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Abstract Amblypygi is an arachnid order possessing a unique pair of spined pedipalps: appendages that perform in prey capture, courtship, and contest. Pedipalp length, hypothesized to be under sexual selection, varies markedly across amblypygid species, and pedipalp spination, thought to reflect selection for function in prey capture, also differs interspecifically. Differences in pedipalp shape between species may indicate that the relative strength of selection for prey capture and sexual selection vary across the group. However, interspecific differences in pedipalp shape have not been quantified, due to difficulties in identifying homologous features. For the first time, we quantify trends in amblypygid pedipalp shape complexity. We use elliptical Fourier analysis to quantify 2D complexity in pedipalp outlines across eleven species and six genera. We find that complexity significantly decreases as pedipalp length increases. This appears to be driven by relative spine length, suggesting that a trade‐off exists between pedipalp length and spination. Furthermore, significant female‐biased sexual dimorphism in shape complexity is present in the tibial segment of the amblypygid pedipalp. Our results provide novel insights into the drivers of amblypygid pedipalp evolution and suggest that a functional trade‐off between performance in prey capture and other functions under sexual selection exist in this enigmatic structure.

Amblypygi is an arachnid order possessing a unique pair of spined pedipalps: appendages that perform in prey capture, courtship, and contest. Pedipalp length, hypothesized to be under sexual selection, varies markedly across amblypygid species, and pedipalp spination, thought to reflect selection for function in prey capture, also differs interspecifically. Differences in pedipalp shape between species may indicate that the relative strength of selection for prey capture and sexual selection vary across the group. However, interspecific differences in pedipalp shape have not been quantified, due to difficulties in identifying homologous features. For the first time, we quantify trends in amblypygid pedipalp shape complexity. We use elliptical Fourier analysis to quantify 2D complexity in pedipalp outlines across eleven species and six genera. We find that complexity significantly decreases as pedipalp length increases. This appears to be driven by relative spine length, suggesting that a trade‐off exists between pedipalp length and spination. Furthermore, significant female‐biased sexual dimorphism in shape complexity is present in the tibial segment of the amblypygid pedipalp. Our results provide novel insights into the drivers of amblypygid pedipalp evolution and suggest that a functional trade‐off between performance in prey capture and other functions under sexual selection exist in this enigmatic structure. [ABSTRACT FROM AUTHOR]

Abstract Background Nervous tissue is an inherent component of the many specialized genital structures for transferring sperm directly into the female’s body. However, the male copulatory organ of spiders was considered a puzzling exception. Based on the recent discovery of nervous tissue in the pedipalps of two distantly related spider species, we investigated representatives of all major groups across the spider tree of life for the presence of palpal nerves. We used a correlative approach that combined histology, micro-computed tomography and electron microscopy. Results We show that the copulatory organ is innervated in all species investigated. There is a sensory organ at the base of the sperm transferring sclerite in several taxa and nervous tissue occurs close to the glandular tissue of the spermophor, where sperm are stored before transfer. Conclusions The innervation of the copulatory organ by the bulb nerve and associated efferent fibers is part of the ground pattern of spiders. Our findings pave the way for unraveling the sensory interaction of genitalia during mating and for the still enigmatic mode of uptake and release of sperm from the male copulatory organ.

The link between form and function is key to understanding the evolution of unique and/or extreme morphologies. Amblypygids, or whip spiders, are arachnids that often have highly elongated spined pedipalps. These limbs are used to strike at, and secure, prey before processing by the chelicerae. Amblypygi pedipalps are multifunctional, however, being used in courtship and contest, and vary greatly in form between species. Increased pedipalp length may improve performance during prey capture, but length could also be influenced by factors including territorial contest and sexual selection. Here, for the first time, we used high-speed videography and manual tracking to investigate kinematic differences in prey capture between amblypygid species. Across six morphologically diverse species, spanning four genera and two families, we created a total dataset of 86 trials (9-20 per species). Prey capture kinematics varied considerably between species, with differences being expressed in pedipalp joint angle ranges. In particular, maximum reach ratio did not remain constant with total pedipalp length, as geometric scaling would predict, but decreased with longer pedipalps. This suggests that taxa with the most elongated pedipalps do not deploy their potential length advantage to proportionally increase reach. Therefore, a simple mechanical explanation of increased reach does not sufficiently explain pedipalp elongation. We propose other factors to help explain this phenomenon, such as social interactions or sexual selection, which would produce an evolutionary trade-off in pedipalp length between prey capture performance and other behavioural and/or anatomical pressures., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)

