First evidence of aggressive chemical mimicry in the Malagasy orb weaving spider <i>Exechocentrus lancearius</i> Simon, 1889 (Arachnida: Araneae: Araneidae) and description of a second species in the genus

The araneid genus Exechocentrus Simon, 1889 and its type species Exechocentrus lancearius were originally described based on a single female specimen from Madagascar, which was missing the abdomen. The first complete adult specimen, a female, of Excechocentrus lancearius was collected in 2000. A second adult female of Excechocentrus sp. was discovered in 2009, about 300 km away from the first locality. We redescribe the neotype of Exechocentrus lancearius and describe the second adult female as Exechocentrus madilina new species. We also report some observations on the natural history of Exechocentrus lancearius, including photographs of its highly modified foraging web, which provide indirect evidence of aggressive chemical mimicry

Spider genus Atimiosa Simon, 1895.

19 p. : ill. ; 26 cm. "March 4, 2010." Includes bibliographical references (p. 17).The genus Atimiosa Simon, 1895, is a junior synonym of Dolichognatha O. P.-Cambridge, 1869. This synonymy is strongly supported by cladistic analyses of morphological characters and examination of types of all known Atimiosa species. Two new combinations resulted from this nomenclatural change, Dolichognatha comorensis (Schmidt and Krause, 1993), new combination, and Dolichognatha quinquemucronata (Simon, 1895), new combination. New illustrations and photographs of these two species and of the poorly known Dolichognatha longiceps (Thorell, 1895) are provided. We also describe for the first time the web architecture of D. longiceps

Monophyly, Taxon Sampling, and the Nature of Ranks in the Classification of Orb-Weaving Spiders (Araneae: Araneoidea)

Under embargo until: 2020-07-11We address some of the taxonomic and classification changes proposed by Kuntner et al. (2019) in a comparative study on the evolution of sexual size dimorphism in nephiline spiders. Their proposal to recircumscribe araneids and to rank the subfamily Nephilinae as a family is fundamentally flawed as it renders the family Araneidae paraphyletic. We discuss the importance of monophyly, outgroup selection, and taxon sampling, the subjectivity of ranks, and the implications of the age of origin criterion to assign categorical ranks in biological classifications. We explore the outcome of applying the approach of Kuntner et al. (2019) to the classification of spiders with emphasis on the ecribellate orb-weavers (Araneoidea) using a recently published dated phylogeny. We discuss the implications of including the putative sister group of Nephilinae (the sexually dimorphic genus Paraplectanoides) and the putative sister group of Araneidae (the miniature, monomorphic family Theridiosomatidae). We propose continuation of the phylogenetic classification put forth by Dimitrov et al. (2017), and we formally rank Nephilinae and Phonognathinae as subfamilies of Araneidae. Our classification better reflects the understanding of the phylogenetic placement and evolutionary history of nephilines and phonognathines while maintaining the diagnosability of Nephilinae. It also fulfills the fundamental requirement that taxa must be monophyletic, and thus avoids the paraphyly of Araneidae implied by Kuntner et al. (2019).acceptedVersio

Interrogating genomic-scale data to resolve recalcitrant nodes in the Spider Tree of Life

Genome-scale data sets are converging on robust, stable phylogenetic hypotheses for many lineages; however, some nodes have shown disagreement across classes of data. We use spiders (Araneae) as a system to identify the causes of incongruence in phylogenetic signal between three classes of data: exons (as in phylotranscriptomics), noncoding regions (included in ultraconserved elements [UCE] analyses), and a combination of both (as in UCE analyses). Gene orthologs, coded as amino acids and nucleotides (with and without third codon positions), were generated by querying published transcriptomes for UCEs, recovering 1,931 UCE loci (codingUCEs). We expected that congeners represented in the codingUCE and UCEs data would form clades in the presence of phylogenetic signal. Noncoding regions derived from UCE sequences were recovered to test the stability of relationships. Phylogenetic relationships resulting from all analyses were largely congruent. All nucleotide data sets from transcriptomes, UCEs, or a combination of both recovered similar topologies in contrast with results from transcriptomes analyzed as amino acids. Most relationships inferred from low-occupancy data sets, containing several hundreds of loci, were congruent across Araneae, as opposed to high occupancy data matrices with fewer loci, which showed more variation. Furthermore, we found that low-occupancy data sets analyzed as nucleotides (as is typical of UCE data sets) can result in more congruent relationships than high occupancy data sets analyzed as amino acids (as in phylotranscriptomics). Thus, omitting data, through amino acid translation or via retention of only high occupancy loci, may have a deleterious effect in phylogenetic reconstruction.publishedVersio

