Use of the Brix value with cuticle indices to describe haemolymph biochemistry parameters in Homarus americanus H. Milne Edwards, 1837 (Decapoda: Malacostraca: Nephropidae)

The Brix value was incorporated into a classification system in combination with the indices of carapace rigidity and setal stage to provide a framework for studying haemolymph biochemistry. The system was applied to a pre-existing dataset to generate descriptive statistics and reference intervals, where possible, for 18 parameters from commercial-size male and female American lobsters, Homarus americanus H. Milne Edwards, 1837, in Atlantic Canada. The lobsters were sampled on fishing vessels within 5 min of the hauling of commercial traps, providing a good representation of the range of values expected for trappable American lobster in their natural environment. In addition to expected trends in protein associated with the moult cycle, trends apparently related to reproductive status of females, region, and season were also observed in the concentrations of triglycerides, cholesterol, and lactate as well as alkaline phosphatase activity. The classification system could prove useful in other studies of crustacean physiology, especially where haemolymph-derived parameters are examined.