HR: 1330h
AN: NB33P-14    [Abstracts]
TI: Life History and Reproductive Timing of the Endangered Illinois Cave Amphipod, Gammarus acherondytes
AU: * Venarsky, M P
EM: vesuccio@siu.edu
AF: Southern Illinois University, 1125 Lincoln Drive, Carbondale, IL 62901 United States
AU: Wilhelm, F M
EM: fwilhelm@zoology.siu.edu
AF: Southern Illinois University, 1125 Lincoln Drive, Carbondale, IL 62901 United States
AU: Anderson, F A
EM: feander@siu.edu
AF: Southern Illinois University, 1125 Lincoln Drive, Carbondale, IL 62901 United States
AU: Taylor, S J
EM: sjtaylor@inhs.uiuc.edu
AF: Illinois Natural History Survey, 607 East Peabody Drive, Champaign, IL 61820 United States
AB: To aid the recovery of endangered species requires an understanding of their basic biology. Armed with such knowledge, meaningful management plans with realistic objectives can be established. We examined the life history and reproductive biology of Gammarus acherondytes, a federally endangered cave amphipod, in Reverse Stream, Monroe Co., Illinois. The population was sampled non-destructively at monthly intervals from October 2003 to February 2005. The density of gravid females peaked twice annually, (November-December and June-July) indicating major reproductive events. Gravid females also occurred at other times of the year but at low densities. Two major peaks in the density of newborn young were also observed, which lagged the density of gravid females by approximately 1-2 months. We believe this reproductive pattern is related to the influx of organic matter from mid summer storm events and leaf abscission in autumn. Young grew at a rate of 0.034 mm/day and likely reach reproductive size in one year. Adults are iteroparous and may live for several years. Our results suggest that limiting cave access in highly visited caves during peak reproduction may be a simple strategy to increase the abundance of G. acherondytes.
DE: 9810 New fields (not classifiable under other headings)
DE: 9901 NABS Student Award - Basic Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly