Age, growth, and movements of giant bullies (Gobiomorphus gobioides) in the Kakanui River estuary, South Island, New Zealand

Abstract

The giant bully, Gobiomorphus gobioides (Valenciennes), is widespread throughout New Zealand, but remains one of our least known freshwater fish. During a study of seasonal fish abundance and movements in the Kakanui River estuary, South Island, New Zealand, giant bullies captured mainly in fyke nets were measured and tagged. Growth rates and movements were calculated for the 19 fish recaptured. Growth rates corresponded with mean growth rates back‐calculated from otoliths— scales were considered to overestimate age, and no age classes were evident from length‐frequency distributions. Seasonal changes in condition were associated with spawning during spring‐summer.

Keywords:

• giant bully
• Gobiomorphus gobioides
• movements
• condition
• growth
• tagging
• recaptures