Porrhomma rakanum Yaginuma & Saito, 1981

Růžička, Vlastimil, 2018, A review of the spider genus Porrhomma (Araneae, Linyphiidae), Zootaxa 4481 (1), pp. 1-75: 58

publication ID

https://doi.org/10.11646/zootaxa.4481.1.1

publication LSID

lsid:zoobank.org:pub:BFC4982D-BB84-4141-BDFD-203F23CD1585

persistent identifier

http://treatment.plazi.org/id/03C6A93B-FFEF-FFEC-FF7C-FD5086C13DA7

treatment provided by

Plazi

scientific name

Porrhomma rakanum Yaginuma & Saito, 1981
status

 

Porrhomma rakanum Yaginuma & Saito, 1981 

Figs. 51A –EView FIGURE 51.

Porrhomma rakanum Yaginuma & Saito, 1981  — Yaginuma & Saito (1981): p. 33, Figs. 1–4View FIGURE 1View FIGURE 2View FIGURE 3View FIGURE 4 (descr. ♂ ♀).

Material examined. JAPAN. Porrhomma rakanum  , paratypes No. 3–4, Rakan-ana Cave, Koya , Nomura-cho , Ehime Prefecture, 28 Nov 1968, 2 ♂, Masataka Yosida  ; paratypes No. 15–19, Rakan-ana Cave, Koya, Nomuracho , Ehime Prefecture, 28 Nov 1968, 5 ♀, Masataka Yosida (ASJ). 

Diagnosis. Among four species of the magnum -group, P. ohkawai  and P. rakanum  are characterised by absent eyes. P. rakanum  differs from P. ohkawai  by the presence of only two dorsal spines on Fe I. It was recorded exclusively in caves in Japan.

Description. Male holotype. Carapace pale, 0.65 mm wide, eyes absent or almost absent. Abdomen pale. Fe I with two dorsal spines and one prolateral spine, Fe II with one dorsal spine. Ti I –II with one retrolateral spine. Tm Mt I = 0.29, Mt I/CW = 1.92 ( Yaginuma & Saito 1981).

Embolic section characteristic for magnum -group. AP shorter than broad, the space between AP and PA quite open. Velum with pigmented margin ( Fig. 51AView FIGURE 51).

♀ (from Rakan-ana Cave, Japan, 28 Nov 1968). Epigynum with lateral wings ( Fig. 51BView FIGURE 51). Copulatory ducts very long, with ascending and descending parts. Main sacks oriented upwards, appendices narrowed, oriented towards the abdominal wall ( Figs. 51C –EView FIGURE 51).

Ecology. Known exclusively from caves.

Global distribution. Recorded only in the Rakan-ana Cave in Ehime Prefecture, Shikoku Island , Japan. See Fig. 52View FIGURE 52. 

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Linyphiidae

Genus

Porrhomma

Loc

Porrhomma rakanum Yaginuma & Saito, 1981

Růžička, Vlastimil 2018
2018
Loc

Porrhomma rakanum

Yaginuma & Saito 1981
1981