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The stomach contents of 105 preserved specimens of giant kokopu, Galaxias argenteus (Gmelin 1789), collected from various locations around New Zealand between c. 1963 and 1994, were used to investigate giant kokopu diet. A total of 76 food taxa, predominantly invertebrates, were identified and categorised as either of aquatic or terrestrial origin from the 91 stomachs that contained food items. Aquatic Trichoptera, Gastropoda, and Hemiptera comprised 29.1, 12.6, and 14.4% by abundance respectively, and terrestrial Coleoptera 12.2% by abundance. Adult terrestrial Coleoptera were the most commonly occurring taxa, and were found in 59% of the stomachs that contained food. Food items of aquatic origin occurred in 94.5% of the giant kokopu stomachs that contained food and comprised 74.9% of the items by abundance. Although fewer items of terrestrial origin were encountered, they nevertheless appeared to be a significant component of the diet, and occurred in 83.5% of the giant kokopu stomachs that con...

The giant kokopu (Galaxias argenteus (Gmelin 1789)) is endemic to New Zealand, and is regarded as threatened. A perceived decline of the species has been attributed mostly to the loss and degradation of its habitat. To determine habitat requirements, information from the New Zealand Freshwater Fisheries Database, and from field surveys in the South Island were analysed. These indicated that five habitat features are important: in‐stream cover, deep water, low water velocity, proximity to the sea, and overhead shade/riparian cover. These features were important in two distinct regions surveyed and for both juvenile and adult fish. The effects of different types of riparian and in‐stream cover were examined, but it appeared that the presence of some form of cover was more important than its composition. The conservation and management of giant kokopu will probably continue to be based upon management of their habitat, and these processes will be enhanced by the knowledge of the species’ habitat req...

The age and growth of alpine galaxias (Galaxias paucispondylus) and longjawed galaxias (G. prognathus) were determined from samples of fish collected from the Rangitata River, Canterbury, New Zealand. Both species are small (total length up to 112 mm and 87 mm respectively), slender fish with entirely freshwater life histories. Aged from sagittal otoliths, the majority of fish were age 0+ and age 1+, although alpine galaxias up to age 4+ and longjawed galaxias up to age 3+ were found. Growth of both species was greatest during their first year of life. Alpine galaxias continued to grow in subsequent years, but fish of ages 2+, 3+, and 4+ were exclusively females. Longjawed galaxias showed little increase in length after their first year of growth, but for all ages > 0+ the females were significantly larger than males. Overall, both species are not only similar to each other, but also similar to the dwarf galaxias (G. divergens) and the common river galaxias (G. vulgaris), particularly in terms of...