Impact of wave exposure on seasonal morphological and reproductive responses of the intertidal limpetFissurella crassa(Mollusca: Archaegastropoda)

Abstract

Intertidal organisms have long been considered an ideal system to quantify how physical variations determine differential energy allocations in specimens inhabiting environmental gradients such as exposure to wave action. In habitats with differential intertidal wave exposure (sheltered, Sh; and exposed, E) seasonal gonadal and foot weight variations and their associations with exposure and food availability (algae abundance) were determined in the keyhole limpet Fissurella crassa. Gonadal weight is used as a measure of reproduction allocation whereas foot weight is an indirect indicator of energy allocation to survival. RNA:DNA ratio in limpets obtained from Sh and E habitats during the two different seasons was used as an indicator of biosynthetic capability. Our results indicate that algae abundance in E sites was higher in summer and lower in winter compared to Sh sites. In E sites the muscular foot weight of limpet was higher in summer in contrast to Sh sites where F. crassa muscular foot weight of limpet was higher in winter. Gonadal weight in Sh sites was higher in summer and remained constant in winter; whereas in E sites gonadal weight was lower in summer and higher in winter. RNA:DNA ratios indicate that regardless of intertidal wave exposure, F. crassa showed higher biosynthetic capability in summer. Energetic allocation in animals that inhabit sheltered intertidal habitats would support constant allocation towards reproduction. In contrast, animals that inhabit exposed habitats may favour seasonally reproduction allocation at expense of survival.

The shell phenotypic variability of the keyhole limpetFissurella latimarginata: insights from an experimental approach using a water flow flume

“…All the specimens used in the water flume experiments were collected in autumn and winter. As indicated previously, the foot weight in limpets from sheltered environments may increase during the winter (Pulgar et al, 2012), thus increasing their resistance capacity to wave action. Although significant differences in A fi , L fi and W fi were found between environments for the maximum velocity resisted, a clear overlap was observed (Fig.…”

“…On a small scale, this segregation with respect to shell size offers ecological advantages, allowing intertidal molluscs to thrive across a range of contrasting habitats, resulting in the reduction of intraspecific competition (Livore et al, 2018). This segregation has implications for physiology and survival, with compensatory processes in individuals from wave-swept habitats; these processes are evident from the variations in the energy allocated to growth or reproduction between individuals living in sheltered and exposed environments (Pulgar et al, 2012). In specimens living in sheltered habitats, it is expected that maintenance costs will be low relative to those in specimens inhabiting exposed sites; an increase in foot weight has been observed in limpets from sheltered environments during winter and, although no effects on reproduction were observed, this increase in foot weight likely enables limpets to remain associated with the substrate (Pulgar et al, 2012).…”

“…Rocky intertidal habitats are exposed to a greater magnitude of hydrodynamic forces (Denny & Gaines, 1990), with daily and seasonal variations that involve changes in the degree of immersion, isolation, nutrient accessibility and exposure to different levels of wave action (Newell, 1979;Truchot & Duhanel-Jouve, 1980). These spatial and temporal variations in wave action among environments (Helmuth & Hofmann, 2001;Dahlhoff, Stillman & Menge, 2002) have probably influenced the evolutionary strategies of intertidal organisms (Prowse & Pile, 2005), resulting in distinct behavioural, morphological and physiological responses (Goodrich, 1934;Trussell et al, 1993;Carvajal-Rodríguez, Conde-Padín & Rolán-Alvarez, 2005;Pulgar et al, 2012;Le Pennec et al, 2017). The ability of a single genotype to express different phenotypes in different environments, a phenomenon known as phenotypic plasticity, is a common response to spatial variation in wave exposure (Trussell, 1997;Livore et al, 2018).…”

Upwelling affects food availability, impacting the morphological and molecular conditions of the herviborous limpet Fissurella crassa (Mollusca: Archeogastropoda)

“…To address the effects of upwelling on the consumer -resource interaction, we measured the temporal variation of algal cover as well as the morphological and molecular responses in the herbivorous limpet Fissurella crassa (Lamarck, 1882) at both upwelling and non-upwelling sites in central Chile. Fissurella crassa is one of the most abundant intertidal (Pulgar et al, 2012), herbivorous species, and it represents the greatest catch per unit effort among keyhole limpets caught by shell fishermen (Oliva & Castilla, 1986).…”

Weathering the Storm: The Implications of Wave Exposure on the Distribution, Phenotype and Growth of a Temperate Reef Fish

“…These responses to environmental conditions can have cascading effects on the frequency and intensity of species interactions and biological processes (e.g., succession; Menge andSutherland 1987, Denny andHelmuth 2009). In the marine environment, particularly in the intertidal zone, the influence of wave action on species traits is a focal point of research (Trussell 2002, Harley and Helmuth 2003, Silva et al 2010, Pulgar et al 2012, Hayne and Palmer 2013. Organisms inhabiting this zone have adapted their behavioural, physiological and life history characteristics to their environment.…”