Ophiobyrsa intorta (Koehler, 1922)

Mills, V. Sadie & O'Hara, Timothy D., 2013, Ophiuroids (Echinodermata; Ophiuroidea) of biogenic habitats on the continental shelf of New Zealand, Zootaxa 3613 (5), pp. 401-444 : 427-428

Ophiobyrsa intorta (Koehler, 1922)

Figs.11–12

Ophiobyrsella intorta Koehler, 1922: 27 –29, pl. 4(2–5), 92(4).

Ophiobyrsa rudis .—Koehler, 1930: 49 (in part) [Non Ophiobyrsa rudis Lyman T, 1878 ; see O'Hara, 1998]. Ophiobyrsa intorta .—Clark, A.M., 1965: 39–40.—O'Hara, 1998: 42.

Material Examined. East Coast North Island. TAN1108/250, NIWA 75542 (1).

Comparative Material. Ophiobyrsa intorta (Koehler, 1922) : TAN0413/130, Mahina Knoll, Bay of Plenty, 37° 21.34´S, 177° 5.98´E to 37° 21.29´S, 177° 6.22´E, 260–280 m, 14/11/2004, NIWA 14814 (1). TAN0413/140, Mahina Knoll, Bay of Plenty, 37° 21.35´S, 177° 6.09´E to 37° 21.21´S, 177° 6.08´E, 259–294 m, 14/11/2004, NIWA 14811 (1).

Diagnosis. Numerous small spines covering entire disc surface dorsally and ventrally. Two (rarely fewer) oral papillae on each jaw side. 4–5 arm spines at arm base, distalmost spines transformed into denticulate hooks. Single, very small tentacle scale.

Description. See Koehler (1922a).

Distribution. New Zealand (110–294 m), Indonesia (300 m), Philippines (969–1346 m).

Remarks. Two specimens collected from the Bay of Plenty (NIWA 14811, 14814) have been identified as O. intorta . Each has five arm spines and two oral papillae, though sometimes only a single oral papilla is visible on the side of the oral plates, suggesting that these are easily lost and not a reliable character. These specimens represent the first records of this genus and species in New Zealand waters.

The single specimen collected from Ranfurly Bank (NIWA 75542, Figs. 11–12 ), with a disc diameter intermediate to the two specimens collected in the Bay of Plenty, differs in having seven arm spines at the arm base, reducing to six by mid arm, and only a single oral papilla at each side of the oral plates. The paucity of specimens prevents any further determination or dissection to examine skin-covered plates at this time, but it is possible that there is more than one species of Ophiobyrsa in New Zealand waters.

Figures

FIGURE 11. Dorsal side of Ophiobyrsa intorta (Koehler, 1922) (NIWA 75542, TAN 1108 / 250) showing live colour. Scale bar = 1 cm.

FIGURE 12. Spines from mid-distal arm of Ophiobyrsa intorta (Koehler, 1922) specimen (NIWA 75542, TAN 1108 / 250). The hooked spine is the first ventral arm spine, the rest of the arm spines resemble the spine on the left. Scale bar = 0.2 mm.