||The cryptic bivalve species, Nutricola tantilla and N. confusa live sympatrically in protected intertidal areas of the eastern Pacific Ocean. To confirm species level status, we conducted a phylogenetic analysis using the histone, H3, nuclear primer and two mitochondrial primers, CO1 and 16S. When compared between species, the CO1 and H3 sequences differ by an average of 12.7% and 3.06% respectively. A difference this large is not common among cryptic bivalve species. We investigated one potential mechanism for maintaining reproductive isolation and describe and quantify the morphology of the spermatozeugmata. We use a novel method for inducing spawning in Nutricola and acquiring spermatozeugmata, a selelctive serotonin reuptake inhibitor (SSRI). The results do not allow for definitive conclusions about the method of reproductive isolation in Nutricola , but this study is the first to (1) include N. confusa in a phylogenetic analysis and (2) describe spermatozeugmata in Venerid bivalves.