Physiological Responses of Largemouth Bass, Micropterus salmoides, Exposed to Salinity

Abstract

1990. Physiological responses of largemouth bass, Micaopaerus salrnoides, exposed to salinity. Can. 8 . Fish. Aquat. Sci. 47: 2358-2363 Plasma osmotic and electrolyte concentrations as well as branchial Na'/K+ and Mg* + ATPase activities were determined in the field for largemouth bass, Micrspterus sa%moides, from a brackish marsh and freshwater lake in southcentral Louisiana. Laboratory experiments were conducted to evaluate plasma chemistry and gill ATPase activities of largemouth bass from both locations exposed to 0, 4, 8, and 12% salinity. No significant differences in physiological responses were detected between marsh and freshwater largemouth bass exposed to 0, 4, or 1 2%0. Exposure to 1 2% salinity resulted in osmotic stress in largemouth bass from both locations. At 8%0, marsh largemouth bass had significantly higher plasma solutes and Dower gill ATPase activities than freshwater fish. Different physiological responses by marsh and freshwater largemouth bass during exposure to 8%0 salinity indicated that marsh largemouth bass have adapted to environments of variable sali nity by reducing active ion transport and tolerating elevated plasma ion levels. La pression osmotique et les concentrations des 6lectrolytes dans le plasma de mGme que I'activite de la Na*/K+ ATPase et de la Mg' + ATPase dans les branchies ont 4t6 determinees chez des achigans 3 grande bouche, Micropterus salrnsides, provenant d'un marais d'eau saurnatre et d'un lac d'eau douce du centre-sud de la Louisiane. La chimie du plasma et I'activite des ATPases au niveau des branchies ont 6t6 6tudiees chez tes deux groupes d'achigans qui ont 6te expapst% des salinit6s de 8, 4, 8 et 12%0. Aucune difgrence significative n'a 6t6 obsewee dans les r6ponses physiologiques des achigans de marais et d'eau d o u c~ pour les salinites de 0, 4 et 12%~. A 12%, les achigans des deux provenances ont subi un stress osmotique. A 8%0, les achigans de marais montraient des concentrations de solut6s plasmatiques seeperieures et des activites branchiales ATPasiques inferieures A celles des achigans d'eau douce. Les r6ponses physiologiques differentes observees chez ces deux groupes d'achigan lors de leur exposition 2 une salinite de 8 %~ montrent que les achigans de marais se sont adapt& aux variations de salinite de leur milieu en reduisant le transport actif des ions et en developpant une tolerance aux concentrations elevees d'ions dans leur plasma.

Survival, osmoregulation and oxygen consumption of YOY coastal largemouth bass,Micropterus salmoides (Lacepede) exposed to saline media

“…At 8%o, marsh M. salmoides have significantly higher plasma solute concentrations and lower gill Na+'/K+ 1 ATPase activity than freshwater individuals . They argued that marsh M. salmoides had adapted to saline habitats (up to 8%o) by reducing active ion transport and tolerating elevated plasma ion levels (Meador & Kelso, 1990a) . M. salmoides from both populations were severely influenced by 12%o with all individuals stopping feeding within I week and all dying within 120 d (Meador & Kelso, 1990b) .…”

The influence of salinity and prey salt content on growth and intestinal Na+/K+-ATPase activity of juvenile bluegill,Lepomis macrochirus

“…1983, Hwang 1988, Laurent & Perry 1991 in terms of saltwater tolerance and survival . Freshwateradapted fishes replace most salts by active transport at the gills, but the gill Na+/K+ -ATPase activity of largemouth bass collected from low-salinity habitats in Louisiana was not significantly different from the activity measured under freshwater conditions (Meador & Kelso 1990b) suggesting that little change occurred when salinity increased up to 12%o S. There was also no change in gill Na'/K+-AT Pase activity between a 0% NaCl diet and a 12% supplemental NaCI diet in brook charr, Salvelinus fontinalis (Pelletier & Bessner 1992) . Results from these studies indicate that structures other than the gills should be examined for Na+/K +-ATPase activity relative to external salinity or dietary NaCl .…”

Fish Composition and Abundance in New Jersey Salt Marsh Pools: Sampling Technique Effects

“…Therefore, alternative gear types may be useful in some marsh environs. The cast net has been used by other investigators to collect fishes in shallow habitats and to supplement impoundment collections (Meador and Kelso 1990;Stevens 2006a). It has also been utilized in the sampling of shallow wetland pools (Sheaves and Johnston 2008).…”