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CHAPTER 3 A Revision of the Afrotropical Species of Hersiliola Thorell and Tama Simon with Description of a New Genus Tyrotama (Araneae: Hersiliidae)
Abstract
The genera Hersiliola Thorell and Tama Simon, two ground active spider genera, in the family Hersiliidae of the Afrotropical Region are revised. Hersiliola macullulata Thorell 1870, H. simoni (O.P.-Cambridge 1872) and H. versicolor Blackwall, 1865 are redescribed. Hersiliola fragilis Lawrence, 1928 and H. australis (Simon, 1893) both known from southern Africa are transferred to a new genus, Tyrotama. Three Tama species T. arida Smithers, 1945, T. bicava Smithers, 1945 and T. incerta, Tucker, 1920 are transferred to Tyrotama gen. nov. Tama obscura Smithers, 1945 is synonymized with T. arida. The males of T. arida and T. bicava are described for the first time. Three Tyrotama species T. gamkasiensis, T. makalaliensis, and T. taris are described as new. A key to the species of Tyrotama gen. n. is provided. Three Hersiliola species are valid. Tyrotama consists of six valid species, three are redescriptions and three newly described. Only females are known for H. versicolor, T. incerta, T gamkasiensis, T. taris, and only males for T. makalaliensis.
Key words: Afrotropical Region, Araneae, Hersiliidae, key, new genus, Tama, Hersiliola, Tyrotama.
INTRODUCTION
The family Hersiliidae is a small family with a worldwide distribution that prior to this study comprised 145 species in 7 genera (Platnick 2004). They are medium-sized three-clawed, entelegyne spiders characterized by their markedly elongated posterior spinnerets and long legs I, II and IV (Baehr 1998; Rheims & Brescovit, 1994). The hersiliids have diverse life-styles with most of the species being arboreal, found on tree bark. However, members of Hersiliola Thorell and Tama Simon are ground active spiders found under stones where they build irregular webs(Smithers 1945, Lawrence 1964).
The genus Hersiliola was described by Thorell in 1870, and consists of ten species in the Palearctic and Afrotropical regions. There are five species known for the Afrotropical Region. Dufour (1831) described the first Hersiliola species from the Afrotropical Region, Hersiliola macullulata, as Aranea macullulata. Simon (1882) transferred Aranea macullulata to Hersiliola and considered Hersilia oraniensis Lucas, 1846 a junior synonym of Hersiliola macullulata. Hersiliola simoni was first described by O.P.-Cambridge in 1872 as Hersiliada simonii and Blackwall described Hersiliola versicolor in 1865. Simon (1893) described the first Hersiliola species, H. australis from the Southern parts of the Afrotropical Region and subsequently Lawrence (1928) described Hersiliola fragilis from Namibia.
The genus Tama was described by Simon (1882) based on the type species Tama edwardsi, a ground-living spider inhabiting the arid regions of the Mediterranean Region. Numerous species have since then been added to Tama, including doubtful additions of arboreal species. Until recently the genus was considered to be the most widespread of all the hersiliid genera with representatives in the Neotropical, Afrotropical, Palearctic and Australian Regions. However, after the first revision of the Australian hersiliids by Baehr Baehr (1987), it was found that the Australian Tama species belongs somewhere else and they were all transferred to a new genus, Tamopsis Baehr & Baehr. Similar transfers were made of the Neotropical Tama After a revision of the hersiliids of that region by Rheims & Brescovit (2004) the known Tama species were transferred to three newly described genera and the genus Neotama Baehr & Baehr.
Simon (1893) provided some revisionary work on Hersiliola and Tama of the Afrotropical Region. However, uncertainty exists around the validity of characters used to distinguish them (Smithers 1945). Baehr & Baehr (1993) speculated that they possibly belong in the genus Neotama and questioned the correct placement of the Afrotropical Tama species.
A study of all available material from the Afrotropical Region showed that the Tama and Hersiliola species of the southern and central regions differ from the species found in North Africa and the Mediterranean Region. A new genus Tyrotama was erected to house the species previously listed in Tama and Hersiliola of the Afrotropical Region. Tama is now only known from the Mediterranean Region – Spain, Portugal and Algeria, while species of Hersiliola are known from the Palearctic and northern parts of the Afrotropical Region.
This paper is the first in a series on the Hersiliidae of the Afrotropical Region. We erect a new genus, Tyrotama gen. nov., based on results of a cladistic analysis, redescribe six species, synonymize one species, transfer three species to Tyrotama, and describe three new species. A key to the Tyrotama species is provided.
MATERIAL AND METHODS
Study area: The area covered by this study is the Afrotropical Region, including the islands in both the Indian and Atlantic oceans. Reference is made to the distribution of species from the rest of Africa (countries outside the Afrotropical Region), only if such species also occur, at least partly, in the Afrotropical Region. Terminology follows Baehr & Baehr (1993) in part.
