Ophionereis squamulosa Koehler, 1914

Ophionereis squamulosa Koehler, 1914 View in CoL

Ophionereis squamata View in CoL — Koehler 1913: 560.

Ophionereis squamulosa View in CoL — Koehler 1914: 44; Tommasi 1970: 87, Fig. 92; 1999; Albuquerque 1986: 195, Fig. 31a–c, est. XI, Fig. 2a–c View FIGURE 2 ; Tommasi & Aron 1987: 3; Guille & Albuquerque 1987: 147; Albuquerque & Guille 1991: 12; Manso 1993: 194; 2004:19; Magalhães et al. 2005: 63; Ventura et al. 2006: 351; Ventura & Veríssimo 2007b: 243, Fig. A–D; Manso et al. 2008: 186, Fig. 11 View FIGURE 11 ; Oliveira et al. 2010: 8; Viana 2010: 22, Fig. 5A–H View FIGURE 5 ; Barboza & Borges 2012: 9; Gondim et al. 2013a: 72 View Cited Treatment , Fig. 9 f–j View FIGURE 9 ; Souto & Martins 2017: 306.

Material examined: Formosa Beach , Cabedelo, PB: 6°58’55.5”S 34°48’55.3”W, 1 spec. ( UFPB /ECH–2440). Bessa Beach, João Pessoa, PB: 7º04'33.0"S 34º49'30.0"W, 2 spec. ( UFPB /ECH–2444). Cabo Branco Beach, João Pessoa, PB: 7°08'41.1"S 34°47'43.9"W, 1 spec. ( UFPB /ECH–2439); 7°10' S 34°42' W, 2 spec. ( UFPB /ECH–643). Carapibus Beach, Conde, PB: 7°18'03.0"S 34°47'53.0"W, 1 spec. ( UFPB /ECH–2441); 7°17'59.0"S 34°47'54.0"W, 1 spec. ( UFPB /ECH–2442); 7º17'55.9"S 34º47'53.6"W, 1 spec. ( UFPB /ECH–2443) GoogleMaps .

Description: specimen UFPB/ECH–2444. Circular disc ( dd = 11.12 mm and dh = 1.74 mm), covered dorsally by small and imbricated scales, of which the largest are close to the radial shield (RS) and edge of the disc. Separated, small, semicircular RS, twice as long as wide ( Fig. 7A View FIGURE 7 ). Ventral interradial region with scales like those dorsal ones ( Fig. 7B View FIGURE 7 ). Wide bursal slits, extending to the seventh ventral arm plate (VAP), with several genital papillae in their edges and genital scales ( Fig. 7B View FIGURE 7 ). Jaw with large octagonal oral shield, with rounded proximal edge and slightly tapered distal. Large madreporite, with a small whitish circular depression in the middle portion and visible pores in the distal edge ( Figs. 7B, C View FIGURE 7 ). Triangular adoral shield, tapered proximally and not touching. Small Lyman’s ossicle, longer than wide, with proximal edge very elongated, large adoral shield spine wider than long, secondary adoral shield spine longer than wide, rounded buccal scale, longer than wider, in the same specimen one or three infradental papillae ( Fig. 7C View FIGURE 7 ). Five arms ( aw = 4.68 mm), about four to five times longer than the dd, tapering distally. Hexagonal dorsal arm plate (DAP), wider than long, with a straight proximal edge ( Figs. 7F View FIGURE 7 ; 8B View FIGURE 8 ). Large accessory plate, occupying the entire side of the DAP ( Figs. 7F View FIGURE 7 ; 8D View FIGURE 8 ). Pentagonal VAP, as long as wide, with slight lateral indentations ( Figs 7G View FIGURE 7 ; 8C View FIGURE 8 ); first ventral arm plate with proximal edge slightly tapered and the distal rounded ( Fig. 7C View FIGURE 7 ). A large and spatulated tentacle scale, exceeding more than half the length of the VAP ( Fig. 7G View FIGURE 7 ). Three arm spines tapered with slightly flattened apex, being the median larger ( Figs. 7F, G View FIGURE 7 ; 8H View FIGURE 8 ).

Microstructures: oral plate wider than long, abradial muscular area well delimited ( Fig. 7D View FIGURE 7 ); adradial joint area not evident; large dorsal tentacle compartment and ventral tentacle compartment ( Fig. 7E View FIGURE 7 ). Elongated dental plate, proximal region with straight edge and rounded distal, outer portion with two dental tooth sockets (Ts), separated by protruding knobs; internally the plate has two dental cavities divided in four Ts, separated by a large Septum ( Fig. 8A View FIGURE 8 ). Lateral arm plate with convex proximal region ( Fig. 8E View FIGURE 8 ); inner portion with a single large perforation, positioned in the ventral region ( Fig. 8F View FIGURE 8 ); outer portion with three C-shaped spine articulations ( Fig. 8G View FIGURE 8 ). Vertebrae zygospondylous type: dorsal view of the vertebra with medium portion V-shaped, dorsal groove slightly deep and wide dorso-distal muscular fossae ( Fig. 8I View FIGURE 8 ); ventral view of the vertebra with elongated and deep ventral groove in the middle region, with four muscular fossaes well defined, being the view proximal deeper and the view distal circular ( Fig. 8J View FIGURE 8 ); Vertebra proximal ( Fig. 8K View FIGURE 8 ) and distal ( Fig. 8L View FIGURE 8 ) view with dorsal muscle area very larger than ventral muscle area.

Intraspecific variations: younger specimens present dorsal reticulation which differs from Ophionereis reticulata , since not form circles (spots), arranged more irregularly, similar a labyrinth, with the reticulations more evident near the radial shield. Color light brown, with disc covered by a thin dark brown reticulation, that form circles (spots) not uniform ( Fig. 7A View FIGURE 7 ). Arms with transverse bands that intercalate among four to six lighter plates and one darker ( Fig. 7F View FIGURE 7 ).

Taxonomic comments: the species has also been described to have five or six oral papillae and three very short arm spine ( Tommasi 1970).

Morphometric variations: a total of seven specimens were analyzed. Bigger dd: 11.12 mm, smaller dd: 6.79 mm. Average dd = 8.91 mm with sd = 1.28 mm, dh = 1.16 mm with sd = 0.27 mm, aw = 3.98 mm with sd = 0.37 mm, la = 38.21 mm with sd = 6.87 mm ( Table 3).

Substrate: the specimens were sampled under rocks and associated to rodoliths. They can also be found in sediment of sand very coarse ( Manso et al. 2008), on a gravel bottom, dead shells ( Tommasi 1970), and marine phanerogam banks ( Hendler et al. 1995; Gondim et al. 2013a).

Bathymetric distribution: from shallow waters to 40 m ( Tommasi 1970; Gondim et al. 2013a).

Geographic distribution: Florida, Bahamas, Haiti, Dry Tortugas, Puerto Rico, St. Thomas, Tobago, Belize, Brazil ( Tommasi 1970; Hendler et al. 1995). In Brazil: Paraíba ( Gondim et al. 2013a), Bessa Beach, Cabo Branco Beach, Carapibus Beach, and Formosa Beach (present study), Alagoas ( Miranda et al. 2012) and Bahia ( Magalhães et al. 2005; Manso et al. 2008; Souto & Martins 2017).