Monophyly, taxon sampling, and the nature of ranks in the classification of orb-weaving spiders (Araneae: Araneoidea)

We address some of the taxonomic and classification changes proposed by Kuntner et al. (2019) in a comparative study on the evolution of sexual size dimorphism in nephiline spiders. Their proposal to recircumscribe araneids and to rank the subfamily Nephilinae as a family is fundamentally flawed as it renders the family Araneidae paraphyletic. We discuss the importance of monophyly, outgroup selection, and taxon sampling, the subjectivity of ranks, and the implications of the age of origin criterion to assign categorical ranks in biological classifications. We explore the outcome of applying the approach of Kuntner et al. (2019) to the classification of spiders with emphasis on the ecribellate orb-weavers (Araneoidea) using a recently published dated phylogeny. We discuss the implications of including the putative sister group of Nephilinae (the sexually dimorphic genus Paraplectanoides) and the putative sister group of Araneidae (the miniature, monomorphic family Theridiosomatidae). We propose continuation of the phylogenetic classification put forth by Dimitrov et al. (2017), and we formally rank Nephilinae and Phonognathinae as subfamilies of Araneidae. Our classification better reflects the understanding of the phylogenetic placement and evolutionary history of nephilines and phonognathines while maintaining the diagnosability of Nephilinae. It also fulfills the fundamental requirement that taxa must be monophyletic, and thus avoids the paraphyly of Araneidae implied by Kuntner et al. (2019)

Hispaniolan spiders

21 p. : ill. ; 26 cm.Includes bibliographical references (p. 20-21).A new species of ochyroceratid spider, Ochyrocera cachote, n.sp., is described and its unique web architecture is documented. This is the first record of Ochyroceratidae for the extant fauna of Hispaniola. Additional new family records include Symphytognathidae (Patu sp. and Symphytognatha sp.) and Mysmenidae (Microdipoena sp.), with the latter family having been previously recorded from the fossil amber fauna. This makes a new total of 46 spider families recorded from the extant Hispaniolan fauna, but on the whole the island's araneofauna remains poorly known and warrants further investigation

Opopaea.

156 pages : illustrations, maps ; 26 cm. Part of the Goblin Spider Planetary Biodiversity Inventory (http://research.amnh.org/oonopidae/)The Opopaea fauna of Madagascar is documented for the first time. There are 27 species of Opopaea on the island of which 26 are newly described here and 25 are apparently endemic to Madagascar: Opopaea andranomay, n. sp., O. ankarafantsika, n. sp., O. ankarana, n. sp., O. antsalova, n. sp., O. andringitra, n. sp., O. antsiranana, n. sp., O. bemarivo, n. sp., O. bemaraha, n. sp., O. berenty, n. sp., O. betioky, n. sp., O. itampolo, n. sp., O. kirindy, n. sp., O. manderano, n. sp., O. mahafaly, n. sp., O. manongarivo, n. sp., O. namoroka, n. sp., O. sandranantitra, n. sp., O. torotorofotsy, n. sp., O. tsimaloto, n. sp., O. tsimbazaza, n. sp., O. tsimembo, n. sp., O. tsinjoriaky, n. sp., O. tsingy, n. sp., O. vohibazaha, n. sp., O. foulpointe, n. sp. and O. maroantsetra, n. sp. (shared with Kenya and the Comoros Islands), and O. concolor (Blackwall, 1859), a cosmopolitan species. All species are described and illustrated. An identification key to the species and maps of their distribution in Madagascar are also provided