«Taxonomic Revision, Molecular Phylogeny and Zoogeography of the huntsman spider genus Eusparassus (Araneae: Sparassidae) Dissertation for attaining ...»
The first step was to define the genus and find out its diagnostic characters to clearly define and distinguish it from the closely similar genera (e.g. Olios of the Sparassinae) and putative Eusparassinae members (e.g. Peseudomicrommata, Arandisa, Carparachne, Leucorchestris and Palystella). For this purpose a neotype for E. dufouri Simon, 1932 was designated and re-described as the type species of the genus in order to fix Eusparassus identity and avoid further problem in identification of the genus.
Without any doubt, the largest Sparassidae genus in species number (Platnick 2013), Olios is the most similar taxon to Eusparassus according to somatic characters (Moradmand 2013). This similarity has caused many misidentifications and misplacements between these two genera in the past (Jäger et al. 2002;
Moradmand and Jäger 2012a). Along with revising Eusparassus, it was necessary for my study to check several types of Olios as well. This resulted in transferring six species from Olios to Eusparassus and conversely two species from Eusparassus to Olios. According to my results Eusparassus could be characterized by a combination of somatic characters but mainly based on the copulatory organs. The somatic characters include the presence of intermarginal denticles in some Eusparassus spp.
(absent in Olios spp.), presence mostly of a single bristle on the posterior margin of the cheliceral basal segment close to the base of the fangs but that number can reach a maximum of five (mostly 10 in Olios spp.). Eusparassus is distinguished from the other Eusparassinae genera by the number of ventral tibial spines: I–IV 2 pairs (3 pairs in e.g. Arandisa and Pseudomicrommata) and by relative diameters of AME which is subequal to or larger than ALE (smaller than ALE in the other genera).
However, like in other groups of spiders the best characters to diagnose Eusparassus species were found to be those of the copulatory organs: male palp, female epigyne and vulva (see chapters 3.1, 3.2). Levy (1989) emphasized on the females‘ copulatory organs and the lateral view of the vulva as a diagnostic character. In substitution, I provided a drawing from anterio-dorso-lateral view of the left half of the vulvas for a better understanding of the internal duct system. Through examination of females, it should be noted here that epigynes must be dissected to examine the vulva, since at least one un-described genus in Africa shows somehow a very similar shape of epigyne (Olios croseiceps Pocock, 1898 currently misplaced in Olios) which may lead to misidentifications in the future.
Another finding of this study was the synonymy of the monotypic genus Cercetius Simon, 1902 with Eusparassus. It was concluded after discovery of adult specimens of Cercetius perezi from its type locality. Prior to this study, Cercetius perezi was known solely from a single immature holotype but male and female were described for the first time (Moradmand 2013). I applied both morphological (see chapter 3.2) and molecular data (see chapter 3.3) to confirm this synonymy. But since the forgotten generic name Cercetius was erected one year before Eusparassus, thus the case was referred to the International Commission on Zoological Nomenclature for an action under the plenary power (Moradmand and Jäger 2012b) but before any formal decision usage of the both names must be retained (ICZN 1999).
Second step was to distinguish among different Eusparassus species. This step was the most time consuming task since I had to get access to several scientific collections and examine all the previously described types for a detailed examination (illustration, measurement and description). Prior to this study, 29 nominal species were known. I found out that more than 50% of them were misplaced or mistakenly synonymized.
The following 21 species were re-described examining the particular type specimens: Eusparassus dufouri, E. levantinus, E. atlanticus, E. barbarus, E.
syrticus, E. oraniensis, E. letourneuxi, E. fritschi, E. walckenaeri, E. laevatus, E.
vestigator, E. tuckeri, E. doriae, E. kronebergi, E. maynardi, E. pearsoni, E. potanini, E. pontii, E. oculatus, E. fuscimanus and E. xerxes. Eight species were described as new to science: Eusparassus arabicus (male, female) from the Arabian Peninsula, E.
educatus (male, female) from Namibia, E. reverentia (male, female) from Burkina Faso and Nigeria, E. jaegeri (male, female) from South Africa and Botswana, E.
jocquei (male, female) from Zimbabwe, E. borakalalo (female) from South Africa, E.
mesopotamicus (male, female) from Iran, Iraq and Turkey and E. schoemanae (male, female) from South Africa and Namibia.
