ECOLOGICAL NICHE MODELS BY TITYUS SERRULATUS LUTZ & MELLO, 1922 AND TITYUS STIGMURUS (THORELL, 1876) (ARACHNIDA: SCORPIONES)

Posted by
  ECOLOGICAL NICHE MODELS BY TITYUS SERRULATUS LUTZ & MELLO, 1922 AND TITYUS STIGMURUS (THORELL, 1876) (ARACHNIDA: SCORPIONES) Summary Scorpions are venomous animals with high plasticity and can serve as models for biogeographical, natural history, and evolutionary studies. Ecological niche modeling can help in understanding essential characteristics of the geographic distribution of species, as well as allowing the prediction of future distribution patterns. Our objective was to model the ecological niche of the scorpion species *Tityus serrulatus * and *Tityus stigmurus* , as well as to identify the variables that influence their distribution in different biomes and their range limits in the Amazon, Caatinga, and Cerrado biomes. Data were obtained from 12 Brazilian arachnological collections. Bioclimatic variables were obtained from the WorldClim database, and niche modeling was implemented using the Maximum Entropy algorithm. The results showed that the Atlantic Forest bio...

Silk gland morphology of the net-casting spider Deinopis spinosa

Posted by


 Silk gland morphology of the net-casting spider Deinopis spinosa

Net-casting spiders (Deinopidae) are cribellate spiders that spin a rectangular, sticky net that is held stretched between the claws of their first two pairs of legs. Deinopids produce eight distinct silk types, but knowledge of the silk-producing morphologies is mostly limited to the spigots associated with different fibers. As there have been no studies of deinopid silk gland structure, we dissected all the silk glands from Deinopis spinosa and document their number and morphology. We found silk gland position and morphology consistent with the type and number of silk spigots described for Deinopidae. Notably, for the first time, we describe the silk glands associated with cribellate silk: paracribellate, pseudoflagelliform, and cribellar silk glands. Our findings support the homology of pseudoflagelliform glands with araneoid flagelliform glands and will have importance for informing our understanding of spider web evolution.


Sandra M Correa-Garhwal, Jay Stafstrom, Richard H. Baker et al. Silk gland morphology of the net-casting spider Deinopis spinosa, 11 October 2023, PREPRINT (Version 1) available at Research Square [https://doi.org/10.21203/rs.3.rs-3420193/v1]