Crikey steveirwini, Stanisic, John, 2009

Stanisic, John, 2009, Crikey steveirwini gen. et sp. nov. from montane habitats in the Wet Tropics of northeastern Queensland, Australia (Gastropoda: Eupulmonata: Camaenidae), Zootaxa 2206, pp. 62-68 : 63-66

Crikey steveirwini sp. nov.

( Fig. 1 )

Etymology. In memory of the late Steve Irwin, wildlife warrior, environmental educator and Queensland Museum medallist.

Diagnosis. Shell moderately large with an elevated spire and rounded whorls; light creamy yellow base colour with darker brown suffusions and bands; sculpture of numerous strongly incised spiral striae crossed by weak axial growth ridges; lip barely thickened and weakly reflected; imperforate. Penis without a verge; epiphallus entering penis through an apical pore surrounded by a muscular collar; epiphallic flagellum absent.

Material examined. (All north-east Queensland.) Holotype. QMMO 78184, Mount Spurgeon, 7 km north, 16°22’S, 145°13’E, 1250 m G.B. Monteith, H. Janetzki, L. Roberts, 19.x.1991 ( Fig. 1 A).

Paratypes. QMMO 34222, 1 subadult, same data as holotype; QMMO 27117, 1 adult, Lambs Head, 10 km west of Edmonton, 17°01’S, 145°39’E, 1200 m, rainforest, G. B. & S. R. Monteith, 8.i.1990 ( Fig. 1 C); QMMO 27118, 1 adult, Mount Lewis Road, 30 km from highway, 16°30’S, 145°16’E, 1200 m, rainforest, ANZSES Expedition, 14.i.1990; QMMO 20911, 1 adult, Mount Lewis Road, Old Barracks Area, 16°35’S, 145°16’E, 1000 m, K. McDonald, G. Baines, 16.iii.1989 ( Fig. 1 B).

Other material. QMMO 34221, 1 subadult, Stewart Creek, c. 4 km north-north-east Mount Spurgeon, 16°24’S, 145°13’E, 1300 m, G.B. Monteith, H. Janetzki, L. Roberts, 16.x.1991; QMMO 57999, 1 subadult, Mount Lewis, summit, 16°35’S, 145°17’E, P. Hasenpusch, 28.xii.1995; QMMO 69655, 1 subadult, Mossman, c. 14 km west-south-west on Main Coast Range, 16°30’S, 145°16’E, rainforest, R. Crookshanks, 19.v.2001 ( Fig. 1 D); QMMO 70536, 1 adult (dissected) & 1 subadult, Mossman, c. 14 km west-south-west on Main Coast Range, 16°30’S, 145°16’E, rainforest, among shrubs, R. Crookshanks, L. Free, 3.ii.2002.

Description. Shell: Shell thin, turbinate with an elevated spire, with 4 7/8 (holotype) evenly rounded whorls, the last descending more rapidly in front; apex and spire strongly elevated, sutures moderately impressed; protoconch approximately 1 1/2 whorls with sculpture of crowded, slightly curved, fine radial growth ridges; teleoconch whorls with moderately crowded, strongly incised spiral striae crossed by weak axial growth ridges. Aperture lunately ovate; lip slightly thickened and weakly reflected. Umbilicus absent. Colour light creamy-yellow with dark chocolate-brown spiral bands of various widths and a lighter brown spiral band subsuturally; base with a light-brown suffusion, lip dark chocolate-brown.

Measurements, based on 3 (including 2 damaged) adults (QMMO 20911, QMMO 27117, QMMO 78184 = holotype):

height 14.61–16.59 mm (holotype 14.61 mm; mean 15.32 mm)

diameter 11.24–12.26 mm (holotype 12.26 mm; mean 11.60 mm)

H/D ratio 1.19–1.47 (holotype 1.19 mm; mean 1.32 mm)

Genital anatomy: Penis without a verge; epiphallus entering penis through an apical pore surrounded by a muscular collar; longitudinal pilasters in the lower chamber; epiphallic flagellum absent (genitalia not figured due to destruction of material during dissection). Otherwise typical of the family Camaenidae . Based on one dissected adult specimen (QMMO 70536).

Distribution and habitat. Wet Tropics (Main Coast Range, Lamb Range and Spurgeon Uplands), northeast Queensland at altitudes mainly above 1000 m ( Fig. 2 ); living in rainforest and presumed arboreal though hitherto only collected from the forest floor and among low shrubs.

Remarks. Crikey steveirwini differs from all other Australian arboreal camaenids by the combination of rounded body whorl, strongly elevated spire, relatively simple, weakly reflected lip and lack of a penial verge and epiphallic flagellum. Other arboreal camaenids occurring in the Wet Tropics comprise Rhynchotrochus macgillivrayi (Forbes, 1851) , Noctepuna mayana (Hedley, 1899) , Noctepuna cerea (Hedley, 1894) and Meliobba shafferyi Iredale, 1940 . These species have angulate to strongly carinate body whorls, usually more complex apertural lips and often larger, more robust shells. The most conchologically similar arboreal camaenid is the south-east Queensland Posorites fucata (Pfeiffer, 1853) , which also has a creamy-white shell with several brown to black spiral bands and sculpture of incised spiral striae.

The only adult specimen available for dissection was poorly preserved making interpretation of reproductive structures difficult. However, teasing apart structures, while destructive, revealed sufficient detail to enable a description of the genitalia. Anatomically, C. steveirwini differs from the other arboreal camaenids found in the Wet Tropics and elsewhere along the east coast by the absence of a penial verge and epiphallic flagellum. Entry of the epiphallus to the penis is through a simple pore surrounded by a muscular collar. All other papuinids thus far dissected by the author have a conical verge (Stanisic, unpublished).

Conchologically C. steveirwini also bears some vague similarity to the introduced and unrelated, arboreal cerastid Rhachistia histrio (Pfeiffer, 1855) . But apart from the gross similarity in overall shell shape, R. histrio differs in having a white shell with interrupted dark brown bands and suffusions, and a simple lip that is not thickened or reflected. In northeastern Queensland R. histrio is found in the vine thickets of the Forty Mile Scrub and the Kinrara lava flow, south of Mount Garnet, inland north-east Queensland and thus far has not been recorded from the more easterly rainforests of the Wet Tropics.

Figures

FIGURE 1. Crikey steveirwini gen. et sp. nov. showing variation in banding pattern. A. Holotype, QMMO 78184, height = 14.61 mm. B. Paratype, QMMO 20911, Mt Lewis, height = 14.77 mm. C. Paratype, QMMO 27117, Lambs Head, height = 16.59 mm. D. QMMO 69655, Main Coast Range, height = 13.63 (subadult).

FIGURE 2. Distribution map showing the location of all known records of C. steveirwini in north-east Queensland (inset shows regional location).