Description: “Head a rounded knob projecting from anterior margin of cephalothorax and situated nearly at right angles to body axis, with deeply buried tripartite eye near center of dorsal surface. One or two pairs of anchors, simple or forked, on lateral margins of cephalothorax; sometimes an unpaired anchor on center dorsal margin or paired anchorsrising from dorsal side of cephalothorax; all anchors conical and soft, branched or not. Neck soft, slender, cylindrical, enlarged gradually into cylindrical trunk; trunk with bilobed or double pregenital prominence in front of vulvae. Abdomen short, more or less distinctly trisegmented, bluntly rounded, terminating in pair of small, segmented caudal rami. Egg strings elongated conical or ovoid; eggs multiseriate. First antenna nearly cylindrical, with 3 or 4 segments; second antenna bi- or tri-segmented, tipped with small, stout claw. Proboscis conical, very short. Mandible clawlike, without teeth; first maxilla nodular, tipped with minute conical chitinous projection; second maxilla terminating in two stout claws. Maxilliped trisegmented; second segment with minute, thick-stalked spine and rounded, conical protuberance on distal inner margin; terminal segment with five claws of different lengths. Four pairs of legs biramose, first pair just behind head, others at increasing distances posteriorly; a fifth pair of unsegmented stumps just in front of vuvlae. Parasitic on outside surface of freshwater fishes, boring into underlying tissue; occasionally parasitic on amphibians” (Hoffman and Williams Jr., 1999).
Life Cycle: "There are several juvenile stages of the Lernaea parasites. Eggs hatch and after two molts occur, the copepod must swim to find a host in a couple days. Upon finding a host, the parasite will molt several more times. During the 6th copepod stage, females mate with males and mature into adults while males die after mating. The egg sacs form on the females and drop when eggs are mature" (Paul).
Sources: Hoffman, G.L. and Williams Jr., E.H. 1999. Parasites of North American Freshwater Fishes, Second Edition, p. 317.
Paul, K. Anchor Worm (Lernaea). http://www.pond-life.me.uk/fishhealth/lernaea Accessed Jan 21, 2016.