Comparative study of spinning field development in two species of araneophagic spiders (Araneae, Mimetidae, Australomimetus)

External studies of spider spinning fields allow us to make inferences about internal silk gland biology, including what happens to silk glands when the spider molts. Such studies often focus on adults, but juveniles can provide additional insight on spinning apparatus development and character polarity. Here we document and describe spinning fields at all stadia in two species of pirate spider (Mimetidae: Australomimetus spinosus, A. djuka). Pirate spiders nest within the ecribellate orb-building spiders (Araneoidea), but are vagrant, araneophagic members that do not build prey-capture webs. Correspondingly, they lack aggregate and flagelliform silk glands (AG, FL), specialized for forming prey-capture lines in araneoid orb webs. However, occasional possible vestiges of an AG or FL spigot, as observed in one juvenile A. spinosus specimen, are consistent with secondary loss of AG and FL. By comparing spigots from one stadium to tartipores from the next stadium, silk glands can be divided into those that are tartipore-accommodated (T-A), and thus functional during proecdysis, and those that are not (non-T-A). Though evidence was more extensive in A. spinosus, it was likely true for both species that the number of non-T-A piriform silk glands (PI) was constant (two pairs) through all stadia, while numbers of T-A PI rose incrementally. The two species differed in that A. spinosus had T-A minor ampullate and aciniform silk glands (MiA, AC) that were absent in A. djuka. First instars of A. djuka, however, appeared to retain vestiges of T-A MiA spigots, consistent with a plesiomorphic state in which T-A MiA (called secondary MiA) are present. T-A AC have not previously been observed in Australomimetus and the arrangement of their spigots on posterior lateral spinnerets was unlike that seen thus far in other mimetid genera. Though new AC and T-A PI apparently form throughout much of a spider’s ontogeny, recurring spigot/tartipore arrangements indicated that AC and PI, after functioning during one stadium, were used again in each subsequent stadium (if non-T-A) or in alternate subsequent stadia (if T-A). In A. spinosus, sexual and geographic dimorphisms involving AC were noted. Cylindrical silk gland (CY) spigots were observed in mid-to-late juvenile, as well as adult, females of both species. Their use in juveniles, however, should not be assumed and only adult CY spigots had wide openings typical of mimetids. Neither species exhibited two pairs of modified PI spigots present in some adult male mimetids

Hers and his: Silk glands used in egg sac construction by female spiders potentially repurposed by a \u27modern\u27 male spider

Cylindrical silk gland (CY) spigots distinguish a large clade of modern spiders, the CY spigot clade, which includes all entelegyne spiders and their closest relatives. Following a widespread paradigm, CYs and their spigots are only known to occur in female spiders and they produce silk used in the construction of egg sacs. Here we report the occurrence of a CY spigot or CY nubbin on each posterior median spinneret (PMS) in males (5th stadium and later) of the spider Australomimetus maculosus. Late juvenile males had a CY spigot on each PMS, whereas adult males either had a CY spigot or, more often, a non-functional CY nubbin. This indicates that potential CY use by males is at least largely limited to late juvenile instars and is not involved with egg sac construction. Despite the presence of CY spigots in both sexes, sexual dimorphism with respect to CYs was still evident since males lacked the CY spigot on each posterior lateral spinneret present in late juvenile and adult females, and CY spigots of males never had the wide shaft and opening of adult females. This study adds to our knowledge of spinning apparatus variability in modern spiders and demonstrates an exception to the paradigm that, in the CY spigot clade, such spigots are restricted to female spiders

A new species of Charinus (Amblypygi: Charinidae) from Ghana, with notes on West African whip spiders

The fauna of whip spiders (Amblypygi) in Western Africa is poorly known but probably diverse. Here, I describe the new species Charinus kakum sp. n. based on female morphology, and accompanied by DNA sequence data. The species is small and differs from other African species of Charinus in the low number of pseudosegments on leg IV, female genital features, spination patterns of the pedipalp, and small body size. It was collected from wet tropical rainforest in Kakum National Park, Ghana and is only the fourth species of Charinus to be recorded from the highly diverse Western African biodiversity hotspot. With a total body length of not even 6 mm it is also one of the smallest whip spiders in the world

