Latitudinal compensation in oyster ciliary activity

Abstract

Summary 1.Theories of latitudinal compensation predict that individuals living in colder temperature regimes should physiologically compensate for the slowing of standard physiological rates, owing to the relatively low temperature of their local environments, by increasing their metabolic rate in colder water temperatures relative to individuals living in warmer water temperature regimes.2. This hypothesis was tested with oyster strains originally from geographically separated populations that were raised in a common environment for seven generations. The physiological parameter measured was ciliary activity across a temperature gradient. 3. Support for the latitudinal compensation hypothesis was found: the strain originally from the colder temperature regime had more active cilia at lower experimental temperatures than individuals originally from the warmer temperature regime. Ciliary activity of the more northern Long Island Sound oysters was significantly greater than activity in the more southern Delaware Bay oysters at temperatures of -1, 2 and 6°C. 4. These results suggest that there is genetically based physiological differentiation between these populations of oysters consistent with the latitudinal compensation for local temperature regime.

Local Adaptation in Marine Invertebrates

“…As expected, the majority of these studies documented countergradient variation in rates of respiration, development, or growth across a latitudinal gradient of temperature (Ament 1979, Walsh & Somero 1981, Lonsdale & Levinton 1985, Palmer 1994, Dittman 1997, Sokolova & Pörtner 2001, Freeman & Byers 2006, Sanford et al 2006. In all cases, physiological rates and/or growth were greater in populations from higher latitudes, a pattern also observed in several field transplant studies (Parsons 1997, Trussell 2000.…”

Latitudinal compensation in female reproductive rate of a geographically widespread reef fish

“…In this model, high-latitude individuals exhibit reaction norms for physiological activity that are shifted to a lower range of temperatures compared to those of low-latitude individuals. This model is supported by physiological activity measured in several marine invertebrates (Dehnel 1955, Levinton 1983, Lonsdale & Levinton 1985, Dittman 1997. Another model for latitudinal compensation focuses on latitudinal differences in seasonality rather than average temperature (adaptation-to-seasonality model or countergradient variation (CnGV) model).…”

The European oyster (Ostrea edulis) and its epibiotic succession

“…Ballyreagh would, therefore, be exposed to a potential high nutrient enrichment in the form of organic particulates and dissolved organic material which is also likely to increase suspended sediment and add to the level of turbidity at the site. The increased organic enrichment during periods of flood water run-off could result in eutrophication and increase the risk of de-oxygenation through microbial activity (Shumway, 1990;Dittman, 1997). Epibiota sensitive to these conditions will not colonise in this restrictive environment, and this was reflected in the species diversity index for Ballyreagh when compared with that of Greyabbey.…”