Stridulatory organs have not been previously investigated for harvestmen in the family Cosmetidae. During a field study, we observed the infrequent production of vibrations by adult Cynorta marginalis Banks, 1909. Using SEM, we examined the surfaces of several appendages for potential stridulatory organs. Our observations indicate that C. marginalis has denticles on the mesal surfaces of the basichelicerites that when rubbed together may function as an isomorphous stridulatory organ. In addition, there are denticles on the ectal surfaces of the basichelicerites and furrowed ridges on the femora of the pedipalps that may represent heteromorphous stridulatory organs. We did not observe any sexual dimorphism in morphology at either anatomical location. We also examined the appendages of two additional cosmetid harvestmen: Paecilaema inglei Goodnight & Goodnight, 1947, a species that also stridulates when held and Erginulus clavotibialis (Pickard-Cambridge, 1905), a species that has not been observed to produce vibrations. As in C. marginalis, we observed denticles on mesal and ectal surfaces of the basichelicerites and a furrowed ridge on the mesal surfaces of the femora of the pedipalps of adult P. inglei. In contrast, the basichelicerites of E. clavotibialis had relatively fewer and smaller denticles on the external surfaces of the chelicerae and the mesal surface of the femora of the pedipalps lacked ridges and were relatively smooth. Our comparative morphological data supports the hypothesis that there are cosmetid harvestmen that may use surface features on the chelicerae and pedipalps to produce vibrations which may function as a secondary defense mechanism. [ABSTRACT FROM AUTHOR]

Dicranopalpus larvatus is redescribed based on type material. Recent first findings of this rare species on Sardinia enable to provide the essential morphological characters. Original drawings are presented with emphasis on penial and pedipalpal morphology. Dicranopalpus larvatus is a small, short-legged, ground-dwelling species endemic to Italy that matures in autumn and winter and has completed its life cycle in April. Additional information on phenology, life cycle, ecology, distribution and systematic position is given. [ABSTRACT FROM AUTHOR]

Lacinius insularisRoewer, 1923, is recorded for the first time as part of the Turkish harvestmen fauna. Prior to this, the species was only known from the island of Crete in Greece. The new collections were made on Nif mountain in İzmir Province (far western Turkey). In this study, L. insularis is redescribed based on adults from Turkey. Its detailed description, morphological characteristics, distribution and measurements are given. Also, genitalia, body dorsal view, chelicerae, and pedipalp are illustrated. In addition, this species is compared with similar species. [ABSTRACT FROM AUTHOR]

Members of the Neobisiidae are currently classified in two subfamilies, Neobisiinae and Microcreagrinae. Taxonomic assignment to subfamily is based upon two morphological characters, neither of which is consistently found within either subfamily. The form of the galeae is elongate and hyaline in the Microcreagrinae, but reduced and sclerotic in the Neobisiinae. However, some members of the Microcreagrinae also have reduced galeae. The position of trichobothrium ist located on the fixed finger of the pedipalp chelae is generally positioned subdistally and closer to trichobothrium est in Neobisiinae but sub-basally and closer to trichobothrium ib in Microcreagrinae. However, members of the genus Parobisium, currently assigned to the subfamily Neobisiinae, have a microcreagrine-like subbasal trichobothrium ist. Since neither subfamily is defined by an undisputed apomorphy, the monophyly of both groups has long been questioned. In this study, we tested whether or not the two subfamilies are monophyletic by inferring the phylogeny of the family using DNA sequence data from the mitochondrial protein-coding gene, COI, and the nuclear ribosomal gene 28S. Results of the molecular phylogenetic analyses indicate that neither of the subfamilies is monophyletic as presently defined. We transfer the genus Parobisium to the Microcreagrinae in order to simultaneously obtain a monophyletic Neobisiinae and resolve character inconsistency for the position of trichobothrium ist, which is sub-distal in all Neobisiinae taxa included in our study. We also find that reduction of the galea is not a reliable character state at the subfamily level, and has occurred at least three times independently within the family. [ABSTRACT FROM AUTHOR]

