Jackson Estuarine Laboratory

Title

Variation in the Size and Composition of Ejaculates Produced by Male American Lobsters, Homarus Americanus H. Milne Edwards, 1837 (Decapoda: Nephropidae)

Abstract

Variation in the quality of ejaculate produced by male American lobsters, Homarus americanusMilne Edwards, 1837, has been previously described, but never quantified. This study examined the size and composition of ejaculates produced by 111 males ranging from 60 to 108mm in carapace length (CL). Ejaculates were obtained via electrical stimulation, photographed and then processed for histology. Half of the males produced an ejaculate from each gonopore, 29% produced only one ejaculate, and the remainder (21%) produced none. Males as small as 64mmCL produced an ejaculate containing sperm. Ejaculate weight increased with male size, but there was a negative relationship between ejaculate weight and the percent of the ejaculate that was composed of sperm mass. Variation observed in the size and composition of ejaculates produced by similarly-sized males indicates that not all males invest equally in reproduction. Additionally, larger males may invest disproportionately more in the sperm plug (acellular component), possibly as paternal assurance.

Publication Date

9-1-2015

Journal Title

Journal of Crustacean Biology

Publisher

The Crustacean Society

Digital Object Identifier (DOI)

https://doi.org/10.1163/1937240X-00002365

Document Type

Article

Rights

© 2015 by The Crustacean Society