Lipistius malayanus

Peter J. Schwendinger, 2017, A revision of the trapdoor spider genus Liphistius (Mesothelae: Liphistiidae) in peninsular Malaysia; part 1, Revue suisse de Zoologie 124 (2), pp. 391-445 : 393-395

publication ID	https://doi.org/ 10.5281/zenodo.893555
DOI	https://doi.org/10.5281/zenodo.6042347
persistent identifier	https://treatment.plazi.org/id/4C30A452-FFE6-FFF3-B99D-FE733975FB0E
treatment provided by	Plazi
scientific name	Lipistius malayanus
status

Treatment

The malayanus -group

Diagnosis: Distinguished from the trang -group by an indistinctly split embolus proper ( Fig. 3B, D, F, H View Fig. 3 ) and from all other species groups by distal edge of contrategulum proventrally ending in a V-shaped or U-shaped row of denticles (the clearest synapomorphy of this group; Figs 4C View Fig. 4 ; 6A, C; 8A, D). Vulval plate strongly sclerotised, with a large, undivided CDO and with a large, undivided receptacular cluster ( Figs 5 View Fig. 5 , 7 View Fig. 7 , 9 View Fig. 9 ).

Description: Small to large species (carapace length of males 4.36-12.04, carapace width 3.64-10.99); body colouration uniformly dark (in large species: L. malayanus and L. endau ; Fig. 2A View Fig. 2 ) or brown with annulated legs and palps (in smaller species: L. johore and L. gracilis sp. nov.). Male palp with membranous and sclerotised part of embolus proper in close contact with each other (both distinctly separated in trang - group), together forming a closed tube; dorsal wall of sclerotized part of embolus proper straight and directed proventrad ( L. malayanus ; Fig. 4 View Fig. 4 G-H), curved prodorsad ( L. endau ; Fig. 6F, H View Fig. 6 ) or bent prodosad ( L. gracilis sp. nov.; Fig. 8 View Fig. 8 F-G); para-embolic plate short or absent ( Figs 4D View Fig. 4 , 6E View Fig. 6 ); tegulum with coarsely dentate proximal edge (corresponding to dorsal extension of terminal apophysis in Heptathelinae; see Schwendinger & Ono, 2011), distal margin (corresponding to marginal apophysis) indistinct, not drawn into a prominent edge ( Figs 4 View Fig. 4 D-F, 6D-E, 8E); contrategulum with indistinct ventral process or without, distal edge carrying several teeth, prolateral ones numerous, tiny and forming a serrate crest ( L. gracilis sp. nov.; Fig. 8 View Fig. 8 D-G), few and small ( L. malayanus ; Fig. 4 View Fig. 4 G-L), or only represented by a single large triangular tooth ( L. endau ; Fig. 6F View Fig. 6 , H-O), proventral denticles of distal edge forming a downwardcurved V-shaped ( Fig. 4C View Fig. 4 ) or U-shaped row ( Figs 6A, C View Fig. 6 ; 8D), dorsal apex of contrategulum widely to narrowly tongue-shaped ( Figs 4 View Fig. 4 G-L; 6F, H-O; 8F-G); subtegulum always without apophysis; paracymbium quite small and shallow to large and deep ( Figs 4A View Fig. 4 , 6B View Fig. 6 , 8B View Fig. 8 ); cumulus very low, indistinct, carrying several long, thick bristles; retrolateral tibial apophysis relatively short and carrying long apical megaspines ( L. malayanus and L. endau ; Figs 4 View Fig. 4 A-B, 6A-B) or quite long and carrying distinctly shorter megaspines ( L. gracilis sp. nov.; Fig. 8 View Fig. 8 A-C, I-J); both apical lobes of cymbium weakly developed ( Fig. 8D View Fig. 8 ). Vulva ( Figs 5 View Fig. 5 , 7 View Fig. 7 , 9 View Fig. 9 , 10A View Fig. 10 ): poreplate strongly pigmented and sclerotised, wider than long, its anterior margin more or less distinctly recurved, with or without anterolateral lobes or processes, never with mediolateral processes; CDO and ventral receptacular cluster large to very large, both undivided; posterior stalk wide (in L. endau even covering entire width of genital atrium; Fig. 7 View Fig. 7 ), somewhat trapezium-shaped or almost triangular ( Fig. 10A View Fig. 10 ); genital atrium with few to many lateral hairs and with no, few or numerous median hairs.

