Chilondonella at around 40X.  At 10X, it is ciliated and glides.  At 40X, it is obviously dented on one side and the cilia are more obvious. More pictures: http://www.wa.gov.au/westfish/sf/broc/fhinfo/fhinfo05.html#SKIN

Oodinium at 40X, with characteristic pinch at one end.  At 10X looks like grains of sand.  More pictures: http://www.dlc.fi/~jarvij/sverige/sjukdino.htm

GYRODACTYLUS at around 40X.  They are very visible at 10X.  The hooks on head and hooks in the middle of the body are diagnostic.

ADULT ICH AT 40X

ICH TOMITES AT 40X

ICH AT AROUND 10X

LERNEA, http://www.wa.gov.au/westfish/sf/broc/fhinfo/fhinfo05.html#SKIN

RED SORES

ARGULUS http://www.biosci.ohio-state.edu/~parasite/argulus.html  http://www.wa.gov.au/westfish/sf/broc/fhinfo/fhinfo05.html

TRICHODINA  http://www.wa.gov.au/westfish/sf/broc/fhinfo/fhinfo05.html

COSTIA   http://www.wa.gov.au/westfish/sf/broc/fhinfo/fhinfo05.html