Males were described for the first time for E. atlanticus and E. fritschi as in the females of E. vestigator. The following species are known only by females: E.
syrticus, E. borakalalo, E. pontii, E. maynardi and E. pearsoni. Neotypes were designated for Eusparassus dufouri from Portugal (Chanca), E. walckenaeri from Egypt (Cairo), E. barbarus, E. oraniensis and E. letourneuxi (latter three from Algeria) in order to establish their identity and to avoid misidentification with sympatric congeners since their type specimens were either not designated at all or get lost.
For the same reason, one specimen from each syntype series of the following species was selected and designated as lectotype: E. kronebergi from Afghanistan, E. maynardi from Pakistan, E. pearsoni from India and E. syrticus from Tunisia. Four nominal species E. oraniensis, E. vestigator, E. tuckeri and E. potanini were found to be senior synonyms of E. dufouri maximus, E. rufobrunneus, O. furcatus and E.
In contrast, five species were removed from being junior synonyms and reestablished as valid species: E. kronebergi from Afghanistan and E. doriae from central Iran (both previously considered junior synonyms of E. walckenaeri), E.
maynardi from Baluchistan in Pakistan and E. pearsoni from Ghats in India (both previously considered junior synonyms of E. xerxes) and E. fritschi (previously considered a junior synonym of E. oraniensis). Six species were transferred from the genus Olios to Eusparassus including Eusparassus xerxes, E. maynardi, E. pearsoni, E. vestigator, E. laevatus and E. tuckeri.
I found 14 species misplaced in Eusparassus recognizing that nearly half of the described species prior to this revision were misidentified as Eusparassus. Two were transferred from Eusparassus to Olios: O. flavovittatus from Pakistan and O.
quesitio (replacement name for O. concolor Caporiacco, 1939) from Ethiopia. Three species [―Eusparassus‖ shefteli Chamberlin, 1916 described from Peru, ―Eusparassus‖ bicorniger (Pocock, 1898) from East Africa and ―Eusparassus‖ laterifuscus Strand, 1908 from Madagascar] were proven to be misplaced in Eusparassus but cannot currently to be assigned to any known Sparassidae genera.
The type specimens for the following nine Eusparassus species were destroyed but according to their original descriptions they are clearly misplaced in Eusparassus and thus recognized as nomina dubia: “Eusparassus” sexdentatus Strand, 1906;
“Eusparassus” quinquedentatus Strand, 1906; “Eusparassus” subadultus Strand, 1906; “Eusparassus” fulviclypeus Strand, 1906; “Eusparassus” nigrichelis Strand, 1906; “Eusparassus” cornipalpis Strand, 1906; “Eusparassus” palystiformis Strand, 1907; “Eusparassus” ubae Strand, 1906 and ―Eusparassus‖ lilus Strand, 1907.
Finally, 30 valid Eusparassus species (including C. perezi) were (re)described, of which 24 are known by both sexes and six only by females.
Third step was to classify species to species-groups. After defining the genus and (re)describing the species, I looked for shared traits among Eusparassus species to propose species-groups. A combination of diagnostic characters of both somatic and copulatory structures was applied which led to proposing the following six
species-groups (arranged according to species counts):
1) dufouri species-group (8 species): Eusparassus dufouri, E. barbarus, E.
oraniensis, E. fritschi, E. letourneuxi, E. atlanticus, E. syrticus and E. levantinus. The group is distributed in NW Africa to Iberian Peninsula;
2) doriae species-group (7 species): Eusparassus doriae, E. oculatus, E. potanini, E. maynardi, E. kronebergi, E. fuscimanus and E. mesopotamicus. The group is distributed from the Middle East to Central and parts of South Asia;
3) jaegeri species-group (4 species): Eusparassus jaegeri, E. jocquei, E.
schoemanae and E. borakalalo. The group is distributed in southern and SE Africa;
4) walckenaeri species-group (3 species): Eusparassus walckenaeri, E. laevatus and E. arabicus. The group is distributed from the eastern Mediterranean to Arabia and parts of NE Africa;
5) vestigator species-group (3 species): Eusparassus vestigator; E. reverentia; E.
pearsoni. The group is distributed in Central to East Africa and an isolated area in India,
6) tuckeri species-group (2 species): Eusparassus tuckeri, E. educatus. The group is distributed in SW Africa.
