Fish louse, Argulus foliaceus

gpmatthews · Post by **gpmatthews** » Thu Aug 30, 2007 2:51 pm

Microscope: Wild M8
Surface illumination
Sample from garden pond
30 Aug 2007
Length ~5 mm
Top and underside views

Microscope: Zeiss Standard 16
Ocular: Zeiss Kpl W 10/18
Objective Zeiss plan 1.6/0.03 - 5/0.1
Diffuse transmitted light
Sample from garden pond
30-Aug-2007

I guess the upper image suggests why it is called foliaceus. The underside view shows clearly the two suckers that the louse uses to attach itself to fish. The upper view shows this is a female with eggs. The lower image of the second set shows the compound eyes fairly well.

This was a devil to get acceptable illumination... just the wrong size specimen!

I spotted the beast swimming in the garden pond tonight after dark - I could see its shadow in the garden light.

Raul G · Post by **Raul G** » Sat Sep 01, 2007 12:04 pm

Hi Graham,
Great contrast!
What is surface illumination?

gpmatthews · Post by **gpmatthews** » Sat Sep 01, 2007 1:58 pm

Surface illumination: I used a lamp to illuminate the specimen from above i.e. shining on the surface of the specimen.

Planapo · Post by **Planapo** » Sun Sep 09, 2007 11:52 am

Nice find and nicely documented, Graham. Thanks for sharing!

Parasites as Argulus with their strange morphology and life history have always been fascinating me, hence it´s a pleasure to see good photos of them.

Best wishes,
Betty