Micropholcomma Crosby & Bishop, 1927

Rix, Michael & Harvey, Mark, 2010, The spider family Micropholcommatidae (Arachnida: Araneae: Araneoidea): a relimitation and revision at the generic level, ZooKeys 36 (36), pp. 1-321 : 23-24

publication ID

https://doi.org/10.3897/zookeys.36.306

publication LSID

lsid:zoobank.org:pub:ADCACC88-6C78-4386-8E33-3F98234ECE92

DOI

https://doi.org/10.5281/zenodo.3789411

persistent identifier

https://treatment.plazi.org/id/7E13878E-FFA0-1B6C-FF32-1E2EFDE28972

treatment provided by

Plazi (2020-04-27 05:57:33, last updated 2024-11-28 19:19:42)

scientific name

Micropholcomma Crosby & Bishop, 1927
status

 

Genus Micropholcomma Crosby & Bishop, 1927

Micropholcomma Crosby & Bishop, 1927: 152 . Type species by original designation Micropholcomma caeligenus Crosby & Bishop, 1927 . Roewer, 1942: 392. Hickman, 1944: 183. Bonnet, 1957: 2905. Forster, 1959: 297. Hickman, 1981: 65. Brignoli, 1983: 374. Rix, 2008: 343. Platnick, 2009.

Microlinypheus Butler, 1932: 103 . Type species by monotypy Microlinypheus bryophilus Butler, 1932 . Roewer, 1942: 617. Synonymised by Hickman, 1944: 186. Bonnet, 1957: 2885.

Plectochetos Butler, 1932: 106 . Type species by monotypy Plectochetos longissimus Butler, 1932 . Roewer, 1942: 617. Bonnet, 1958: 3707. Synonymised by Forster, 1959: 297.

Affinities. The genus Micropholcomma appears to be the sister-lineage to Pua novaezealandiae from New Zealand ( Fig. 4 View Figure 4 ).

Diagnosis. Species of Micropholcomma can be distinguished from all other Micropholcommatini except Pua novaezealandiae by the presence of a normal, non-bifurcate embolus ( Fig. 9A View Figure 9 ); and can be distinguished from Pua by the presence of a long embolus (length> 5× width) which is usually looped or coiled ( Figs 9A View Figure 9 , 12A, 17B). Other diagnostic characters include the presence (and presumed retention) of posterior tracheae (shared with Gigiella ) and the presence of a male leg I-pedipalpal stridulatory system (Fig. 21D).

Description. Very small, entelegyne Araneoidea ; total length 0.70 to 1.30. Cephalothorax: Carapace without glandular depressions above maxillae; cuticle without glandular pits (Fig. 18C); margins fused to sternum via pleural sclerites. Eight (Fig. 18C), rarely six or (in troglomorphic taxa) fewer eyes present on anterior margin of pars cephalica; AME, if present, smallest. Chelicerae with or without bulging anterior projections in males; promargin with true teeth, a pair of fused setal sockets adjacent to base of fang and single peg tooth in males (Fig. 19F).

Legs and female pedipalp: Legs three-clawed ( Fig. 20D View Figure 20 ), covered with smooth or serrate hair-like setae; femur I of males with prolateral stridulatory denticles (Fig. 18C). Trichobothria present on legs; tibiae each with two or three trichobothria ( Fig. 20C View Figure 20 ); metatarsi without trichobothria. Female pedipalp four-segmented (with fused tibiatarsus) or reduced to a vestigial nubbin; claw absent (Figs 19C–D).

Abdomen: Abdomen oval or globose; anterior sclerite present around epigastric region and petiole; large dorsal scute present on males (Fig. 14), absent (Fig. 16B) or (rarely) present (Fig. 13B) on females; lateral sclerotic strips present on males; posterior sclerotic ring surrounding spinnerets and colulus. Six spinnerets situated posterior to fleshy colulus ( Figs 22A, 22C View Figure 22 , 23 View Figure 23 A–B); PMS of M. bryophilum with single medial AC gland spigot; PLS of M. bryophilum with complete triad. Anterior tracheal system welldeveloped, with relatively large lateral atria and multiple radiating tracheae (Fig. 15B); second tracheal tubes on each side looping mesally and extending through petiole into cephalothorax (Fig. 12D); posterior tracheal spiracle present, tracheae quadritracheate.

Genitalia: Male pedipalp (Fig. 21) small to large, relatively simple; patella with distally-directed, flanged or hooked ligulate retrolateral apophysis and retrolateral stridulatory ridges; tegulum smooth, with curved evaginated tegular ridge; embolus exposed, long (length> 5× width), usually looped or coiled. Female genitalia (Figs 15A–E) with pair of separate, globular anterior spermathecae; insemination ducts coiled around fertilisation ducts; fertilisation ducts posteriorly-directed.

Distribution. Eastern and western mainland Australia and Tasmania (Fig. 217). Two undescribed female specimens from Rivière Bleue and Mont Mou, New Caledonia (QMB S60522 View Materials , QMB S72474) probably also belong in this genus, but males are required to confirm the identification.

Composition. Seven described species, Micropholcomma bryophilum ( Butler, 1932) , M. caeligenum Crosby & Bishop, 1927 , M. linnaei Rix, 2008 , M. longissimum ( Butler, 1932) , M. mirum Hickman, 1944 , M. parmatum Hickman, 1944 , M. turbans Hickman, 1981 , and the new species M. junee . Undescribed species are also known from throughout the range of the genus.

