Dougaloplus sp.

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 : 55

Dougaloplus sp.

Fig. 17A‒F

Material examined. 24 individuals at eight stations. TALUD IV, Sta. 19, 1 ind. (ICML-EMU-11158-A); Sta. 25, 1 ind. (ICML-EMU-11158-B). TALUD VII, Sta. 19, 9 ind. (ICML-EMU-9014-A) and 1 ind. (ICML-EMU-9014-B). TALUD VIII, Sta. 3, 1 ind. (ICML-EMU-11159-A); Sta. 20, 4 ind. (ICML-EMU-11159-B) and 4 ind. (ICML-EMU-11670). TALUD IX, Sta. 4, 1 ind. (ICML-EMU-11160-A); Sta. 21B, 1 ind. (ICML-EMU-11160-B). TALUD XII, Sta. 13, 1 ind. (ICML-EMU-11161).

Comparative material. Amphilimna pentacantha H.L. Clark, 1911 (junior synonym of Dougaloplus amphacanthus ( McClendon, 1909)) , holotype: USNM 25614. Paratypes, 10 ind.: MCZ OPH- 3172, MCZ OPH-3384. Amphioplus hexacanthus H.L. Clark, 1911 (junior synonym of Dougaloplus amphacanthus ( McClendon, 1909)) , syntype, 1 ind.: MCZ OPH- 3169. Amphiura notacantha Lütken & Mortensen, 1899 (original name of Dougaloplus notacanthus (Lütken & Mortensen, 1899) , holotype: USNM 19543 (Supplementary file 2).

Description (ICML-EMU-9014-A). DD = 7 mm. Disc malformed. Dorsal disc covered by imbricated scales, largest in the center, and by pointed spines on interradius and RS. Primary plates not evident. RS bar-like, elongated and narrow, meeting distally, separated by scales except distally ( Fig. 17A ). Ventral interradii covered by scales smaller than dorsal disc ( Fig. 17B ). OSh broader than long, rounded pentagonal, distal edge concave. Madreporite slightly larger than OSh. AdSh scalene triangular, separated. Jaws bearing four oral papillae at each side; AdShSp rounded, the shortest; 2AdShSp pointed; BSc pointed; IPa quadrangular-rounded. vT quadrangular ( Fig. 17C ). Arms slender. DAP broader than long, widely oval, separated from each other ( Fig. 17D ). VAP longer than broad, pentagonal, slightly separated from each other. Up to five ArSp, small (approximately one arm segment in length), pointed, ventralmost the longest, dorsalmost the shortest. Tentacle pores with one round TSc ( Fig. 17E ). Color pattern dorsally and ventrally beige-whitish (ethanol preservation) ( Fig. 17A‒F ).

Habitat and distribution. The material examined was collected in the southern Gulf of California and off Guerrero; 778‒ 1,395 m depth.

Remarks. The genus Dougaloplus is represented in eastern tropical Pacific by three species: Dougaloplus amphacanthus ( McClendon, 1909) , Dougaloplus gastracanthus (Lütken & Mortensen, 1899) , and Dougaloplus notacanthus (Lütken & Mortensen, 1899) . Compared with the material of Dougaloplus sp. examined, D. amphacanthus is characterized by a dorsal disc densely covered with spines, two tentacle scales, and a bifurcated tip on the arm spines. Dougaloplus sp. is close to D. gastracanthus and D. notacanthus (which are very similar in appearance), but these two species differ from our material in having less spines on the dorsal disc, and the elongated and pointed oral papillae. Information and material of D. gastracanthus and D. notacanthus are restricted to the original description of D. gastracanthus (Lütken & Mortensen 1899) and the damaged holotype of D. notacanthus ; additional, non-type material of these two species is not available. More specimens of these species are needed to elucidate whether Dougaloplus sp. belongs to either D. gastracanthus or D. notacanthus , or if it belongs to a new species.

Figures

FIGURE 17. Dougaloplus sp. (ICML-EMU-9014-A, DD = 7 mm). A, Dorsal disc; B, Ventral disc; C, Mouth; D, Dorsal arm; E, Ventral arm; F, Dorsal view. Ophiocnida californica Ziesenhenne, 1940 (ICML-EMU-11175, DD = 6 mm). G, Dorsal disc; H, Ventral disc; I, Mouth; J, Dorsal arm; K, Ventral arm; L, Dorsal view.