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Aerial exposure tolerance of a newly discovered galaxiid
Author(s) -
Chakona A.,
Swartz E. R.,
Magellan K.
Publication year - 2011
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.1095-8649.2011.02913.x
Subject(s) - biology , ventilation (architecture) , fish mortality , ecology , fish <actinopterygii> , zoology , fishery , mechanical engineering , engineering
Laboratory experiments were conducted to investigate tolerance and physiological responses of Galaxias ‘nebula’, a newly discovered and widespread African galaxiid, to aerial exposure. This species can tolerate emersion for at least 36 h. Changes in water level and dewatering did not induce the fish to burrow into the substratum or find refugia, nor was there detectable mucus production following aerial exposure. Opercular movement, a proxy for gill ventilation rate, however, did vary with changes in water level. The initial steady ventilation rate increased significantly when the fish were partially emersed and ventilation ceased immediately upon total air exposure. When fish were re‐immersed, there was first a period of hyperactivity with a corresponding inflated gill ventilation rate which was restored to pretreatment levels within 2 h. This is the first documented case of amphibious capabilities in an African galaxiid, which has implications for the interpretation of its widespread distribution pattern.