Journal of Fish Biology (2014) 84, 748–758 doi:10.1111/jfb.12320, available online at wileyonlinelibrary.com Short and long-term strategies to facilitate aerial exposure in a galaxiid K. Magellan*†‡, S. Pinchuck§ and E. R. Swartz† *Department of Ichthyology and Fisheries Science, Rhodes University, P. O. Box 94, Grahamstown 6140, South Africa, †South African Institute for Aquatic Biodiversity, Private Bag 1015, Grahamstown 6140, South Africa and §Electron Microscopy Unit, P. O. Box 94, Grahamstown 6140, South Africa This study investigated two potential strategies to survive short and longer-term aerial exposure in a galaxiid. This scaleless fish possesses cutaneous pores that dilated in the short-term (15 min–3 h) but contracted over longer periods (15 h) out of water, suggesting that these organs are used to cope with shorter durations of air exposure. Pores on the abdominal surface showed the greatest variation while those on the operculum surface hardly changed. Conversely, thickening of the epithelial layer of secondary gill lamellae showed a slower increase but persisted in an approximately linear fashion over the duration of this study, indicating that this is a strategy that facilitates longer-term aerial exposure. Thus, this species has the capacity to accommodate both short and long-term exposure to air. © 2014 The Fisheries Society of the British Isles Key words: air breathing; cutaneous respiration; electron microscopy; gill epithelial layer; gill mod- ification. INTRODUCTION Many fish species have the capacity for air breathing (Gee & Gee, 1995; Yoshiyama et al., 1995; Graham, 1997; Martin et al., 2004; Sayer, 2005) and this may occur over various time scales ranging from seconds to months or even years. One clear distinction in duration concerns the two major types of air-breathing fishes (Gra- ham, 1997). Aquatic air breathers gulp air at the water surface but do not leave water (Gonzales et al., 2006), whereas amphibious air breathers use atmospheric oxygen when exposed to air and may be able to survive when completely emerged (Graham, 1997; Sayer, 2005; Taylor et al., 2008), so are likely to be able to sur- vive aerial exposure over longer periods than aquatic air breathers. Another factor likely to influence exposure duration is habitat. Intertidal fishes such as the blennies (Blenniidae; Graham et al., 1985), sculpins (Cottidae; Yoshiyama et al., 1995) and gobies (Gobiidae; Gee & Gee, 1995; Gonzales et al., 2006), which are regularly and cyclically exposed to air (Graham et al., 1985; Gee & Gee, 1995; Yoshiyama et al., 1995; Gonzales et al., 2006), will be able to accommodate shorter periods of ‡Author to whom correspondence should be addressed at present address: Institut d’Ecologia Aqu` atica, Universitat de Girona, E-17071 Girona, Catalunya, Spain. Tel.: +34 666 78 53 81; email: kit8x@hotmail.com 748 © 2014 The Fisheries Society of the British Isles