Big Spider, Big Genome: Chromosome-level genome of a North American tarantula (Aphonopelma marxi) and comparative genomics across 300 million years of spider evolution

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  Image Credit: WikiCommons Big Spider, Big Genome: Chromosome-level genome of a North American tarantula (Aphonopelma marxi) and comparative genomics across 300 million years of spider evolution Abstract The comparison of chromosome-level genomes allows biologists to investigate new axes of organismal evolution. Spiders comprise a significant proportion of known arachnid diversity, with many complex morphologies and unique natural histories, yet comparative genomics in spiders has been limited due to the number of available genomes. We present a de novo chromosomal reference genome of a mature male tarantula, Aphonopelma marxi, and comparatively examine spider genome evolution across the Order Araneae. Using PacBio HiFi and Hi-C sequencing, the final 6.5 Gb assembly consists of 17 autosomes, 1 X chromosome, and 127 unplaced scaffolds, with an N50 of 370 Mb and Arachnida (odb10; 2934 genes) BUSCO of 96.7%. By comparing 20 additional spider genomes from 15 families, we find mygalomo...

Abdominal pattern polymorphism and distribution of the giant golden orb-weaving spider, Nephila pilipes (Fabricius, 1793) (Araneae: Araneidae), in the Philippines

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Abdominal pattern polymorphism and distribution of the giant golden orb-weaving spider, Nephila pilipes (Fabricius, 1793) (Araneae: Araneidae), in the Philippines

Abstract 
The giant golden orb-weaving spider, Nephila pilipes (Fabricius, 1793), is notable for its color polymorphism. Here, we report the pattern polymorphism of this species. A Nephila species with unusual abdominal patterning from the Philippines is confirmed herein as N. pilipes based on its somatic structures and genitalia. The abdominal pattern consists of rows of subquadrate yellow spots on the dorsum, which is distinct from the typical longitudinal yellow stripes in N. pilipes. We provided the distribution of the spotted variant based on citizen science data on the internet, suggesting that this particular variation may be regionally endemic in the Philippines. Keywords: aposematism, arachnids, citizen science, intraspecific variation, Nephilinae. 


Acuña, Darrell & Maglangit, Erl Pfian & Santiago, Myla & Guevarra Jr, Leonardo. (2025). Abdominal pattern polymorphism and distribution of the giant golden orb-weaving spider, Nephila pilipes (Fabricius, 1793) (Araneae: Araneidae), in the Philippines. Philippine Journal of Systematic Biology. 18. AZ-BB. 10.26757/pjsb202418006.