New records of the great raft spider Dolomedes plantarius in Brandenburg (Araneae: Pisauridae)

The great raft spider, Dolomedes plantarius (Clerck, 1757), is a rare and endangered species in Germany and other European countries. Current data on its distribution and ecology are briefly reviewed. Five new (or overlooked) localities for this spider from the Spreewald-region of Brandenburg in eastern Germany are provided, together with an updated distribution map. One record, based on the authors’ own collections, is described and figured in detail, with the egg-carrying female discovered in reeds at the edge of a fairly large body of open water. Both direct and indirect protective measures for the habitats of this species in the Spreewald-region are recommended

Raising the Dead: Rediscovery and redescription of some lost spider types (Araneae) described by Eugène Simon

In this paper, we are redescribing type material from the Zoological Museum in Hamburg that was thought to be lost. These specimens were described in 1902 by Eugène Simon from material collected in Southern Patagonia and Fireland but the species were subsequently considered nomina dubia, or simply not considered at all. The rediscovery of this material leads to the revalidation of two genera and four species. The genera Clitistes and Zilephus are reinstated and the species Clitistes velutinus Simon, 1902 (Dictynidae), Zilephus granulosus Simon, 1902, Minyriolus australis Simon, 1902 (both Linyphiidae), and Lycosa michaelseni Simon, 1902 (Lycosidae) are redescribed. To avoid further confusion, we designate lectotypes for: Linyphiidae: Minyriolus australis Simon, 1902, Gongylidiellum uschuaiense Simon, 1902, Neriene fuegiana Simon, 1902, Clitistes velutinus Simon, 1902, Zilephus granulosus Simon, 1902; Amphinectidae: Rubrius radulifer Simon, 1902; Hahniidae: Hahnia michaelseni Simon, 1902, Bigois antarctica Simon, 1902 and Lycosidae: Lycosa michaelseni Simon, 1902. For all prior nomina dubia and newly designated lectotypes, the type specimens are re-described and properly illustrated for the first time

Comparative study of spinning field development in two species of araneophagic spiders (Araneae, Mimetidae, Australomimetus)

External studies of spider spinning fields allow us to make inferences about internal silk gland biology, including what happens to silk glands when the spider molts. Such studies often focus on adults, but juveniles can provide additional insight on spinning apparatus development and character polarity. Here we document and describe spinning fields at all stadia in two species of pirate spider (Mimetidae: Australomimetus spinosus, A. djuka). Pirate spiders nest within the ecribellate orb-building spiders (Araneoidea), but are vagrant, araneophagic members that do not build prey-capture webs. Correspondingly, they lack aggregate and flagelliform silk glands (AG, FL), specialized for forming prey-capture lines in araneoid orb webs. However, occasional possible vestiges of an AG or FL spigot, as observed in one juvenile A. spinosus specimen, are consistent with secondary loss of AG and FL. By comparing spigots from one stadium to tartipores from the next stadium, silk glands can be divided into those that are tartipore-accommodated (T-A), and thus functional during proecdysis, and those that are not (non-T-A). Though evidence was more extensive in A. spinosus, it was likely true for both species that the number of non-T-A piriform silk glands (PI) was constant (two pairs) through all stadia, while numbers of T-A PI rose incrementally. The two species differed in that A. spinosus had T-A minor ampullate and aciniform silk glands (MiA, AC) that were absent in A. djuka. First instars of A. djuka, however, appeared to retain vestiges of T-A MiA spigots, consistent with a plesiomorphic state in which T-A MiA (called secondary MiA) are present. T-A AC have not previously been observed in Australomimetus and the arrangement of their spigots on posterior lateral spinnerets was unlike that seen thus far in other mimetid genera. Though new AC and T-A PI apparently form throughout much of a spider’s ontogeny, recurring spigot/tartipore arrangements indicated that AC and PI, after functioning during one stadium, were used again in each subsequent stadium (if non-T-A) or in alternate subsequent stadia (if T-A). In A. spinosus, sexual and geographic dimorphisms involving AC were noted. Cylindrical silk gland (CY) spigots were observed in mid-to-late juvenile, as well as adult, females of both species. Their use in juveniles, however, should not be assumed and only adult CY spigots had wide openings typical of mimetids. Neither species exhibited two pairs of modified PI spigots present in some adult male mimetids

