Amphichondrius granulatus (Lütken & Mortensen, 1899 )

Granja-Fernández, Rebeca, Hendrickx, Michel E., Rangel-Solís, Pedro Diego & López-Pérez, Andrés, 2023, Deep-sea Ophiuroidea (Echinodermata) collected during the TALUD cruises in western Mexico, Zootaxa 5259 (1), pp. 1-71 : 51-52

Amphichondrius granulatus (Lütken & Mortensen, 1899)

Fig. 16A‒F

Amphiura granulata Lütken & Mortensen, 1899: 155‒156 , pl. 10, figs. 1‒4.

Amphipholis granulata . H.L. Clark 1917: 437‒438.

Amphichondrius granulosus Nielsen, 1932: 304‒306 , fig. 21.— H.L. Clark 1940: 337.— Boolotian & Leighton 1966: 4, 10, fig. 8.

Amphichondrius unamexici Caso, 1983: 209‒212 , figs. 1-17.

Amphichondrius granulatus . Hendler 1996: 128‒131, fig. 7.4.

See Hendler (1996) for other synonymous records.

Material examined. Four individuals at three stations. TALUD XIV, Sta. 4, 1 ind. (ICML-EMU-11660); Sta. 10, 2 ind. (ICML-EMU-12993). TALUD XV, Sta. 23, 1 ind. (ICML-EMU-12992).

Comparative material. Amphiura granulata Lu ̈tken & Mortensen, 1899, syntypes, 2 ind.: MCZ OPH- 1406. Amphichondrius granulosus Nielsen, 1932 , holotype: NHMD OPH- 169. Amphichondrius unamexici Caso, 1983 , paratypes, 225 ind.: ICML-UNAM 3.40.0, USNM E47909 (Supplementary file 2).

Description (ICML-EMU-12993). DD = 5 mm. Disc circular and flat. Dorsal disc covered by imbricated scales; marginal oval scales placed between each pair of RS. Primary plates round, separated. RS half-circular, meeting but with a k-plate inserted proximally ( Fig. 16A ). Ventral interradii covered by granules ( Fig. 16B ). OSh as broad as long, spearhead-shaped with distal lobe. Madreporite slightly larger than OSh. AdSh scalene triangular, meeting in front of OSh. Jaws bearing three oral papillae at each side; AdShSp wide, rectangular, the largest; 2AdShSp similar in shape to AdShSp but much smaller; IPa quadrangular. vT quadrangular ( Fig. 16C ). Arms slender. DAP broader than long, oval, contiguous ( Fig. 16D ). VAP broader than long, pentagonal, slightly separated from each other. LAP with up to three ArSp, small (approximately one arm segment in length), all similar in size, tapering, blunt tip. Tentacle pores with two TSc, adradial elongated, abradial rounded ( Fig. 16E ). Color pattern dorsally and ventrally beige-whitish (ethanol preservation) ( Fig. 16A‒F ).

Habitat and distribution. California, USA, Mexico, Panama, Gorgona Island, Colombia, Ecuador, and the Galapagos Islands (Lütken & Mortensen, 1899; Nielsen 1932; Caso 1983; Hendler 1996; Solís-Marín et al. 2013); 18‒730 m depth ( Maluf 1988; Hendler 1996), coralline, muddy, sandy and rocky substrates (H.L. Clark 1940; Caso 1983; Hendler 1996). The material examined was collected off western Baja California Sur and in the Gulf of California; 325‒ 625 m.

Remarks. Previously recorded off western Baja California, in the Gulf of California, off Nayarit, Guerrero, and Oaxaca ( Granja-Fernández et al. 2015, 2021); record off western Baja California Sur is new for Mexico.

Figures

FIGURE 16. Amphichondrius granulatus (Lütken & Mortensen, 1899) (ICML-EMU-12993, DD = 5 mm). A, Dorsal disc; B, Ventral disc; C, Mouth; D, Dorsal arm; E, Ventral arm; F, Dorsal view. Amphipholis pugetana (Lyman, 1860) (ICML-EMU- 11163, DD = 4 mm). G, Dorsal disc; H, Ventral disc; I, Mouth; J, Dorsal arm; K, Ventral arm; L, Dorsal view.