A new species of the scorpions Compsobuthus iraqensis sp.nov , was described for the first time in Iraq and world which is collected from Salahuddin governorate in Iraq .This species are characterized by pedipalps and chela are very thin and very long,the sixth segments of metasoma are very tall and less in width.The body color and legs are yellowish except the end of acelus is radish ,the total length between 26-40 mm, and the rows of granules on the movable finger of pedipalp have 10 rows,The Compsobuthus. iraqensis sp. nov. is almost similar to the species Compsobuthus. persicus,(11) from Iran, which it differed by some characters , Internal granules in all rows on the movable finger of pedipalp and in the number of granular in the metasoma segment. This study for the first time is described and recorded this species. [ABSTRACT FROM AUTHOR]

The genus Butheolus Simon, 1882 is revised based on new material from Dhofar Province in Oman. B. gallagheri Vachon, 1980 is redescribed, and a related new species, B. harrisoni sp. n., is also described. The species B. anthracinus (Pocock, 1895) is redescribed and moved to a new genus Xenobuthus gen. n., that is differentiated from Butheolus by size, pedipalp finger dentition, setation, granulation and hemispermatophore structure, and a related new species, X. xanthus sp. n., is also described. Revised diagnoses are provided for the genus Butheolus, and for the species B. thalassinus Simon, 1882, and B. villosus Hendrixson, 2006, a key is given for the species examined in this study, and the status of other related species discussed. [ABSTRACT FROM AUTHOR]

The modestly diverse order Amblypygi Thorell, 1883 includes five families, of which Charinidae Quintero, 1986 is the most diverse and with the widest geographical distribution. The family currently comprises three genera, Catageus Thorell, 1889, Charinus Simon, 1892 and Sarax Simon, 1892, the first known by one species from a single locality in Myanmar, the second with currently 74 species globally distributed, and the last with 17 species present in Southeast Asia and India. In this paper we describe and illustrate a new genus to accommodate the species Sarax davidovi Fage, 1946 based on unique characters. Weygoldtia gen. nov. (Laos, Vietnam and Cambodia) is supported by two synapomorphies: the presence of a straight crest anterior to the lateral eyes and the longitudinal orientation of the rod sensilla on tarsus of leg I. The new genus can be distinguished from Charinus and Sarax by the number of trichobothria on distitibia IV and the presence of one or two setae on the base of the cleaning organ on pedipalp tarsus. The enigmatic species Catageus pusillus Thorell, 1889 (the single species in the genus) is here synonymized with Stygophrynus cavernicola (Thorell, 1889) (family Charontidae Simon, 1892) and a neotype is designated. As Stygophrynus cavernicola is the type species of the genus, the synonymization of the two species results in the synonymy of the genera. Following the principle of priority, Catageus is maintained and all nine species of Stygophrynus Kraepelin, 1895 now have the following new combination: Catageus berkeleyi (Gravely, 1915), comb. nov., C. brevispina (Weygoldt, 2002), comb. nov., C. cavernicola , comb.nov., C. cerberus (Simon, 1901), comb. nov., C. dammermani (Roewer, 1928), comb. nov., C. longispina (Gravely, 1915), comb. nov., C. moultoni (Gravely, 1915), comb. nov., C. orientalis (Seiter and Wolf, 2017), comb. nov. and C. sunda (Rahmadi and Harvey, 2008), comb. nov. [ABSTRACT FROM AUTHOR]

