ARTEMIA AS VECTOR OF FILAMENTOUS BACTERIA

From: carhawkins@telstra.easymail.com.au
To: artemia-l@sparklist.com
Sent: February 29, 2000

QUESTION:

I would like to know if anyone as experienced problems with filamentous bacteria being passed onto fish via Instar II Artemia?

I know that grown-on Artemia are affected by filamentous bacteria, but I need to learn whether brine shrimp themselves could be hosts to these bacteria, and thereby be carriers to predator fish.

Rachelle Hawkins
Senior Biologist
Seahorse Australia Pty Ltd.
PO BOX 363 Beauty Point
Tasmania 7270, Australia

*****************************

COMMENTS 1:

I feed ongrown Artemia (1.5-2.5 mm) to rock lobster phyllosoma larvae. I had problems with filamentous bacteria (Leucothrix mucor) when feeding larvae in static culture. This was probably a result of poor water conditions (high ammonia, low dissolved oxygen) allowing proliferation of the bacteria carried in via the Artemia. I no longer have this problem because I use flow-through culture to maintain high water quality. I also disinfect the Artemia before feeding each day with 100 ppm formaldehyde for at least 10 min.

Dr. Arthur Ritar
Tasmanian Aquaculture & Fisheries Institute

University of Tasmania
Marine Research Laboratories, Nubeena Crescent
Taroona Tasmania 7053, Australia

Tel. +61 3 62277294
Fax +61 3 62277298
e-mail: Arthur.Ritar@utas.edu.au

*********************************

COMMENTS 2:

It would be interesting to learn if: (1) you are decapsulating the Artemia cysts prior to incubation, (2) have you isolated the filamentous bacteria and identified them? (3) have you tried the product Hatch Controller by INVE or their A1 SELCO's?

We routinely culture bacteria from the chorion of the Artemia cysts and most of the time have limited non-pathogenic species. Instar II requires some additional incubation time which could easily provide the substrate for the bacteria to bloom.

Howard W. Newman
Artemia Task Force
Inve Group

e-mail: Bshrimp@aol.com

**********************************

COMMENTS 3:

When we ran intensive cultures at seawater salinity Artemia was often
contaminated by Leucothrix (filamentous bacteria) that attach to the
exoskeleton; probably not a pathogen to the Artemia; however, when the colonisation became too thick (hairy Artemia) they were hampered in swimming and feeding behavior and died.

Prof. P. Sorgeloos

Laboratory of Aquaculture & Artemia Reference Center

Rozier 44

B-9000 Gent, Belgium

e-mail: Patrick.Sorgeloos@rug.ac.be

home