Maternal Lipid Provisioning Mirrors Evolution of Reproductive Strategies in Direct-Developing Whelks

Area of Science:

• Marine Biology
• Evolutionary Biology
• Reproductive Ecology

Background:

• Maternal effects, such as energetic input to offspring, are crucial for shaping life history evolution.
• Direct-developing marine gastropods exhibit diverse reproductive strategies, impacting offspring provisioning.

Purpose of the Study:

• To investigate how contrasting reproductive strategies in three sympatric whelk species affect hatchling provisioning.
• To analyze inter- and intraspecific differences in lipid content and composition among whelk hatchlings.

Main Methods:

• Comparative analysis of lipid content (μg hatchling⁻¹) in offspring of Cominella virgata, Cominella maculosa, and Haustrum scobina.
• Identification and quantification of energetic lipids, including wax ester (WE) and methyl ester (ME), in hatchlings.
• Assessment of inter- and intracapsular variability in sibling provisioning.

Main Results:

• Lipid content per hatchling was independent of size, with Haustrum scobina having the highest lipid content despite being the smallest.
• Energetic lipids (WE, ME) were present only in multi-encapsulated hatchlings (C. maculosa, H. scobina).
• Lipid composition in Cominella species reflected taxonomic affinities, suggesting phylogenetic influence on non-adelphophagic development.

Conclusions:

• Interspecific variation in lipids provides insights into the evolution of maternal provisioning in direct-developing species.
• Reproductive strategies significantly mediate the quantity and quality of maternal energetic input to offspring.
• Haustrum scobina exhibited high intracapsular variability, indicating less controlled allocation to individual hatchlings.