Development of a Minimally Invasive Technique to Stabilize Buoyancy-Challenged Goldfish (Carassius auratus)
Buoyancy disorders of pet goldfish, especially in the round-bodied ornamental goldfish like orandas, lionheads, bubble-eyes, Ryukins, and moors, is one of the most common and frustrating problems confronting the pet fish hobbyist and aquatic animal veterinarian. Differential diagnoses for this condition include swimbladder torsion, swimbladder inflammation, enteritis, neoplasia, and anatomical anomaly of the swimbladder. Many cases are idiopathic, and a study published by the Japan Aquaculture Society1, describes the condition in detail. In fact, the authors name this syndrome "tenpuku disease," which essentially means, "capsized." Several other publications have discussed the problem of improperly buoyant goldfish (Johnson, 1993, Tocidlowski et. al., 1998, Lewbart, 1998). Contributing factors for this condition include the genetically selected rotund body type of the fish and the fact that goldfish, members of the cyprinid family, are physostomous (there is an open connection between the esophagus and the swimbladder). Diet and temperature appear to be linked with tenpuku disease when infectious or neoplastic causes are not involved (Johnson, 1993). Some workers feel that floating foods, like pellets or flakes, may exacerbate or even cause the problem.
Most clinical cases present with a recent history of the goldfish appearing inverted at the surface of the water or on the bottom. The condition may be transient or permanent, and most fish remain alert and eating. Frequently, other fish in the aquarium or pond are unaffected. While a number of medical and surgical procedures have been attempted to correct this problem, results are frequently unrewarding.
Since many of these fish are otherwise healthy, a method of righting the inverted or laterally recumbent fish to a normal attitude in the water column would make the patient and owner more comfortable. A Floy® anchor tag (http://www.floytag.com/) and fine fabric tags equipped with a small buoyant piece of material (cork fishing float) were used to address this syndrome and provide relief to the patient. The tag was applied under aseptic conditions to the epaxial musculature just left of midline (initially, a needle and fine suture were used to "test" for appropriate site selection and size of the buoyancy device). Unfortunately, the initial fine fabric tag was expelled within five days, but we are conducting studies to refine and improve this technique. These tags are inserted into fish with a minimal amount of effort, expense, and trauma (anesthesia and analgesia are required). Floy® tags are an industry standard for fisheries biologists who need to identify fish and crustaceans for research projects and mark-recapture studies.
The authors would like to thank the NCSU-CVM Veterinary Teaching Hospital for funding portions of this work.
1. Tanaka D, Wada S, K. Hatai. 1998. Gross, radiological and anatomical findings of goldfish with tenpuku disease. Suisanzoshoku 46(2):293-299.
2. Johnson EL. 1993. Your fishes' health column. Tropical Fish Hobbyist Magazine, Neptune City, NJ, 96-98.
3. Lewbart G. (ed.). Self-Assessment Colour Review of Ornamental Fish. 1998. Manson Publications, London & Iowa State University Press, Ames, IA, 192 pp.
4. Tocidlowski ME, CA Harms. 1998. What is your diagnosis? JAVMA 213(3):353-354.