Reproductive Morphology, Histology, and Gametogenesis in \u3cem\u3eOrnithodoros parkeri\u3c/em\u3e (Cooley) (Acarina: Argasidae)

Adult males recently ecdysed from second, third, or fourth instar nymphs had a complete reproductive system which included paired testes, paired vasa deferentia, a single seminal vesicle, a single ejaculatory duct, and an accessory gland with 2 single and 8 paired lobes. Each accessory gland lobe was composed of one type of tissue, spongy or granular. Probable secretory flow in these lobes was outlined. Cytological descriptions of spermatogenesis were similar to those reported for other tick species. Primary spermatocytes, under-going the first meiotic division, possessed 9 autosomal bivalents and 1 sex bivalent, 2n=2G. Spermatogenesis was complete in a few unfed fifth instar nymphs examined and in all unfed-unmated adult males examined. Unfed-unmated adult males 2 weeks post-ecdysis could mate with fed adult females which would subsequently lay viable eggs. The female reproductive system of fourth instar nymphs (which could ecdyse into adult females) was complete, except for absence of paired ampullae, and included a single ovary, paired oviducts, a single uterus, a vagina, and paired accessory glands. Primary oocyte development was divided into 5 growth phases. Meiotic divisions of oocytes were not observed. Accumulation of sperm in ampulla of adult females, absence of sperm in the ovary and proximal portions of the oviducts, and apparent decreased pliability of eggs after passing through ampullae indicated that fertilization may occur in the ampullae

DNA metabarcoding analysis of three material types to reveal Joro spider (Trichonephila clavata) trophic interactions and web capture

International audienceIntroduced species alter established trophic interactions and molecular analysis can resolve changes in community structure and associated foraging links. Joro spiders (Trichonephila clavata) were recently introduced to the United States and their range is rapidly expanding across the east coast. Here, we used DNA metabarcoding of fecal samples, prey remains from webs, and dissected guts to compare diet composition of female Joro spiders in the southeastern United States. We amplified DNA from three material types using arthropod-targeted COI primers and sequenced with IIlumina MiSeq. Prey remains from webs had the highest diversity, richness, as well as the highest proportion of prey reads relative to Joro spider reads. Recovery of prey reads from fecal samples and dissected gut content was low and both were overwhelmed by Joro spider DNA. Although fecal samples and gut content had high proportions of Joro spider reads, fecal samples had higher prey diversity and richness. Moreover, we detected prey DNA from fecal samples several days after capture from the field, which reveals initial gut retention time estimates for fecal samples collected from web-building spiders. Combined, our results offer a first glimpse at the complexity of trophic associations for an introduced web-building spider and identify a viable material, prey remains from webs, as a source of prey DNA for estimates of biodiversity associated with web-building spiders. KEYWORDS golden-orb weaver, molecular gut content analysis, introduced species, spider web, trophic interactions

DataSheet_1_DNA metabarcoding analysis of three material types to reveal Joro spider (Trichonephila clavata) trophic interactions and web capture.pdf

Introduced species alter established trophic interactions and molecular analysis can resolve changes in community structure and associated foraging links. Joro spiders (Trichonephila clavata) were recently introduced to the United States and their range is rapidly expanding across the east coast. Here, we used DNA metabarcoding of fecal samples, prey remains from webs, and dissected guts to compare diet composition of female Joro spiders in the southeastern United States. We amplified DNA from three material types using arthropod-targeted COI primers and sequenced with IIlumina MiSeq. Prey remains from webs had the highest diversity, richness, as well as the highest proportion of prey reads relative to Joro spider reads. Recovery of prey reads from fecal samples and dissected gut content was low and both were overwhelmed by Joro spider DNA. Although fecal samples and gut content had high proportions of Joro spider reads, fecal samples had higher prey diversity and richness. Moreover, we detected prey DNA from fecal samples several days after capture from the field, which reveals initial gut retention time estimates for fecal samples collected from web-building spiders. Combined, our results offer a first glimpse at the complexity of trophic associations for an introduced web-building spider and identify a viable material, prey remains from webs, as a source of prey DNA for estimates of biodiversity associated with web-building spiders.</p