Response of the tropical spiny lobster Panulirus ornatus to protein content of pelleted feed and to a diet of mussel flesh

Abstract

In an 8-week growth experiment, juvenile spiny lobsters (Panulirus ornatus) grew best on a feed containing at least 610 g kg−1 crude protein on a dry matter basis (DM) and a digestible protein to digestible energy ratio of 29.8 mg kJ−1. The study entailed a six treatment by four replicate randomized block experiment with 222 wild-caught P. ornatus of mean initial weight (±SD) of 2.5 ± 0.19 g. The lobsters were fed one of five isolipidic feeds (approximately 130 g kg−1 DM) in which the crude protein was serially incremented between 330 and 610 g kg−1 DM, or a reference diet comprising the flesh of frozen green-lip mussels. Lobsters fed the pelleted feeds had high survival (79 ± 4.5%) and responded to increasing dietary crude protein content with progressively higher growth rates, with the daily growth coefficient improving from 0.72% day−1 with 330 g kg−1 crude protein to 1.38% day−1 with 610 g kg−1 crude protein. Both growth rate and survival were low with the mussel diet (0.80% day−1and 41 ± 4.5%, respectively). These results demonstrate that tropical spiny lobsters grow well when fed high-protein, high lipid, pelleted feeds, but feeding on a sole diet of freshly thawed green-lip mussels was unsatisfactory.