Ophiothrix brasiliensis, Santana & Manso & Almeida & Alves, 2020

Santana, Alisson, Manso, Cynthia L. C., Almeida, Ana C. S. & Alves, Orane F. S., 2020, Taxonomic review of Ophiothrix Müller & Troschel, 1840 (Echinodermata Ophiuroidea) from Brazil, with the description of four new species, Zootaxa 4808 (1), pp. 51-78 : 59-62

Ophiothrix brasiliensis n. sp.

( Figs. 6 , 7 )

urn:lsid:zoobank.org:act:23CD96FB-BD3F-4947-960A-1656BD73D4A2

Ophiothrix (Ophiothrix) angulata: Tommasi 1970: 54–60 . [São Paulo, Brazil]

Ophiothrix ailsae: Guille & Albuquerque 1987: 147 . [Espírito Santo, Brazil]

Ophiothrix ailsae: Albuquerque & Guille 1991: 9 . [Espírito Santo, Brazil]

Ophiothrix angulata: Borges et al. 2002: 58–59 , fig. 34c–d. [São Paulo, Brazil]

Ophiothrix angulata: Borges et al. 2005: 65–66 . [São Paulo, Brazil]

Ophiothrix angulata: Manso et al. 2008: 194 , fig. 21a–c. [Bahia, Brazil]

Ophiothrix (Ophiothrix) angulata: Viana 2010: 10–14 , fig. 2a–h. [Bahia, Espírito Santo and Rio de Janeiro, Brazil]

Ophiothrix brachyactis: Oliveira et al. 2010: 8 . [Rio de Janeiro, Brazil]

Ophiothrix (Ophiothrix) angulata: Gondim et al. 2013: 67–68 , fig. 2f–j. [Paraíba, Brazil]

Ophiothrix (Ophiothrix) angulata: Gondim et al. 2013: 514–515 , fig. 4a–b. [Piauí and Maranhão, Brazil]

Not Ophiura angulata Say, 1825: 145–146 . [South Carolina, United States]

Not Ophiothrix brachyactis Clark, 1915: 269–270 [Florida, United States]

Not Ophiothrix ailsae Tommasi, 1970: 60–61 , figs. 58–59. [São Paulo, Brazil]

Holotype: UFBA 01731 , Salvador, Bahia, Brazil, 12º57’S; 38º21’W, 0 m, coll. VII/2014 by A. Santana, A.C. Almeida & D. Menezes . Paratypes: UFBA 00736 (01 specimen) ; UFBA 00737 (01 specimen) ; UFBA 00738 (01 specimen), Salvador, Bahia, Brazil, 12º57’S; 38º21’W, 0 m, coll. 1998–2006 . Additional specimens: ZUEC 01215 (01 specimen), Pará, Brazil, 00º21’– 00º37’S, 46º58’– 44°40’W, 44–50 m, coll. 1967–2009 ; ZUEC 02442 (03 specimens) , LIMCE 00362 (08 specimens) , LIMCE 00206 (02 specimens) , LIMCE 00112 (01 specimen), Ceará, Brazil, 03º40’S; 38º38’W, 0 m, coll. 2002 by A.C.M Queiroz, O.P. Lopes , T.M. Garcia & C.B. Melo ; UFBA 00666 (01 specimen) , UFBA 00301 (03 specimens) , UFBA 01070 (06 specimens) , UFBA 01127 (01 specimen), Salvador, Bahia, Brazil, 12º58’– 13º05’S, 38º31’– 38º39’W, 12 m, coll. 1997–2010 ; UFBA 01128 (01 specimen), Madre de Deus , Bahia, Brazil, 12º42’S, 38º37’W, 0 m, coll. XII/1994 by Celso Rodrigues; UFBA 00897 (01 specimen) UFBA 01126 (01 specimen) , UFBA 01129 (01 specimen), Camamu Bay , Bahia, Brazil, 13º45’– 13º56’S, 38º50’– 38º59’W, 0–28 m, coll. 2004–2009 by Lameb; MZUSP 01043 (02 specimens) , MZUSP 01044 (01 specimens) , ZUEC 00571 (01 specimens), Ubatuba , São Paulo, Brazil, 23º13’– 23º27’S, 44º45’– 45º02’W, 0–23 m, coll. 1960–2012 ; UFBA 00532 (01 specimens), Ilha do Mel , Paraná, Brazil, 25º32’S, 48º19’W, coll. VII/1992 by C. Manso; ZUEC 02322 (04 specimens) , ZUEC 02325 (02 specimens), Matinhos Paraná, Brazil, 25º50’– 25º53’S, 48º26’– 48º32’W, coll . V /2014 by M.L. Bueno & P. Guilherme; UFBA 00601 (01 specimen), Santa Catarina, 27º35’S, 48º32’W, coll. IV/2007 by P. Guilherme, Y. Tavares & G. Silvério.

Type locality. Salvador, Bahia, Brazil.

Etymology. The specific name alludes to the Brazilian type locality.

Diagnosis. Disc (interradial regions) covered by short spines with 2–6 thorns at the apex; radial shields triangular, with uniform coverage of short bifid and trifid spines; ventral arm plates square shaped, with straight proximal edge and concave distal edge.

