Amphipholizona delicata H.L. Clark, 1915

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, Zootaxa 4097 (3), pp. 381-395: 384-388

publication ID

http://dx.doi.org/10.11646/zootaxa.4097.3.6

publication LSID

lsid:zoobank.org:pub:161B0314-A85E-4324-A0D8-F2EFFC15685B

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http://treatment.plazi.org/id/03B68798-FFF1-FFFD-FF43-6DE2FBBFFD47

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scientific name

Amphipholizona delicata H.L. Clark, 1915
status

 

Amphipholizona delicata H.L. Clark, 1915 

Figures 1View FIGURE 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. 12 a-b.― Albuquerque, 1986: 258 –260, fig. 38 a –c, pl. 15, figs. 1 a –c.― Tommasi & Aron, 1987: 3.― Monteiro, 1990: 735 –738, figs. 1 a –e.― Albuquerque & Guille, 1991: 17.― Manso, 1993: 193.― Borges et al., 2002: 32, figs. 19 a –b; 2004: 157.― De Léo, 2003: 71, 87, 115, 121.― Criales-Hernández et al., 2006: 1262.― Borrero-Pérez et al., 2008: 172, 182, fig. 9 a –b.― Oliveira et al., 2010: 5, fig. 3 p (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), 00º 14 ′ 3 ″ S 45 º04′ 12 ″W, St. 21, Geomar I, 0 4 June 1969; MZUSP 784, 1 spm. (dd = 4.01 mm), 02º04′ S 40 º 29 ′ W, Canopus Commission, 29 June 1965; MZUSP 772, 1 spm. (with damaged disc), 04º 43 ′0″ S 50 º 28 ′ 0″W, St. D III, Pesca Norte Commission, 30 November 1968; MZUSP 782, 1 spm. (with damaged disc), 02º 15 ′0″ S 48 º 15 ′ 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 48 º04′ 0″W, St. 154, Geomar III, 21 April 1971; MZUSP 891, 1 spm. (dd = 3.09 mm), 04º 29 ′ 5 ″ S 50 º 12 ′ 0″W, St. 1793 A, 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 -R 3, 0 1 February 2007, 500 m. EQMN 2770, 1 spm. (dd = 4.29 mm), 16 º 332 ′S 38 º 444 ′W, REVIZEE Central II, # 7 C, 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. 1View FIGURE 1 A). Radial shields large, approximately twice longer than wide, united along all their extension ( Fig. 1View FIGURE 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. 1View FIGURE 1 A). Distal margin of interradius with three large plates ( Fig. 1View FIGURE 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. 1View FIGURE 1 B, C). Bursal slits short, localized on the lateral margin of the oral shields ( Fig. 1View FIGURE 1 B, C, D). Jaw short ( Fig. 1View FIGURE 1 B, C, D). Oral shields smaller than the adoral shields, diamond-shaped, with proximal angle acute and distal angle slightly wider ( Fig. 1View FIGURE 1 C, D). Adoral shields large, tumid, trapezoid, united proximally ( Fig. 1View FIGURE 1 C, D). Madreporite not differentiated. Infradental papillae rectangular, with proximal margin rounded ( Fig. 1View FIGURE 1 C, D). Two oral papillae, distal rectangular and opercular, proximal small and triangular ( Fig. 1View FIGURE 1 C, D).

Five cylindrical, long arms, approximately six times the diameter of the disc ( Fig. 1View FIGURE 1 A, B). Dorsal arm plate fan-shaped, with distal margin rounded ( Fig. 1View FIGURE 1 A, F, 2 G, F). Simple and fine stereom with minute thorns ( Fig. 2View FIGURE 2 G). Lateral arm plate visible dorsally and ventrally ( Fig. 1View FIGURE 1 A, B, E, F), with simple stereom ( Fig. 2View FIGURE 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. 2View FIGURE 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. 2View FIGURE 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 2View FIGURE 2 C). Ventral arm plate pentagonal, lateral and distal margins rounded ( Fig. 1View FIGURE 1 E). Simple and fine stereom with minute thorns ( Fig. 2View FIGURE 2 H). First ventral arm plate very small, narrow, pentagonal, and twice longer than large ( Fig. 1View FIGURE 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. 2View FIGURE 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. 1View FIGURE 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. 2View FIGURE 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. 2View FIGURE 2 J). A well-developed suture line in dorsal and ventral view ( Fig. 2View FIGURE 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. 3View FIGURE 3 A, B, C). Abradial genital plate scale-like, articulated laterally with adradial genital plate ( Fig. 3View FIGURE 3 A).

Color. Individuals preserved in alcohol are whitish ( Fig. 1View FIGURE 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.

MCZ

Museum of Comparative Zoology

MZUSP

Museu de Zoologia da Universidade de Sao Paulo

Kingdom

Animalia

Phylum

Echinodermata

Class

Ophiuroidea

Order

Ophiurida

Family

Ophiolepididae

Genus

Amphipholizona

Loc

Amphipholizona delicata H.L. Clark, 1915

Gondim, Anne Isabelley, Christoffersen, Martin Lindsey, Dias, Thelma Lúcia Pereira & Solís-Marín, Francisco Alonso 2016
2016
Loc

Amphipholizona delicata

Gondim 2013: 513
Solis-Marin 2013: 633
Barboza 2012: 5
Benavides-Serrato 2011: 222
Oliveira 2010: 5
Borrero-Perez 2008: 172
Criales-Hernandez 2006: 1262
De 2003: 71
Borges 2002: 32
Manso 1993: 193
Albuquerque 1991: 17
Monteiro 1990: 735
Tommasi 1987: 3
Albuquerque 1986: 258
Tommasi 1974: 13
Downey 1969: 18
Clark 1918: 43
Clark 1915: 335
1918