| Scorpionfish: A link between stress disruption and parasitism |
This study takes a look at how California scorpionfish (Scorpaena guttata)
and their stress axis is associated with parasite infestation. In collaboration
with Dr. Julianne Kalman at Cabrillo Marine Aquarium, Orange County
Sanitation Disctrict (OCSD) and California State University-Long Beach, we
sampled different locations; an outfall site and far-field sites off of Newport
Beach, California and looked at impacted stress axis as well as parasite
infestation. A normal stress response (cortisol) allows organisms to face
certain events (predators, illness, infestation, etc.) without much harm or
deleterious affects, however, having a disrupted stress response (stress
axis) can inhibit the organism from getting through a stressful event without
much harm. The California scorpionfish is a common fish found off southern
California waters and is important in commercial and recreational fishing.
The results of the study showed that scorpionfish sampled from the outfall
site (located near the OCSD outfall pipe in which treated wastewater is
released into the ocean) had significantly reduced stress responses (reduced
cortisol levels) compared to scorpionfish sampled from far-field sites. Yet,
those same fish from the outfall site had extremely high incidence of
parasite infestion, while the fish with a "normal" stress response had
significantly lower incidence of parasite infestation. We believe that the
impacted stress axis has left the fish vulnerable for parasite infestation.
Although there are other possibilities, such as, the high incidence of
infestation alone has driven the organism to have an impacted stress
response, we believe that the stressful environment has contributed to the
impaired stress response because we have discovered other fish species
with altered stress responses and almost no parasite infestation. In the
study we found 3,718 total parasites on 71 fish, with 4 different types of
parasites found (copepods, isopods, leeches, branchiurans). The copepod
group made up 3,596 of the total parasites. One species of copepod,
Naobranchia scorpaenae, made up 3,263 of the total parasites found. All
collaborators are continuing to study this complex relationship between
parasitism, stress and environmental impacts and are working hard at
defining exactly how this occurrence has come to be. Future studies will
continue to look at stress and parasites and will strive to obtain what a
normal pre-stress and post-stress level of cortisol response is for this fish.
Sampling other outfall sites in the region and sampling other fish species.
and their stress axis is associated with parasite infestation. In collaboration
with Dr. Julianne Kalman at Cabrillo Marine Aquarium, Orange County
Sanitation Disctrict (OCSD) and California State University-Long Beach, we
sampled different locations; an outfall site and far-field sites off of Newport
Beach, California and looked at impacted stress axis as well as parasite
infestation. A normal stress response (cortisol) allows organisms to face
certain events (predators, illness, infestation, etc.) without much harm or
deleterious affects, however, having a disrupted stress response (stress
axis) can inhibit the organism from getting through a stressful event without
much harm. The California scorpionfish is a common fish found off southern
California waters and is important in commercial and recreational fishing.
The results of the study showed that scorpionfish sampled from the outfall
site (located near the OCSD outfall pipe in which treated wastewater is
released into the ocean) had significantly reduced stress responses (reduced
cortisol levels) compared to scorpionfish sampled from far-field sites. Yet,
those same fish from the outfall site had extremely high incidence of
parasite infestion, while the fish with a "normal" stress response had
significantly lower incidence of parasite infestation. We believe that the
impacted stress axis has left the fish vulnerable for parasite infestation.
Although there are other possibilities, such as, the high incidence of
infestation alone has driven the organism to have an impacted stress
response, we believe that the stressful environment has contributed to the
impaired stress response because we have discovered other fish species
with altered stress responses and almost no parasite infestation. In the
study we found 3,718 total parasites on 71 fish, with 4 different types of
parasites found (copepods, isopods, leeches, branchiurans). The copepod
group made up 3,596 of the total parasites. One species of copepod,
Naobranchia scorpaenae, made up 3,263 of the total parasites found. All
collaborators are continuing to study this complex relationship between
parasitism, stress and environmental impacts and are working hard at
defining exactly how this occurrence has come to be. Future studies will
continue to look at stress and parasites and will strive to obtain what a
normal pre-stress and post-stress level of cortisol response is for this fish.
Sampling other outfall sites in the region and sampling other fish species.
| Scorpionfish: A link between stress disruption and parasitism |
| Each little dark spot on this gill is a parasite feeding on blood on this scorpionfish |
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SUMMARY
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provided by Dr. Julianne Kalman
provided by Dr. Julianne Kalman