Nodothauma magnifica, Criscione & Hallan & Puillandre & Fedosov, 2021

Criscione, Francesco, Hallan, Anders, Puillandre, Nicolas & Fedosov, Alexander, 2021, Where the snails have no name: a molecular phylogeny of Raphitomidae (Neogastropoda: Conoidea) uncovers vast unexplored diversity in the deep seas of temperate southern and eastern Australia, Zoological Journal of the Linnean Society 191, pp. 961-1000 : 975-978

NODOTHAUMA MAGNIFICA SP. NOV.

( FIG. 3A)

Z o o B a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: FE4DEFB1-2CB0-49DF-9C6C-9AA1042C2365.

Holotype: Australia, GAB, 1927 m, IN2015_C02_137, (–35.558, 134.083), AMS C.532707.

Paratypes: Australia, GAB , 1570 m, IN2015_C02_435, (–34.072, 130.267), one wet ( SAMA D44139) ; 1912 m, IN2015_C01_054, (–35.202, 131.629), one wet ( SAMA D44255) ; 1509 m, IN2015_C02_134, (–35.345, 134.045), one wet ( AMS C.532689) ; 1509 m, IN2015_C02_134, (–35.345, 134.045), one wet ( AMS C.571573); one wet ( AMS C.571637) ; 1927 m, IN2015_C02_137, (–35.558, 134.083), one wet ( AMS C.571739) .

Distribution: Known only from the Great Australian Bight.

Etymology: From the Latin adjective magnificus, grand, referring to the large shell of this species.

Description

Shell ( Fig. 3A) large (H = 71.6 mm, W = 24.9 mm), elongate-fusiform, walls solid, opaque. Protoconch eroded. Teleoconch of about seven orange-brownish whorls; spire outline slightly concave. Shoulder pronounced, situated slightly adapical to whorl mid-height in early whorls, and indistinct on late teleoconch whorls. Subsutural ramp wide, concave to lightly convex; suture impressed. Spiral sculpture below subsutural ramp of well-defined cords, about 12 on penultimate whorl and in excess of 40 on last adult whorl; weaker, but distinct spirals of similar spacing present on lower half of subsutural ramp. Axial sculpture of low opisthocline riblets confined largely to penultimate and last adult whorls, unevenly spaced; elsewhere, collabral growth lines only, most prominent on subsutural ramp with slightly raised cordlets at uneven intervals, reflecting shape of anal sinus. Last adult whorl evenly convex below subsutural ramp, weakly demarcated from long, evenly tapering siphonal canal, producing slight concavity in apertural view. Aperture elongate-pyriform, approximately half of shell length; outer lip thin, unsculptured; inner lip with distinct, wide whitish callus; innermost part of columella marked by prominent, elongate burnt-orange vertical stain. Anal sinus wide, moderately deep, broadly U-shaped.

Cephalic tentacles broad, muscular, cylindrical, of medium length, with well-developed eyes at their outer base. Rhynchostomal lips thick, with thick-walled, moderately long introvert. Rhynchocoel capacious, internal walls lined in tall, dark red epithelium; oesophagus lined with epithelium of similar appearance. Radula and venom apparatus absent.

Remarks

Nodothauma magnifica has some similarities to Abyssobela atoxica Kantor & Sysoev, 1989 , notably in the whorl profile, spiral sculpture, the presence of dark content inside the rhynchocoel and the absence of a radula and venom apparatus ( Kantor & Sysoev, 1989; Y. Kantor, pers comm.). However, A. atoxica does not possess eyes (Y. Kantor, pers. comm.), whereas in N. magnifica the eyes are well-developed and large. Polychaete fragments and foraminiferae have been recovered from the intestine of specimen SAMA D44255.