Full stomachs at empty tides: tidal cycle affects feeding activity and diet of the sandy beach gastropod Olivella minuta

Author(s)

Checon, Helio H. ; Silva, Mariana O. ; Corte, Guilherme N. ; Yokoyama, Leonardo Q. ; Teodosio, M. Alexandra ; Turra, Alexander

• Document type: Journal article
• Source: Journal of Molluscan Studies; v. 86, p. 9-pg., 2020-08-01.

Abstract

Olivella minuta is an abundant neogastropod on sandy beaches from Texas (USA) to southern Brazil. This study aimed to characterize and compare the feeding activity and diet of a Brazilian population of O. minuta in different tidal zones (intertidal and subtidall, and different tidal levels (high and low tides), with three combinations of tidal zone and level being studied (intertidal during low tide, intertidal during high tide and subtidal). The results showed that diet composition was generally similar among tidal conditions, with O. minuta being a generalist, feeding on 45 different food items. Feeding activity, however, was higher in the intertidal during low tide, whereas the richness and diversity of food items were higher in the intertidal during high tide. The higher feeding activity of O. minuta during low tide may be linked to a lower risk of predation; at low tide organisms may be able to feed for a longer time, arid this may be particularly true on beaches with fine sand, where water retention is higher than that on beaches with coarse sand. The higher diversity of food items consumed in the intertidal during high tide is likely related to the increased prevalence of planktonic food during high tide. Our results indicate that tidal zone and level may strongly influence the feeding activity of coastal soft-bottom species and that species may show higher feeding activity during low tide. Given the current loss of intertidal habitats due to anthropogenic activity and climate-change associated factors, our study has important implications, highlighting the importance of intertidal areas for the ecology and conservation of sandy beach species. (AU)

• FAPESP's process: 09/17585-6 - Population ecology of Olivella minuta (Link, 1807) (Gastropoda, Olividae) in the intertidal of Araçá and Barequeçaba beaches, northern coast of São Paulo State
• Grantee: Alexander Turra
• Support Opportunities: Regular Research Grants
• FAPESP's process: 18/22036-0 - Evaluating the potential of different benthic indicators to assess sandy beach ecological integrity: subsides for management and monitoring practices
• Grantee: Hélio Hermínio Checon
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 09/15893-5 - Interpopulation variability in sandy beaches: case study about the zonation, reproduction, and growth of Olivella minuta (Gastropoda, Olividae)
• Grantee: Leonardo Querobim Yokoyama
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 17/17071-9 - Preserving sandy beaches: biodiversity, goods and services, and impacts on a neglected ecosystem
• Grantee: Guilherme Nascimento Corte
• Support Opportunities: Scholarships in Brazil - Post-Doctoral