Amphipholizona delicata H.L. Clark 1915
Creators: name: Gondim, Anne Isabelley
name: Christoffersen, Martin Lindsey
name: Dias, Thelma Lúcia Pereira
name: Solís-Marín, Francisco Alonso
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Echinodermata
Ophiuroidea
Ophiurida
Ophiolepididae
Amphipholizona
Amphipholizona delicata

description: Amphipholizona delicata H.L. Clark, 1915
Figures 1 A–F, 2 A–M, 3 A–D
Amphipholizona delicata H.L. Clark, 1915: 335 –336, pl. 20, figs. 1–2.― A.H. Clark, 1918: 43, 47, 49, 51.― Downey, 1969: 18.― Tommasi, 1974: 13 -14, figs. 12a-b.― Albuquerque, 1986: 258 –260, fig. 38a–c, pl. 15, figs. 1a–c.― Tommasi & Aron, 1987: 3.― Monteiro, 1990: 735 –738, figs. 1a–e.― Albuquerque & Guille, 1991: 17.― Manso, 1993: 193.― Borges et al., 2002: 32, figs. 19a–b; 2004: 157.― De Léo, 2003: 71, 87, 115, 121.― Criales-Hernández et al., 2006: 1262.― Borrero-Pérez et al., 2008: 172, 182, fig. 9a–b.― Oliveira et al., 2010: 5, fig. 3p (table).― Benavides-Serrato et al., 2011: 222, 350–351, 2 figures.― Barboza & Borges, 2012: 5.― Gondim et al., 2013: 513.― Solís-Marín et al., 2013: 633 (list).
Type material. Museum of Comparative Zoology. Holotype: MCZ OPH- 785. Paratypes: MCZ OPH- 832, 883, 3929.
Type locality. Off Barbados, Caribbean Sea, from 139 to 188 m.
Material examined. MZUSP 783, 1 spm. (dd = 3,88 mm), St. 21 DC 35, 82 m, 15 May 1987; MZUSP 781, 4 spms. (dd = 1.98, 2.54, 2.95, 3.35 mm), 00º14′3″ S 45º04′ 12″W, St. 21, Geomar I, 0 4 June 1969; MZUSP 784, 1 spm. (dd = 4.01 mm), 02º04′ S 40º29′ W, Canopus Commission, 29 June 1965; MZUSP 772, 1 spm. (with damaged disc), 04º43′0″ S 50º28′ 0″W, St. D III, Pesca Norte Commission, 30 November 1968; MZUSP 782, 1 spm. (with damaged disc), 02º15′0″ S 48º15′ 0″W, St. 166, Geomar III, 23 April 1971; MZUSP 804, 1 spm. (dd = 2.85 mm), BT 2, 2º trawling, 25 November 1973; MZUSP 848, 1 spm. (dd = 2.29 mm), St. 55, van Veen grab 2, summer monitoring; MZUSP 889, 4 spm. (dd = 2.20, 2.47, 2.69, 2.72 mm), 02º07′0″ S 48º04′ 0″W, St. 154, Geomar III, 21 April 1971; MZUSP 891, 1 spm. (dd = 3.09 mm), 04º29′5″ S 50º12′ 0″W, St. 1793A, N-NE I Commission, 18 February 1967; UFSITAB 52, 1 spm. (dd = 2.50 mm), Campos Basin, Rio de Janeiro, BCA-082-MO, #MO 13-R3, 0 1 February 2007, 500 m. EQMN 2770, 1 spm. (dd = 4.29 mm), 16º332′S 38º444′W, REVIZEE Central II, #7C, van Veen grab, 26 October 1997.
Diagnosis. Interradius covered by three rows of polygonal plates. Arms long and cylindrical. Dorsal arm plates flabelliform, sterom with minute thorns. Ventral arm plate pentagonal, sterom with minute thorns. Tentacle scales restricted to first five arm segments.
Description. Disc circular (dd = 4.29 mm), covered by flattened plates, polygonal, of varied size and shapes (Fig. 1 A). Radial shields large, approximately twice longer than wide, united along all their extension (Fig. 1 A). A small triangular plate may be present separating the distal ends of the radial shields. Interradius covered by three rows of polygonal plates, the central row with the largest plates (Fig. 1 A). Distal margin of interradius with three large plates (Fig. 1 A) Central region of disc occupied by 30 polygonal plates. Ventral interradius covered by imbricating plates of variable sizes and shapes, smaller than the dorsal plates (Fig. 1 B, C). Bursal slits short, localized on the lateral margin of the oral shields (Fig. 1 B, C, D). Jaw short (Fig. 1 B, C, D). Oral shields smaller than the adoral shields, diamond-shaped, with proximal angle acute and distal angle slightly wider (Fig. 1 C, D). Adoral shields large, tumid, trapezoid, united proximally (Fig. 1 C, D). Madreporite not differentiated. Infradental papillae rectangular, with proximal margin rounded (Fig. 1 C, D). Two oral papillae, distal rectangular and opercular, proximal small and triangular (Fig. 1 C, D).
