Hatchery practices for Patella aspera and P. ordinaria: evaluating culture vessels requirements

Abstract

AbstractInnovation in limpet production requires knowledge of the optimal qualities and limitations of the culture vessels. Two limpet species from Madeira fishery, Patella aspera and P. ordinaria, were used to evaluate the influence of culture vessel shape (microtubes, test tubes, centrifuge tubes, specimen cups, disposable cups, vials, flasks and beakers), composition (polypropylene and glass), volume (1.5 ml to 1.5 L) and stocking density on oocyte incubation and larval culture through nine assays. Moreover, three assays evaluated the use of microtubes and the isolation of trochophores, instead of pediveligers, for eventual settlement induction. The results showed effective hatching in most culture vessels regardless of composition or volume, except when the shape of the bottom caused oocyte clustering. Larval culture was not influenced by any variable under scrutiny (shape, composition, volume or rearing density). Microtubes were useful for settlement, while the placement of trochophores in the settling vessels, instead of pediveligers, proved inefficient and even led to failed cultures. The best settlement was obtained when the pediveligers were isolated from the water column of the beakers and transferred to clean vessels with renewed water and coralline algae as substrate. The current findings could be extrapolated to other marine invertebrates that share similar life stage requirements.