Sexual dimorphism is a common feature of life. Researchers have noted that some species of Amblypygi (Class Arachnida) exhibit male-biased sexual dimorphism, but a broad overview of the prevalence of sexual dimorphism in the order does not exist. In order to provide such an overview, we imaged and measured morphological characteristics of 390 amblypygids from 36 species. Our aim was to gain insight into general patterns of sexual dimorphism across the order. We found that, generally, males have larger pedipalps, longer antenniform legs, but smaller carapace widths relative to conspecific females for nearly all species studied. Species ranged from no sexual dimorphism ( Phrynus exsul and Charinus insularis ) to male pedipalps almost double the length of females in some species ( Charon grayi , Euphrynichus amanica ). Phylogenetic patterns remain unclear in Amblypygi and our data better match geographic patterns than evolutionary history. We thus suggest that sexual dimorphism is ancestral for the order, but has been reduced or lost in some species. [ABSTRACT FROM AUTHOR]

Liocheles australasiae (Fabricius, 1775) is reported for the first time from Sri Lanka. Sri Lankan population is fully complemented with color photos of live and preserved females, as well as its habitat [ABSTRACT FROM AUTHOR]

The North American vinegaroon, Mastigoproctus giganteus (Lucas, 1835), is demonstrated to comprise a complex of range-restricted species rather than a single widespread polymorphic species. Seven species are recognized based on morphological characters of the adult males, including the arrangement of spines on the prodorsal margin of the pedipalp trochanter, the position of the epistoma on the carapace, the presence of a stridulatory organ on opposing surfaces of the chelicerae and the pedipalp coxa, the presence of a patch of setae on sternite V, and the shape and macrosculpture of the retrolateral surface of the pedipalp femur. The two currently recognized subspecies are elevated to species: Mastigoproctus mexicanus (Butler, 1872), stat. nov., and Mastigoproctus scabrosus (Pocock, 1902), stat. nov. Mastigoproctus floridanus (Lönnberg, 1897) is revalidated from synonymy with M. giganteus. Redescriptions of M. giganteus and the other three species, based on both sexes, are provided, and three new species described: Mastigoproctus cinteotl, sp. nov., from Tamaulipas, Mexico; Mastigoproctus tohono, sp. nov., from Arizona and Sonora, Mexico; Mastigoproctus vandevenderi, sp. nov., from Sonora, Mexico. The present contribution raises the diversity of the Order Thelyphonida Latreille, 1804, in North America from one species to seven. Three species occur in the United States (one each in Arizona, Texas, and Florida), six species occur in Mexico, and two species occur in both countries. [ABSTRACT FROM AUTHOR]

Observations on the entire life cycle of most scorpion species are scarce. Here, we present precise data of the embryonic and postembryonic development for Lychas tricarinatus with additional notes on Tityus trivittatus . By rearing captive-born Lychas tricarinatus specimen from the Odisha province (India) in isolation until maturation, we could show that virgin females gave birth to offspring proving that specimens are capable of parthenogenetic reproduction. Further, we describe an all-female population of Tityus trivittatus from the Corrientes province (Argentina), which originated from a fully bi-sexual population. In addition we describe the ontogenetic development of these two parthenogenetic, buthid scorpions under laboratory conditions. The Dyar’s constant was evaluated for the carapace, metasomal segment V, and the movable finger of the pedipalp among the instars. The calculated growth factor has a total grand average of 1.26. Lychas tricarinatus females reached maturity after 220 days postembryonic development. Moreover, L. tricarinatus females started to reproduce in the 6 th or 7 th instar and gave birth to an average of 21 neonates after 96 days of embryonic development. Tityus trivittatus matured in the 5 th or 6 th instar and gave birth after 230 days to an average of 13 neonates. [ABSTRACT FROM AUTHOR]

Background: Gene duplications provide genetic material for the evolution of new morphological and physiological features. One copy can preserve the original gene functions while the second copy may evolve new functions (neofunctionalisation). Gene duplications may thus provide new genes involved in evolutionary novelties. Results: We have studied the duplicated homeobox gene homothorax (hth) in the spider species Parasteatoda tepidariorum and Pholcus phalangioides and have compared these data with previously published data from additional spider species. We show that the expression pattern of hth1 is highly conserved among spiders, consistent with the notion that this gene copy preserves the original hth functions. By contrast, hth2 has a markedly different expression profile especially in the prosomal appendages. The pattern in the pedipalps and legs consists of several segmental rings, suggesting a possible role of hth2 in limb joint development. Intriguingly, however, the hth2 pattern is much less conserved between the species than hth1 and shows a species specific pattern in each species investigated so far. Conclusions: We hypothesise that the hth2 gene has gained a new patterning function after gene duplication, but has then undergone a second phase of diversification of its new role in the spider clade. The evolution of hth2 may thus provide an interesting example for a duplicated gene that has not only contributed to genetic diversity through neofunctionalisation, but beyond that has been able to escape evolutionary conservation after neofunctionalisation thus forming the basis for further genetic diversification. [ABSTRACT FROM AUTHOR]

