Phylogenomics of paleoendemic lampshade spiders (Araneae, Hypochilidae, Hypochilus), with the description of a new species from montane California

Lampshade web spider Ectatosticta davidi chromosome-level genome assembly provides evidence for its phylogenetic position

The spider of Ectatosticta davidi, belonging to the lamp-shade web spider family, Hypochilidae, which is closely related to Hypochilidae and Filistatidae and recovered as sister of the rest Araneomorphs spiders. Here we show the final assembled genome of E. davidi with 2.16 Gb in 15 chromosomes. Then we confirm the evolutionary position of Hypochilidae. Moreover, we find that the GMC gene family exhibit high conservation throughout the evolution of true spiders. We also find that the MaSp genes of E. davidi may represent an early stage of MaSp and MiSp genes in other true spiders, while CrSp shares a common origin with AgSp and PySp but differ from MaSp. Altogether, this study contributes to addressing the limited availability of genomic sequences from Hypochilidae spiders, and provides a valuable resource for investigating the genomic evolution of spiders.

Revision of the western Nearctic spider genus Cybaeina including the description of Neocybaeina gen. nov. and Rothaeina gen. nov. (Araneae: Cybaeidae: Cybaeinae)

This paper is the last in a series revising the Nearctic Cybaeinae spider fauna (Araneae: RTA clade: Cybaeidae) exclusive of Cybaeozyga Chamberlin & Ivie. The forested habitats of the west coast of North America are home to a diverse array of endemic Cybaeinae spider taxa. Many of these have very restricted distributions, especially within an area of the western United States of America from the Olympic Peninsula of northwestern Washington to the northern half of the California Floristic Province of California, a well-known biodiversity hotspot. Here we revise the genus Cybaeina Chamberlin & Ivie recognizing three species: the type species Cybaeus minutus Banks (= Cybaeina minuta (Banks)), C. confusa Chamberlin & Ivie, and a single new species C. dixoni Bennett spec. nov. We describe Neocybaeina Bennett gen. nov. with type species Cybaeina xantha Chamberlin & Ivie (= Neocybaeina xantha (Chamberlin & Ivie) comb. nov.) and a single new species N. burnetti spec. nov. Finally we describe Rothaeina Bennett gen. nov. with type species Cybaeina sequoia Roth (= Rothaeina sequoia (Roth) comb. nov.) and four new species R. beaudini Bennett spec. nov., R. jamesi Bennett spec. nov., R. mackinleyi Bennett spec. nov., and R. petersoni Bennett spec. nov. In addition to descriptions of the genera and both sexes of their included species (except for N. burnetti spec. nov. and R. beaudini Bennett spec. nov. which are known from females only), we provide diagnoses, illustrations, distribution maps, and, for the three species of Cybaeina and the five of Rothaeina gen. nov., identification keys. In closing, we discuss conservation implications for this cryptic and infrequently collected group of western Nearctic Cybaeinae, several of which are short-range endemic species.

DNA barcodes reveal population-dependent cryptic diversity and various cases of sympatry of Korean leptonetid spiders (Araneae: Leptonetidae)

Leptonetidae are tiny, rarely encountered spiders that mainly inhabit moist environments, such as caves, leaf litter, and rock piles. Because they are microhabitat specialists, most leptonetid species have short-range endemism, and rarely occur in sympatry. Their small size, relatively simple habitus features and reproductive organ structure increase the difficulty of identification. The identification of leptonetids and other spiders may also be time-consuming due to their sexual dimorphism, polymorphism, and lack of diagnostic characteristics in juveniles. DNA barcoding has been used as an effective tool for species identification to overcome these obstacles. Herein, we conducted a test of DNA barcoding based on 424 specimens of Korean Leptonetidae representing 76 morphospecies. A threshold of 4.2% based on maximum intraspecific genetic divergence was estimated to efficiently differentiate the morphospecies. The species assignments tested by five species delimitation methods (ABGD, ASAP, GMYC, PTP, and bPTP) were consistent with the morphological identifications for only 47 morphospecies (61.8%), indicating many cases of cryptic diversity among the remaining morphospecies. Furthermore, sympatry in leptonetids, which are known to be rare, was revealed to be common in South Korea, especially in epigean species. Our results showed that sympatries within families, congeners, and intraclades potentially occur throughout the entire region of Korea.