RESUMEN

A new troglobitic species of Chelodesmidae, Cayenniola albaserratan. sp., from the Água Clara cave system, Caatinga Domain, Bahia, Brazil is described. The new species is only the sixth known troglobitic chelodesmid, the first troglobitic species in the Priodesmini, and the first member of the tribe recorded from the state of Bahia. Unique among the Priodesmini, male C. albaserratan. sp. possess greatly elongated pre-gonopodal tarsal claws and differ from the only congener, Cayenniola styliger (Jeekel, 1963),by a combination of gonopodal and somatic characters including classical troglomorphic traits such as a nearly unpigmented body and remarkably long antennae, legs, and tarsal claws. Cayenniola styliger is only known from the type locality in the Amazon rainforest of coastal French Guiana, suggesting that C. albaserratan. sp. may represent a relictual species from the Caatinga Domain of Brazil. We provide ecological notes and evaluate the potential threats to the habitat of C. albaserratan. sp., considering both the subterranean environment and the surrounding areas.

RESUMEN

Abstract Somatic characters are shared by many Chelodesmidae groups, and generic placement and species identifications traditionally have been based on gonopodal morphology. Female genitalic characters have been largely neglected and are rarely photographed or illustrated. This is rather unfortunate as the morphology of female genitalia presents important characters and may be decisive for developing a more robust family classification. We describe the heretofore unknown female of Sandalodesmus araujoi (Schubart, 1946), previously known only from the male holotype collected in São Paulo, Brazil in December 1943; discuss the utility of female genitalic characters for species delineation in Sandalodesmus; and report the first case of a mass occurrence in the Chelodesmidae. While an attempt at a formal diagnosis of Sandalodesmus females based on genitalic characters is premature, the vulvar morphology of the three taxa examined in this study suggests that female genitalia are species-specific. Some characters (i.e., asymmetric valves, presence of digitiform projections and reduction of setae on the internal basal portion of the valves) are constant between the species, suggesting utility for generic-level delineation. Mass occurrences of millipedes are typically unpredictable and likely related to variations in environmental conditions and/or anthropogenic modifications of natural habitats. Although the mass occurrence of S. araujoi reported herein was only observed once, the event coincides with the mating period of millipedes during the rainy season in Brazil. On the other hand, the region where the species was found has been the target of intense urban development, including replacement of natural habitats with residential areas, which may have influenced its population dynamics.

Resumo Os caracteres somáticos são compartilhados por muitos grupos de Chelodesmidae, e o posicionamento genérico e as identificações de espécies tradicionalmente têm sido baseadas na morfologia do gonópodo. Carateres genitais das fêmeas foram amplamente negligenciados e raramente são fotografados ou ilustrados. Isso é lamentável, pois a morfologia da genitália feminina apresenta características importantes e pode ser decisiva para o desenvolvimento de uma classificação mais robusta. Neste trabalho, descrevemos a até então desconhecida fêmea de Sandalodesmus araujoi (Schubart, 1946), anteriormente conhecida apenas pelo holótipo macho coletado em São Paulo, Brasil, em dezembro de 1943; discutimos a utilidade de caracteres genitais femininos para delineamento de espécies em Sandalodesmus; e relatamos o primeiro caso de ocorrência em massa para Chelodesmidae. Embora uma tentativa de diagnose formal para fêmeas de Sandalodesmus com base em caracteres genitais seja prematura, a morfologia vulvar dos três táxons examinados neste estudo, sugere que a genitália feminina é espécie-específica. Alguns caracteres (e.g. válvulas assimétricas, presença de projeções digitiformes e redução de cerdas na margem interna das válvas) são constantes entre as espécies do gênero, sugerindo utilidade para delineamento em nível genérico. Ocorrências em massa de milípedes são tipicamente imprevisíveis e provavelmente relacionadas a variações nas condições ambientais e/ou modificações antropogênicas de habitats naturais. Embora a ocorrência em massa de S. araujoi aqui relatada tenha sido observada apenas uma vez, o evento coincide com o período de reprodução dos milípedes durante a estação chuvosa no Brasil. Por outro lado, a região onde a espécie foi encontrada tem sido alvo de intenso desenvolvimento urbano, incluindo substituição de habitats naturais por áreas residenciais, o que pode ter influenciado sua dinâmica populacional.

RESUMEN

Somatic characters are shared by many Chelodesmidae groups, and generic placement and species identifications traditionally have been based on gonopodal morphology. Female genitalic characters have been largely neglected and are rarely photographed or illustrated. This is rather unfortunate as the morphology of female genitalia presents important characters and may be decisive for developing a more robust family classification. We describe the heretofore unknown female of Sandalodesmus araujoi (Schubart, 1946), previously known only from the male holotype collected in São Paulo, Brazil in December 1943; discuss the utility of female genitalic characters for species delineation in Sandalodesmus; and report the first case of a mass occurrence in the Chelodesmidae. While an attempt at a formal diagnosis of Sandalodesmus females based on genitalic characters is premature, the vulvar morphology of the three taxa examined in this study suggests that female genitalia are species-specific. Some characters (i.e., asymmetric valves, presence of digitiform projections and reduction of setae on the internal basal portion of the valves) are constant between the species, suggesting utility for generic-level delineation. Mass occurrences of millipedes are typically unpredictable and likely related to variations in environmental conditions and/or anthropogenic modifications of natural habitats. Although the mass occurrence of S. araujoi reported herein was only observed once, the event coincides with the mating period of millipedes during the rainy season in Brazil. On the other hand, the region where the species was found has been the target of intense urban development, including replacement of natural habitats with residential areas, which may have influenced its population dynamics.