Diplocentrus duende n. sp. is described based on adult males collected from a locality in the Tehuacán–Cuicatlán Valley, Mexico. This species has punctate pedipalp surfaces, a condition present only in four other species of this specious genus. As suggested here, this condition has evolved independently in these species within the “ mexicanus ” group of Diplocentrus from the rest of the diplocentrids. [ABSTRACT FROM AUTHOR]

En Venezuela, la escorpiofauna consta de 17 géneros y 202 especies. En algunos grupos la taxonomía no ha sido aclarada; por lo tanto, son necesarias investigaciones adicionales que contribuyan a mejorar el conocimiento sobre la identidad taxonómica y relaciones entre sus componentes. La morfometría geométrica es una herramienta que ha sido utilizada como apoyo a la sistemática en distintos organismos. El objetivo del presente trabajo fue analizar la conformación y tamaño isométrico en 5 especies de escorpiones. Se fotografiaron 266 individuos de 4 especies de Buthidae: Centruroides testaceus, Rhopalurus laticauda, Tityus clathratus y T. discrepans, y una de Scorpionidae: Tarsoporosus yustizi. Se registraron configuraciones de coordenadas (x,y) en 5 estructuras a partir de puntos anatómicos de referencia (PAR) y PAR deslizantes. Los resultados mostraron separación completa de las especies de Buthidae por medio de tricobotrias dorsales en la patela del pedipalpo, y una consistente separación en el nivel familiar en las estructuras restantes. Las placas delgadas permitieron la visualización de compresión horizontal del esternón en las especies de Buthidae y compresión vertical en la de Scorpionidae. Se determinó la similitud de coxas, quela y caparazón entre R. laticauda y C. testaceus. La disposición de tricobotrias y la conformación del esternón permitió la diferenciación entre T. discrepans y T. clathratus.The Venezuelan scorpionfauna comprises 17 genera and 202 species. In some taxa the taxonomy is unclear, and additional studies that contribute to the knowledge about taxonomic identity and relationships are necessary. Geometric morphometrics is a tool that has been used as support to the systematics in different organisms. The goal was to analize the isometric size and conformation in five scorpions species. We photographed 266 individuals of four speceis of Buthidae: Centruroides testaceus, Rhopalurus laticauda, Tityus clathratus and T. discrepans, and one species of Scorpionidae: Tarsoporosus yustizi. Coordinate (x,y) configurations from landmarks and semilandmarks were registered in five structures. The results showed the complete separation in Buthidae species through dorsal trichobotria on patella pedipalp; and a consistent separation at family level in the remaining structures. The thin plate spline showed the sternum horizontal compression in the Buthidae species and the vertical compression in Scorpionidae. Similarity in coxae, chelae and caparace between R. laticauda and C. testaceus was determined. The trichobotria disposition and the sternum conformation allows to discriminate T. discrepans and T. clathratus.

Calocheirus asiaticus was described by Dashdamirov (1991) and subsequently briefly redescribed by Dashdamirov & Schawaller (1993) on the basis of the specimens collected from central Asia. The generic position of C. asiaticus is discussed here and redefined as Cardiolpium asiaticum new comb. A full description and illustrations of several newly collected specimens from Fars Province, southern Iran, are given. [ABSTRACT FROM AUTHOR]

