Fastosarion ephelis, Hyman & Köhler, 2019

Hyman, Isabel T. & Köhler, Frank, 2019, Phylogeny and systematic revision of the helicarionid semislugs of eastern Queensland (Stylommatophora, Helicarionidae), Contributions to Zoology 88 (4), pp. 351-451 : 419

Fastosarion ephelis sp. nov.

Figs. 18 , 19C , 20E , 23D–E

Helicarionidae MQ 16: Stanisic, 2018: figs. 4E, 6D.

Etymology From ephelis (Greek, meaning freckle), referring to the speckled appearance of the animal; noun in apposition; noun in apposition.

Material examined

Types: Holotype: QM MO85835 ( Broken River , Eungella NP, MEQ, coll. Apr 1996, J. Leroi).

Paratypes: QM MO58082 (same data as holotype) .

Non-type material: See table 1 .

Diagnosis

External morphology: Shell (fig. 19C) medium-sized (14.2 mm), amber, darkening along aperture, 3.2 whorls, globose, flattened, thin, last whorl very large. Body (fig. 20E) at least 25 mm long, pale orange-brown speckled with cream, head and sole paler, outer field of sole slightly darker than inner fields. Mantle lobes and shell lappets large, pale brown, smooth, very finely speckled. Tail not keeled, slime grooves weak.

Genital anatomy: Genitalia (fig. 23D–E) moderately long; bursa copulatrix of moderate length, duct distinct, bursa oval. Penis long, cylindrical, internally with one ridged longitudinal pilaster, inner penial wall sculptured with rather large, diamond-shaped pustules; 80% of penis contained in penial tunica. Epiphallus approx. 1.5 times penis length; entering penis through a short verge; epiphallus arms equal in length; epiphallic caecum of moderate length; flagellum of moderate length, slender.

Remarks

This species was previously identified through curatorial work as Helicarionidae MQ 16. Despite frequent collecting in the Eungella region, F. ephelis is only known from two lots of material from Eungella NP (fig. 18). It seems likely that this species is much rarer than other semislugs from the same area, including F. comerfordae , F. aquavitae and F. mcdonaldi . It can be distinguished from all of these by its intermediate size (smaller than the first two and larger than the latter). Fastosarion comerfordae and F. aquavitae have a more robust, globose shell, while F. mcdonaldi has a much thinner, more reduced shell. Moreover, this species is easily distinguished by its pale, speckled appearance.

Figures

FIGURE 18 Distribution of Clade B species. █ = F.alyssa, ▼ = F.deensis, × = F.ephelis, ♢ = F.hannianus, ▲ = F. insularis, ◻ = F.katatonos, ∆ = F.longimentula, ● = F.mcdonaldi, ♠ = F.minerva, ◆ = F.papillosus, ♣ = F.pustulosus, ♥ = F.rowani, Ǫ = F.sarina, ▽ = F.tuljun.

FIGURE 19 Shells of Clade B species. A. Fastosarion alyssa (type locality of D.peterbrocki), NMV F230748. B. Fastosarion deensis, MO85834 (holotype). C. Fastosarion ephelis, MO85835 (holotype). D. Fastosarion hannianus, MO56684.E. Fastosarion insularis sp. nov., MO76354. F. Fastosarion katatonos, MO85837 (holotype). G.Fastosarion longimentula, MO65313.H. Fastosarion mcdonaldi, MO50434.I. Fastosarion minerva, MO78358. J.Fastosarion papillosus, MO78896 (Mt Superbus).K.Fastosarion papillosus, MO62397 (Kroombit Tops). L.Fastosarion pustulosus, MO78894 (Kalpowar SF).M. Fastosarion rowani, MO85839 (holotype). N. Fastosarion sarina, MO85840 (holotype).O. Fastosarion tujun (Denham Range), MO76081 (holotype). Scale bar 5 mm.

FIGURE 20 Fastosarion live images (Clade B). A-D.Fastosarion alyssa, A:AM C.512537, Mt Etna Caves; B:AM C.512480, Mt Ossa; C:AM C.512579, The Hummock. D: NMV F230748,Brandy Creek (Type locality of F.peterbrocki; A.Moussalli, NMV). E. Fastosarion ephelis (J. Stanisic).F.Fastosarion hannianus (QM image).G. Fastosarion mcdonaldi, Mt Dalrymple (QM image). H. Fastosarion rowani, AM C.512541,Dan Dan NP.

FIGURE 23 Genitalia.A–C.F.deensis, MO85834, Mt Morgan. D-E.F.ephelis, MO85835, Broken River.A, D. Reproductive system.Arrows show the junction of the penis and epiphallus.B, E.Penis interior.F.Spermatophore.Scale bars 1 mm (E), 2 mm (A–D).