Event Title

Are Little Brown Bats Ingesting Microcystin Through Hexagenia Mayfies

Location

Hager-Lubbers Exhibition Hall

Start Date

15-4-2015 3:30 PM

Description

Microcystis aeruginosa is a type of cyanobacteria capable of producing a hepatotoxin called microcystin (MC). As toxic M. aeruginosa overwinters in the sediments of lakes, it is consumed by some mayfly larva, such as those of the Hexagenia spp., and thus MC bioaccumulates in these insects. Each summer, Hexagenia emerge from the lake to reproduce. While individual Hexagenia may only live for 48 hours, the emergence of these species can last for several weeks, providing a temporary food source for many terrestrial organisms such as birds and bats. Little brown bats, Myotis lucifugus, feed opportunistically on aquatic insects. To test if microcystin is moving from aquatic to terrestrial ecosystems via trophic transfer, we 1) tested the bat feces for the presence of Hexagenia mayflies; and 2) tested the bat livers and feces for microcystin. In June 2013, bat feces were collected from underneath a maternity roost near Little Traverse Lake (Leelanau County, MI). That same night, one male little brown bat was caught and humanely euthanized. Insect DNA was extracted from feces (n=20), amplified with a Polymerase Chain Reaction (PCR) and sequenced. Levels of MC in liver tissue (n=1) and feces (n=20) were determined using an Enzyme-linked Immunosorbent Assay (ELISA). Pilot data reveal that M. lucifugus are not consuming Hexagenia mayflies, but MC is present in bat feces. From these results, we can conclude that M. lucifugus are ingesting microcystin, but the exact source is still unknown.

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Apr 15th, 3:30 PM

Are Little Brown Bats Ingesting Microcystin Through Hexagenia Mayfies

Hager-Lubbers Exhibition Hall

Microcystis aeruginosa is a type of cyanobacteria capable of producing a hepatotoxin called microcystin (MC). As toxic M. aeruginosa overwinters in the sediments of lakes, it is consumed by some mayfly larva, such as those of the Hexagenia spp., and thus MC bioaccumulates in these insects. Each summer, Hexagenia emerge from the lake to reproduce. While individual Hexagenia may only live for 48 hours, the emergence of these species can last for several weeks, providing a temporary food source for many terrestrial organisms such as birds and bats. Little brown bats, Myotis lucifugus, feed opportunistically on aquatic insects. To test if microcystin is moving from aquatic to terrestrial ecosystems via trophic transfer, we 1) tested the bat feces for the presence of Hexagenia mayflies; and 2) tested the bat livers and feces for microcystin. In June 2013, bat feces were collected from underneath a maternity roost near Little Traverse Lake (Leelanau County, MI). That same night, one male little brown bat was caught and humanely euthanized. Insect DNA was extracted from feces (n=20), amplified with a Polymerase Chain Reaction (PCR) and sequenced. Levels of MC in liver tissue (n=1) and feces (n=20) were determined using an Enzyme-linked Immunosorbent Assay (ELISA). Pilot data reveal that M. lucifugus are not consuming Hexagenia mayflies, but MC is present in bat feces. From these results, we can conclude that M. lucifugus are ingesting microcystin, but the exact source is still unknown.