Ophiacantha quadrispina H.L. Clark, 1917

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 : 39

publication ID	https://doi.org/10.11646/zootaxa.5259.1.1
publication LSID	lsid:zoobank.org:pub:4306F52E-FD24-45B0-B307-66B71173D805
DOI	https://doi.org/10.5281/zenodo.7795113
persistent identifier	https://treatment.plazi.org/id/03AB87FA-FF87-FFF2-FF7B-FC35FC91FEE6
treatment provided by	Plazi (2023-04-03 13:18:02, last updated 2024-11-28 20:47:02)
scientific name	Ophiacantha quadrispina H.L. Clark, 1917
status

Treatment

Ophiacantha quadrispina H.L. Clark, 1917 View in CoL

Fig. 10G‒L View FIGURE 10

Ophiacantha quadrispina H.L. Clark, 1917: 432‒433 View in CoL , pl. 1, figs. 3‒4, pl. 2, fig. 3.

Material examined. Three individuals at three stations. TALUD XIV, Sta. 7, 1 ind. (ICML-EMU-11674); Sta. 15, 1 ind. (ICML-EMU-11216). TALUD XV, Sta. 23, 1 ind. (ICML-EMU-12997).

Comparative material. Syntypes, 4 ind.: MCZ OPH-4478 , USNM E686 About USNM , USNM E687 About USNM , USNM E688 About USNM (Supplementary file 2) .

Description (ICML-EMU-12997). DD = 9.9 mm. Disc pentagonal. Dorsal disc covered by granules and scales. Primary plates not evident. RS oval, small (covering ¼ of disc radius), separated ( Fig. 10G View FIGURE 10 ). Ventral interradii covered by scales and some elongated granules distally. Genital slits with conspicuous imbricated scales ( Fig. 10H View FIGURE 10 ). OSh broader than long, diamond-shaped with rounded edges, distally elongated. Madreporite larger than OSh.AdSh longer than broad, slender, distally projecting and surrounding AdSh, meeting in front of Osh or separated. Jaws bearing 6‒7 papillae at each side; AdShSp rounded; LOPa 4‒5, elongated, pointed, some of them placed in two rows; IPa pointed. vT quadrangular, located behind the pair of IPa ( Fig. 10I View FIGURE 10 ). Arms fragile. First DAP covered by scattered granules; subsequent DAP as long as broad, diamond-shape, meeting. Longitudinal swollen keel along the DAP ( Fig. 10J View FIGURE 10 ). VAP broader than long, pentagonal with rounded edges, meeting or almost meeting. LAP with four ArSp, large (approximately 2.5 arm segments in length), smooth, flattened, dorsalmost largest, ventralmost shortest. First seven tentacle pores with two TSc; subsequent pores with one lanceolate TSc ( Fig. 10K View FIGURE 10 ). Color pattern in dorsal disc and arms brown, ventral side beige ( Fig. 10G‒L View FIGURE 10 ). DAP with longitudinal brown and beige bands (ethanol preservation) ( Fig. 10J View FIGURE 10 ).

Habitat and distribution. Mexico and the Galapagos Islands, Ecuador; 183‒ 871 m depth, muddy, sandy, and rocky substrates and gorgonians (H.L. Clark 1917; Maluf 1988; see Remarks). The material examined was collected off western Baja California Sur and in the northern Gulf of California; 203‒871 m depth.

Remarks. The genus Ophiacantha is a heterogeneous taxon that contains several groups of species that are difficult to place taxonomically ( O’Hara & Stöhr 2006). According to Christodoulou et al. (2019), Ophiacantha quadrispina clusters with Ophiotoma species and some Ophiomitra and Ophiopristis , suggesting that it does not belong to Ophiacanthidae but to the Ophiotomidae . Consequently, a complete revision of the genus is needed to determine the correct generic placement of O. quadrispina . Ophiacantha quadrispina was previously known only in the Gulf of California ( Granja-Fernández et al. 2015) and at a maximum depth of 549 m ( Maluf 1988). Material examined from off western Baja California Sur (27º8′11″N; 114º32′54″W) represents a new distribution record and an extension of its lower bathymetric limit to 871 m depth.

References

Christodoulou, M., O'Hara, T. D., Hugall, A. F. & Martinez-Arbizu, P. (2019) Dark ophiuroid biodiversity in a prospective abyssal mine field. Current Biology Report, 29, 3909 - 3912. https: // doi. org / 10.1016 / j. cub. 2019.09.012

Clark, H. L. (1917) Reports on the scientific results of the expedition to the Eastern Tropical Pacific in charge of Alexander Agassiz, by the U. S. Fish Commission Steamer Albatross from October, 1904, to March, 1905, Lieut. Commander L. M. Garrett U. S. N., Commanding. XXX. Ophiuroidea. Bulletin of the Museum of Comparative Zoology at Harvard College, 61 (12), 429 - 453.

Granja-Fernandez, R., Herrero-Perezrul, M. D., Lopez-Perez, R. A., Hernandez-Morales, A. & Rangel-Solis, P. D. (2015) A literature review of the Ophiuroidea (Echinodermata) from the Pacific coast of Mexico. Revista de Biologia Tropical, 63 (2), 37 - 47.

Maluf, L. Y. (1988) Composition and distribution of the central Eastern Pacific Echinoderms. Natural History Museum of Los Angeles County, Technical Report, 2, 1 - 306.

O'Hara, T. D. & Stohr, S. (2006) Deep water Ophiuroidea (Echinodermata) of New Caledonia: Ophiacanthidae and Hemieuryalidae. In: Forges, R. & Justine, J. L. (Eds.), Tropical deep-sea benthos. Vol. 24. Memoires du Museum national d´Histoire naturelle, Paris, 193, pp. 33 - 141.

Figures

FIGURE 10. Ophiacantha pacifica Lütken & Mortensen, 1899 (ICML-EMU-11195, DD = 7 mm). A, Dorsal disc; B, Ventral disc; C, Mouth; D, Dorsal arm; E, Ventral arm; F, Dorsal view. Ophiacantha quadrispina H.L. Clark, 1917 (ICML-EMU-12997, DD = 9.9 mm). G, Dorsal disc; H, Ventral disc; I, Mouth; J, Dorsal arm; K, Ventral arm; L, Dorsal view.