Five cylindrical, long arms, approximately six times the diameter of the disc (Fig. 1 A, B). Dorsal arm plate fan-shaped, with distal margin rounded (Fig. 1 A, F, 2 G, F). Simple and fine stereom with minute thorns (Fig. 2 G). Lateral arm plate visible dorsally and ventrally (Fig. 1 A, B, E, F), with simple stereom (Fig. 2 A), pairs contiguous dorsally and ventrally (except in the proximal segments). Isolated plate from proximal arm about as high as wide, simple stereom with minute thorns on the distal portion (Fig. 2 A). Inner side of lateral plate with undifferentiated ridge, two oval well defined and prominent knobs, one proximal and the other distal, inner perforation not discernible (Fig. 2 B). Arm spine articulation formed by two lip-shaped ridges parallel and of same length, slightly curved, separated at both ends, among them are two large openings of nearly equal size (muscle and nerve opening) (Figure 2 C). Ventral arm plate pentagonal, lateral and distal margins rounded (Fig. 1 E). Simple and fine stereom with minute thorns (Fig. 2 H). First ventral arm plate very small, narrow, pentagonal, and twice longer than large (Fig. 1 D). Three to six arm spines, thin, of which dorsal one is the largest (1.5 times longer than one arm segment), remaining spines decreasing in ventral direction. Arm spines with minute thorns (Fig. 2 D). Tentacle pore large. Tentacle scale, longer than wide, half the length of the ventral arm plate, restricted to first five arm segments (Fig. 1 B, C, E).
Vertebrae longer than wide, non-keeled, dorsal median groove V-shaped, with a well-developed lateral curved groove, and a zygospondylous articulation (Fig. 2 I, J, L, M). In proximal view the aboral muscle area (am) is large and winged, the oral muscle area (om) is slightly rectangular and concave (Fig. 2 J). A well-developed suture line in dorsal and ventral view (Fig. 2 L, M).
Adradial genital plate long, covering the three first arm segments, and in contact with the two first lateral arm plates by a long groove (Fig. 3 A, B, C). Abradial genital plate scale-like, articulated laterally with adradial genital plate (Fig. 3 A).
Color. Individuals preserved in alcohol are whitish (Fig. 1). We have no information on the color patterns of living specimens.
Variations. Disc diameter varied from 1.98 to 4.29 mm in examined specimens. Few morphological variations were observed and these are all related to the ontogenetic stage of specimens. As a rule, juvenile specimens have the primary plates occupying the entire center of the disc and a single row of plates in the interradius. All specimens examined in this study have tentacle scales at least up to the fifth arm segment. Only one specimen (dd = 2.50 mm) had tentacle scales restricted to the first arm segment. Probably the tentacle scales of the following arm segments had become detached, as the specimen was otherwise quite damaged. Borges et al. (2002) analyzed specimens from Brazil with dd between 2.86 and 3.07 mm, which had tentacle scales until the third arm segment. Benavides-Serrato et al. (2011) studied specimens from Colombia with 3 mm dd and observed tentacle scales up to the fourth arm segment.
Distribution. Barbados, Colombia and Brazil (Atlantic Ocean) (Solís-Marín et al. 2013). In Brazil from Amapá, Pará (Marajó Island), Maranhão, Espírito Santo (continental shelf, Banco Jaseur), Rio de Janeiro (Oliveira et al. 2010), and São Paulo (Monteiro 1990).
Depth range. From 15 to 600 m (Borges et al. 2002).
Remarks. H.L. Clark (1915) described Amphipholizona delicata from 19 specimens collected off Barbados between 139 and 188 m in depth. These specimens were previously identified by Lyman as Ophiozonella antillarum (Lyman, 1878) (originally Ophiozona antillarum). According to H.L. Clark (1915), Lyman thought that these specimens could be juvenile specimens of Ophiolepis Müller & Troschel, 1840 (as Ophiozona Lyman, 1865), but he himself was not satisfied with such an identification. H.L. Clark (1915) reexamined the specimens and on the basis of the peculiar arrangement of the oral frame plates and of the plates of the dorsal surface of the disc, did not believe this species belonged to either Ophiolepis or Ophioplocus Lyman, 1862 (as Ophioceramis Lyman, 1865), and consequently described them as a new genus and species.
Amphipholizona delicata differs from its congeneric form A. perplexa new comb. in having long, cylindrical arms, and tentacle scales up to the fifth arm segment. It differs from Ophiozonella antillarum (Ophiolepididae) in that the latter has oval radial shields, separated along their entire length, has four oral papillae, has a long and narrow bursal slit, two small arm spines, and a single tentacle scale on the arm.
Amphipholizona delicata is relatively more common than A. perplexa, being frequently collected along the southeastern coast of Brazil. However, this species is rarely captured in large numbers of individuals.
Ecological notes. Amphipholizona delicata is found on substrates formed by silty clay, biodetricit sand, and calcareous algae (Albuquerque 1986), very find sand and organic matter (Monteiro 1990), and coralline gravel (Albuquerque & Guille 1991). According to De Léo (2003), A. delicata may feed both on particles in suspension, under favorable current conditions, and on organic matter deposited on the seafloor.
description: Published as part of Gondim, Anne Isabelley, Christoffersen, Martin Lindsey, Dias, Thelma Lúcia Pereira & Solís-Marín, Francisco Alonso, 2016, Taxonomic status of the genera Amphipholizona H. L. Clark, 1915 (Ophiuroidea, Ophiolepididae) and Amphigyptis Nielsen, 1932 (Hemieuryalidae): systematic placement and synonymy, pp. 381-395 in Zootaxa 4097 (3) on pages 384-388, DOI: 10.11646/zootaxa.4097.3.6, http://zenodo.org/record/261980