Amphiura kinbergi Ljungman, 1872,

Alitto, Renata A. S., Bueno, Maristela L., Guilherme, Pablo D. B., Domenico, Maikon Di, Christensen, Ana Beardsley & Borges, Mic, 2018, Shallow-water brittle stars (Echinodermata: Ophiuroidea) from Araçá Bay (Southeastern Brazil), with spatial distribution considerations, Zootaxa 4405 (1), pp. 1-66: 26-28

publication ID

https://doi.org/10.11646/zootaxa.4405.1.1

publication LSID

lsid:zoobank.org:pub:D33BF380-5AF7-4645-86C7-9981C528EAF0

persistent identifier

http://treatment.plazi.org/id/03C3B82F-9235-C963-07C8-F88DFDBF38FB

treatment provided by

Plazi

scientific name

Amphiura kinbergi Ljungman, 1872
status

 

Amphiura kinbergi Ljungman, 1872 

( Fig. 8View FIGURE 8)

Type locality. Ubatuba , Brazil. 

Maximum size. dd up to 9 mm (Barboza & Borges 2005).

Material examined. 4 specimens (dd: 3.5–6.4 mm) from subtidal: ZUEC OPH 2129, St. 34, 1 spm; ZUEC OPH 2212, St. 71, 1 spm; ZUEC OPH 2274, St. XXVI, 1 spm; ZUEC OPH 2341, St. 20H, 1 spm.

Description. Disc: (dd: 3.5 mm) star-shaped, covered by a narrow border of small and imbricating scales around the radial shields. Other portions bear small scattered and transparent scales. Radial shields four times as long as wide, large (accounting for more than half of the disc radius) ( Fig. 8AView FIGURE 8). Ventral interradius with numerous, small and transparent scales embedded in the skin. Bursal slits broad ( Fig. 8BView FIGURE 8). Oral shields rounded diamondshaped, as long as wide, broadly rounded distally with an obtuse angle proximally. Madreporite well developed and with pores distally. Adoral shields triangular, wider distally, with deeply concave proximal sides and separated proximally. Two lateral oral papillae, distal larger and perpendicular to the jaw, buccal scale tapered and set deeper on jaw. A pair of blunt infradental papillae, larger than lateral oral papillae ( Fig. 8CView FIGURE 8).

Arms: dorsal arm plates trapezoid, straight proximally, rounded distally and contiguous ( Fig. 8D,FView FIGURE 8). Ventral arm plates pentagonal, as long as wide, contiguous ( Fig. 8E,GView FIGURE 8). Two small tentacle scales (about 1/5 of the length of the ventral arm plate) attached only at lateral arm plate ( Fig. 8EView FIGURE 8). Seven arm spines at proximal segments, decreasing to six distally; second arm spine from ventral hatchet-shaped ( Fig. 8EView FIGURE 8).

Lateral arm plates ( Fig. 8H,IView FIGURE 8): general outline: ventral portion projecting ventro-proximalwards; ventro-distal tip not projecting ventralwards. Outer surface ornamentation: trabecular intersections not protruding. Outer proximal edge: surface lined by discernible band of different stereom structure, restricted to central part; without spurs; central part not protruding; surface without horizontal striation. Spine articulations: on same level as remaining outer surface, ventralwards increasing in size; distance between spine articulations increasing dorsalwards. Lobes simply separated, dorsal lobe clearly larger than the ventral lobe; lobes parallel, dorsalmost bent, and oriented nearly horizontal; stereom massive; sigmoidal fold absent. Inner side, ridges and knobs: dominated by two separate central knobs; without additional dorsal structure on inner side; single large perforation on inner side.

Vertebrae: zygospondylous of universal type and keeled. Large groove proximal side of vertebrae dorsally corresponding to distalwards projecting dorso-distal muscular fossae of distal side ( Fig. 8JView FIGURE 8). Zygocondyles dorsalwards converging and zygosphene fused with pair of zygocondyles ( Fig. 8KView FIGURE 8). Dorso-distal muscular fossae transformed distalwards almost projecting beyond zygocondyles (true keel) ( Fig. 8LView FIGURE 8). Zygosphene not projecting beyond ventral edge of zygocondyles ( Fig. 8MView FIGURE 8).

Taxonomic comments. A. kinbergi  has keeled vertebrae, which are similar to that present in A. princeps  , but different from Hemipholis cordifera  and Ophiothrix angulata  . The dorsal projections and depressions connected by dorsal accessory muscles are more evident in H. cordifera  and O. angulata  than in A. kinbergi  and A. princeps  . The holotype of A. kinbergi  was described by Ljungman (1872). However, due to the loss of this specimen, the species was re-described from a Brazilian collection sampled from Ubatuba, southeastern Brazil ( Thomas 1965; Tommasi 1970).

Remarks. It occurs in calcareous algae, mud, sand and rubble ( Tommasi 1970; Manso et al. 2008; Lima et al. 2011). A. kinbergi  was collected from sand (coarse and medium sand) and rubble bottom with van Veen grab (2 spms), dredge (1 spm), and multicorer (1 spm).

Distribution. Tropical Atlantic (realm), Tropical Southwestern Atlantic (province): Northeastern and Eastern Brazil ( Albuquerque & Guille 1991; Borges & Amaral 2005; Magalhães et al. 2005; Manso et al. 2008; Lima et al. 2011; Gondim et al. 2013b). Temperate South America (realm), Warm Temperate Southwestern Atlantic (province): Southeastern Brazil ( Thomas 1965; Borges & Amaral 2005).

From 3 up to 300 m depth ( Alvarado & Solís-Marín 2013). The present study samples occurred at depths ranging from 20 to 21.5 m.

Selected references. Ljungman (1872): p. 643; Thomas (1965): p. 638, fig.1; Borges & Amaral (2005): p. 265, fig. a –d; Manso et al. (2008): p. 193, fig. 20a –c [as Amphiura kinbergi  ]; Fell (1962): p. 10 [as Hemilepis kinbergensis  ]; Tommasi (1970): p. 48 [as Amphiura (Hemilepis) kinbergi  ]; Albuquerque (1986): p. 72, fig. 13a –c [as Amphiura (Ophiolepis) kinbergi  ].