Effect of γ-amino Butyric Acid on Limpet Populations: Towards the Future Management and Conservation of Endangered Patellid Species

Abstract

Many neurotransmitters, such as γ-amino butyric acid (GABA), can act as chemical cues influencing settlement and metamorphosis in benthic marine invertebrates. This effect has been described especially in mollusks, such as mussels, clams, or haliotids. This study describes the first record of the effect of GABA on patellogastropod populations. Special attention was paid to the effect of the compound on recruitment processes. The experiment was carried out using 10 × 10 cm artificial limestone plates that were drilled into intertidal rocks at different inclinations, and periodically treated with a 1 mM GABA solution. A total of five limpet species was considered (four patellid limpet species and the pulmonate Siphonaria pectinata). Each individual recorded on the plates as well as within a 20 × 20 cm quadrant was measured, identified to species level, and its straight-line distance to the application point was registered. Treated surfaces were the first to possess both adults and recruits. Individuals also were found in a higher number around GABA-treated plates than around controls. The results indicated that the compound may not only enhance recruitment, but also might accelerate it. Recruits were located at higher distances from GABA treated plates than from control surfaces. This supports the hypothesis that this is the life history stage most sensitive to the compound. The behavior shown by the individuals belonging to the two endangered patellid species present in the study area (Patella ferruginea and Cymbula nigra) also were analyzed. For the former, the results indicated that the use of GABA may have similar effects on recruitment similar to the presence of adult conspecifics. This is the first report of the effect of GABA on patellid limpet recruitment and population dynamics. Conservational implications of the results are discussed.

Density and distribution of Patella ferruginea in a Marine Protected Area (western Sardinia, Italy): Constraint analysis for population conservation

“…The maturation of the gonads begins in September and therefore the reproductive season occurs in autumn (MMAMRM, 2008). Settlement is positively influenced by chemical cues of adult conspecifics (Rivera-Ingraham et al, 2011).…”

Presence of Gamma-Aminobutyric Acid (Gaba) in the Pedal Mucus of the Critically Endangered Species Patella ferruginea

“…For the family Patellidae, only one study by Rivera-Ingraham et al (2011) experimentally tested the effects of GABA on limpet behavior and recruitment. With the present study we confirm that GABA is naturally secreted in the pedal mucus of P. ferruginea, reinforcing the hypothesis that chemical cues, and GABA in particular, play a role in the species life cycle.…”

“…Under natural conditions P. ferruginea settles gregariously. GABA had effects on the settlement of larvae similar to the presence of adult conspecifics (Rivera-Ingraham et al 2011), thus indicating that the adults may be a source of signaling chemicals that stimulate settlement. In this study, we aimed to determine if GABA is naturally present in the pedal mucus of P. ferruginea and to detect possible changes related to size and reproductive cycle.…”

“…A variety of chemicals can act as signals to induce metamorphosis, including gamma-aminobutyric acid (GABA), which has been identified as an important signal compound in gastropods (e.g., García-Lavandeira et al 2005;Laimek et al 2008;Rivera-Ingraham et al 2011).…”

“…Rivera-Ingraham et al (2011) examined whether GABA enhanced the recruitment of several limpet species (including P. ferruginea) to artificial plates used as units for reintroduction. The study highlighted how the application of GABA in intertidal areas enhanced recruitment of limpet larvae and caused settlement to start earlier than in controls.…”