Ophioderma appressum ( Say, 1825 )

Ophioderma appressum ( Say, 1825) View in CoL

Ophiura apressa — Say, 1825 —141; Rathbun 1879: 151.

Ophioderma appressum View in CoL — Lima-Verde 1969: 12; Boffi 1972: 319; Tommasi 1999; Ventura et al. 2006: 351; Gondim et al. 2008: 154; Lima & Fernandes 2009: 60.

Ophioderma apressum — Brito 1962: 1, Fig. 8 View FIGURE 8 ; Costa & Costa 1962: 3, Pr. 1, Fig. 3–4 View FIGURE 3 View FIGURE 4 ; Alves & Cerqueira 2000: 546; Neto et al. 2005: 213; Magalhães et al. 2005: 63; Ventura & Veríssimo 2007a: 241, Fig. A–F; Pawson et al. 2009: 1195; Oliveira et al. 2010: 7; Stöhr et al. 2022.

Ophioderma apressa — Tommasi 1970: 65, Fig. 62–63; Lima et al. 2011: 4, Fig. 3E View FIGURE 3 ; Miranda et al. 2012: 138, Fig. 2A View FIGURE 2 ; Barboza & Borges 2012: 7; Gondim et al. 2013a: 80, Fig. 13 a–e View FIGURE 13 , 14f View FIGURE 14 ; Paim et al. 2015: 12–13; Souto & Martins 2017: 307; Prata et al. 2017: 6, Fig. 7 View FIGURE 7 ; Borrero-Perez et al. 2019: 191; Prata et al. 2020: 7, Fig. 5e–f View FIGURE 5 .

Material examined: Bessa Beach, João Pessoa, PB: 7º04'33.0"S 34º49'30.0"W, 1 spec. ( UFPB /ECH–2445). Formosa Beach, Cabedelo, PB: 6º58'38.8"S 34º48'57.4"W, 4 spec. ( UFPB /ECH–2446); 6°58'55.5"S 34°48'55.3"W, 1 spec. ( UFPB /ECH–2450). Carapibus Beach, Conde, PB: 7°18'03.0"S 34°47'53.0"W, 3 spec. ( UFPB /ECH–2447); 7º17'55.9"S 34º47'53.6"W, 2 spec. ( UFPB /ECH–2448). Barra de Mamanguape reefs, Rio Tinto, PB: 6°45'49.35"S 34°55'4.85"W, 3 spec. ( UFPB /ECH–2449); 6°45'54.0"S 34°55'04.0"W, 1 spec. ( UFPB /ECH–2451) GoogleMaps .

Description: specimen UFPB/ECH–2446. Circular disc ( dd = 17.12 mm and dh = 5.72 mm), dorsally covered by imbricate scales under the numerous granules. These granules are smaller in the center of the disc and larger near the interradial region. Radial shield not visible, completely covered by granules ( Fig. 3A View FIGURE 3 ). Interradial ventral region covered by granules ( Fig. 3B View FIGURE 3 ). Two short bursal slits (BS) distant from each other, in which the first slit starts close to the jaw until the second ventral arm plate (VAP), and the other BS extends from the fifth to the middle of the sixth VAP ( Fig. 3B View FIGURE 3 ). Mandible covered with granules larger than the dorsal surface. Cordiform and without granules on the oral shield ( Figs. 3B, C View FIGURE 3 ). Madreporite, with a small whitish circular depression in the median portion ( Figs. 3B, C, D View FIGURE 3 ). Small, well separated, without granules in adoral shield, with a well-tapered proximal portion ( Figs. 3C, E View FIGURE 3 ). Lyman’s ossicle elliptic, adoral shield spine wider than long, secondary adoral shield spine longer than wide, three long lateral oral papillae, long infradental papillae, and large tooth papillae ( Fig. 3C View FIGURE 3 ). Five arms ( aw = 3.94 mm), about 4–5 times longer than the dd and distally tapered. Dorsal arm plate (DAP), wider than long, and overlaps, a more distal triangular DAP ( Figs. 3F View FIGURE 3 ; 4B View FIGURE 4 ). VAP square, with a rounded distal edge, and the lateral margins with slight indentations ( Figs. 3G View FIGURE 3 ; 4C View FIGURE 4 ); first ventral arm plate, semi-elliptical, wider than long ( Fig. 3C View FIGURE 3 ). Two parallel tentacle scales, the external one flattened and the internal one slightly larger and spatulate ( Fig. 3G View FIGURE 3 ). Ten short arm spines, which progressively decrease in size until the dorsalmost arm spine. The ventralmost arm spine larger and flattened, while the others are smaller and pointed ( Figs. 3F, G View FIGURE 3 ; 4G View FIGURE 4 ).