Nomenclatural remarks. The gender of the genus name “ Micropholcomma ” was not specified by Crosby and Bishop (1927), although the type species was described with a masculine specific epithet (as M. “ caeligenus ”). The name Micropholcomma was clearly derived from the theridiid taxon name “ Pholcomma ” Thorell, and as highlighted by Levi (1964), this name should be treated as neuter. To this end, Brignoli (1983) and Davies (1985) amended the suffix endings of the species names, all of which were previously masculine or feminine.

Bonnet P (1957) Bibliographia Araneorum, Tome II (3 me partie: G- M). Douladoure, Toulouse, 1927 - 3026.

Bonnet P (1958) Bibliographia Araneorum, Tome II (4 me partie: N- S). Douladoure, Toulouse, 3027 - 4230.

Brignoli PM (1983) A Catalogue of the Araneae Described Between 1940 and 1981. Manchester University Press, Manchester, 755 pp.

Butler LSG (1932) Studies in Australian spiders, No. 2. Proceedings of the Royal Society of Victoria 44: 103 - 117.

Crosby CR, Bishop SC (1927) New species of Erigoneae and Theridiidae. Journal of the New York Entomological Society 35: 147 - 154.

Davies VT (1985) Araneomorphae (in part). In: Walton DW (Ed) Zoological Catalogue of Australia, Vol. 3. Mygalomorphae, Araneomorphae (in part), Pseudoscorpionida, Amblypygi and Palpigradi. Australian Government Publishing Service, Canberra, 48 - 125.

Forster RR (1959) The spiders of the family Symphytognathidae. Transactions of the Royal Society of New Zealand 86: 269 - 329.

Hickman VV (1944) On some new Australian Apneumonomorphae with notes on their respiratory system. Papers and Proceedings of the Royal Society of Tasmania 1944: 179 - 195.

Hickman VV (1981) New Tasmanian spiders of the families Archaeidae, Cycloctenidae, Amaurobiidae and Micropholcommatidae. Papers and Proceedings of the Royal Society of Tasmania 115: 47 - 68.

Levi HW (1964) The American spiders of the genera Styposis and Pholcomma (Araneae, Theridiidae). Psyche 71: 32 - 39.

Platnick NI (2009) The World Spider Catalog, Version 10.0. American Museum of Natural History, New York. http: // research. amnh. org / entomology / spiders / catalog / [accessed 20. X. 2009]

Roewer CF (1942) Katalog der Araneae von 1758 bis 1940. 1. Band (Mesothelae, Orthognatha, Lapidognatha: Dysderaeformia, Scytodiformia, Pholciformia, Zodariiformia, Hersiliaeformia, Argyopiformia). Paul Budy, Berlin, 1040 pp.

Gallery Image

Figure 4. Optimal cladogram for the Micropholcommatidae under equal and implied weights, and one of six equally parsimonious trees recovered from an equal weights analysis of the ‘new’ matrix (length = 135; see Appendix II). With the exception of the highlighted (*) node ‘Patelliella adusta + Micropholcommatini’, all clades shown were recovered in all iterations of an implied weights analysis (K=1–6); the phylogenetic position of P. adusta changed to ‘P. adusta + Textricellini’ under K-values 1–5. Unambiguous character optimisations are shown for each node, and bold species are newly described, with generic type species highlighted (*).

Gallery Image

Figure 9. Left pedipalps of male Micropholcommatini, Textricellini and Taphiassinae, showing trajectory of the sperm ducts: A Micropholcomma caeligenum Crosby & Bishop B Tinytrella pusilla (Forster) C Taphiassa punctata (Forster). Scale bars = 0.065 mm (65 µm). Numbered arrows denote the trajectory of the ducts, from the subtegular fundibule (1) to the base of the embolus.

Gallery Image

Figure 20. Scanning electron micrographs of female Micropholcomma bryophilum (Butler) from near Marysville, Victoria (WAM T94453): A leg I tarsal organ B leg I lyriform organ C leg I tibial trichobothrium D leg IV claws, showing elongate inferior claw.

Gallery Image

Figure 22. Scanning electron micrographs of spinnerets of female Micropholcomma bryophilum (Butler) from near Marysville, Victoria (WAM T94453) (left) and paratype female Austropholcomma florentine sp. n. from the Florentine Valley, Tasmania (FMC) (right): A–B anterior lateral spinnerets C–D posterior lateral spinnerets. Arrows denote the anterior, mesal direction.

Gallery Image

Figure 23. Scanning electron micrographs of posterior median spinnerets of female (left) and male (right) Micropholcommatini: A–B Micropholcomma bryophilum (Butler) from near Marysville, Victoria (WAM T94453) C–D Pua novaezealandiae Forster from the Makarora Valley, New Zealand (AMNH) E–F Austropholcomma florentine sp. n. from the Florentine Valley, Tasmania (FMC) G–H Tricellina gertschi (Forster & Platnick) from near Chaitén, Chile (AMNH). Note the apparent loss of the anterior CY gland spigot in female Austropholcomma and Tricellina. Arrows denote the anterior, mesal direction.

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Micropholcommatidae

SubFamily

Micropholcommatinae

Tribe

Micropholcommatini