Species included: Liphistius endau , L. malayanus , L. gracilis sp. nov. and presumably also L. johore (male still unknown).

Relationships: Species of the malayanus -group are most similar and probably closely related to species of the tioman -group. The two large species, L. malayanus and L. endau , are closer to each other than to the much smaller L. gracilis sp. nov. (distinguished by serrate distal edge of contrategulum and by sharp bend in wide dorsal wall of sclerotised part of embolus proper). Small size, details of the vulval plate and geographical proximity suggest a close relationship between L. gracilis sp. nov. and L. johore , but this can only be confirmed when the male of the latter species is discovered.

Key to the species of the malayanus -group:

1 Small spiders (carapace length of mature males and females 4.36-5.34, carapace width 3.64-4.22) with brown body colouration and annulated limbs; lateral and posterolateral margins on ventral side of poreplate not bulging ( Fig. 9B, D, F View Fig. 9 ; Platnick & Sedgwick, 1984: fig. 80).........................................................................................................2

- Large (carapace lengths in males 7.90-12.04, carapace width 7.0-10.99), uniformly dark-coloured spiders; lateral and posterolateral margins of poreplate on ventral side of vulval plate bulging ( Figs 5B, J View Fig. 5 ; 7B, E, G)..................3

2 Vulval plate with indistinct transition between poreplate and posterior stalk, the latter wide in transition zone; anterior margin of poreplate without or with only indistinct anterolateral invaginations; genital atrium with numerous lateral and median hairs ( Fig. 9A, C, E View Fig. 9 ) ...................................................................... L. gracilis View in CoL sp. nov.

- Vulval plate with distinct transition between poreplate and posterior stalk, the latter very narrow in transition zone; anterior margin of poreplate with pronounced anterolateral invaginations; genital atrium without hairs ( Fig. 10A View Fig. 10 ) (male unknown) ........................................................................................................................................... L. johore View in CoL

3 Dorsal and ventral wall of sclerotised part of embolus proper equally wide, both ends facing proventrad ( Fig. 4 View Fig. 4 G- H), dorsal wall ending in indistinct rounded lobe ( Fig. 4 View Fig. 4 C-F); membranous part of embolus proper distally narrow ( Figs 3F, H View Fig. 3 ; 4C); distal edge of contrategulum with one to several small denticles ( Fig. 4C View Fig. 4 , G-L); paracymbium about as deep as wide ( Fig. 4A View Fig. 4 ). Dorsal side of vulval plate with anterolateral corners of genital atrium not bulged and elevated above level of poreplate; usually no median hairs in genital atrium ( Fig. 5A View Fig. 5 , C-H, but see Fig. 5I View Fig. 5 ); receptacular cluster not divided into subclusters ( Fig. 5B, J View Fig. 5 )............................................................... L. malayanus

- Dorsal wall of sclerotised part of embolus proper wider than ventral wall, end of dorsal wall bent prodorsad ( Fig. 6F, H View Fig. 6 ) and forming pronounced lobe ( Fig. 6 View Fig. 6 C-E); membranous part of embolus proper distally wide ( Fig. 6C View Fig. 6 , F-H); distal edge of contrategulum with a single large triangular tooth ( Fig. 6F View Fig. 6 , H-O); paracymbium much deeper than wide ( Fig. 6B View Fig. 6 ). Dorsal side of vulval plate with anterolateral corners of genital atrium bulged and elevated above level of poreplate; median hairs usually present in genital atrium ( Fig. 7A View Fig. 7 , C-D, F); receptacular cluster divided into three more or less distinct subclusters ( Fig. 7B, E, G View Fig. 7 )............................................................. L. endau View in CoL

Distribution: All described species of this group occur in the western and southern part of peninsular Malaysia ( Fig. 1 View Fig. 1 , localities 1-9); an undescribed species appears to be present in the northeastern corner of the country ( Fig. 1 View Fig. 1 , locality 13).