[Melanie]

I think the white thing is a sand flea and not sea lice.

Sand fleas are parasitic crustaceans common throughout the North Pacific. They are amphipods, rather than copepods. They attach themselves to other water creatures by digging into the flesh or scales and eat at the animals they are attached to. Small fish, swordfish, sunfish, flying fish, starfish, and even whales are attacked by the different kinds of parasitic crustaceans.

Flea size can vary from as small as a short grain of rice to 3 or 4 times larger. Their distribution is spotty, and they seem to be more common on sandy bottom. ‘Hot’ spots in their distribution may change from season to season or year to year. These may be very localized, such that a part of a set can be severely impacted by fleas, while another part shows no damage. Fleas appear to be more active at night, and the effect on captive fish is also more evident on longer sets. These seem to be additive, so that a long night set might have worse predation than a short night set, etc.

Flea predation starts with the presence of fleas on the surface of the body. They appear to first remove (eat?) the slime, then the top layer of the skin. The fleas seem to enter the body first through holes eaten through the skin membrane either near the eye, anus, or dorsal fins. First evidence of fleas (other than their physical presence on the body) can be a non-glossy whitened appearance in these areas where the slime and scales have been eaten. This is still a non-fatal condition.

Once the fleas have penetrated the body, we consider the fish to be dead. Penetration near the anus or eye is often evident by the presence of a hole about .25 centimeter in diameter.