Holotype description. A specimen with 6.55 mm of disc diameter. Five arms, 3–4 times as long as the disc diameter. Disc circular, 2.6 mm high, dorsal surface covered covered by small, rounded and imbricated scales that support short and hyaline spines, with 2–6 thorns at the apex. Central and radial primary plates not visible ( Figs. 6 A–D). Radial shields flat, scalene triangular, longer than wide, proximal edges tapered and distally rounded, separated by 1–2 elongated scales, covered by small bifid and trifid spines ( Fig. 6E ). Ventral interradius covered by imbricated scales with small bifid and trifid spines. Genital plates at the base of arms. Oral shields lozenge-shaped, as long as wide, with tapered proximal edge and rounded distal and lateral edges. Madreporite wider than other oral shields and circular in shape. Adoral shields triangular, tapered proximal to oral shields and distally extending around the oral shields. With cluster of dental papillae on the apex of jaw and covering at least helf the height of the dental plate. Infradental papilla and oral papillae absent Oral tentacle pore visible ( Fig. 6D ). Arms dorsoventrally compressed, tapering gradually toward arm tip. Dorsal arm plates lozenge-shaped, with elongated proximal edge, as long as wide, with longitudinal black and white stripes ( Figs. 6G, I ). Ventral arm plates square, with straight proximal edge and distally concave ( Figs. 6H, J ). Lateral arm plates cover part of the dorsal arm surface; bearing 8–10 vitreous arm spines proximally and 6–8 distally, the second upper spine is the longest ( Fig. 6J ). Arm spines glassy, 2.5 cm long, with marginal spines and a crown of spines at the tip ( Fig. 7E ); sometimes the lower spine modified into a hook. Arm spine articulation vertical, with two ridges slightly curved, opening at both ends, surrounding two circular openings with similar size ( Fig. 7E ). One spiniform tentacle scale. Arm vertebrae with zygospondylus articulation, with a dorsal keel extending distalwards into a large groove on the proximal face of the following vertebra. Zygocondyles dorsalwards converging and zygosphene fused with a pair of zygocondiles ( Figs. 7 A–D).

Variations. The disc of Ophiothrix brasiliensis n. sp. varies in shape from circular to pentagonal. The dorsal arm plates also vary from lozenge to fan-shaped. The coverage of the radial shields is not uniform and can be sparse and dense in different regions of the disc of the same individual.

Color pattern. Ophiothrix brasiliensis n. sp. commonly have disc purple colored, with black and white stripes along the entire extension of the arms. Also, eventually white spots are seen in dorsal arm plates.

Remarks. Most of the specimens here assigned to O. brasiliensis n. sp. were previously attributed to O. angulata . However, interradial spines of O. brasiliensis n. sp. have 2–6 thorns at the apex while those of O. angulata are bifid or trifid. Also, the ventral arm plates of O. brasiliensis n. sp. are wider than long, with straight proximal edge and distally concave, whereas those of O. angulata are heart-shaped.

Guille & Albuquerque (1987) and Albuquerque & Guille (1991), based on the same specimen from Espírito Santo, misidentified O. brasiliensis n. sp. as O. ailsae . Ophiothrix ailsae was described by Tommasi (1970) based on a single specimen from Vitória Island (São Paulo State, Brazil) and was characterized by the presence of red bands of pigmentation on the arms and the disc covered only by trifid spines. Ophiothrix specimens studied by Guille & Albuquerque (1987) and Albuquerque & Guille (1991) are deposited at MZUSP and were analyzed here. However, all individuals have discs covered by spines with 2–6 thorns at the apex, thus differing from the diagnostic character provided by Tommasi (1970). Moreover, these specimens fit all other morphological features of O. brasiliensis n. sp., being here reassigned to this new species. Also, the unique specimen from Brazil (Rio de Janeiro) attributed to O. brachyactis ( Oliveira et al. 2010) is here reassigned to O. brasiliensis n. sp. due to the coverage of the disc (with spines in O. brasiliensis n. sp. and with granules in O. brachyactis ; see Discussion).

Ophiothrix brasiliensis n. sp. can be distinguished from all species of Ophiothrix by the combination of short spines with 2–6 thorns at the apex covering the interradial regions of the disc and short bifid and trifid spines, covering the radial shields.

Distribution. Western Atlantic: Brazil (Pará, Maranhão, Piauí ,, Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Alagoas, Bahia, Espírito Santo, Rio de Janeiro, São Paulo, Paraná, Santa Catarina and Rio Grande do Sul).

Figures

FIGURE 6. Ophiothrix brasiliensis n. sp.: A, Dorsal view of the disc; B–D, SEM detail of spines on the disc; E, detail of radial shields coverage; F, oral frame; G, dorsal arm plates; H, ventral arm plates; I, SEM image of dorsal arm plate; J, SEM image of ventral arm plate (UFBA 01731, holotype, Bahia, Brazil). Scale bars: A, E–H = 1 mm; B–C = 50 μm; D = 20 μm; I–J = 100 μm.

FIGURE 7. SEM photographs of vertebrae, lateral arm plates and arm spines of Ophiothrix brasiliensis n. sp.: A, proximal surface; B, distal surface; C, dorsal surface; D, ventral surface; F, lateral arm plate; E, arm spine (UFBA 01731). Scale bars: A–F = 200 μm.