The rigid leg segments of arthropods are flexibly connected by joints, which usually consist of two ball-and-bowl hinges, permitting a uniaxial pivoting up to 140°. Here, we report the occurrence of hyperflexible joints (range of movements = 160-200°) in the pedipalps (second pair of appendages) of some harvestmen (Sabaconidae and Nemastomatidae), representing some of the most flexible leg joints among arthropods. Hyperflexion is achieved by a reduction of hinges and a strong constriction of the joint region. We demonstrate that hyperflexion occurs during prey capture and is used to clamp appendages of the prey, in addition to attachment by glue secreted by specialized setae. By means of high-speed video recordings, we found that in the Sabaconidae the tibiotarsal joint of the pedipalp can flex extremely rapidly (<5 ms), limiting prey escape. This is the fastest reported predatory strike in arachnids and caused both by leverage and a click mechanism. By comparative analysis of different related taxa, we retraced joint evolution and found that hyperflexion has independently evolved in Sabaconidae and Nemastomatidae, with totally different joint kinematics. We hypothesize that (rapid) hyperflexion evolved to enhance the efficiency of the pedipalp as a means of prey capture, because in springtails detachable scales limit the action of the sticky secretion of pedipalpal setae. [ABSTRACT FROM AUTHOR]

The experiment was aimed at demonstrating the relationship between deformities of the front part of the prosoma accompanied by changes in the brain structure in bicephalous Tegenaria atrica and exposure of their embryos to temperature fluctuations. By exposing spider embryos to alternating temperatures of 14 and 32 °C for the first 10 days of embryonic development, we obtained eight two-headed individuals, subsequently divided into three groups according to morphological differences. We described in detail morphological abnormalities of the prosoma identified in members of each group. Histological examination confirmed a close relationship between morphological deformities and the brain structure of teratogenically changed spiders. The fusion of appendages (pedipalps and chalicerae) was accompanied by the fusion of corresponding ganglia. The absence of appendages (pedipalps) was accompanied by the absence of corresponding ganglia. This correlation may have resulted from previously impaired neuromere development which led to changes in the morphological structure of the prosoma. Since no deformities were identified in control animals, it can be concluded that bicephaly was caused by exposing embryos to alternating temperatures. [ABSTRACT FROM AUTHOR]

Diplocentrus izabal sp. n. is herein described on basis to one male (holotype) and two females from El Estor municipality, Izabal department, eastern Guatemala. It seems to be a close relative of Diplocentrus lachua Armas, Trujillo & Agreda, 2012, from which it differs by having carapace almost smooth, with anteromedian notch Vshaped; pectines with 11 teeth in both sexes, and carapace clearly longer than pedipalp manus and metasomal segment V (D. lachua has carapace minutely granulate, with anteromedian notch U-shaped; pectines with 13 teeth in the males (female unknown), and carapace as long as both pedipalp manus and metasomal segment V). [ABSTRACT FROM AUTHOR]

Pedipalps are the most versatile appendages of arachnids. They can be equipped with spines (Amblypygi), chelae (Scorpiones), or adhesive pads (Solifugae), all of which are modifications to grasp and handle fast-moving prey. Harvestmen (Opiliones) show a high diversity of pedipalpal morphologies. Some are obviously related to prey capture, like the enlargement and heavy spination of Laniatores pedipalps. Many Dyspnoi, by contrast, exhibit thin, thread-like pedipalps that are covered with complex glandular setae (clavate setae). These extrude viscoelastic glue that is used to immobilize prey items. Comparable setae (plumose setae) have previously been found in representatives of both Eupnoi and Dyspnoi, yet comprehensive data on their distribution are lacking. This study examined the distribution and ultrastructure of glandular setae in harvestmen and related them to pedipalpal morphology. Pedipalpal and setal characters were analysed in a phylogenetic framework. We found that glandular setae are synapomorphic for and widespread in the Palpatores clade (Eupnoi plus Dyspnoi). Their occurrence correlates with pedipalp morphology and feeding habit. Remnants of arthropod cuticular structures or secretions, frequently found attached to glandular setae, and behavioural observations, underlined the importance of the setae for capturing and securing prey. We hypothesize that glandular setae evolved as an adaptation to capture small and agile prey, which are hard to catch with a capture basket. Details of ultrastructure indicate that the setae are derived sensilla chaetica, with both a secretory and sensory function. Derived ultrastructural characters of the glandular setae, such as slit-like channel openings and a globular arrangement of the microtrichia, may increase their effectiveness. The functional role of further pedipalpal modifications, such as apophyses, stalked and hyperbendable joints, and curved segments, as well as sexual dimorphism and ontogenetic polymorphism, are discussed. Some implications of the results obtained for the taxonomic treatment of Phalangiidae are also discussed. These results shed new light on the biology and evolutionary history of this fascinating group of arthropods. [ABSTRACT FROM AUTHOR]

