Topic
Gomphus externus
About: Gomphus externus is a research topic. Over the lifetime, 2 publications have been published within this topic receiving 11 citations.
Papers
Journal Article•
TL;DR: Progomphus obscurus and Gomphus externus larvae were studied in both laboratory and field during July, 1976, regarding their burrowing habits and their association with substrates as mentioned in this paper.
Abstract: Progomphus obscurus and Gomphus externus larvae were studied in both laboratory and field during July, 1976, regarding their burrowing habits and their association with substrates. They were found to burrow completely beneath bottom substrates by using their front and middle legs, never deeper than 2 cm; small larvae burrowed less deeply. — Field studies revealed that both spp, occurred in the stream in relatively high numbers and were distributed in either a contagious or random manner. Population structure of both spp. was similar and consisted mainly of late instars. Statistical analysis of physical factors measured (substrate particle size, digested organics and detritus) and the occurrence of each sp. demonstrated a correlation between particle size and occurrence of each sp. P. obscurus lends to inhabit microhabitats in stream where sand substrate (1-0.625 mm) predominates. Microdistribution of G. externus is most strongly correlated with the amount of silt/clay substrate present (less than or equal to 0.0625 mm), but percentage of organics was also significant. Although other environmental factors may have had an effect on the distribution of these 2 spp., the primary factor was substrate particle size.
12 citations
1 Jan 2003
TL;DR: Field and laboratory observations on the reproduction of Gomphus externus, G graslinellus and Progomphus obscurus are presented from Illinois, United States as discussed by the authors.
Abstract: Field and laboratory observations on the reproduction of Gomphus externus, G graslinellus and Progomphus obscurus are presented from Illinois, United States Mating of G externus in the field took 12 min 2 phases were distinguished, the first consisted of tapping movements of the cj hamulus, the second of pumping movements of the cf abdomen The ovary yielded 5100 eggs of which 690 were laid during hand-held oviposition in the laboratory Only eggs laid by the $ but not the ones dissected from the ovary developed a sticky jelly coat around themselves Eyespots of developing embryos were visible after 13 days This 5 had stored approximately 200 thousand sperm (about 160 bundles) in her spermalheca The sperm were still mobile 3 days after mating A comparison of the penis horn length and the length of the spermathecal tubes revealed that
1 citations
Performance Metrics
| Year | Papers |
|---|---|
| 2003 | 1 |
| 1982 | 1 |