ABSTRACT

Inanga (Galaxias maculatus) are found in a range of freshwater habitats around much of the Southern Hemisphere. Although they are reasonably well studied within New Zealand, little is known about the populations found in coastal pond systems. This study focussed on inanga diet and population dynamics within a shallow pond complex in coastal Southland, investigating age, growth, distribution, and diet of juvenile inanga over a spring to autumn period. Otolith analysis indicated a three-month period (September to November) during which fish are hatching, with fish that hatched earlier growing more slowly than later fish. Inanga were found in only one location within the pond complex – a site featuring low water nutrient levels and less access by trout. Diet analysis showed high selectivity for chydorids and chironomid larvae, indicating a mixture of both benthic and pelagic foraging. Overall, this study has provided insight into inanga population dynamics in ponds, which have not previously been observed.

摘要

Inanga ( Galaxias maculatus) 分布于南半球大部分地区的一系列淡水栖息地。尽管在新西兰对它们进行了相当深入的研究，但人们对沿海池塘系统中发现的种群知之甚少。本研究的重点是南部沿海浅水池塘综合体内的伊南加饮食和种群动态，调查春秋期间幼年伊南加的年龄、生长、分布和饮食。耳石分析表明有三个月（9 月至 11 月）的鱼正在孵化，孵化较早的鱼比孵化较晚的鱼生长得更慢。Inanga 只在池塘综合体的一个地方被发现——一个水体营养水平低且鳟鱼较少进入的地方。饮食分析表明对壶腹和摇蚊幼虫有很高的选择性，表明底栖和远洋觅食的混合体。总的来说，这项研究提供了对池塘中 inanga 种群动态的洞察力，这是以前没有观察到的。