Fastosarion katatonos, 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 : 424-427

Fastosarion katatonos sp. nov.

Figs. 18 , 19F , 26

Etymology

From katatonos (Greek: broader than high), referring to the wide aperture of the shell; noun in apposition.

Material examined

Types: Holotype: QM MO85837 ( Rockhampton , c. 6km NE at Mt Archer, nr base, 23° 20' 40" S, 150° 34' 50" E, coll. 25 Jul 1994, J. Stanisic, D. Potter, G. Ingram, C. Eddie).

Paratypes: QM MO54515 (same data as holotype) .

Non-type material: See table 1 .

Diagnosis

External morphology: Shell (fig. 19F) small to medium-sized (8.8–12.3 mm), pale golden, 3.0–3.9 whorls, subglobose with a low spire, last whorl very large. Body 25 mm long, colour (in ethanol) beige, darker on tail with a pale keel. Mantle lobes and shell lappets large, lappets with dark streaks, right lappet with a row of five warts at base and few smaller pustules scattered randomly, left lappet with eight warts arranged in two rows.

Genital anatomy: Genitalia (fig. 26) with moderately short vagina; bursa copulatrix short; duct swollen, bursa spherical. Penis moderately large, mostly cylindrical, slender, swollen proximally, inner penial wall sculptured with very fine transverse lamellae, becoming coarser proximally; penis interior with two longitudinal pilasters, major pilaster branches distally, then proximally becomes swollen and irregular; 60% of penis contained in penial tunica. Epiphallus approx. same length as penis, entering through simple pore; epiphallus 2 equal in length to epiphallus 1; epiphallic caecum moderate length, terminating with a swollen region consisting of multiple small outpocketings; flagellum short, slender.

Remarks

Fastosarion katatonos (referred to above as ‘ Helicarionidae sp. Mt Archer’) is found in vine thickets at Mt Archer (northeast of Rockhampton) and also further to the northeast at Hidden Valley, near Yeppoon (fig. 18). It has been previously considered to be part of F. pustulosus ( Stanisic et al., 2010) , and shares with this species a very similar shell and the presence of warts and dark streaks on the shell lappets. However, F. katatonos has a slightly lower spire and more numerous warts on the shell lappets, and anatomically the two species can be very easily distinguished by their very different penial anatomy and the shape of the epiphallic caecum.

This species forms the sister taxon to F. minerva , F. deensis and F. rowani in our phylogenetic analysis. It shares some similarities with these species, in particular the subglobose shell with a relatively high whorl count and the presence of rows of warts on its shell lappets, but is smaller in size with a unique genital anatomy. This species is set apart by its distinctive epiphallic caecum shape and short flagellum, its proximally swollen penis with fine transverse lamellae, equal length epiphallus arms and its short bursa copulatrix with a swollen duct.

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 26 Genitalia of F.katatonos, MO85837, Mt Archer.A. Reproductive system.Arrow shows the junction of the penis and epiphallus.B. Penis interior. Scale bars 1 mm.