Microstructures: dissociated dental plate, wider in the proximal portion, without septum, with about seventooth sockets (Ts) with thick protruding knobs; the Ts are separated by three segmentations: the first segment has three small and circular Ts and a fourth larger; the second segment has a single large and semicircular Ts; and the last segment with two Ts, being one larger and the other smaller and circular ( Fig. 4A View FIGURE 4 ). Lateral arm plate ( LAP ) with a slightly convex proximal region, ten spine articulation, ventral portion larger. The LAP inner portion with a single and small perforation ( Figs. 4D, E, F View FIGURE 4 ). Vertebrae zygospondylous type: dorsal and ventral view wider than long; middle portion of the vertebra dorsal view flattened, with dorsal groove smooth and dorso-distal muscular fossae large ( Fig. 4H View FIGURE 4 ); vertebra ventral view with deep muscular fossae elongated and deep ventral groove, with very evident junction; elongated portion of zygosphene (Zp), projecting beyond the ventral edge ( Fig. 4I View FIGURE 4 ); vertebra proximal view ( Fig. 4J View FIGURE 4 ) and distal view ( Fig. 4K View FIGURE 4 ) as long as wide, with dorsal muscle area bigger than the ventral muscle area; vertebra distal view with large zygocondyle and distinct of the Zp portion ( Fig. 4K View FIGURE 4 ).

Intraspecific variations: the oral shield may be expanded laterally, almost completely covering the adoral shield (AdSh) these vary from triangular to rounded. In the young specimens, the disc tends to be pentagonal, with AdSh covered by granules, dorsal arm plate triangular, and lateral arm plate with at most nine arm spines. Disc coloration varies from dark brown to caramel, and some young individuals show whitish spots in the ventral region; arms with transverse bands that intercalate between lighter and darker dorsal arm plates ( Figs. 3A, F View FIGURE 3 ).

Taxonomic comments: the species was also described by having under the granules small disc scales that cover all the disc ( Benavides-Serrato et al. 2011), oval radial shield, oval to cordiform oral shield, adoral shield (AdSh) covered by granules slightly larger than those from the dorsal surface, nine to ten oral papillae, lateral arm plate ( LAP ) with seven to nine arm spine (ASp), two or three tentacle scale (TSc), and whitish spots in the distal edge of the disc ( Tommasi 1970; Prata et al. 2020). Or the AdSh can be laterally enlarged and not covered by granules, seven to eight oral papillae, LAP with seven ASp, and two TSc ( Gondim et al. 2013a).

Morphometric variations: a total of 15 specimens were analyzed. Bigger dd: 17.12 mm, smaller dd: 5.83 mm. Average of dd = 10.49 mm with standard deviation (sd) of 3.95 mm, dh = 2.60 mm with sd = 1.30 mm, aw = 2.43 mm with sd = 0.81 mm, la = 41.97 mm with sd = 15.81 mm ( Table 1).

*values corresponding to the measurement of one to three specimens.

Substrates: in the present study the specimens were collected under rocks and associated with rhodoliths (calcareous algae), protecting themselves from luminosity ( Lima & Fernandes 2009), but they can also occur in rock crevices ( Alves & Cerqueira 2000), marine phanerogam banks and on coral gravel ( Hendler et al. 1995; Gondim et al. 2013a).

Bathymetric distribution: intertidal region up to 364 m ( Tommasi 1970; Gondim et al. 2013a; Prata et al. 2020).

Geographic distribution: Texas, South Carolina, Bermuda, Florida, USA, Bahamas, Cuba, Belize, Jamaica, Haiti, Puerto Rico, Colombia, Venezuela, Brazil, Ascension Island, Senegal, Angola ( Tommasi 1970; Hendler et al. 1995). In Brazil: Ceará (Lima–Verde 1969), Paraíba in the Cabo Branco Beach, Seixas reefs and Barra de Mamanguape reefs ( Gondim et al. 2008; 2013a; Prata et al. 2017; 2020), Bessa Beach, Carapibus Beach and Formosa Beach (present study), Pernambuco ( Lima & Fernandes 2009), Alagoas ( Oliveira et al. 2010; Lima et al. 2011; Miranda et al. 2012) and Bahia ( Alves & Cerqueira 2000; Magalhães et al. 2005; Oliveira et al. 2010; Souto & Martins 2017).