''Lernaea'' is a genus of

copepod Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (inhabiting sea waters), some are benthos, benthic (living on the ocean floor) ...

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

s whose members are commonly called ''anchor worms'' and are parasitic on

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

fishes.

Life cycle

Anchor worms mate during the last free-swimming (copepodid) stage of development. After mating, the female burrows into the flesh of a fish and transforms into an unsegmented, wormlike form, usually with a portion hanging from the fish's body. Eggs are released from the posterior "tails" (egg sacs) into the water, where they hatch within 24 to 36 hours. The

nauplii Nauplius, Nauplia or Nauplios , may refer to : Greece-related * Nauplius (mythology), in Greek mythology, the son of Poseidon and Amymone, the father of Palamedes, and also the name of an Argonaut * Nauplia Nafplio ( ell, Ναύπλιο) is a ...

will go through three stages before molting into copepodids, which associate with fish gills. After a further five stages and mating, the male leaves the host and dies, while the female transitions into the anchored stage (may move to different fish host).

Diagnosis

Symptoms of anchor worm can be as follows: # Anchor worms (''Lernaea'' sp.) can be seen with the naked eye # Frequent rubbing or "flashing" # Localised redness # Inflammation on the body of the fish # Tiny white-green or red worms in wounds # Breathing difficulties # General lethargy

Treatment

There are several treatments for anchor worm in the aquarium/pond.

Potassium permanganate Potassium permanganate is an inorganic compound with the chemical formula KMnO4. It is a purplish-black crystalline salt, that dissolves in water as K+ and , an intensely pink to purple solution. Potassium permanganate is widely used in the c ...

is usually considered the best treatment and can be used either as a tank treatment or a "dip". Other treatments include a salt dip, a

formalin Formaldehyde ( , ) (systematic name methanal) is a naturally occurring organic compound with the formula and structure . The pure compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde (refer to section Fo ...

dip, and modern

antiparasitic Antiparasitics are a class of medications which are indicated for the treatment of parasitic diseases, such as those caused by helminths, amoeba, ectoparasites, parasitic fungi, and protozoa, among others. Antiparasitics target the parasitic agent ...

s. Salt in the aquarium at 1 to 2 tablespoons may help prevent secondary infections. Manual removal of the parasite is one of the surest ways to get rid of it; this can be done by holding the fish in the hand and removing the parasites with a pair of tweezers, being careful not to break the tail off leaving the head embedded and dipping the fish back into water every few seconds so it can breathe. Sometimes the parasite can burrow so deeply that pulling it out can cause more trauma than leaving it in and just treating it.

References

{{Taxonbar, from=Q3808877 Cyclopoida genera Parasitic crustaceans Animal parasites of fish