Responses of the mussel Brachidontes rodriguezii to aerial exposure: implications on growth and physiological condition

Abstract

The length of aerial exposure (i.e., environmental conditions) of an organism, due to daily tides, induces physiological responses. A mark–recapture field experiment was conducted in two intertidal zones (low tide and high tide) using the stain calcein AM to determine growth, as measured by shell length, of the mussel Brachidontes rodriguezii (d’Orbigny, 1842) along its vertical distribution off the north Argentinean coast. In the high intertidal zone, B. rodriguezii exhibited slower growth in shell length because of the physiological stress resulting from aerial exposure during low tides. In the low intertidal zone and during spring, B. rodriguezii exhibited faster growth in shell length. It is suggested that growth of B. rodriguezii relies on several environmental factors (temperature, photoperiod, and aerial exposure) that fluctuate according to tidal height.

Reproductive aspects of Brachidontes rodriguezii in the high intertidal; extreme environmental effects

“…The oocytes sizes reported in the lower level were a little bigger than our results for the high level. Previous studies also showed that B. rodriguezii has a lower growth index in high intertidal (Torroglosa & Giménez, 2019b). A similar situation was observed in populations of Mytilus edulis under stressful conditions: lower somatic growth and smaller oocytes (Bayne et al 1982).…”

“…These aerial conditions include high temperature and desiccation, along with a lower food supply (Connell, 1972); as long as mussels are exposed to the marine condition, food intake rises and the effect of high temperature decreases (Petes et al 2008). Previous studies carried out in the same area revealed some reproductive features of B. rodriguezii in the low level of intertidal (Torroglosa & Giménez, 2019a) and given the differential exposure to aerial conditions reported for the study area (Torroglosa & Giménez, 2019b) and the probable effects of exposure to high temperature, the objective of this study were to describe reproductive features of males and females of B. rodriguezii in the high intertidal level on the coast of Buenos Aires Province, Argentina. We predicted that under conditions of high-stress mussels would exhibit some trade off in reproductive aspects like shifts in the reproductive cycle or the size of gametes leading to a successful reproductive strategy under extreme environmental conditions.…”

“…The stress conditions increase in the higher intertidal zone as consequence of tides, organisms spend less time feeding and the longer exposure to aerial conditions leads to desiccation (Petes et al 2008;Helmuth et al 2011). Previous studies carried out in the same area revealed some reproductive features of B. rodriguezii in the low intertidal (Torroglosa & Giménez, 2019a) and a differential growth probably due to tides (Torroglosa & Giménez, 2019b).…”

Epibiosis in sedimentary coastal environments: Effects of an introduced barnacle on a native mussel

“…Those mussels were left in the field for 30 days. Based on the relatively fast response of condition index and growth of B. rodriguezii to environmental conditions (see Torroglosa & Giménez, 2019), this experimental period was considered long enough. In laboratory, the mussels were processed and the %CI calculated as described above.…”

Reproductive aspects and energy allocation compromise to aerial exposure in the intertidal mussel Brachidontes rodriguezii. A case study at two tidal levels

“…In the intertidal, environmental stress increases along a vertical gradient, because organisms in the higher level are exposed to air conditions for a longer period than those at low tide (Connell, 1972;Menge and Sutherland, 1987). Also, in the upper intertidal limit exhibit physiological consequences of prolonged air exposure as reduced growth (Menge et al, 2002;Somero, 2002;Torroglosa and Giménez, 2019a), protein damage (Halpin et al, 2004) and higher oxidative stress (Andrade et al, 2018).…”