Raveniola Zonstein 1987
Year: 2024
Type: other
Abstract: Raveniola Zonstein, 1987 Raveniola Zonstein, 1987: 1014. Brachythele [part] – Ausserer 1871: 177. — Simon 1891: 304. — Caporiacco 1934: 113. — Spassky 1937: 363–367; 1952: 193. — Spassky & Minenkova 1940: 140. — Charitonov 1946: 19; 1948: 135. — Brignoli 1972: 409. — Mkheidze 1983: 155. — Fet 1984: 37. — Zonstein 1984b: 41–45; 1985: 158–160. Anemesia [part] – Denis 1958: 82. Raveniola – Zonstein & Marusik 2012: 74. — Li & Zonstein 2015: 3. — Zonstein et al. 2018: 5. — Zonstein 2021: 209. Type species Brachythele virgata Simon, 1891, by original designation. Diagnostic characters According to Zonstein et al. (2018: 5), Raveniola and Sinopesa share the presence of two (sometimes three) retroventral megaspines located sequentially on tibia I in males (a unique position among male nemesiids) and paired spermathecae in females, each two-branched (or with a lateral diverticulum); a maxillary serrula and preening combs are absent. Raveniola differs from Sinopesa chiefly by having a noticeably longer and denser leg scopula (vs a short and rare scopula in the latter genus), and a developed leg and carapace setation. General characteristics of Central Asian species It should be noted that no common characters shared only by Central Asian Raveniola spp., and distinguishing these species from all the Western and Eastern Asian congeners, were found. At the same time, in three Central Asian species groups based on R. caudata, R. concolor and R. diluta sp. nov., each of them possesses at least one unique group trait (see the corresponding group diagnoses). Regarding the remaining group based on R. virgata, the members differ from most other species but show some resemblance to several extra-regional congeners, viz. R. niedermeyeri and R. vonwicki from Iran, and R. hebeinica from China (Figs 444, 448, 459, 538, 540, 545, cf. Zhu et al. 1999: figs 1–10; Zonstein & Marusik 2012: fig. 39; Zonstein et al. 2018: figs 158, 164, 185, 197, 210–212). Morphological peculiarities of Central Asian Raveniola species HABITUS. The studied spiders are mostly small or medium-sized nemesiids with a carapace length of 3–12 mm. CEPHALOTHORAX. Carapace broadly oval and hirsute, with cephalic part slightly to noticeably higher than thoracic part. Male thoracic fovea very short, pit-like, T-shaped, or gently recurved. Female thoracic fovea short and narrow, nearly straight in most species, or very gently arched (procurved or recurved) in some species. Eye tubercle moderately elevated (better developed than in species from Western Asia). Chelicerae in some species with weak rastellum composed of spike-shaped setae. Maxillae generally with numerous cuspules confined to probasal edge; maxillary serrula absent, as in other Raveniola spp. STRUCTURES OF LEGS I–IV. Leg scopula varies from dense and moderately long to thin and short. Scopula distal on metatarsi I–II, generally entire on tarsi I and II, divided by setae or absent on tarsi III and IV; females also with usually entire scopula on palpal tarsus. Tarsi I–IV without spines. PTC I–IV biserially and densely dentate (females possess lesser dentate paired claws than conspecific males), unpaired claw small, curved and bare. MALE PALP. Tibia long, fairly slender and spinose. Cymbium with or without spines. Copulatory bulb inserted at apical part of cymbium. Embolus tapering or broadly tipped, with or without keels and ridges, varying in length from relatively short to long and slender. SPERMATHECAE. A pair of wide or narrow spermathecae, each with two distinct branches. In many species, the spermathecal base and the inner branch are poorly differentiated from each other and together they form a continuous spermathecal trunk. Long or short outer branch (lateral diverticulum) always distinct. SPINNERETS. Two pairs or one pair of spinnerets. PMS vary from medium-sized to very small, with or without functional spigots, or absent in some species. Apical segment of PLS ranges from triangular (most species) to digitiform or even elongate in some species. Species included In view of the new congeners included herein, Raveniola currently comprises 66 species; 29 of them occur in Central Asia: R. afghana sp. nov., R. alajensis sp. nov., R. caudata Zonstein, 2009, R. concolor Zonstein, 2000, R. cucullata sp. nov., R. diluta sp. nov., R. dolosa sp. nov., R. fedotovi (Charitonov, 1946), R. ferghanensis (Zonstein, 1984), R. hirta sp. nov., R. ignobilis sp. nov., R. inopinata sp. nov., R. insolita sp. nov., R. karategensis sp. nov., R. kirgizica sp. nov., R. kopetdaghensis (Fet, 1984), R. mikhailovi Zonstein, 2021, R. nenilini sp. nov., R. ornata sp. nov., R. ornatula sp. nov., R. ovchinnikovi sp. nov., R. pallens sp. nov., R. pamira sp. nov., R. redikorzevi (Spassky, 1937), R. sororcula sp. nov., R. tarabaevi sp. nov., R. virgata (Simon, 1891), R. vulpina sp. nov., and R. zyuzini sp. nov. Species grouping To assist with identifications, the species treated here are assigned to four species groups, according chiefly to the structure of the spinnerets and the male and female