|March 8, 2006
Hot Springs, AR –There’s a new bug in town that Lake
Ouachita anglers should be aware of this year. A copepod parasite has
infested Lake Ouachita. For those wondering just what a copepod is, they
are very small marine and freshwater crustaceans of the subclass Copepoda.
They have an elongated body and a forked tail.
| Stripe Bass copepod parasite (Actheres ssp.)
Over the past three years, one particular freshwater copepod has infested
fisheries in Virginia, North Carolina, Tennessee and Texas. The parasites
are most commonly found on striped bass in these fisheries, but where the
infestation is high, they can also be found on largemouth bass and
According to Arkansas Game and Fish Commission biologist Brett Hobbs, who
recently conducted gill-netting samples on the South Fork of Lake Ouachita
near Mt. Ida, biologists observed the parasitic copepods, Actheres, in the
mouth and gill raker area of striped bass. "All stripers in the netting
sample did have some of the parasites. Thus far we classify the
infestation as light to moderate although it may get worse before it gets
better," Hobbs said.
Tennessee Wildlife Resources Agency reports several species of parasitic
copepods can inflict great harm and even kill fish, but Actheres is not
considered to be one of them. Virginia Department of Game and Inland
Fisheries reported Actheres contributed to a striped bass die-off in Smith
Mountain Lake. They reported the stripers were in poor shape due to
reduced shad forage in the lake and large stripers collected from the
die-off had high numbers of Actheres, Hobbs explained.
| Copepod (Actheres ssp.)
"This parasitic copepod is visible as the adult stage in the mouth of the
host fish. The adult stage is about 2 to 3 millimeters long and creamy to
white-yellow colored. For you anglers out there, they are shaped like an
Uncle Josh pork frog (body with split tail)," Hobbs stated. "The tail
portion of the copepod is actually egg sacs which will distribute into the
water and hatch into a larval free-swimming form which will infect other
fish," he added.
A leading researcher, Dr. Thomas Shahady from Lynchburg College in
Virginia, has ongoing research which is testing the effect of this
parasite on the respiration of the host fish. Early study results indicate
the parasites increase respiration rate which could be most problematic
during low dissolved oxygen periods, Hobbs said. "The bad news is this
parasite persists in affected lakes for at least several years after
infestation, but typically in lower numbers. We will have to wait for
further research findings to determine how harmful this parasite will be
to our fisheries," Hobbs said.
In the mean time, anglers should not move fish from one water body to
another to avoid contamination. Also, livewells should be drained to avoid
moving the larval form.