Description of a new genus and five new species of tube-dwelling spider family Segestriidae (Araneae: Synspermiata) from Odisha, India.

The six-eyed spider family Segestriidae is poorly documented from India, with only five species belonging to two genera. Here we describe a new genus, Indoseges gen. nov. with five new spp. viz. I. malkhangiri sp. nov., I. sushildutta sp. nov., I. chilika sp. nov., I. narayani sp. nov. and I. satkosia sp. nov. from Odisha. The first two spp. are described based on both male and female specimens and the rest on females only. The new genus resembles the genus Ariadna Audouin, 1826; still, males differ with respect to first leg spines, shape and position of apophysis and in the palp structure, and females having distinct spination in palp tarsi and femur of first two legs, and in the genitalia structure. Along with a distribution map of the Segestriids of India this paper also provides natural history information about the new genus, a discussion on its relationship with Ariadna, and the putative synapomorphies that define its placement in the subfamily Ariadninae.

The taxonomy of the American Ariadna Audouin (Araneae: Synspermiata: Segestriidae).

The spider genus Ariadna Audouin, 1826 currently comprises 102 of 127 described species of Segestriidae. Its distribution comprises all continents (except Antarctica), but it is mostly found on the tropical and subtropical regions. We present a comprehensive taxonomic revision of Ariadna in the American continent, including 2,519 specimens (i.e., type and non-type) from 30 arachnological collections. We present 31 nominal species, among which eight species are new to the science: Ariadna reginae n. sp. from Central America; Ariadna aurea n. sp., Ariadna caparao n. sp., Ariadna gaucha n. sp., Ariadna ipojuca n. sp., Ariadna lemosi n. sp. and Ariadna ubajara n. sp. from Brazil; and Ariadna lalen n. sp. from Chile. Nine species are proposed as junior synonyms: A. pragmatica Chamberlin, 1924 and A. scholastica Chamberlin, 1924 with A. bicolor (Hentz, 1842), A. gracilis Vellard, 1924 and A. conspersa Mello-Leitão, 1941 with A. obscura (Blackwall, 1858), A. murphyi (Chamberlin, 1920) with A. tarsalis Banks, 1902, A. pusilla (Nicolet, 1849) and A. ashantica Strand, 1916 with A. maxima (Nicolet, 1849), A. dubia Mello-Leitão, 1917 with A. boliviana Simon, 1907, and A. spinifera Mello-Leitão, 1947 with A. mollis (Holmberg, 1876). Ariadna comata O. P.-Cambridge, 1898 is revalidated. Two species became nomina dubia: Ariadna solitaria Simon, 1892 and A. tubicola Simon, 1893. The allotype of A. crassipalpa described by Camargo (1950) and the paratype of A. levii described by Grismado (2008), were identified as A. mollis and A. maxima, respectively and have been considered as misidentifications. The male of A. cephalotes and A. comata, and the female of A. calilegua are described for the first time.

Revision of the spider genus Gippsicola Hogg, 1900 (Araneae: Segestriidae).

Gippsicola Hogg is one of the four genera included in the family Segestriidae. Currently this monotypic Australian genus is represented by Gippsicola raleighi Hogg, 1900, a species described based on an immature specimen from Victoria, Australia. In this work we present a taxonomic revision of this genus, with an elucidative diagnosis, redescribing G. raleighi based on detailed morphologic characters of adult male specimens. Also, we are describing three new species: Gippsicola robusta n. sp. and G. lineata n. sp., both represented by males and females, and G. minuta n. sp., only known by the male. We provide some enlightenment on the systematics of Gippsicola and putative synapomorphies for the subfamily Segestriinae.

Revalidation of the spider genus Citharoceps Chamberlin, 1924 (Araneae, Segestriidae).

Citharoceps Chamberlin was diagnosed by the presence of a very distinctive stridulatory apparatus composed of two patches of ridges on the sides of the cephalic region, and a stridulatory thorn on the prolateral region of the femur I. Currently, this genus is a junior synonym of Ariadna Audouin, with the assumption that the stridulatory apparatus could constitute an exclusive feature of its unique known species, Citharocepsfidicina Chamberlin, currently senior synonym of Citharocepscalifornica Chamberlin & Ivie. In the present study, Citharoceps is revalidated and redescribed based on the occurrence of the stridulatory apparatus in Citharocepsfidicina and Segestriacruzana Chamberlin & Ivie, and also on the presence of distinguishable characters, such as the length of the labium-sternum junction, ventral median spine on male metatarsi I, and strong sclerotized interpulmonary fold in females, forming a conspicuous median flap. Segestriacruzana is transfered to Citharoceps, with Citharocepscalifornica removed from the synonym of Citharocepsfidicina, and proposed as a junior synonym of Citharocepscruzana, due to the similarity between the additional material examined and the original description. Males of Citharocepsfidicina and Citharocepscruzana are described for the first time.

Comparative cytogenetics of seven Ctenidae species (Araneae).

The present study elevates the number of cytogenetically analyzed ctenid species and genera from two to eight and six, respectively, presenting comparisons between chromosomal data obtained and the phylogenetic hypothesis proposed in the literature. Six ctenid species presented 13 autosomal pairs, exhibiting either X1X2O (Ctenus ornatus, Ctenus sp., Parabatinga brevipes and Phoneutria nigriventer) or X1X2X3O sex chromosome systems (Nothroctenus sp. and Viracucha andicola). Asthenoctenus borellii showed 2n ♂ = 20 + X1X2O. In all species, the chromosomes were telocentric. Some cells of one C. ornatus specimen exhibited one extra chromosome that, considering the behavioral similarities between the two chromosomes, can be considered to be supernumerary, derived from or giving rise to a sex chromosome. Silver impregnation revealed nucleolar organizer regions on one autosomal pair of C. ornatus and P. nigriventer (Cteninae) and two pairs of V. andicola (Acanthocteninae). Chromosomal data suggests that the X1X2X3O system arose several times in the evolution of entelegyne spiders, and that conversion of an X1X2O system into an X1X2X3O system and vice-versa has been a relatively common event in spiders. All the chromosomal data corroborate the close relationship between Ctenus and Phoneutria, the placement of P. brevipes within Cteninae, the placement of Anahita in a separated branch within Cteninae, and the inclusion of A. borellii in a distinct group within the ctenids (Viridasiinae), all of which are as proposed by phylogenetic hypotheses available in the literature.