copulatory organs. These assignments are preliminary, because males and females in some species are unknown and they are not based on a phylogenetic grouping, though some of the groups may indeed reflect phylogenetic relationships. Distribution and ecology Within Central Asia, representatives of Raveniola are distributed from the western part of Kopetdagh (Turkmenistan) in the west, through the Badkhyz Plateau and Hindu-Koh Mts (passing and skirting the desert plains of the huge Turan Depression), to southeastern Kazakhstan in the north-east and to Ladakh (northwestern India) in the south-east (see Fig. 747). Due to the greater diversity of Central Asian landscapes, compared to Western Asian ones, there is a wider range of inhabited biotopes (including semi-deserts and highlands) and of the corresponding ecological strategies and adaptations. Like Western Asian congeners, most Central Asian Raveniola spp. use natural retreats (usually cavities under rocks or abandoned burrows of other animals) to build primitive burrow-like dwellings, sparsely covered with silk. However, some species inhabiting lowland arid bioms or, conversely, highland biotopes, are found to be true bothrobiont spiders digging deep open burrows with silk lining or without it. Key to the Central Asian species groups of Raveniola Zonstein, 1987 Males 1. Embolus broadly tipped (Figs 379–384, 466–468). Apical segment of PLS elongate (Figs 555– 557) ............................................................................................................................... caudata group – Embolus with well-defined thin and curved subapical part (Figs 385–465, 469–478). Apical segment of PLS triangular (as in Figs 563, 568, 593, 605, 609, 614) or shortly digitiform (as in Figs 581, 604, 612) ................................................................................................................................................... 2 2. Embolus needle-shaped and evenly tapering, with subapical part very gently curved and lacking bends and keels, as in Figs 439–465, 478 ....................................................................... virgata group – Embolus with proximal and apical parts separated by bend (often provided with keel), as in Figs 385– 438, 469–477 ..................................................................................................................................... 3 3. Cymbium shorter (Figs 352–364). Narrowly tapering proximal part of embolus considerably longer than its apical part (Figs 385–428). PMS present (Figs 560, 563, 565, 571, 573, 575, 584) ............................................................................................................................. concolor group – Cymbium longer (Figs 365–369). Broadly tapering proximal part of embolus slightly longer than its apical part (Figs 429–438). PMS absent (Figs 589, 591, 585) ......................................... diluta group Females 1. Apical segment of PLS elongate (as in Fig. 558) ......................................................... caudata group – Apical segment of PLS triangular (as in Figs 559, 561, 562, 567, 569, 572, 586, 588, 594, 600, 607, 615, 618) or shortly digitiform (Figs 578, 579, 582)......................................................................... 2 2. PMS relatively large (Figs 566, 576, 585), medium-sized (Figs 564, 572, 574, 587) or small (Figs 568, 570, 578–580, 582–583), but always with apical spigots (as in Figs 482–483). Numerous (> 25) maxillary cuspules arranged in a wide triangular area (Figs 230–242). Spermathecae as in Figs 489–525 ............................................................................................................... concolor group – PMS tiny (Figs 599, 603, 611, 613, 615, 617), without spigots (as in Figs 485–486), or absent (as in Figs 592, 594). Less numerous (<25) cuspules spread along probasal maxillary heel (Figs 243– 255). Spermathecae different (see Figs 526–554) ............................................................................. 3 3. PMS absent. Spermathecae with wide bases and short robust inner branches (Figs 526– 533) .................................................................................................................................. diluta group – PMS usually present (absent in R. kopetdaghensis). Spermathecae with narrow bases; shape of inner branch differs (Figs 534–554)......................................................................................... virgata group Data on natural history Habitats Depending on the altitude, prevailing landscape, precipitation regime and thermal conditions, all inhabited biotopes can be conditionally divided into three main zonal types. The first of these includes a harsh and periodically dry zone of foothills and low mountain ridges limited by lower and upper boundaries at altitudes of 450–500 m and 1000–1500 m, respectively
Author: Zonstein, Sergei L.
Institution: Tel Aviv University
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W6892980872
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