Maturing longer than a foot and needing significant space for swimming, the tang quickly outgrows a small aquarium. Different species of tang reach different sizes, and knowing how fast your particular tang species is going to grow will help you plan for the long-term well-being of this interesting fish.
Tangs, of taxonomic family Acanthuridae, grow fastest in their first 2 to 5 years of life. The vlamingi tang, (Naso vlamingii) for example, can live up to 45 years but does 80 percent of his growing in the first 5. The average blue tang (Acanthurus coeruleus) will reach 4 to 5 inches long in the first year of life, averaging around 0.3 to 0.4 inches of growth a month. Yellow tangs (Zebrasoma flavescens) average 10 to 12 inches in the first year for a growth rate of 0.8 to 1 inches a month. Vlamingi tang put on an average of 3 to 4 inches a year. While development varies by species and individual, you should plan for at least 3 to 4 inches of growth a year for your tang while he is young.
The size of a full grown tang varies by species, but most grow to a foot longer. The blue tang reaches 15 inches, the vlamingi tang reaches 23.6 inches and the naso tang (Naso lituratus) reaches up to 18 inches. The tomini tang (Ctenochaetus tominiensis), one of the smallest available species, grows to around 6 inches, and can be kept in a smaller tank than his larger cousins. Be sure to research your particular tang species before bringing one home.
Planning for the Tank You Have
Many hobbyists purchase a young tang with the hopes that by the time he outgrows his tank they will be able to afford a larger one. While that may be tempting, it is best to plan for the tank you have, not for the tank you hope to have. Tangs grow quickly and need a large amount of swimming space to be healthy. The absolute minimum tank size for smaller species is 55 gallons, while larger species need a minimum of 75 to 180 gallons to be healthy, and would do well with even more space.
Signs Your Tank Is Too Small
A tang kept in a tank that is too small can develop behavior problems. If your tang is hiding or inactive, he is under stress, most likely from a small tank size. This problem can lead to stunted growth, longer term behavior problems and fatality if the tang is not moved to a larger area. A healthy tang should swim the length of the aquarium frequently throughout the day.
Keeping This Rapidly Growing Fish
It is crucial to keep up with your tang's growing needs. Proper nutrition and ample space to swim are necessary for a tang's development, regardless of the species. Try to invest in a tank the size your full-grown tang will need to avoid stressing him with frequent moves.