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...

In Memoriam: Giraldo Alayón García

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In Memoriam: Giraldo Alayón García - Photo © Facebook/National Museum of Natural History of Cuba

In Memoriam: Giraldo Alayón García

The arachnological community mourns the loss of Giraldo Alayón García, a Cuban zoologist whose work helped bring the spiders of Cuba and the wider Caribbean into clearer scientific view.

As a researcher and curator at Cuba’s National Museum of Natural History, Dr. Alayón devoted decades to studying arachnids. His publications on spider taxonomy, evolution, and biogeography gave other researchers a stronger foundation for understanding the region’s biodiversity. He also shared that knowledge through teaching and scientific exchange far beyond Cuba.

For those of us who care about taxonomy, his legacy is a reminder of the patient work behind every species description: examining specimens, recording differences, and preserving knowledge that others can build upon. His contributions will continue to guide the study of Caribbean spiders for years to come.

Arácnido Taxonomy extends its condolences to Dr. Alayón’s family, friends, colleagues, and the many people who learned from his work. May he rest in peace.

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En memoria de Giraldo Alayón García

La comunidad aracnológica lamenta la pérdida de Giraldo Alayón García, zoólogo cubano cuyo trabajo contribuyó a ampliar el conocimiento científico sobre las arañas de Cuba y del Caribe.

Como investigador y curador del Museo Nacional de Historia Natural de Cuba, el Dr. Alayón dedicó décadas al estudio de los arácnidos. Sus publicaciones sobre taxonomía, evolución y biogeografía de las arañas sentaron bases para quienes continúan investigando la biodiversidad de la región. También compartió sus conocimientos mediante la enseñanza y el intercambio científico dentro y fuera de Cuba.

Para quienes valoramos la taxonomía, su legado nos recuerda el trabajo paciente que hay detrás de cada descripción de una especie: examinar ejemplares, documentar sus diferencias y preservar conocimientos sobre los que otros podrán construir. Sus contribuciones seguirán acompañando el estudio de las arañas del Caribe durante muchos años.

Desde Arácnido Taxonomy, expresamos nuestras condolencias a su familia, amistades, colegas y a todas las personas que aprendieron de su trabajo. Que en paz descanse.