Slide preparation: The epigyne of the female and the left palp of the male (where available, otherwise the right) were removed and mounted temporarily on slides in Heinze’s modified PVA mounting medium (Meyer & Rodrigues 1966).
Illustrations: All illustrations were made with a stereomicrocope Zeizz Stemi SV 6, using a camera lucida. Scanning electron micrographs were taken with a JEOL (JSM 840) microscope.
Measurements: Where enough material was available, ten specimens of both sexes were measured for each species. Measurements were made under a stereomicroscope using an ocular micrometer with up to 50× magnifications. All measurements are given in millimetres with the observed ranges in parentheses. The following measurements were taken. TL – total length; carapace: CL – carapace length (measured from clypeal edge to posterior edge); CW – carapace width (measured over widest part of carapace); CLL – clypeus length (measured from outer edge of AME to anterior edge of clypeus). Eyes: size of eyes is given as relative to AME in the following order: AME: ALE: PME: PLE. Legs: LL – length of leg (each segment from femur to tarsus was measured and the sum of the measurements given as the leg length); length ratio of legs is relative to leg I. Spinneret length (measured each segment). Epigyne: length and width.
Abbreviations: The following abbreviations are used in this paper:
AER – anterior eye row; ALE – anterior lateral eye; AME – anterior median eye; bS – basal segment of posterior lateral spinneret; c – copulatory duct; CHI – cheliceral index (derived by dividing total length of chelicera by its width); CI – carapace index (derived by dividing length of carapace by its width); CL – carapace length; CLI – clypeal index (derived by dividing length of clypeus with length of median ocular quadrangle); CLL – clypeus length; co – copulatory opening; CW – carapace width; dtp – distal tegular projection; el – epigyne length; ew – epigyne width; f – fertilization duct; Fe – femur; lb
– lateral border; LL – length of leg; MOQ – median ocular quadrangle; MOQ-AW – MOQ anterior width; MOQ-PW – MOQ posterior width; mp – median plate; Mt – metatarsus; Pat – patella; PER – posterior eye row; PLE – posterior lateral eyes; PME – posterior median eyes; sr – seminal receptacle; s – spermathecae; Ta – tarsus; Tib – tibia; TL – Total length; tS – terminal segment of posterior lateral spinneret.
Material examined: A total of 147 specimens from North Africa and the Afrotropical Region housed in southern African, European and American institutions, were studied. Material was received on loan from the following institutions: AMNH – American Museum of Natural History, New York, USA; CASC – California Acadamy of Sciences, Golden Gate Park, San Francisco, California, USA; CAUB – Collection Arachnida Universitat de Barcelona, Barcelona, Spain; DNSM – Durban Natural Science Museum, Durban, South Africa; HECO – Hope Entomological Collection, Oxford University Museum of Natural History, Oxford, United Kingdom; MNHN – Museum National d’Histoire naturelle, Paris, France; MNHU – Museum für Naturkunde der Humboldt Universität, Berlin, Germany; MRAC – Koninklijk Museum voor Midden Afrika, Tervuren, Belgium; NCA –National Collection of Arachnida, ARC – Plant Protection Research Institute, Pretoria, South Africa; NM – Natal Museum, Pietermaritzburg, South Africa; NMB – National Museum, Bloemfontein, South Africa; ; NMN – National Museum of Namibia, Windhoek, Namibia; SAM – South African Museum, Cape Town, South AfricaTMP – Northern Flagship Institute (Transvaal Museum), Pretoria, South Africa.
TAXONOMY
Genus Hersiliola Thorell, 1870 Hersiliola Lucas, 1846: 163; Thorell, 1870: 110; Simon, 1882: 256; 1893: 445; Smithers, 1945: 1; Baehr & Baehr, 1993:1; Levy, 2003: 1; Rheims et al., 2004: 343.
Type species: Aranea macullulata Dufour, designated by Thorell, 1870.
Discussion
Five species of the genus Hersiliola were known from the Afrotropical Region prior to this study. Comparison of material at hand showed that the southern African species H. australis Simon, 1893 (South Africa) and H. fragilis Lawrence, 1928 (Namibia) do not belong to Hersiliola. Both species were transferred to the new genus Tyrotama.
Diagnoses
Hersiliola resembles Tama and Tyrotama gen. n. in the depressed dorsal surface of eye tubercle; unarmed chelicerae; elongate clypeus; inclined thorax and leg IV being the longest. It differs from Tama in leg III being >0.5 length of leg I; metatarsi uniarticulate without a flexible zone; cymbium digitate and presence of hook-shaped median tegular apophysis. It differs from Tyrotama gen n. in the flattened bulbus of male palp; filiform, elongate, spirally coiled embolus (Figs. 2a,b); elongate, coiled copulatory ducts, small seminal receptacles (Fig. 2g & Table 1).
Description
Female. Size: small to medium-sized (range 5.6 – 6.83). Colour: carapace varies from pale yellow to dark brown, border dark, varying in thickness; clypeus pale with dark or pale markings; eye tubercle dark; sternum, labium and endites pale; dorsum pale
