The Effects of CaCO₃Buffering on the Hemolymph Acid-Base Level of the American Lobster (Homarus americanus)

Abstract

An improvement in the survival rate of lobsters held in an aerial environment is needed to allow shipment by commercial flights to potentially lucrative distant markets in the Pacific rim. Despite some degree of facultative breathing out of water, a reduction in gill function reduces the lobsters' respiratory and excretory capacities. This results in potentially lethal blood levels of NH 3 and/or low levels of pH. A series of experiments were conducted on the effects and practicality of buffering the blood acid-base level by immersing lobsters for several days in seawater with added CaCO 3 prior to shipment. Elevation in the ammonia and magnesium concentrations over time and fluctuations in the calcium contents of the blood were observed. Treatment differences for Ca 2+ and NH 3 were not significant but the differences were significant for protein and Mg 2+ levels. As a result, we concluded that treatment with the CaCO 3 solution did not significantly affect the acid-base balance of lobsters. The fluctuations in lobster Gulnihal Ozbay, MS, is affiliated with Marine Bioresources, former Graduate Student,

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

“…Truchot (1983) reported that intracellular buffers, which function to maintain haemolymph acid‐base levels, are mainly proteins, various polypeptides, and organic phosphate compounds. Consequently, measuring the protein concentration of a lobster's blood can provide valuable information to determine its condition (Ozbay 1996).…”

Effect of Holding and Packing Conditions on Hemolymph Parameters of Freshwater Prawns, Macrobrachium rosenbergii, during Simulated Waterless Transport

“…All hemolymph samples were taken from the pericardial sinus (Lallier and Truchot 1989; Chen and Chen 2003) using a 1 mL syringe with a 25‐gauge needle at room temperature. Approximately 0.30 mL of hemolymph was taken from each prawn and 0.10 mL was used immediately for measuring pH, pCO 2 , pO 2 , HCO 3 , tCO 2 , and K + using a VetStat blood gas analyzer (IDEXX Laboratories, Westbrook, ME, USA) as used by Ozbay and Riley (1999). The remaining portion of the hemolymph sample (0.20 mL) was mixed with a like amount of a buffered citrate anticoagulant (Cheng et al 2003) and stored at 4 C for 24 h. It was then tested for glucose, lactate, ammonia, total protein, magnesium, and calcium using a VetTest analyzer (IDEXX Laboratories).…”

“…In crustaceans, a number of hemolymph parameters have been measured in an effort to indicate stress. These include osmoregulatory capacity (Lignot et al 1999), acid–base balance, and ion concentrations (Chen and Chen 2003), as well as ammonia, total protein, calcium, and magnesium (Ozbay and Riley 1999). Measurement of these physiological indicators could help focus efforts on the sublethal changes during waterless transport which have the greatest impacts on the animal's health and survival.…”

“…The reported iso‐osmotic point for M. rosenbergii is 17 ppt (Singh 1980). Ozbay and Riley (1999) stated that American lobsters, Homarus americanus , accumulate excess amounts of hemolymph CO 2 when exposed to air, but are able to maintain hemolymph acid–base balance by mobilizing CaCO 3 from their exoskeleton. Therefore, holding the animal in a buffering environment prior to packing might increase the animal's ability to maintain its internal acid–base balance.…”

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.…”