ABSTRACT
Growth is a diachronic process that influences many other processes; thus, the knowledge of growth parameters is a prerequisite for a better understanding of lobster biology and for applying sensible fisheries regulations for commercially important stocks. Lobsters can only increase in length through molting, and aging is difficult as the frequency of molting varies throughout an individual’s lifetime. There are no known specific differences in molting physiology or in growth modalities of scyllarid lobsters compared with those of other lobsters. The growth phenomenon depends on external variables, including the influence of nutrition, season, temperature, light, and photoperiod, as well as other environmental or stressful parameters that may be found in artificial settings; in cases where conditions are suboptimal, reductive molts can occur. Literature specifically dealing with adult crustacean growth is limited, and information on scyllarids is even scarcer. Some data exist for the slipper lobsters of the genus Scyllarides, mainly of the Mediterranean species, which may constitute a case study for the whole family. These data are discussed and limitations of data obtained both in the laboratory and in the wild are reviewed. The inadequacy of the usual models, in particular the von Bertalanffy growth function (vBGF), to actually describe decapod growth is also examined. The parameters of the seasonalized vBGF obtained in the laboratory for Scyllarides latus (Latreille, 1802) are CL∞ = 127.2 mm, k = 0.20, C = 1.0, ts = 0.83, which are in agreement with data from long-term recaptures in the wild, and not far from the values for the Galápagos species S. astori Holthuis, 1960. The vBGF suggests that Scyllarides species are long lived, with a yearly molt in the adult phase, and incremental increases in carapace length per molt of around 6%. Other information is presented on morphology, morphometry, seasonality, and length-frequency distributions from commercial catches in Italian waters.
