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Physiological responses to salinity stress in the Managua Cichlid, Cichlasoma managuense
Author(s) -
Ai Chunxiang,
Chen Xifei,
Zhong Ziqing,
Jiang Yunxia
Publication year - 2020
Publication title -
aquaculture research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 89
eISSN - 1365-2109
pISSN - 1355-557X
DOI - 10.1111/are.14796
Subject(s) - salinity , biology , cichlid , brackish water , juvenile , osmoregulation , endocrinology , zoology , medicine , fishery , ecology , fish <actinopterygii>
The present study was designed to examine the physiological responses of juvenile managua cichlid, Cichlasoma managuense under short‐term salinity stress, that is transferring C. managuense from freshwater to brackish water of salinity 0 (control group), 3‰, 6‰, 9‰, 12‰ or 15‰ for 48, 96, 144 and 192 hr respectively. The results showed that gill Na + /K + ‐ATPase (NKA) activity revealed a decreased (48 hr), increased (96 hr) and then slightly decreased (144 hr, 192 hr) response with increasing salinity and the lowest NKA level was consistently detected at 9‰ salinity treatment; gill Ca 2+ /Mg 2+ ‐ATPase (CMA) activities in all salinity treatments were significantly higher than that of the control group ( p < .05) before 144 hr; the RNA/DNA ratio was significantly reduced when exposed to high salinities (≥9‰), suggesting growth inhibition; serum cortisol level gradually decreased at low salinities (up to 6‰) but dramatically increased at high salinities of 12‰ and 15‰; and both serum glucose/lactic acid levels and heat shock protein 90 (HSP90) level in liver/muscle were decreased at the salinity between 9‰ and 6‰ but increased at the salinity between 12‰ and 15‰, which was a U‐shape response curve. Taken together, our data suggest that C. managuense can adapt well at salinity up to 0‰–9‰ and high salinity may cause detrimental effects.