Two new arthropod toxins purified from the venom of the Mexican scorpion Centruroides nigrescens

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  Two new arthropod toxins purified from the venom of the Mexican scorpion Centruroides nigrescens Abstract The venom of the slender black scorpion Centruroides nigrescens , from the State of Guerrero México, was fractionated by Sephadex G–50 gel filtration, followed by carboxymethyl cellulose ion separation and high–performance liquid chromatography, permitting to obtain two new peptides toxic to arthropods. The estimate LD 50 of the soluble venom for the insect Acheta domesticus was 11.1 μg/g body weight, and for the arthropod Armadillidium vulgare was 61.1 μg body weight . The amino acid sequence of toxin Cnige1 (toxic to A. domesticus and A. vulgare ) contains 65 amino acids, with a molecular mass of 7273.37 mass units, whereas toxin Cnige2, toxic to A. domesticus , contains 68 amino acids, with a molecular mass of 7548.81 units. Both peptides are well packed, containing 8 cysteines, which in the native venoms are forming 4 disulfide bridges each. The amino acid sequences f...

Multiple origins and complex evolutionary history of Cryptops centipedes (Chilopoda: Scolopendromorpha: Cryptopidae) inhabiting East Asian islands, with systematics of Japanese species

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Multiple origins and complex evolutionary history of Cryptops centipedes (Chilopoda: Scolopendromorpha: Cryptopidae) inhabiting East Asian islands, with systematics of Japanese species

Abstract

Cryptops Leach, 1814 is a genus of generally small, blind centipedes that mostly inhabit epigean habitats. With more than 150 species described worldwide, Cryptops is one of the most widespread and speciose genera within the class Chilopoda. Although previous studies have indicated a complex evolutionary history, the biogeography of Cryptops species largely remains unclear owing to a lack of molecular data from some regions such as the easternmost part of Asia. Moreover, the taxonomic status of several species from this region also remains uncertain. In this study, we addressed systematics and phylogeography of Cryptops species from East Asian islands, mainly the Japanese Archipelago and the Ryukyu Islands. Here, based on molecular phylogeny of nuclear and mitochondrial loci as well as morphology, we reexamined the taxonomic accounts of C. japonicus Takakuwa, 1934, C. navis Chamberlin, 1930, and C. striatus Takakuwa, 1936, and describe a new species, Cryptops dupliporussp. nov. Molecular phylogenetic and dating analyses showed that the East Asian species are non-monophyletic, originating from at least three independent lineages. The analyses also showed significant differences in the degree of intraspecific divergence among species, presumably reflecting different dispersal abilities and colonization histories to the East Asian islands. Our results indicate that the species richness of Cryptops on East Asian islands is an outcome of ancient relics of continental origin as well as recent radiation, possibly through colonization from southwestern Pacific islands by oceanic currents.

Cryptops is one of the most widespread and speciose genera of centipedes, but its evolutionary history remains unclear owing to insufficient biogeographic and systematic studies. This study clarifies the systematic status of four East Asian species of Cryptops, including a new species. Molecular analyses show that these species originated from at least three divergences, revealing both continental relict and recently colonized lineages. This study demonstrates complex spatial and temporal processes shaping species diversity and distributions, which may be common in centipedes.

Taro Jonishi, Takafumi Nakano "Multiple origins and complex evolutionary history of Cryptops centipedes (Chilopoda: Scolopendromorpha: Cryptopidae) inhabiting East Asian islands, with systematics of Japanese species," Invertebrate Systematics, 40(8), 1-32, (28 August 2026) https://doi.org/10.1071/IS26025