Coughlan, AmI, and Canning, Adam (2025) The influence of rainbow trout on dwarf galaxiid habitat preferences. Fishes, 10 (9). 456.

Preview

PDF (Published Version) - Published Version Available under License Creative Commons Attribution. Download (671kB) | Preview

Abstract

Introduced salmonids are a major threat to New Zealand’s non-migratory galaxiids, yet evidence for predator-driven habitat shifts remains limited. We experimentally tested whether dwarf galaxiids (Galaxias divergens) altered habitat use in response to rainbow trout (Oncorhynchus mykiss) presence or odour. Two habitat contrasts were offered: coarse versus fine substrate and open versus vegetated cover, under three predator treatments (trout-present, trout-odour-only, trout-absent). Generalised linear mixed models showed no significant effects of trout treatment on galaxiid habitat choice in either experiment. Substrate use was stable, with a consistent preference for coarse substrate regardless of predator cues, while vegetation cover had no detectable influence on behaviour. These results suggest that trout presence is unlikely to deter dwarf galaxiids from entire river reaches, but their limited behavioural response may leave them more exposed to predation where refuge is scarce. Habitat enhancement, particularly maintaining coarse substrate and reducing fine sediment, is likely to support the resilience of this short-lived, r-selected species.

Item ID:	89052
Item Type:	Article (Research - C1)
ISSN:	2410-3888
Keywords:	fish conservation; introduced species management; Oncorhynchus mykiss; Galaxias divergens; anti-predator behaviour; refuge use
Copyright Information:	© 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
Date Deposited:	07 Oct 2025 23:56
FoR Codes:	31 BIOLOGICAL SCIENCES > 3103 Ecology > 310301 Behavioural ecology @ 50% 31 BIOLOGICAL SCIENCES > 3103 Ecology > 310304 Freshwater ecology @ 50%
SEO Codes:	18 ENVIRONMENTAL MANAGEMENT > 1803 Fresh, ground and surface water systems and management > 180301 Assessment and management of freshwater ecosystems @ 50% 18 ENVIRONMENTAL MANAGEMENT > 1803 Fresh, ground and surface water systems and management > 180302 Control of pests, diseases and exotic species in fresh, ground and surface water @ 50%
Downloads:	Total: 1 Last 12 Months: 1
	More Statistics