Pinkfloydia, 2011

Dimitrov, Dimitar & Hormiga, Gustavo, 2011, An extraordinary new genus of spiders from Western Australia with an expanded hypothesis on the phylogeny of Tetragnathidae (Araneae), Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 161 (4), pp. 735-768 : 754-756

PINKFLOYDIA HORMIGA & DIMITROV GEN. NOV.

Type species: Pinkfloydia harveii Dimitrov & Hormiga sp. nov.

Etymology: The genus is named after the British psychedelic and progressive rock band Pink Floyd. In its heyday Pink Floyd was an innovative group that created music, which was an eclectic mixture of styles. The band also pioneered the use of very sophisticated lights and lasers in their live shows and often had highly innovative album covers. Pinkfloydia has very unusual morphological features and its name aims to reflect its uniqueness. Pinkfloydia is an undeclinable proper name and feminine in gender.

Diagnosis: Pinkfloydia can be easily distinguished from all other tetragnathid genera by the conspicuously enlarged PME placed on short ocular protrusions and by the conical and distinctively elevated cephalic area ( Figs 9A , 10A, 12A, 14G). All other eyes are placed at the same level on the prominent cephalic region and are much smaller in size ( Figs 9B , 10C, 12A, D, 14E). Males of Pinkfloydia differ from other tetragnathid males in having several conspicuously large macrosetae at the base of the paracymbium ( Figs 8A–C , 13A–D, G ) and an area of the cymbium covered with numerous modified short setae (cuspules) concentrated dorsally on the cymbial ectomedian process ( Figs 8B, E , 13A, C, H, I ). In addition, the Pinkfloydia male palp has a well developed metine embolic apophysis and an embolus that carries numerous short denticles ( Figs 8A–C , 13B, E, F , 14A); the cymbium has a well developed cymbial ecto-basal and cymbial ecto-median processes ( Figs 8A , 13A, D ).

Females are diagnosed by the presence of a flat epigynal plate that has numerous pores opening on its ventral surface ( Figs 8F , 15D–E, G; no similar plate has been described in any other member of Tetragnathidae ). Copulatory openings are displaced caudally and hidden by the distal edge of the epigynum in a transversal groove ( Figs 8G, H , 15F).

Description: Tiny spiders, total length 2.77–3.75 in males, 3.54–4.51 in females (but note that so far P. harveii is the only known species in this new genus). Cephalothorax brown, longer than wide – 1.36–1.61 long in males and 1.68–1.86 in females – with a well marked fovea ( Figs 9C , 10B); cephalic area conical, conspicuously elevated and slightly projected over the chelicerae ( Figs 9A , 10A, 12A, 14G). Sternum slightly longer than wide; conspicuously narrower distally, and with a ridged cuticle (Figs 12C, 14J). AME slightly larger than ALE and PLE but much smaller than PME; PME much larger than the other eyes and placed over small rounded rises at the top of the elevated cephalic area; PLE and ALE juxtaposed over a slight elevation (Figs 12A, 14G). Clypeus height more than one AME diameter, slightly higher in males than in females. Chelicerae cylindrical, longer and slender in males, with three teeth on the anterior and two teeth on the posterior margin (Figs 12D, 14E). Chelicerae with two small denticles near the fang joint (Fig. 12I). Legs without dorsal femoral trichobothria in both sexes. Abdomen rounded with a prominent caudal tubercle, more elongated in males (Figs 12F, H, 15B, C). Spinneret morphology (studied in one male and two females) as in most other tetragnathid spiders: ALS with about 30 piriform gland spigots in females and about 20 in males, ordered roughly in four (females) or three (males) arched lines (Figs 14B, 16D). PMS with two aciniform gland spigots, between the cylindrical and the minor ampu- tate gland spigots ( Fig. 16E, F ). PLS with six aciniform gland spigots ordered in a straight line between the cylindrical spigots and the ‘araneoid triplet’ ( Fig. 16G ). Flagelliform and aggregate gland spigots well developed in females ( Fig. 16G ) but reduced in adult males (Fig. 14C). Flagelliform spigot conical, apically pointed; aggregate spigots with wider bases and wide sockets ( Fig. 16G ). Epiandrous fusules placed in a shallow epigastric groove and arranged in three groups separated by low cuticular ridges (Fig. 14D). Tracheal spiracle placed very close to the spinnerets. Tracheal system consisting of two longer lateral tubes and two shorter medial ones (Fig. 14F, I). All tracheal tubes confined to abdomen (i.e. do not enter the prosoma). Male pedipalp with very large modified setae on paracymbium ( Figs 8A–C, E , 13A, B, G ). Cymbium carrying cymbial ecto-basal and cymbial ecto-median processes ( Figs 8A, B, E , 13A, D ). A field containing numerous short modified setae (cuspules) arranged in longitudinal lines is placed dorsally over the cymbial ecto-median process, which extends over the cymbium ( Figs 8E , 13A, C, D, H, I ). Tegulum well sclerotized, large and spherical in shape ( Figs 8A–C , 13B ). Conductor and embolus coiling together and arising apically from the centre of the tegulum ( Figs 8A, C , 13E, F ). Conductor well sclerotized, with a robust apical apophysis ( Fig. 13F ). Embolus with robust metine embolic apophysis, dorsoapically with numerous short denticles and a distinctively slender apex ( Fig. 13F ). Spermatic duct enters the tegulum (towards the fundus) through the embolus base, widening in diameter shortly after ( Fig. 8D ). Spermatic duct without switchbacks and one and a half spiral turns before reaching the fundus ( Fig. 8D ).

