Porrhomma nekolai, Růžička, 2018

Růžička, Vlastimil, 2018, A review of the spider genus Porrhomma (Araneae, Linyphiidae), Zootaxa 4481 (1), pp. 1-75 : 43-45

Porrhomma nekolai new species

Figs. 38A–F , 39 .

Male holotype, RUSSIA: Chukotka Autonomous Okrug, Christ Bay, env. of Egvekinot Town , SE slope, under stones, 15 Jul 1988, leg. Yu. M. Marusik ( ZMMU) . Paratypes: 1 ♀, with same data as for holotype ; 1 ♂ 3 ♀, Egvekinot Town , S slope, stony habitats in mountain tundra, 15 Jul 1988, leg. Yu. M. Marusik ; 1 ♀, Chukotka Autonomous Okrug, Amguema River, 67°03'N, 178°58'W, stony habitats, 22 Jul 1988, leg. Yu. M . Marusik; 1 ♂ 1 ♀, Magadan Area, Duchka River , env. of Magadan, 13 Sep 1986, leg. Yu. M. Marusik ( ZMMU) . ♀, CANADA: Yukon Territory, Kluane Lake, Cultus Bay , 61°11'N, 138°20'W, 1650 m a.s.l., 10–23 Jul 1993, leg. Yu. M. Marusik ( CNC) . Ƌ, USA, Iowa, Delaware County, Elk River East , ca 7 km WSW of Colesburg, 42.6284°N, 91.9209°W, 13 July 1998, leg. V. Růžička ( NMP, No. P 6A 6384). Ƌ, USA , Iowa, Delaware County, Backbone Cave, July , 45 yds from end, u. wood ( AMNH) .

Etymology. The species is named after Jeffrey C. Nekola (University of New Mexico, Albuquerque, USA).

Diagnosis. A large group of species is characterised by embolus of middle length and S-shaped ascending parts of copulatory ducts: P. borgesi , P. cambridgei , P. convexum , P. errans , P. nekolai , P. oblitum , P. pygmaeum and P. rosenhaueri . P. nekolai new species can be distinguished from all these species by the following combination of characters: large species (CW> 0.70), eyes reduced (PME–PME 1.7–2.0), legs very long (Mt I/CW> 1.3).

Description. Male holotype (from Chukotka, Christ Bay, Egvekinot Town, 15 Jul 1988). Carapace yellowbrown, 1.10 mm long, 0.77 mm wide, eyes reduced, PME–PME = 1.7 ( Fig. 38A ). Abdomen greyish-yellow. Fe I with one dorsal and one prolateral spine. Ti I with one prolateral spine, Ti I–II with one retrolateral spine. Mt I/CW = 1.43.

Embolus of middle length with a narrow velum. AP has the form of a bird head, it is slender, narrowed ( Fig. 38B ).

Male paratype (from Iowa, Delaware County, Elk River East, 13 July 1998): A palp ( Fig. 39 ).

Female paratype (together with holotype): carapace 0.78 mm wide, PME–PME = 1.8, Tm Mt I = 0.60, Mt I/ CW = 1.31. Ascending parts of the ducts are S-shaped. Spermathecae are formed behind the ascending part of the ducts ( Figs. 38C–F ).

Variation. Ƌ ♀. Carapace 0.71–0.78 mm wide, PME–PME = 1.6–2.0, Tm Mt I = 0.58–0.61, Mt I/CW = 1.31– 1.47 (N = 4).

Comments. I recorded my first male under stones in Iowa, in 1998. I was accompanied by Jeffrey C. Nekola, an author of the concept of algific talus slopes as palaeorefugia ( Nekola 1999). In collections of the AMNH, I found the second male, collected in a cave, also in Iowa. Later, I obtained the material from Yukon Territory and Chukotka Peninsula, collected by Yuri M. Marusik during the research of spiders in stony habitats ( Marusik 2004). I decided to choose a complete pair from Chukotka for the description.

Ecology. Specimens from Chukotka and Yukon Territory were collected in stony habitats. In Iowa, one male was collected in algific talus slope developed in limestone and one in a cave. It is in coincidence with the knowledge that lithobiontic species colonise more cold habitats (such as freezing scree slopes and caves) in warmer parts of their distribution area ( Růžička 1990, 2011; Růžička et al. 2012).

Global distribution. North-East Asia; Nearctic: from Yukon Territory to Iowa. See Fig. 40 .

Figures

FIGURE 38. A–F, Porrhomma nekolai new species from Chukotka, Christ Bay, Egvekinot Town. A, ♂ carapace, frontal view. B, embolic section. C, epigynum. D–F, vulva, ventral, caudal and dorsal. Scale bars, 0.1 mm.

FIGURE 39. Porrhomma nekolai new species from Delaware County, Elk River East, U.S.A., Iowa, male palp. Scale bar, 0.1 mm.

FIGURE 40. Records of Porrhomma nekolai new species.