Physicochemical environments and tolerances of cyprinodontoid fishes found in estuaries and salt marshes of eastern North America

Abstract

Individuals of 28 species of cyprinodontoid fishes have been reported from estuaries/salt marshes of the Atlantic and Gulf coasts of North America. Some species show limited latitudinal distributions and/or occupy a limited range of habitats; others are widely distributed and/or occupy a wide range of habitats. A literature survey was made of conditions of water temperature, dissolved-oxygen (DO) concentrations, and salinities at sites where individuals of each species had been collected, and of laboratory-determined tolerances or lethal limits and other responses to those abiotic conditions. Individuals of Cyprinodon variegatus showed the widest overall range of tolerance of environmental temperatures, -1.9-45.4°C, with Gambusia rhizophorae showing the highest lower temperature-tolerance limit, 17°C. The only species highly sensitive to hypoxia was Floridichthys carpio, which showed ''stress'' at DO levels of 6-8 mg kg -1 . All showed use of aquatic surface respiration, except for Kryptolebias marmoratus, which uses aerial respiration in the presence of H 2 S, and/or under hypoxic conditions. Individuals of C. variegatus were found to tolerate ambient salinities ranging from <0.5 to 125.2, or higher, and several species of the genus Fundulus were found to tolerate concentrations ranging from < 0.5 to ‡100. However, some of the species discussed cannot tolerate salinities beyond those of dilute brackish waters. In most instances, laboratory-determined tolerance limits of temperature and salinity were wider than conditions under which individuals of these species had been found in nature. The majority of available information related to adult individuals, with few studies focused on immature stages; however, existing information permitted a brief review of spawning, incubation, and early development features in Fundulus heteroclitus. Suggestions were made, based on existing information, as to species that would be most likely to show altered population distributions resulting from continued global warming. These included five species that have tropical/subtropical, or subtropical/temperate distributions. Also, a few others were included that show extensive latitudinal distributions, most extending northward into cooler temperate regions of the Atlantic coast. At present, none of these species has shown a range alteration that can be attributed to global warming.

Development of the morpholino gene knockdown technique in Fundulus heteroclitus: A tool for studying molecular mechanisms in an established environmental model

“…Although killifish are widespread, they have small home ranges, which make them ideal for studying the effects of local stressors (Lotrich, 1975). They are tolerant of significant changes in many environmental conditions, including salinity (Griffith, 1974;Wood and Marshall, 1994;Nordlie, 2006), pH (Gonzalez et al, 1989), temperature (Umminger, 1971;Dunson et al, 1993;Smith and Able, 1994;Nordlie, 2006), and oxygen (Wannamaker and Rice, 2000;Smith and Able, 2003;Stierhoff et al, 2003;Nordlie, 2006). Specific killifish populations have adapted to a variety of anthropogenic stressors, including polycyclic aromatic hydrocarbons (PAH) (Meyer et al, 2002;Ownby et al, 2002;Meyer and Di Giulio, 2003), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (Prince and Cooper, 1995a,b), polychlorinated biphenyls (PCB) (Nacci et al, 1999;Bello et al, 2001), and mercury (Weis et al, 1981).…”

Body size mediated effects of multiple abiotic stressors on the growth and social behaviour of an estuarine fish, Australian Bass (Macquaria novemaculeata)

“…However, it is possible that juvenile bass are more tolerant of an increase (compared to a decrease) in salinity levels, given that hatching and larval survival rates of bass increase with incubation salinities of up to 35 ppt (Van der Wal 1985). Therefore, increasing salinities may exert an impact on behavioural rather than growth rate changes in bass, although further work investigating the influence of developmental stage of exposure (Bachman et al 2008) and rate of salinity increases (Nordlie 2006) on growth rates would be important to confirm this suggestion.…”

“…This is a surprising result, given that salinity is considered an important determinant of performance in aquatic organisms (Boeuf and Payan 2001;Chen et al 1996;Tsuzuki et al 2003;Varsamos et al 2005;Bachman and Rand 2008;Nordlie 2006). Salinity is expected to affect estuarine fish via an increased energy expenditure required for osmoregulation under hypo-and hyperosmotic conditions (Swanson 1998;Bachman and Rand 2008), in turn affecting higher level activities such as growth and activity (Boeuf and Payan 2001).…”

Physiological performance measures and tolerance limits of estuarine indicator species in South Florida

“…However, at low temperatures, the worms can tolerate low salinities for prolonged periods of time (Kenny, 1969). Though tolerant of a wide range of salinities (0-164 ppt) when gradually acclimated, Cyprinodon variegatus (Sheepshead minnow) has shown a high degree of mortality when exposed to rapid changes in salinity (Serafy, 1997;Nordlie, 2006). Hence, the rate of salinity change that an organism experiences is a likely factor in its ability to tolerate variable salinity environments (Nordlie, 2006).…”

“…Two of the most important factors affecting the overall functionality of an estuary are the timing and quality of the freshwater inflow, which subsequently affect the salinity regimes of the area (Montagna et al, 2002). Salinity is considered to be one of the primary environmental factors affecting the growth and survival of aquatic organisms because it can influence both physiological and ecological processes , Tsuzuki et al 2003, Varsamos et al, 2005, Nordlie, 2006). …”