Phylogeny and systematic revision of the helicarionid semislugs of eastern Queensland (Stylommatophora, Helicarionidae)
Author
Hyman, Isabel T.
Australian Museum, 1 William St, Sydney NSW 2010, Australia Isabel. Hyman @ austmus. gov. au
Isabel.Hyman@austmus.gov.au
Author
Köhler, Frank
Australian Museum, 1 William St, Sydney NSW 2010, Australia
text
Contributions to Zoology
2019
2019-10-03
88
4
351
451
http://dx.doi.org/10.1163/18759866-20191416
journal article
10.1163/18759866-20191416
6388d839-a72d-4598-a141-053897bfc900
1875-9866
8343061
1935CAD4-4BD5-450D-92AC-63D1A5D84CD9
Stanisicarion aquila (
Cox, 1868
)
Figs. 14J–L
,
33
,
34B
,
36C–E
,
38
,
39A–D
Vitrina aquila
Cox, 1868: 109
.
Vercularion aquila:
Iredale, 1941: 6–7
.
Macularion aquila
:
Stanisic,
2010
in
Stanisic et al., 2010: 312
.
Material examined
Types
:
Holotype
:
AM
C.101185 (Eagle Scrub, Brisbane, Qld).
Non-type material
: See
table 1
.
Description
External morphology
: Shell (figs. 14J–L, 34B) medium-sized (
14–18.3 mm
), amber, 3.9–4.2 whorls, subglobose with a low spire. Body (figs. 36C–E)
40–45 mm
long, light orange-brown to grey, tail often darker, depressions of slime network darker (giving tail a diagonally striped appearance), eyestalks dark grey, foot border sometimes orange. Mantle lobes and shell lappets moderately large, pustulose, with numerous, discrete, raised black spots or ridges. Dark line along mantle edge. Tail keeled at tip, keel paler, slime network prominent.
Genital anatomy:
Genitalia (figs. 38, 39A–D) with moderately long vagina; bursa copulatrix moderately long, duct distinct, bursa oval. Penis long, slender, internally pustulose; 50–80% of penis contained in penial tunica. Epiphallus longer than penis; epiphallus enters penis through a short, pointed verge, partially fused to the penis wall; epiphallus 2 much longer than epiphallus 1; epiphallic caecum very short; flagellum moderately long, slender, irregularly coiled or twisted. Spermatophore a soft capsule with a simple tail-pipe; terminal end hooked with several small spines.
Remarks
Stanisicarion aquila
is currently recorded from Mullumbimby in northeastern NSW to Kenilworth in southeastern Qld (
Stanisic et al., 2010
), where it is found in rainforest habitats under logs, rocks and fallen palm fronds (fig. 33). This relatively broad range and some variation in external morphology (Stanisic, pers. comm.) led
Stanisic et al. (2010)
to suggest that
S. aquila
may represent more than one species. Semislugs from northern NSW have brown bodies with orange markings and discrete raised spots on the shell lappets, while those from Mt Tamborine in southern Qld have cream bodies with orange markings and raised short ridges rather than spots on their shell lappets (fig. 34A–C). Further north still, semislugs from Conondale and the Sunshine Coast are grey rather than cream, with no orange colouring and much less visible spots on the shell lappets (fig. 34A–C). These three morphs form separate clades in the phylogenetic tree, but sampling across the entire range has revealed little anatomical variation and a degree of genetic variation consistent with other widespread species (COI: 1.4%, 16S:2.2%).
A population of this species was also discovered in Cicada Glen in northern Sydney and is assumed to have been introduced, perhaps in plants being brought in to a nearby nursery. It matches the Conondale population in its body colour and genetics.
Both introduced and native populations of
S. aquila
occur within the range of congener
S. freycineti
, but
S. freycineti
is generally found in dry sclerophyll forest and open woodland rather than rainforest and the two species have not been recorded in sympatry.
Stanisicarion aquila
can be distinguished by its larger, more highly whorled but less globose shell and more highly pustulose shell lappets, usually with visible spots or ridges. It is also sympatric with arboreal semislug
Fastosarion papillosus
, but can be distinguished by its larger size and evenly pustulose lappets, in contrast to the single row of papillae on the shell lappet of
F. papillosus
.