April 14, 2010 First time ever found mites in my aquarium while sampling protozoa from my aquarium.
April 29, 2010 More house mites were found in aquarium. One of them is alive!
How the investigation is conducted
The initial investigation focused on the area surrounding the aquarium: carpet, aquarium hood/light and window blinds. The specimen were collected using a piece of 3M tape about 1 1/2 inch long. I hold the tape by both ends then smear and gentle press over the surface in suspected area. Additionally, the carpet was vacuumed and transfer the sample from the vacuum filter to the tape. No mite was found on the carpet or the window blind. A dead house mite body and several pieces of legs were found on the aquarium hood and light.
With the help from the friends at yahoo microscope group, the floating method was introduced to investigate the possibility of fish food being the source of the house mites. A pinchful of aquarium flake food was collected from the flake food left open in the automatic feeder on the shelf close by the aquarium. Saturated Epsom salt solution was added to the flake food in a 2 mL vial and shaked and inverted to separate the mites from the flake food. The vial then set on the desk for 10 minutes to force the mites to float to the surface due to the high density of the saturated salt solution. Couple drops of solution were collected from the top of the vial then transferred to a microscope slide to perform a wet mount. No luck. There isn’t any dust mite in the flake food.
Out of my curiosity, I siphoned about 8 oz of water from the bottom of the aquarium to a water bottle then performed a floating method with the sample. Many more dead mites were found. The area is right below the aquarium filter. The number of bodies that I found in this collection is more than any other collections.
Although the samples from the bottom of the aquarium suggested that the house mites could be dwelled in the aquarium filter. I need to find live dust mites in the aquarium filter to proof. The first sample from the aquarium filter was collected using the tape method described previously. The underside of surface of the aquarium filter was sampled with a piece of 3M tape. The number of mites is more than anytime I have sampled.
Wait! the last one is still alive after I stared it for a little while.
Encouraged by the results from the previous sampling from the aquarium filter, I slightly modified the floating method. Approximately 2 mL of water was used to flush the aquarium filter cover with a pipet. The aquarium filter cover than tilted to allow water to be collected on in a petri dish. The process is repeated approximately 10 times. The petri dish then placed on the binocular compound microscope for observation. As I identified some dust mites in the petri dish, I siphoned water up to allow dry surface to form for observation.
An adult and nymph house mite collected from my aquarium filter.
A nymph house mite collected from aquarium filter. My attempt to stain the specimen with methylene blue failed as it stains the surround debris rather than the dust mite.
Temperature: House mites like warm weather. The winter can get quite cold during the winter even in the deep south. Even with heater on during the winter, the over night temperature can be down 50 degree F in door. This is unsuitable for house mites. The aquarium heater maintain the water temperature from 76 to 80 degree F year arround. This provide them the warm bed for survival over the winter.
Humidity: House mites like high humidity. They don’t drink. They rely on the moisture from the air to make sure that they don’t get dehydrated. The warm water in the aquarian filter provide them with plenty of moisture in the air.
Food: House mite eats dead skins, bacteria, fungi, protozoa and food scraps. I have found many protozoa from the aquarium filter, such as stylonychia, amoeba, rotifer, paramecium and nematode. It is also possible that there are overfeeding foods in the filter. The flake fish food is very high in protein (40% crude protein).
Dark environment: House mites are photophobic. They like to stay in the dark. The interior of the aquarium filter is very dark.
Classification Mites are very diverse groups. It has the second largest number of species in Anthropod, next to insect. I can certainly sure that these are mites as they have eight legs. Could they be aquatic mites since I found them in the aquarium. It seems most aquatic mites are called water mites which has more rounded body and less spiky. Mites are classified by the texture of the cuticle, size, development of the mouth part and legs, spikes, grooves on cutilces and their host. It turn out that the mites I discovered in my aquarium are more like grain mites or flour mites.
Some good references about mites:
Dust Mites by Mettew J Colloff’s