Three species could not be affiliated to any species-group proposed above including: Eusparassus xerxes, E. pontii and Cercetius perezi. The two main somatic characters used to classify species to species-groups were the intermarginal denticles in chelicerae and the ventral opisthosoma marking. Just two species-groups (walckenaeri and jaegeri) have intermarginal denticles in their chelicerae. A distinct dark marking on the ventral opisthosoma is present solely in the dufouri- and vestigator-group members. However these two characters are present in the specimens of Cercetius perezi, too. This species has clearly large solid dark markings like those of the dufouri-group members and at the same time some specimens bear intermarginal denticles in their chelicerae. However, C. perezi adults show a form of copulatory structures different from these groups.
4.2. Molecular phylogenetics
The phylogenetic relationships of Sparassidae with focus on Eusparassus and Eusparassinae were investigated for the first time using four molecular markers (mitochondrial COI and 16S; nuclear H3 and 28S). All of the markers used in this study were verified to be informative in reconstructing phylogenetic relationships of Sparassidae (subfamily Deleninae; Agnarsson and Rayor 2013) and other groups of spiders (i.e. Arnedo et al. 2004; Bayer and Schoenhofer 2013; Crews et al. 2010;
Miller et al. 2010; Dimitrov et al. 2012; Dimitrov et al. 2013). For details on this subject see chapter 3.3.
4.2.1. Eusparassus and its species-groups
The results of molecular phylogeny were in accordance with the diagnoses of the genus and the proposed morphological affinities to classify Eusparassus into species-groups. The genus Eusparassus was recovered monophyletic with the type specimen E. dufouri nested within (using the DNA of the neotype). The monophyly of the dufouri-, doriae- and walckenaeri-group were well supported, while that of the tuckeri-group was not recovered. In the analyses only one single representative of the jaegeri-group was included and of all the proposed species-groups only individuals of the vestigator-group were missing which was because of unavailable suitable tissues for DNA isolation of these taxa.
The doriae- and walckenaeri-group were found as sister clades and both likely sister to the dufouri-group. It supported the hypothesis based on the analysis of the copulatory organs that doriae- and walckenaeri-group members are closely related, despite there are major morphological differences such as presence of intermarginal denticles in the walckenaeri-group which is absent in the doriae-group. On the other side, the single member of the jaegeri-group found to have no close relationships to the walckenaeri-group members, although both have intermarginal denticles in chelicerae. It is likely that gain of this character in the jaegeri- and walckenaeri-group happened independently. The exact position of the tuckeri- and jaegeri-group within the genus was not resolved. Despite not supported with high values, the monophyly of the tuckeri-group cannot be rejected by current analyses.
Cercetius perezi nested well within the Eusparassus clade indicating that the morphologic findings (the proposed synonymy) are supported by molecular phylogeny and verifying that representatives of both nominal genera are actually congeners.
To test the phylogenetic relationships and monophyly of Eusparassinae, all of the originally proposed genera (Eusparassus, Pseudomicrommata and Rhitymna; by Järvi 1912) and the putative Eusparassinae genera (Arandisa, Carparachne, Leucorchestris, Microrchestris and Palystella; by Jäger and Kunz 2003) were included. In this sense, Eusparassinae was not recovered as a monophyletic group. It split into two major clades. One clade contained the type species Eusparassus with all its representatives (including Cercetius perezi) and the second containing the rest of Eusparassinae genera. This branch is named the ―African clade‖ consisting of two subclades: (1) Pseudomicrommata+Arandisa and (2) Carparachne, cf.
Microrchestris, Leucorchestris and Palystella. The ―African clade‖ comprises morphologically similar genera endemic to Africa and mainly southern Africa.
Pseudomicrommata and Arandisa were recovered as the closest relatives which is supported by their unique morphological characters such as the presence of epigynal pockets. In the second clade, the Namibian sand dwelling genera Carparachne and Leucorchestris were recovered as sister taxa and both sister to Palystella.