A recirculated maturation system for marine ornamental decapods

Abstract

The present work describes an easy to operate recirculated maturation system for different types of marine ornamental decapods that: i) demands shorter periods of time to perform routine tasks, while allowing better water quality for broodstock keeping, ii) eliminates the need to capture ovigerous females (or euhermaphrodites) before larval release, minimizing the risks of disrupting reproductive pairs, iii) separates newly hatched larvae from the reproductive pair, impairing adults from preying on larvae and iv) allows live prey to be provided to larvae immediately after hatching if needed. Breeding pairs of the following species were used to test the maturation system: cleaner shrimp Lysmata amboinensis, fire shrimp L. debelius, Monaco shrimp L. seticaudata, peppermint shrimp L. boggesii, cleaning rock pool shrimp Urocaridella antonbruunii, sexy shrimp Thor amboinensis, dancing shrimp Rhynchocinetes durbanensis, boxer shrimp Stenopus cyanoscelis, S. hispidus, hermit crabs Clibanarius tricolor, C. erythropus and the emerald crab Mithraculus sculptus. Larger species displaying strong agonistic behavior toward conspecifics ( L. debelius and S. hispidus) had to be kept in larger divisions (0.20 m × 0.30 m × 0.15 m), while all other species were successfully kept in smaller divisions (0.20 m × 0.15 m × 0.15 m). All tested species were able to successfully mate and produce consecutive larval batches during the experimental period, and routine tasks (e.g. checking for and collecting newly hatched larvae, monitoring molts of breeding pairs, recording the presence of specimens carrying embryos about to hatch, tank siphoning, filters cleaning and water changes) were daily performed in about 1 h. The unidirectional water flow inside each maturation tank, as well as the presence of actinic light in the front glass, allowed newly hatched caridean, stenopodid, anomuran and brachyuran larvae to be successfully removed from the chamber containing the reproductive pair. The simple use of 150 μm mesh size screens inside maturation tanks allowed larval prey ( Artemia nauplii) to be provided to larvae immediately after hatching, avoiding the negative effects of early larval starvation. The use of suitable maturation and larviculture systems will play a vital role for the successful development of profitable commercial scale culture protocols for the most heavily collected marine ornamental decapod species.