Othilia echinophora ( Lamarck, 1816 )

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 : 30-33

Othilia echinophora ( Lamarck, 1816)

Figures 15–16

Asterias echinophora Lamarck, 1816: 560 .

Echinaster echinophorus — Tommasi & Aron 1988: 3; Fernandes et al. 2002: 422; Gondim et al. 2008: 155, fig. 3a; Alves et al. 2012: 758; Miranda et al. 2012: 144; Patrizzi & Dobrovolski 2018: 182.

Echinaster (Othilia) echinophorus — Clark & Downey 1992: 367–371, pls. 89A, B, F, 90F–H; Hendler et al. 1995: 84–85, fig. 27; Hopkins et al. 2003: 100–101, figs. 7–9; Magalhães et al. 2005: 63; Brites et al. 2008: 182–183; Lima & Fernandes 2009: 59; Magris & Deìstro 2010: 59; Xavier 2010: 75; Gondim et al. 2011: 6, fig. 3e; Gondim et al. 2014: 40 , figs. 11e–j, 12e–f; Lopes et al. 2016; Sandino et al. 2017: S294.

Othilia echinophoru s— Souto & Martins 2017: 304, fig. 1B.

Material examined (40 specs, 25–55 mm R). BRAZIL. Bahia (12°45’– 13°00’S; 38°21’– 38°45’W)— Salvador: Barra beach, 6.viii.2004, 1 spec, R 25 mm ( UFBA 30 ); Ribeira beach, intertidal, 20.vi.2005, 2 specs, R 28–30 mm ( UFBA 35 ). Cairu de Salinas , Salinas das Margaridas, intertidal, 26.viii.2007, 3 specs, R 34–40 mm ( UFBA 588 ). Itaparica: Medo Island , intertidal, 29.v.1994, 1 spec, R 45 mm ( UFBA 190 ). Salvador: Frade Island , Nossa Senhora beach, 3 m, 17.x.2008, 6 specs, R 43–55 mm ( UFBA 673 ); Itapuã beach, intertidal, 11.ii.1993, 1 spec, R 40 mm ( UFBA 472 ); Penha beach, 3 m, 10.iv.2008, 24 specs, R 33–54 mm ( UFBA 667 ); Ribeira beach, intertidal, 5.vi.2004, 1 spec, R 38 mm ( UFBA 36 ); intertidal, 5.xii.2004, 2 specs, R 38–43 mm ( UFBA 29 ) .

Description (R 34–55 mm). Disc small, average R/r 4.0. Five short and robust arms, tapering distally, with 7–9 rows of long and robust spines (ca. 1.7 mm) with or without a mammiform base ( Fig. 15A–B ). Abactinal region covered by many papulae and glandular cells; skin not very thick but obscuring plating. Five primary plates on disc, each with a large spine forming a pentagon; one central spine ( Fig. 15C ). Anus near central spine, surrounded by 4–5 robust spinelets. Madreporite flat, peripherally armed with spinelets. Superomarginal spines larger than abactinal ones ( Fig. 15E ). Inferomarginal plates with one (sometimes two) spine each, forming a row. Abactinal and marginal spines sharp, straight or slightly curved, tapering. Actinal plates absent. Terminal plate robust, slightly curved at arm tip, and with five large, unequal spines. Actinal region with several open pores (one row plus scattered pores). Two unequal, curved adambulacral spines. Two equal subambulacral spines forming a V along the furrow ( Fig. 15F ). Interradial region naked, with a prominent, central spine. Oral spines completely covering mouth opening ( Fig. 15D ). Tube feet in two rows, sucking disc present. Pedicellariae absent.

Ontogenetic variation (R 25–30 mm). Average R/r 3.6 ( Fig. 16A–B ). Spines proportionally larger and fewer (7 rows) than in large specimen, arms constricted at the base. Two unequal subambulacral spines, outer spine larger than inner ( Fig. 16E ).

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

Distribution. U.S.A. (FL), Gulf of Mexico, Mexico, The The Bahamas, Caribbean Sea, Cuba, Jamaica, Dominican Republic, Puerto Rico, Nicaragua, Venezuela, Guyana, French Guiana ( Sandino et al. 2017; Mah 2020a). BRAZIL: Amapá, Pará, Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Alagoas, Bahia, Espírito Santo, Rio de Janeiro ( Lamarck 1816; Rathbun 1879; Verrill 1915; Bernasconi 1958; Walenkamp 1979; Ávila-Pires 1983; Tommasi & Aron 1988; Clark & Downey 1992; Magris & Deìstro 2010; Miranda et al. 2012; Alvarado & Solís-Marín 2013; Gondim et al. 2014; Souto & Martins 2017). Depth. Intertidal to 55(65?) m ( Clark & Downey 1992).

