TY - JOUR
T1 - Does the tube of a benthic chironomid larva play a role in protecting its dweller against chemical toxicants?
AU - Halpern, Malka
AU - Gasith, Avital
AU - Broza, Meir
PY - 2002/2/15
Y1 - 2002/2/15
N2 - A laboratory culture of an Israeli benthic midge, Chironomus luridus, was exposed to two chemicals: copper and monochloramine. The objective of this study was to determine the protective nature of Chironomus' larval tube. Three experimental conditions were tested: larva with sand tubes, with silt tubes and without tubes. Larvae without tubes were significantly more sensitive to copper and chloramine than larvae that had sand or silt as tube building substrate. The tubes protected the insects against chemicals throughout 14 days of exposure time. Silt tubes had higher protective value than sand tubes, especially when exposed to copper for a short period of time (LC50/24 h, with silt, sand, or none: 80.0, 7.0 and 3.4 mg l-1 copper, respectively), C. luridus seemed to be better protected against copper than against chloramine (LC50/24 h, with silt, sand, or none: 12.2, 6.4 and 3.7 mg l-1 chloramine, respectively). The acute toxicity of copper to chironomid larvae was investigated using a cytochemical method. Larva in silt tubes had significantly higher non-specific esterase activity in midgut cells than larvae without tubes. We conclude that, in addition to its role in feeding, respiration and anti-predation shelter, the C. luridus tube protects its inhabitant from toxic substances.
AB - A laboratory culture of an Israeli benthic midge, Chironomus luridus, was exposed to two chemicals: copper and monochloramine. The objective of this study was to determine the protective nature of Chironomus' larval tube. Three experimental conditions were tested: larva with sand tubes, with silt tubes and without tubes. Larvae without tubes were significantly more sensitive to copper and chloramine than larvae that had sand or silt as tube building substrate. The tubes protected the insects against chemicals throughout 14 days of exposure time. Silt tubes had higher protective value than sand tubes, especially when exposed to copper for a short period of time (LC50/24 h, with silt, sand, or none: 80.0, 7.0 and 3.4 mg l-1 copper, respectively), C. luridus seemed to be better protected against copper than against chloramine (LC50/24 h, with silt, sand, or none: 12.2, 6.4 and 3.7 mg l-1 chloramine, respectively). The acute toxicity of copper to chironomid larvae was investigated using a cytochemical method. Larva in silt tubes had significantly higher non-specific esterase activity in midgut cells than larvae without tubes. We conclude that, in addition to its role in feeding, respiration and anti-predation shelter, the C. luridus tube protects its inhabitant from toxic substances.
KW - Chironomid tubes
KW - Chironomus
KW - Chloramine
KW - Copper
KW - Freshwater sediment
UR - http://www.scopus.com/inward/record.url?scp=0037085188&partnerID=8YFLogxK
U2 - 10.1023/A:1015665027535
DO - 10.1023/A:1015665027535
M3 - Article
AN - SCOPUS:0037085188
SN - 0018-8158
VL - 470
SP - 49
EP - 55
JO - Hydrobiologia
JF - Hydrobiologia
ER -