Ophiothrix tommasii,

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: 64-67

publication ID

https://doi.org/10.11646/zootaxa.4808.1.3

publication LSID

lsid:zoobank.org:pub:242EEAFF-0966-48A2-9D13-7FF52DDE61A5

persistent identifier

http://treatment.plazi.org/id/BE2B77B4-3034-4375-9412-74CF7CE61CC1

taxon LSID

lsid:zoobank.org:act:BE2B77B4-3034-4375-9412-74CF7CE61CC1

treatment provided by

Plazi

scientific name

Ophiothrix tommasii
status

n. sp.

Ophiothrix tommasii  n. sp.

( Figs. 10View FIGURE 10, 11View FIGURE 11)

urn:lsid:zoobank.org:act:BE2B77B4-3034-4375-9412-74CF7CE61CC1

? Ophiothrix angulata: Alitto et al. 2019: 17–18  . [São Paulo and Paraná, Brazil]

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

Holotype: UFSITAB 00741, Maranhão, Brazil, 02º30’S, 44º01’W, 1 m, coll. III/2015 by J. Prata, R. Amorim and J. AraújoGoogleMaps  . Paratypes: UFBA 01833 (01 specimen)  , UFBA 01834 (01 specimen)  , UFBA 01835 (01 specimen), Maranhão, Brazil, 02º30’S, 44º01’W, 1 m, collGoogleMaps  . III /2015 by J. Prata, R. Amorim and J. Araújo  . Additional specimens: UFSITAB 00056 (01 specimen)  , UFSITAB 00287 (01 specimen)  , UFSITAB 00055 (01 specimen), Maceió , Alagoas, 09°34’– 09º53’S, 35º36’– 35º49’W, coll. 1966GoogleMaps  ; UFBA 01413 (01 specimen), Salvador, Bahia, Brazil, 12º57’S, 38º21’W, 0 m, coll. VII/2006GoogleMaps  by W. Magalhães; UFSITAB 00134 (01 specimen), Bacia de Campos , Rio de Janeiro, Brazil, 21°00’– 22º50’S, 40°00’– 41º58’W, 0–16 m, coll. 1957–2010GoogleMaps  .

Type locality. São José de Ribamar, Maranhão, Brazil.

Etymology. Named in recognition of the contribution of Luiz Roberto Tommasi (1955–2010) to zoology.

Diagnosis. Disc (interradial regions) and radial shields covered by spines with 2–6 thorns at the tip, short spines on the first dorsal arm plate and ventral arm plates rectangular.

Holotype description. A specimen with 7.45 mm of disc diameter. Five arms, 4–5 times times as long as the disc diameter. Disc circular; interradial regions covered by small, rounded and imbricated scales that support spines shorter than 1 mm, with 2–6 thorns at the tip. Central radial primary plates not visible ( Fig. 10View FIGURE 10 A–C). Radial shields flat, scalene triangular, covered by short bifid and trifid spines, longer than wide, with proximal edge tapered and distally rounded, separated by 1–2 elongated scales, in contact distally, with sparsely distributed short spines ( Fig. 10DView FIGURE 10). Ventral interradius covered by imbricated scales similar to the dorsal scales. Genital plates at the base of arms. Oral shields lozenge-shaped, with proximal edge tapered and distal and lateral edges rounded. Madreporite inflated but with a similar shape of other oral shields. Adoral shields with rounded edges, tapered proximal to oral shields. Cluster of dental papillae on the apex of the jaw and covering at least half the height of the dental plate. Infradental papilla and oral papillae absent ( Fig. 10EView FIGURE 10). Oral tentacle pore visible. Arms dorsoventrally compressed, tapering gradually toward arm tip. Arms dorsoventrally compressed, tapering gradually toward arm tip. Dorsal arm plate diamond-shaped, wider than long, obtuse proximal angle and wide distal angle with central projection, projecting onto the proximal edge of the following plate; with short spines on the first plate ( Figs. 10D, F, HView FIGURE 10); white or yellow stripes bordered by black stripes. Ventral arm plates rectangular, wider than long. The plates are contiguous along the entire arm; distal margin slightly concave. Lateral arm plates occupying part of the dorsal surface of arms; supporting 8–10 vitreous arm spines proximally and 6–8 distally, the third upper spine is the longest ( Fig. 10JView FIGURE 10). Arm spines glassy, with marginal spines and a crown of spines at the tip ( Fig. 11EView FIGURE 11); sometimes the lower spine modified in a hook. One spiniform tentacular scale ( Figs. 10G, IView FIGURE 10). Arm spine articulation vertical, with two ridges slightly curved and opening at both ends, surrounding two circular openings with similar size. 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 pair of zygocondyles ( Figs. 11View FIGURE 11 A–D).

Variations. The ventral arm plates vary from rectangular to square in some arm segments.

Color patterns. The external coloration is generally purple, but can be orange. The dorsal arm plates are purple with longitudinal black and white stripes along the arms.

Remarks. At least four Ophiothrix  species with interradial regions of the disc and radial shields covered by spines are reported from the Western Atlantic— viz. O. angulata  , O. cimar Hendler, 2005  , O. oerstedi Lütken, 1856  and O. trindadensis  . Ophiothrix tommasii  n. sp. is readily distinguished from these congeners in having spines with 2–5 thorns at the tip and by the presence of short spines on the dorsal arm plate. Beside these characters, O. tommasii  n. sp. most closely resembles O. angulata  and O. trindadensis  that also have the lower arm spine modified into a hook (absent in O. cimar  and O. oerstedi  ), but is distinct in the shape of the disc (circular in O. tommasii  n. sp., pentagonal in O. angulata  and O. trindadensis  ), and ventral arm plates (cordiform in O. angulata  and O. trindadensis  , rectangular in O. tommasii  n. sp.).

Alitto et al. (2019) assigned specimens from Paraná and São Paulo, south and southeast Brazil, to O. angulata  . These specimens were not fully described and few taxonomic comments were provided. However, one figure was provided (see fig. 6 from Alitto et al. 2019) and at least the short spines on the first dorsal arm plate, only known in specimens of O. tommasii  n. sp., are visible. Additionally, Alitto et al. (2019) refereed that they used the same specimens as Alitto et al. (2018). Alitto et al. (2018) provided a full description and detailed images of these specimens that show several differences between it and O. angulata  , including the shape of the ventral (rectangular in specimens from Alitto et al. (2018, 2019) and cordiform in O. angulata  ) and dorsal arm plates (diamond-shaped in specimens from Alitto et al. (2018, 2019) and fan-shaped in O. angulata  ). Thus, here we assign O. angulata  from Alitto et al. (2018, 2019) to O. tommasii  n. sp.

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

R

Departamento de Geologia, Universidad de Chile

Kingdom

Animalia

Phylum

Echinodermata

Class

Ophiuroidea

Order

Ophiurida

Family

Ophiotrichidae

Genus

Ophiothrix

Loc

Ophiothrix tommasii

Santana, Alisson, Manso, Cynthia L. C., Almeida, Ana C. S. & Alves, Orane F. S. 2020
2020
Loc

Ophiothrix angulata:

Alitto, R. A. S. & Amaral, A. C. Z. & Oliveira, L. & Serrano, H. & Seger, K. R. & Guilherme, P. D. B. & Di Domenico, M. & Christensen, A. B. & Lourenco, L. B. & Tavares, M. & Borges, M. 2019: 18
Loc

Ophiura angulata

Say, T. 1825: 146