Venom Mass Fingerprints for Species Delimitation, Reloaded: A Test Case with Italian Scorpions (Euscorpius)

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  Venom Mass Fingerprints for Species Delimitation, Reloaded: A Test Case with Italian Scorpions (Euscorpius) Abstract Scorpion venoms are complex mixtures of bioactive compounds including proteins, peptides and enzymes. Although venoms exhibit substantial intraspecific variation, some compounds appear to be species-specific, highlighting their potential as chemotaxonomic markers. Venom mass fingerprints (MFPs) derived from Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry (MS) have been proposed as a means of delimiting species. However, their utility for species delimitation has rarely been evaluated against independent sources of taxonomic evidence. In the present study, the performance of MALDI-TOF MS-based venom peptide barcoding (mass ranges of m/z 800‒4500 and m/z 3000‒10,000) was assessed in 52 populations of eight Italian species of the scorpion genus Euscorpius Thorell, 1876, representing different levels of evolutionary divergenc...

Morphology and Chemical Composition of the Nuchal Glands of Indonesian Snakes With a Description of a Novel Type of Glands

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Morphology and Chemical Composition of the Nuchal Glands of Indonesian Snakes With a Description of a Novel Type of Glands

ABSTRACT

Several species of natricine snakes sequester bufadienolides from toads, store them in their nuchal glands, and reutilize them for their defense. This study aimed to examine the presence and morphological features of nuchal glands of natricine snakes distributed in Indonesia, containing several lineages of this group. When the presence of the glands was confirmed, the gland fluids were analyzed to identify their chemical components. Secretions from the parotoid glands of several species of toads in Indonesia were also analyzed. Morphological examination of the glands was conducted by observing the presence or absence of structures and recording the spatial pattern of the glands. The glandular fluids of three snake species and four toad species were extracted and analyzed by liquid chromatography/mass spectrometry (LC/MS). Nuchal glands or organs similar to the glands were found on the head or neck region of preserved or freshly dead specimens of Rhabdophis subminiatus, R. flaviceps, R. rhodomelas, and Rhabdophis spp. of Sulawesi, although such a gland was not found in the other genera of natricine snakes. These Rhabdophis species have different spatial patterns of glands, and particularly Rhabdophis spp. of Sulawesi showed an unusual novel gland form in the temporal and occipital regions of the head, possibly comparable to the nuchal glands. Bufadienolides of the bufogenin and bufotoxin types were identified from all toad gland fluids. In contrast, the glandular fluids of snakes, R. subminiatus, R. flaviceps, and Rhabdophis spp. of Sulawesi store only bufogenin-type bufadienolides. Bufadienolide profiles of snakes and toads indicate that the toxin composition is highly diverse among species. The results suggest that snakes would be able to chemically convert dietary bufadienolides from toads and reutilize some bufadienolides readily. This study demonstrated that the form and location of “nuchal glands” in a snake's body are more diverse than previously recognized.

Anita, S., Inoue, T., Inoue, A., Eto, K., Hamidy, A., Mori, N., & Mori, A. (2025). Morphology and Chemical Composition of the Nuchal Glands of Indonesian Snakes With a Description of a Novel Type of Glands. Journal of Morphology, 286(8), e70071. https://doi.org/10.1002/jmor.70071