Ophiolebes comatulina, Mcknight, Donald G., 2003

Mcknight, Donald G., 2003, New brittle­stars (Echinodermata: Ophiuroidea) from New Zealand waters, Zootaxa 352, pp. 1-36 : 3-5

Ophiolebes comatulina n.sp. Fig. 1 : A, B.

Material examined: NIWA Stns E728 (2); E731 (1).

Depth Distribution: 602– 688 m.

Geographic Distribution: This species is recorded from near White Island, Bay of Plenty (see locality map, p. 32).

Description: Holotype specimen, Stn E728: disc diameter about 5 mm, arms about 20 mm, vertically coiled. Disc inflated above, bulging interradially, and with very narrow depression extending inward from arm base, completely covered with small scales, each with 1–2 small tubercles, these tapering slightly and the truncate tip is finely thorny. Radial shields not evident, though scalation appears slightly denser in these regions. Ventral surface of disc with scales and only a few scattered tubercles. Genital clefts extend to margin and lack papillae or tubercles. Oral shields 4­sided, acutely pointed proximally and distally, lateral point of oral shield meeting first lateral armplate, one oral shield with a distal projection and a straight distal margin. Adoral shields small, meeting within, scarcely widened without, also meeting first lateral armplate proximal to oral shield. Oral plates with 1 pointed apical papilla and 3 pointed oral papillae, the outermost largest and the median smallest; the outer papilla lying just proximal to the second oral tentacle­pore.

Dorsal armplates small, triangular, about as wide as long, slightly separated throughout; lateral armplates meeting narrowly above; at arm base 6 armspines, the uppermost longest, equal to at least 3 arm segments, the combs of opposite sides almost meeting on dorsal midline, and the other spines becoming shorter downwards; all spines pointed, tapering, finely rugose; beyond the middle spines are longest and uppermost is short; 5 short armspines (equal to 1 arm segment) at about mid­arm, all but the uppermost with a slight terminal hook and small teeth along distal margin; uppermost spine simply pointed.

Ventral armplates in contact near armbase, those beyond slightly separated; plates slightly wider than long, truncate on proximal margin, rounded on distal; tentacle­pore lying near the proximal end of plate, the lateral margins concave around it, the plate widening to its maximum width behind pore. One small, pointed tentacle­scale arising from ventral armplate

Colour: (Preserved specimen) uniform cream above and below.

Etymology: comatulina , referring to the fact that all specimens were attached to unidentified comatulid crinoids.

Holotype: Deposited in the collection of NIWA, Wellington No. H­817 (Stn E728).

Paratypes: Deposited in the collection of NIWA, Wellington, No. P­1367 (Stn E728); P­1368 (Stn E731).

Remarks: A paratype (Stn E728) differs from the holotype in having up to 6 oral papillae, irregularly arranged, and all the oral shields are five­sided, squarish distally;1­3 short spines are present on the oral or adoral shields, though slightly spaced from the second oral tentacle­pore; disc tubercles are also present.

The other paratype (Stn E731) has visible ripe gonads, distending the disc, and the dorsal tuberculation is well spaced. All 3 specimens were found entwined in the cirri of unidentified comatulid crinoids, though this may be an artifact of the collecting method.

Species described in the genus Ophiolebes fall into 2 main groups; firstly those species with the radial shields long, bar­like, often concealed; and secondly, those with the radial shields relatively broad, shorter, exposed and quite conspicuous. This new species clearly falls within the first group, and resembles Ophiolebes pachyphylax H.L. Clark in having some long armspines; however in this new species the uppermost armspine is the longest, equal to 3 arm segments, and the radial shields are not evident. Other species of this group are Ophiolebes bacata Koehler with 5 short armspines, and glassy granules embedded in the oral and adoral shields. Ophiolebes scorteus Lyman , the type species, has only the basal tentacle­pore present, and no tentacle­scale. Ophiolebes asaphes H.L. Clark, O. brachygnatha H.L. Clark, O. tuberosa Matsumoto and O. retecta (Koehler) all have the dorsal armplates transversely divided into 2 parts. Paterson (1985) remarked that species with divided armplates also show affinities with Ophiochondrus , referred to the Ophiacanthidae by Mortensen (1936) or the Hemieuryalidae by Fell (1960). Further study is needed to resolve both family and generic status.

Figures

FIGURE 1: Ophiolebes comatulina n. sp. holotype, disc diameter 5 mm. A: dorsal, B: ventral. Ophiolycus farquhari n. sp. disc diameter 6 mm. C: dorsal, D: ventral. Ophiolepis biscalata n. sp. holotype, disc diameter 16 mm. E: dorsal, F: ventral.