Most web spiders use chemical and vibratory cues for intersexual communication prior to mating. Little is known regarding the behavior of the web spider, Pholcus manueli Gertsch, 1937. In the laboratory, we examined the behavior of males in female webs. Some webs were washed and allowed to air dry. Both washed and unwashed webs were tested with and without females. Overall, male behaviors were similar to courtship reported for other pholcid species and their frequency was related to male size. Web washing delayed the initiation of activity, reduced abdomen flexes, and increased the likelihood of pedipalp expansion and aggression. The presence of females caused males to initiate movement sooner and to increase silk pulling behavior. These results suggest that courtship is multimodal and that the vibratory dialog between males and females works along with chemical communication in this species. Hopefully, these data will enhance future studies of sexual selection in pholcids. [ABSTRACT FROM AUTHOR]

The schizomid genus M ayazomus Reddell & Cockendolpher, 1995, endemic to south-eastern Mexico, currently comprises seven species. It was originally proposed to accommodate two species, from Chiapas and Tabasco. Recently, five additional species from Chiapas were described. The monophyly of the genus has never been tested using cladistic analysis. We undertook a phylogenetic analysis using the seven described species of M ayazomus as the ingroup, ten exemplar species representing the most similar New World hubbardiids as the outgroup, and one protoschizomid species to root the tree. The analysis was based on 130 morphological characters (continuous and discrete characters). The resulting topologies recovered M ayazomus as paraphyletic, with H eteronochrus estor Armas & Viquez, 2010, from Guatemala nested within the genus; therefore, we formally propose its synonymy herein. M ayazomus appears to be most closely related to R owlandius Reddell & Cokendolpher, 1995, a South American genus. This contribution also provides new characters derived from the pedipalp setae with important phylogenetic information; as well as the implementation of morphometric ratios, as continuous characters, to partially codify the shape of the male flagellum. The relationships recovered amongst the outgroups used in this contribution are a reliable baseline for future analyses of the phylogeny of the New World schizomids. [ABSTRACT FROM AUTHOR]

The study was aimed at demonstrating the relationship between temperature (as a factor which disturbs morphogenesis) and deformities in the front part of the prosoma in Tegenaria atrica . By exposing spider embryos to alternating temperatures of 14 and 32 °C for the first 10 days of embryonic development, i.e. until the first metameres of the prosoma appeared on the germ band, we obtained individuals with a range of anomalies including those which affected the prosomal morphology. We selected five spiders with deformities of pedipalps or of pedipalps and walking legs for comprehensive analysis. The results indicate a relationship between temperature applied as a teratogenic factor and anomalies in the front part of the prosoma. [ABSTRACT FROM AUTHOR]

This paper presents the intraspecific variability in 5 Ptatybunus species. Four main morphological features have been investigated and compared with the available literature: the habitus, the pedipalp, the penis and the seminal receptacles. The most variable characters are: the habitus in Ptatybunus pinetorum female and the apophysis of the pedipalpal patella in all species. In the case of some characters, important differences have been noticed in comparison with the references. Such differences either extend the range of intraspecific variability of the already described species or determine the description of new species. The paper suggests the existence of hybrid populations. Gynandromorphy is suggested in Platybunus banarescui. [ABSTRACT FROM AUTHOR]

Damage to genital structures during copulation has been reported in about twenty spider families, but never in Lycosidae. Aglaoctenus lagotis (Holmberg, 1876), a South American wolf spider, is one of the few that live their whole lives in funnel-webs. This work reports on the damage to pedipalpal bulbs observed in males of the 'southern Uruguay' form of A. lagotis with multiple copulations. Observed damage consists of the irreversible expansion of the hematodocha and even its explosion. A high copulation cost resulting from multiple and long-lasting copulations could be causing this damage, affecting the mechanism of sperm transference in a definitive way. This is the first report of pedipalp damage in lycosids, and also the first report of damage involving the hematodocha in spiders. [ABSTRACT FROM AUTHOR]

