. 2016: 8, fig. 4A; Lopes & Ventura 2016; Lopes et al. 2016; Sandino et al. 2017: S294; Bueno et al. 2018: 182, fig. 13; Gurjão & Lotufo 2018: 10; Miranda 2018: 14, fig. 10E; Borrero-Peìrez et al. 2019: 5; Torres & Torres 2019: 412.

Echinaster braziliensis — Patrizzi & Dobrovolski 2018: 182.

Echinaster guyanensis — Martins et al. 2012, table 1.

Material examined (56 specs, 17–65 mm R). BRAZIL. Bahia (12°41’– 13°00’S; 38°29’– 38°53’W)— Salvador: Ribeira beach, intertidal, 1.iii.2006, 36 specs, R 17–29 mm ( UFBA 131 , 173 ). Itaparica Island: Medo Island , intertidal, 7.ix.1991, 1 spec, R 29–30 mm ( UFBA 31 , 37 ). Cachoeira: Santiago do Iguape , 15 m, 2.x.2012, 1 spec, R 65 mm ( UFBA 1710 ). Madre de Deus : intertidal, 8.iv.2008, 1 spec, R 56 mm ( UFBA 625 ). Itaparica Island: Medo Island , intertidal, 7.ix.1991, 4 specs, R 36–51 mm ( UFBA 31 , 37 ); Ponta de Areia beach, 4.vi.2000, 2 specs, R 37–48 mm ( UFBA 473 ). Vera Cruz: Duro beach, 1 m, 20.ix.2009, 2 specs, R 41–42 mm ( UFBA 961 ). Salvador: Plataforma beach, intertidal, 29.vii.2007, 7 specs, R 39–60 mm ( UFBA 586 ); Ribeira beach, intertidal, 15.v.1991, 2 specs, R 31–39 mm ( UFBA 38 ); intertidal, 1.iii.2006, 34 specs, R 36–59 mm ( UFBA 131 , 173–175 ); Barra beach, intertidal, 6.vii.2004, 1 spec, R 33 mm ( UFBA 33 ) .

Comparative material. BRAZIL, 2 specs, R 54–55 mm ( ZMB 550–551 , syntypes) .

Description (R 31–65 mm). Disc small, average R/r 4.4 ( Fig. 13A–C ). Five slender arms, tapering distally, with 9–11 rows of long and sharp spines (ca. 1.0– 1.5 mm) without mammiform base. Small secondary plates between abactinal plates; skin not very thick but obscuring plating. Abactinal region covered by many papulae and glandular cells. Five primary plates on disc, each with a spine forming a pentagon; one central spine ( Fig. 13D ). Anus near central spine, surrounded by 3–6 spinelets. Madreporite flat, without spinelets. Superomarginal spines same size as abactinal ones. Inferomarginal plates with one spine each, forming a row; inferomarginal spines larger than others (ca. 1.7 mm). Abactinal and marginal spines sharp, straight or slightly curved, tapering. Actinal plates absent. Terminal plate small, curved, with 6–7 small spines. Actinal region with several closed pores (one row plus scattered pores) ( Fig. 13E ). One curved adambulacral spine. Two subambulacral spines forming a V along the furrow ( Fig. 13F ), proximal region sometimes with third spine; spines are usually equal, but outer spine may be larger than inner. Interradial region naked, sometimes with a central spine. Oral spines completely covering mouth opening. Tube feet in two rows, sucking disc present. Pedicellariae absent.

Ontogenetic variation (R 17–30 mm). Average R/r 3.9 ( Fig. 14A–C ). Spines proportionally larger and fewer (7 rows) than in large specimen; 4–5 small spines on the terminal plate ( Fig. 14D ). Two unequal subambulacral spines, outer spine larger than inner ( Fig. 14E ).

Coloration. Specimens in vivo are light to scarlet red. Specimens in ethanol are brown, dark brown or beige.

Distribution. Gulf of Mexico, Cuba, Honduras, Nicaragua, Panama, Colombia, Guyana, French Guiana, Uruguay, Argentina, Malvinas Islands ( Sandino et al. 2017; Borrero-Peìrez et al. 2019; Mah 2020a). BRAZIL: Pará, Rio Grande do Norte, Paraíba, Pernambuco, Alagoas, Bahia, Espírito Santo, Rio de Janeiro, São Paulo, Paraná, Santa Catarina, Rio Grande do Sul ( Rathbun 1879; Verrill 1915; Bernasconi 1956; Brito 1968; Tommasi 1970; Carrera-Rodriguez & Tommasi 1977; Ávila-Pires 1983; Clark & Downey 1992; Hopkins et al. 2003; Miranda et al. 2012; Alvarado & Solís-Marín 2013; Gondim et al. 2014; Alitto et al. 2016; Bumbeer et al. 2016; Bueno et al. 2018; Miranda 2018; Torres & Torres 2019; Mah 2020a). Depth. Intertidal to 60 m ( Clark & Downey 1992; present paper).

Biological notes. Specimens from Bahia are found in sandy and muddy substrate, commonly on top of rocks. Some populations live in regions of low salinity, such as the delta of the Paraguaçu River. Othilia brasiliensis usually feeds on sponges of the genera Mycale Gray, 1867 , Haliclona Grant, 1841 and Tedania Gray, 1867 (Guerrazi et al. 1999), but they also feed on sea anemones, brine shrimp, true shrimp ( Queiroz 2012; Alcantara & Costa 2019). Lopes & Ventura (2016) described the early developmental stages of O. brasiliensis [as Echinaster (Othilia) brasiliensis ], which is similar to the development of other Echinasteridae species.

Othilia brasiliensis is classified as “Least Concern” by the Ministry of the Environment ( MMA 2018) and its harvesting in Brazil is currently prohibited ( Gurjão & Lotufo 2018).

Syntypes. ZMB 550–552 .

Type locality. Müller & Troschel (1842) were not specific with regards to the type locality of this species and the locality in the specimen label is Brazil. Walenkamp (1979) cited Ubatuba as the type locality but no justification for this assignment was provided.

Remarks. Walenkamp (1976) and Gondim et al. (2014) looked for intraspecific variability in specimens from varied size ranges (R 7–41 mm) but ontogenetic variation was not observed (note that Walenkamp’s specimens were O. guyanensis according to A.M. Clark [1987]).

Clark & Downey (1992) reported the presence of spinelets in the madreporite of O. brasiliensis , these were not found in the specimens described here. They also mention the presence of 4–5 ambulacral spines; the specimens described here and those by Hopkins et al. (2003) have 3–4 spines. Seixas et al. (2019) described the mitochondrial genome of this species; its 16,219 base pairs are AT-rich.

Figures

FIGURE 13. Othilia brasiliensis Müller & Troschel, 1842. (A) Specimens in aquarium. Specimen (R 60 mm) (UFBA 174): (B) abactinal and (C) actinal view of body; (D) spines forming pentagon on disc; (E) oral region; (F) ambulacral furrow. Scale bars: B–E, 20 mm; F, 50 mm.

FIGURE 14. Specimen (R 17 mm) of Othilia brasiliensis Müller & Troschel, 1842 (UFBA 131): (A) specimen in vivo; (B) abactinal and (C) actinal view of body; (D) abactinal view of terminal region of arm; (E) ambulacral furrow; (F) oral region. Scale bars: B–C, 5 mm; D, 1 mm; E–F, 2 mm. (B–F) Photo credit: Alisson Santana.