Four new Mouse Spider species (Araneae, Mygalomorphae, Actinopodidae, Missulena) from Western Australia

Four new species of the Mouse Spider genus Missulena Walckenaer, 1805 (family Actinopodidae) are described from Western Australia based on morphological features of adult males. Missulena leniae sp. n. (from the Carnarvon and Yalgoo biogeographic regions), Missulena mainae sp. n. (Carnarvon), Missulena melissae sp. n. (Pilbara) and Missulena pinguipes sp. n. (Mallee) represent a broad spectrum of morphological diversity found in this genus and differ from other congeners by details of the male copulatory bulb, colour patterns, eye sizes, leg morphology and leg spination. Two of the species, M. pinguipes sp. n. and M. mainae sp. n., are characterised by swollen metatarsi of the fourth legs in males, a feature not previously recorded in the family. A key to males of all named Missulena species from Australia is presented and allows their identification based on external morphology

“High Tide or Low Tide”: Desis bobmarleyi sp. n., a new spider from coral reefs in Australia’s Sunshine State and its relative from Sāmoa (Araneae, Desidae, Desis)

Spiders of the genus Desis Walckenaer, 1837 (Araneae: Desidae) are water-adapted spiders and live in the intertidal zone on reefs, marine debris and under rocks. Here, we describe a new intertidal species from tropical Queensland and name it after Bob Marley, whose song “High Tide or Low Tide” inspired us as it lives in a “high tide low tide” habitat. We also re-describe a close morphological relative, Desis vorax L. Koch, 1872 from Sāmoa. This species was described some 150 years ago from the Godeffroy Collection which holds the oldest major collection of Australasian and Pacific spiders, now mainly hosted in the Centre of Natural History in Hamburg (CeNak). A third species, Desis hartmeyeri Simon, 1909, was described from juvenile specimens only and is considered a nomen dubium. “None but ourselves can free our minds.” Bob Marley, Redemption Song (1980)

The Hercules pseudoscorpions from Madagascar: A systematic study of Feaellidae (Pseudoscorpiones: Feaelloidea) highlights regional endemism and diversity in one of the “hottest” biodiversity hotspots

Madagascar is amongst the “hottest” biodiversity hotspots with extreme levels of diversity and endemism. Throughout the last decades, there has been substantial progress in documenting the Malagasy invertebrate fauna but no study has ever focused on pseudoscorpions (Arachnida: Pseudoscorpiones) in the arachnid fauna. Here we review the Malagasy fauna of Hercules pseudoscorpions (family Feaellidae), which are common in soil habitats of arid biomes across Madagascar. Using morphology and molecular data, we recover three reciprocally monophyletic clades that correspond to three new genera in well-defined biogeographical regions and identify twelve new species: Antsiarananaella gen. nov. for Antsirananaella lorenzorum sp. nov., Antsiarananaella leniae sp. nov., Antsiarananaella faulstichi sp. nov. and Antsiarananaella marlae sp. nov.; Mahajanganella gen. nov. for Mahajanganella fridakahloae sp. nov., Mahajanganella heraclis sp. nov. and Mahajanganella schwarzeneggeri sp. nov.; Toliaranella gen. nov. for Toliaranella fisheri sp. nov., Toliaranella griswoldi sp. nov., Toliaranella mahnerti sp. nov., Toliaranella meridionalis sp. nov. and Toliaranella pumila sp. nov. Local endemism in this fauna is high and most species have small distributions, ranging from 20 km to 350 km linearly. Genetic distances between populations are also high, suggesting restricted dispersal or selection against dispersal in this fauna. Species’ ranges seem to be delimited by geological barriers including volcanic fields (Ambre-Bobaomby in the north of Madagascar), mountain ranges (foothills of the Central Highland Plateau), and rivers (Manankolana, Mandrare, Manombo and Onilahy Rivers and their anabranches), but mainly by different biome habitats. Overall, Madagascar emerges as a global “hotspot” of feaellid radiation and these animals may be used in future studies to test biogeographical hypotheses across xeric biomes on this island