Os caracteres somáticos são compartilhados por muitos grupos de Chelodesmidae, e o posicionamento genérico e as identificações de espécies tradicionalmente têm sido baseadas na morfologia do gonópodo. Carateres genitais das fêmeas foram amplamente negligenciados e raramente são fotografados ou ilustrados. Isso é lamentável, pois a morfologia da genitália feminina apresenta características importantes e pode ser decisiva para o desenvolvimento de uma classificação mais robusta. Neste trabalho, descrevemos a até então desconhecida fêmea de Sandalodesmus araujoi (Schubart, 1946)

RESUMEN

The chelodesmid genus Dibolostethus Hoffman, 2009, the sole member of the tribe Dibolostethini, is reviewed. The genus contains the type species D. sicarius Hoffman, 2009 known only from the Los Rios Province, Ecuador, and two new species from the Tropical Andes, D. inopinatus Means, Bouzan & Ivanov sp. nov. from the Morona-Santiago Province, Ecuador and D. kattani Means, Bouzan, Martínez-Torres & Ivanov sp. nov. from the Valle del Cauca Department, Colombia. We redescribe D. sicarius and provide a revised diagnosis of the genus, images of diagnostic morphological characters, and a key to the males of Dibolostethus. In addition, we provide a summary and a distribution map of the Chelodesmidae of the Tropical Andes Biodiversity Hotspot.

RESUMEN

Millipedes are well-known for their limited dispersal abilities with species restricted to mountains, islands, and patches of forest being important models for formulating and testing biogeographic hypotheses. The order Spirostreptida is composed of nearly 1300 species distributed across the Afrotropical, Oriental, and Neotropical regions. The order is divided into the suborders Cambalidea and Spirostreptidea with the families Pseudonannolenidae (Cambalidea) and Spirostreptidae (Spirostreptidea) occurring in Brazil. To date, there have been no studies on the biogeography of Neotropical Spirostreptida. We employed a multi-approach analysis with Parsimony Analysis of Endemicity, Endemicity Analysis, and Infomap, to detect areas of endemism and patterns of distribution of the order in Brazil. Six areas of endemism are proposed for the 133 Brazilian species: Northern Serra Geral, Southeastern mountain ranges, Cerrado and Atlantic Forest zone, Eastern Cerrado and Serra do Espinhaço, Pantanal, and Southern Amazon and Cerrado zone. Most endemic areas fall within the Atlantic Forest, which has been previously shown to be an important area of endemism for many invertebrate taxa. The richest biomes are the Atlantic Forest with 75 species and the Cerrado with 55 species, while the least rich biomes are the Caatinga with six species and the Pampa with three species. Although the southeastern region of Brazil has the highest species richness, it also has the highest concentration of threatened species. Based on International Union for Conservation of Nature (IUCN) criteria, most Brazilian Spirostreptida are either endangered or critically endangered, with the highest concentration of endangered taxa occurring in the Atlantic Forest biome.

RESUMEN

This study concerns the millipede genus Leptherpum Attems, 1931, which contains nine valid species distributed across the Amazonian rainforest of northeastern South America. The type species L. carinovatum (Attems, 1898) is reexamined based on the type material and high-resolution photographs, including the first scanning electron micrographs of this species. The following three new species are described: Leptherpum tialaura sp. nov. from the state of Pará, Brazil; Leptherpum battirolai sp. nov. from the state of Amazonas, Brazil; and Leptherpum buenovillegasi sp. nov. from the commune of Maripasoula, French Guiana. A brief review of Leptherpum taxonomy and geographic distribution is provided, along with a key to males.

Asunto(s)

RESUMEN

This study concerns the millipede genus Leptherpum Attems, 1931, which contains nine valid species distributed across the Amazonian rainforest of northeastern South America. The type species L. carinovatum (Attems, 1898) is reexamined based on the type material and high-resolution photographs, including the first scanning electron micrographs of this species. The following three new species are described: Leptherpum tialaura sp. nov. from the state of Pará, Brazil; Leptherpum battirolai sp. nov. from the state of Amazonas, Brazil; and Leptherpum buenovillegasi sp. nov. from the commune of Maripasoula, French Guiana. A brief review of Leptherpum taxonomy and geographic distribution is provided, along with a key to males.

RESUMEN

Chelodesmidae is one of the most species rich families within the Myriapoda. However, little is known regarding their association with caves. We provide a list of all Chelodesmidae taxa reported from caves, map their worldwide distribution, and discuss the troglomorphic features of the group. A total of 25 species and subspecies from 20 genera and 2 subfamilies have been recorded from 59 caves and cave systems in 11 countries. These numbers represent a surprisingly modest proportion (~3%) of the approximately 800 described species in the family. Records of cave-dwelling chelodesmids appear to be geographically biased with most taxa reported from the Neotropics, likely due to the greater diversity of the group in the region. The lack of published records from the Afrotropics can undoubtedly be attributed to low sampling efforts. In addition, many studies focusing on cave invertebrates, especially in the tropics, often fail to identify chelodesmid taxa to the species level, thus precluding their inclusion on checklists. The majority of the Chelodesmidae reported from caves do not display obvious adaptations to a subterranean lifestyle and are not troglomorphic. The five troglobitic taxa indicated in this study may represent relictual lineages suggesting that few, if any, radiations of chelodesmids within caves have occurred in the past. Increased efforts are needed to bridge the gap between our current understanding and the true diversity of the group in these fragile and threatened habitats, which is necessary to allow policy makers to prioritize appropriate and effective conservation efforts, including the protection of environments severely impacted by human activities.