Female genitalia entelegyne, with a flat, well chitinized epigynum that has numerous pores dorsally ( Figs 8F–H , 15D–H). These pores might be related to the secretions that form the epigynal plug observed in some of the specimens (Fig. 10E). Spermathecae oval with weakly sclerotized walls ( Figs 8G , 15F, H).

Phylogenetics: Pinkfloydia is a member of the Australian– New Zealand tetragnathid lineage Nanometa clade.

Natural history: See under P. harveii sp. nov.

Composition: The only known member of this genus is P. harveii sp. nov.

Distribution: Western Australia (see under P. harveii sp. nov.).

Figures

Figure 8. Pinkfloydia harveii sp. nov. Male palp (holotype): A, ventral; B, retrolateral; C, prolateral; D, schematic; E, dorsal. Female epigynum: F, ventral; G, dorsal; H, schematic. Abbreviations: C, conductor; CB, cymbium; CD, copulatory duct; CEBP, cymbial ecto-basal process; CEMP, cymbial ecto-median process; E, embolus; F, fundus; FD, fertilization duct; MEA, metine embolic apophysis; P, paracymbium; T, tegulum. Scale bars = 0.2 mm.

Figure 9. Pinkfloydia harveii sp. nov. Male (holotype): A, lateral; B, frontal; C, dorsal; D, ventral. Cephalothorax length is 1.36 mm (see species description for measurements).

Figure 13. Pinkfloydia harveii sp. nov., male. Palp: A, retrolateral; B, ventral; C, dorsal; D, retrolateral close up; E, apical; F, conductor and embolus detail; G, paracymbium; H, modified setae on the CEMP (type I); I, modified setae (cuspules) on the CEMP (type II). Abbreviations: C, conductor; CB, cymbium; CEBP, cymbial ecto-basal process; CEMP, cymbial ecto-median process; E, embolus; MEA, metine embolic apophysis; P, paracymbium; S, spermatheca; ST, subtegulum. Scale bars: A, B, C = 100 Mm; D, E, G = 20 Mm; F = 10 Mm; H = 2 Mm; I = 3 Mm.

Figure 16. Pinkfloydia harveii sp. nov., female. A, fertilization duct detail. B, epigynum dorsal, cuticular glands ductiles. C, copulatory duct detail. Spinnerets: D, ALS; E, PMS; F, spinnerets overview; G, PLS. Abbreviations: AC, aciniform gland spigots; AG, aggregate gland spigots; ALS, anterior lateral spinnerets; CY, cylindrical gland spigots; FL, flagelliform spigot; mAP, minor ampullate gland spigot; MAP, major ampullate gland spigot; PI, piriform gland spigots; PLS, posterior lateral spinnerets; PMS, posterior median spinnerets. Scale bars: A, D, E, G = 10 Mm; B, C = 2 Mm; F = 20 Mm.