PW11 Integrating Sublethal Responses and Ecologically Relevant Endpoints
Exhibit Hall
8:00 AM - Wednesday
(PW189) Sublethal effects of cadmium contributing to growth inhibition in larval topsmelt (Atherinops affinis).
Rose, Wendy1, Cherr, Gary1, Fan, Teresa2, Green, Peter3, Nisbet, Roger4, Norris, Sarah2, Smith, Ed1, Anderson, Susan1, 1 Bodega Marine Laboratory, University of California, Bodega Bay, CA, USA2 Land, Air, and Water Resources, University of California, Davis, CA, USA3 Civil & Environmental Engineering, University of California, Davis, CA, USA4 Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, USA
ABSTRACT- We determined whether sublethal effects of cadmium (Cd) exposure contributed to growth inhibition in larval topsmelt (Atherinops affinis), a model marine species. First, we measured food intake and apoptosis (using the TUNEL assay) of topsmelt larvae exposed to Cd (0-100 ppb) for 14 days. Fish exposed to 50 and 100 ppb Cd were smaller and ate less Artemia nauplii than those in other treatments (p<0.01). Gill apoptosis levels in fish exposed to 50 ppb Cd were higher than those of controls while gill, gut, and liver apoptosis levels of fish exposed to 100 ppb Cd were significantly higher than those of controls. Next, metallothionein (MT) levels were measured in topsmelt larvae exposed to Cd (0-100 ppb) for 14 days. While MT levels were higher in fish exposed to 100 ppb Cd relative to controls (p<0.001), growth was impaired in fish exposed to 50 and 100 ppb Cd. Last, we examined oxygen consumption rates of larval topsmelt exposed to Cd (0-250 ppb) for 1, 7 and 14 days. Oxygen consumption rates of fish from 250 ppb Cd treatments were higher than those in other treatments and decreased with increasing age and size (p<0.05). Numerous factors were associated with growth inhibition of Cd-exposed larval topsmelt; however, effects of Cd were concentration-dependent. We are using these data to generate a model of topsmelt population viability under Cd stress to further address the effects of Cd on fitness of this model marine organism.
Key words: cadmium, topsmelt, growth, sublethal effects