Female morphological traits as predictors of fertility and hatching success in the limpet <i>Patella aspera</i>

ABSTRACT Objective Limpets are a fishery resource with potential as new aquaculture species. Currently, there are no known methods for estimating the broodstock and gamete quality, resulting in a lack of predictability of hatching success. This study was designed to evaluate different morphometric traits as predictors of fertility and hatching success in the limpet Patella aspera Röding, 1798. Methods Individual measurements were taken for adult body morphometry (129 females), gonad morphometry (129 females), and oocyte morphometry (79 females). The oocytes of individual females (80 females) were treated (control and alkaline bath) to enhance hatching success. The ratio of viable larvae was used as a proxy of quality. Statistical analyses included Pearson’s correlations, linear regression models, two-sample t-tests, and principal components analysis. Results The total number of oocytes was positively correlated with the female length and gonadal maturation indices (Orton’s maturation index and the gonadosomatic index). Oocyte shape changed from polyhedral to spherical 3 h after extraction. The alkaline bath increased the ratio of viable larvae in 87.5% of the females. The ratio of viable larvae was negatively correlated with oocyte size and chorion presence and positively correlated with oocyte sphericity. Conclusions Three selection traits are proposed: (1) female length (live specimens) and (2) mature gonads (stripping) for obtaining higher quantities of oocytes and (3) sphericity of oocytes (once stripped) to determine their quality. The alkaline bath will be required to improve hatching success.