Animals with internal fertilization possess complex male genitalia that are characterized by rapid and divergent evolution. Such complexity and divergence renders male genitalia highly species specific. Furthermore, in species with paired genitalia in males and females as is typically the case in spiders, the genital complexity is considered to restrict usage of each male intromittent organ (pedipalp) to a specific genital opening of the female genitalia. Here, we report cases of flexible pedipalp insertion (16%) in the dwarf spider Oedothorax retusus – a species with complex pedipalps. A flexible insertion mode allows males of this species to react to the mating history of the female by circumventing the highly effective mating plugs and mating into the unused side. Our findings disagree with the species isolating lock-and-key hypothesis for explaining divergence in genital morphology as the ‘key’ can be applied to the mirror-inversed female ‘lock’ in the spider species O. retusus. Rather, our data suggest that sexual selection is an important underlying selective regime for the evolution of highly complex and diverse genitalia. [ABSTRACT FROM AUTHOR]

A new species of Sphaerowithius Mahnert, 1988, S. ansieae sp. n., is described from specimens collected in caves in northern Namibia. The specimens show some slight modifications to an obligate cavernicolous existence including small eyes and long, slender pedipalps. [ABSTRACT FROM AUTHOR]

Two species of the genus Vestiferum Martens, 2006 were found in Turkey. One of them, V. funebre (Redikortsev, 1936) is found in Turkey for the first time. The other species V. alatum Martens, 2006 is recorded from a new locality in Turkey. Both species were collected from the northern part of Turkey. Their descriptions, characteristic features, distributions and digital and SEM photographs are presented. [ABSTRACT FROM AUTHOR]

In nuptial gift-giving species females sometimes select their potential mates based on the presence and size of the gift. But in some species, such as the Neotropical polyandrous spider Paratrechalea ornate male gifts vary in quality, from nutritive to worthless, and this male strategy can be in conflict with female nutritional benefits. In this species, males without gifts experience a reduction in mating success and duration, while males that offer worthless or genuine nutritive gifts mate with similar frequencies and durations. The female apparently controls the duration of copulation. Thus, there is scope for females to favour males offering gifts and further if these are nutritious, via post-copulatory processes. We first tested whether females differentially store sperm from males that offer the highest nutritional benefits by experimentally presenting females with males that offer either nutritive or worthless gifts (uninterrupted matings). Second, we carried out another set of experiments to examine whether females can select sperm based only on gift presence. This time we interrupted matings after the first pedipalp insertion, thus matching number of insertions and mating duration for males that: offered and did not offer gift. Our results showed that the amount of sperm stored is positive related to mating duration in all groups, except in matings with worthless gifts. Gift presence itself did not affect the sperm stored by females, while they store similar number of sperm in matings with males offering either nutritive or worthless gifts. We discuss whether females prefer males with gifts regardless, if content, because it represents an attractive and/or reliable signal. Or alternatively, they prefer nutritive nuptial gifts, as they are an important source of food supply and/or signal of male donor ability. [ABSTRACT FROM AUTHOR]

The fossil whip spider Electrophrynus mirus Petrunkevitch 1971 (Arachnida: Amblypygi: Electrophrynidae) from the Mexican Chiapas amber (Miocene: ca 15-20 Ma) is redescribed. Its original referral to an extinct family and genus based on an unusual configuration of the pedipalp is shown to be based on a misinterpretation. The family Electrophrynidae has already been synonymized with Phrynidae. Although E. mirus closely resembles modern phrynids, a key diagnostic character relating to the dorsal pattern of spines on the pedipalp patella is not preserved. Since this incomplete fossil cannot be meaningfully compared either to modern genera or to other whip spiders in Neotropical amber, we believe the pragmatic solution is to treat E. mirus as a nomen dubium. [ABSTRACT FROM AUTHOR]