Biological notes. Othilia echinophora is a relatively abundant species found often in hard substrate, sometimes in sympatry with O. brasiliensis . In the southeast of the state eight specimens were found in fine calcareous sand with calcareous rocks ( Tommasi & Aron 1988). Some populations live in regions of low salinity, such as the delta of the Paraguaçu River. Specimens from Bahia are often found associated with corals ( Souto & Martins 2017), above the sediment, and in rock crevices ( Alves & Cerqueira 2000). Spongivory by Caribbean specimens have been reported ( Waddell & Pawlik 2000).

Othilia echinophora has been used in the treatment of asthma ( Costa-Neto 1999; Alves et al. 2009; Alves & Dias 2010) and its extracts contain low toxicity compounds that can be used to treat cutaneous leishmaniosis ( Parra et al. 2010). In northeastern Brazil, this species is collected for the aquarium trade ( Martins et al. 2012). Othilia echinophora is classified as “Least Concern” by the Ministry of the Environment ( MMA 2018). According to Gurjão & Lotufo (2018), its harvesting in Brazil is currently prohibited.

Lectotype. MNHN-IE-2014072 (Ec As 1976), Muséum National d’Histoire Naturelle, Paris.

Type Location. The type locality cited by Lamarck (1816, p. 560) is “ Virginie ”, which would refer to the state of Virginia, U.S.A.; however, O. echinophora has only been found up to Florida. Clark & Downey (1992) deemed unlikely that Lamarck’s assignment was correct and suggested that the type locality is most likely in northeastern Brazil. We are not aware of any coastal Brazilian locality with this name. Another possibility is that the specimens at the MNHN do not belong to the type series, as the label indicates uncertainty on their status (i.e. “ types supposés”) (but see Perrier [1875, p. 101].

Taxonomic remarks of the genus Othilia

Here we used the characteristic suggested by Hopkins et al. (2003), i.e. presence of a row of closed pores between the adambulacral and the inferomarginal plates in O. brasiliensis versus the presence of open pores in O. echinophora , to distinguish these species. A.M. Clark (1987) distinguished O. brasiliensis from O. echinophora and O. guyanensis by the blunt tip of the abactinal spines (vs. pointed tip) and the presence of intermarginal plates beyond half of the arm length (vs. plates restricted to less than half of the arm length). In our specimens, the tip of the spines in O. brasiliensis are pointier than the tip of the spines in O. echinophora .

Hopkins et al. (2003) used three characteristics to diagnose the Brazilian O. guyanensis , but molecular data did not support its separation from O. brasiliensis . As a result, Lopes et al. (2016) suggested that these two species should be synonymized. Their conclusion, however, is premature because their analysis did not include specimens from the type locality of O. guyanensis and given the similarity among the species of the genus Othilia , the specimens included could have been misidentified. In the diagnostic table presented by A.M. Clark (1987), the best character used to distinguish O. guyanensis from O. brasiliensis and O. echinophora is the flat to slightly concave madreporite (vs. convex). Discussing the status of O. guyanensis is beyond the scope of this study, but similar to Gondim et al. (2014), we have not found specimens unambiguously identified as O. guyanensis in northeastern Brazil.

Order Valvatida Perrier, 1884

Figures

FIGURE 15. Specimen (R 43 mm) of Othilia echinophora (Lamarck, 1816) (UFBA 673): (A) abactinal and (B) actinal view of body; (C) disc; (D) oral region; (E) superomarginal spines (arrow); (F) ambulacral furrow. Scale bars: A–B, 20 mm; C–F, 50 mm.

FIGURE 16. Specimen (R 25 mm) of Othilia echinophora (Lamarck, 1816) (UFBA 30): (A) abactinal and (B) actinal view of body; (C) aboral region of disc; (D) oral region; (E) ambulacral furrow. Scale bars: A–B, 5 mm; C, 1 mm; D–E, 2 mm. Photo credit: Wagner Magalhães.