An analysis of refractometry as a method of determining blood total protein concentration in the American lobsterHomarus americanus(Milne Edwards)

Abstract

Given the high unit value of live American lobsters (Homarus americanus), a non‐destructive field method to assess physiological state is desirable during out‐of‐water transport conditions. This study compared an Uricon® specific gravity refractometer, with a commercial veterinary blood analyser (Vet‐Test), as a method for determining the blood total protein concentration in live, out‐of‐water individuals. Regression analysis of R2 = 0.8641 (n = 64) was observed in determination of blood total protein concentration, y = 0.0036x + 1.0163 where x is the protein concentration in mg dL−1 in Vet‐Test. Our results (R2 = 0.864, SE ± 0.003) support the results (R2 = 0.985) of the previous study conducted by Leavitt & Bayer (1977) in which serum total protein was compared with the refractometric method. We therefore confirm that the refractometric method can be used as a reliable method to indicate health of a lobster by measuring the blood total protein concentration. The results show good correlation between the protein concentrations observed using the refractometric method and a Vet‐Test blood chemistry analyser. anova analysis was significant between the protein refractometer and the Vet‐Test (P < 0.05). Although protein concentration units obtained from both methods were different the results followed the same trends. Refractometry as a method is reliable to determine blood total protein concentrations in the American lobster. Consequently, a refractometric method can be used directly by commercial growers and distributors to assess responses to holding facility conditions and to feeding regimes. Whole blood protein concentrations may provide more information than serum protein concentrations as measured in the study of Leavitt & Bayer (1977).

Juvenile immune system activation induces a costly upregulation of adult immunity in field cricketsGryllus campestris

“…However this long-term upregulation of general immunity depletes resources and comes with a metabolic cost, seen as a reduced adult haemolymph protein load in immune-challenged individuals. Protein load of the haemolymph has been used as an adequate indicator of physiological metabolic condition (Ozbay & Riley 2002;Nakamatsu & Tanaka 2003) and disease resistance (Adamo 2004) in invertebrates. Nymphal nutritional condition positively affected lysozyme activity, while there was no effect on the proPO cascade.…”

“…To obtain a measure of physiological condition we assessed the total protein load of the haemolymph (Ozbay & Riley 2002;Nakamatsu & Tanaka 2003). The concentration of total protein was determined photometrically in 5 ml of diluted haemolymph, using the test solution Roti Nanoquant (K 880.1, Carl Roth GmbH & Co., Karlsruhe, Germany), following the protocol of the manufacturer.…”

Stocking density and shelter type for the optimal growth and survival of western rock lobster Panulirus cygnus (George)

“…Levels of prophenoloxidase in lobsters are known to fluctuate in response to environmental changes and stress (Moullac & Haffner 2000) and they, together with the level of protein in the hemolymph, have been used as an indicator of lobster health (Chang, 1995;Floreto et al, 2000;Osbay & Riley 2002). Comparison of prophenoloxidase levels between 540 P. cygnus sampled in this study and a database of 119 P. cygnus lobsters (both wild caught and wild captive) has revealed that all but one of the test animals were within normal range for prophenoloxidase and similar to some of the larger wild caught lobsters (B. Jones, unpublished data).…”

Spectroscopic Analysis of Hemolymph from the American Lobster (Homarus americanus)

“…Leavitt and Bayer (1977) used a total solids refractometer as a way to analyze THP levels directly in the field without returning to a laboratory to use a spectrometer or other laboratory protocol. This refractometer procedure has since been universally adopted by the lobster industry and is now the most common technique used to determine lobster vitality (Ozbay 1996, Ozbay & Riley 2002. Unfortunately, all techniques to quantify THP, including refractometry, are invasive in that they require drawing a hemolymph sample with needled syringe.…”