Can epibionts prevent bacterial contamination in estuarine crab embryos?

• Grant number: 20/06860-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2020
• End date: May 31, 2021
• Field of knowledge: Biological Sciences - Ecology
• Principal Investigator: Murilo Zanetti Marochi
• Grantee: Dalila Junqueira Borges
• Host Institution: Instituto de Biociências (IB-CLP). Universidade Estadual Paulista (UNESP). Campus Experimental do Litoral Paulista. São Vicente , SP, Brazil

Abstract

The embryonic development of Decapoda in the abdominal chamber of females is susceptible to biotic and environmental variables that can affect their development. The presence of epibionts associated with the egg surface is one of the variables that can affect embryo viability. Bacterial epibiosis on the surface of eggs can lead to the formation of biofilm inhibiting embryonic development with early mortality. However, the positive relationship between embryos and epibionts is still poorly understood for estuarine organisms. Bearing in mind that reproductive success is essential for the maintenance of populations, species continuity and little knowledge on the subject, our objective is to evaluate whether the presence of the ciliate Vorticellidae is beneficial to the embryonic development of the crab Leptuca thayeri when exposed bacterial contact. For this purpose, the volumetric growth rate of the eggs, the hatching rate, and larval viability among four experimental groups will be evaluated: (I) eggs without ciliated epibionts and without bacterial inoculation (SC), (II) eggs without ciliated epibionts, and with bacterial inoculation (SCB), (III) eggs with ciliated epibionts and without bacterial inoculation (CC) and (IV) eggs containing ciliated epibionts and with bacterial inoculation (CCB). We hypothesize that the presence of epibiotic ciliates will inhibit or reduce the colonization of bacteria, which can be harmful to the crab's embryonic development. We hope to clarify this knowledge gap and contribute to future research with estuarine organisms with these results.