PHYTOPLANKTON COMPOSITION OF THE STOMACH CONTENTS OF THE MUSSEL MYTILUS EDULIS L. FROM TWO POPULATIONS: COMPARISON WITH ITS FOOD SUPPLY

Ocean acidification (OA) studies to date have typically used stable open-ocean pH and CO 2 values to predict the physiological responses of intertidal species to future climate scenarios, with few studies accounting for natural fluctuations of abiotic conditions or the alternating periods of emersion and immersion routinely experienced during tidal cycles. Here, we determine seawater carbonate chemistry and the corresponding in situ haemolymph acid–base responses over real time for two populations of mussel ( Mytilus edulis ) during tidal cycles, demonstrating that intertidal mussels experience daily acidosis during emersion. Using these field data to parameterize experimental work we demonstrate that air temperature and mussel size strongly influence this acidosis, with larger mussels at higher temperatures experiencing greater acidosis. There was a small interactive effect of prior immersion in OA conditions (pH NBS 7.7/pCO 2 930 µatm) such that the haemolymph pH measured at the start of emersion was lower in large mussels exposed to OA. Critically, the acidosis induced in mussels during emersion in situ was greater (ΔpH approximately 0.8 units) than that induced by experimental OA (ΔpH approximately 0.1 units). Understanding how environmental fluctuations influence physiology under current scenarios is critical to our ability to predict the responses of key marine biota to future environmental changes.

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Differences in growth rate, body condition, habitat use and food availability between island and mainland lizard populations ofAnolis nebulosusin Jalisco, Mexico

Journal of Tropical Ecology ◽

10.1017/s0266467414000297 ◽

2014 ◽

Vol 30 (5) ◽

pp. 493-501 ◽

Cited By ~ 6

Author(s):

Héctor Hugo Siliceo-Cantero ◽

Andrés García

Keyword(s):

Growth Rate ◽

Habitat Use ◽

Food Availability ◽

Body Condition ◽

Food Supply ◽

Geographic Isolation ◽

Seasonal Fluctuations ◽

Continental Population ◽

Two Populations

Abstract:Lizards of the genusAnolishave been widely studied, however, little is known about the effects of environmental seasonality, food availability and geographic isolation on body condition, growth rate and habitat use of lizards. The existence of an insular and a continental population ofAnolis nebulosus(clouded anole), separated by only 0.47 km, represents an ideal opportunity to address this topic. We compared seasonal fluctuations in food availability (arthropod density) for anoles, as well as body condition, growth rate and habitat use in the two populations. Food availability throughout the year was sampled every 2 mo by trapping arthropods at each site. Lizards were also monitored and measured every 2 mo by surveying three quadrats in each site over 2 y giving a total of 30 visits for each quadrat. Results suggested that composition and density of food supply was similar for the two populations. Nevertheless, food supply responded to seasonality of rainfall, with an increase of 1.5 times during the rainy season. Despite similarity in food availability, insular anoles had body condition that was 5–10 times better, with growth rate twice as fast, and used similar perches. The role of predation, and inter- and intraspecific competition are discussed as possible drivers.

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The cytochemical distributions of zinc (Zn II) and iron (Fe III) in the common mussel, Mytilus edulis, and their relationship with lysosomes

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400036882 ◽

1979 ◽

Vol 59 (4) ◽

pp. 851-858 ◽

Cited By ~ 56

Author(s):

D. M. Lowe ◽

M. N. Moore

Keyword(s):

Mytilus Edulis ◽

Cell Types ◽

Cellular Distribution ◽

Cytoplasmic Inclusions ◽

The Common ◽

Two Populations

Zinc (Zn II) and iron (Fe III) were demonstrated histochemically in cytoplasmic inclusions shown to be lysosomes in a number of cell types in Mytilus edulis. The cellular distribution of the metals differed between the sexes; males were shown to have more zinc (Zn II) in the kidney than females, the latter appearing to use oocytes as an additional means of excretion. Differences in cellular distribution of the metals was also demonstrated between the two populations studied probably reflecting availability of the metals in their respective environment.

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