Organismal homeostasis requires regulation of extracellular acid-base status; however, the mechanisms by which insects regulate haemolymph pH are poorly known. We evaluated the recovery of desert locusts Schistocerca gregaria Forskal from acute acid loads, initiated by HC1 injections into the haemolymph (0.5 pH unit decrease). Haemolymph pH, PCO2 and [HCO3~] recovered in 8-24h, providing the fi...

When Carcinus was exposed to 20 /i-mol I" cadmium, the haemolymph cadmium level was initially dependent upon the salinity of the external medium. After 14 days the mean haemolymph cadmium level in 50% s.w. animals was nearly twice that of 100% s.w. animals. This trend was not sustained, however, and the situation was complicated by occasional inconsistent values. In both in vivo and in vitro co...

The current study was conducted to determine the LC(50) value of ammonia-N as well as the effects of acute exposure to elevated ammonia on the haemolymph osmolality, ionic composition, ammonia-N and pH levels of early juvenile mud crabs, Scylla serrata. The results show that early S. serrata juveniles have a high 96-h LC(50) value of 95.35 mg/L ammonia-N (6.81 mg/L NH(3)-N) or 6.80 mmol/L total...

Although most of humanity relies upon foods that do not require animal pollination [1], production of 39 of the world’s 57 most important monoculture crops still benefits from this ecosystem service [2]. Western honey bees (Apis mellifera) are undoubtedly the singlemost valuable animal pollinators to agriculture because they can be easily maintained and transported to pollinator-dependent crops...

Oral Supplementation with 50, 100 and 150 ?g/ml calcium chloride to the fifth stadium larvae of CSR2xCSR4 biovoltine hybrid silkworm, B. mori on fat body glycogen, protein, and total lipids and haemolymph trehalose and protein have been studied. One of the four normal feeds per day was substituted with treated leaves fed to silkworms at fifth instar larvae. The controls were fed with the leaves...

In vivo magnetic resonance imaging (MRI) and angiography were applied to the marine spider crab Maja squinado for a study of temperature effects and thermal tolerance. Ventilation and haemolymph circulation were investigated during progressive cooling from 12°C to 2°C. The anatomical resolution of MR images from Maja squinado obtained with a standard spin echo sequence were suitable to resolve ...

Acid-toxicity tests were performed using two crayfish species, Procambarus clarki Girard and Orconectes rusticus Girard to determine the median lethal pH (LC60) after 4 days exposure to acid. Four-day LC50 values of pH 2*5-2-8 were observed, indicating that these animals are more acid-tolerant than most fish species. Haemolymph acid-base variables and major ion concentrations were measured duri...

Lipid composition of the fat body and haemolymph of male milkweed bug, On.cc@eltus fasciatus, was determined. Triglycerides were the predominant lipids of the fat body while diglycerides accounted for the major lipid in the haemolymph. Sterols, sterol esters, and non-esterified fatty acids were present in both fat body and haemoIymph besides triglycerides and diglycerides. Only traces of monogl...

Ventilatory control of internal CO(2) plays an important role in regulating extracellular acid-base balance in terrestrial animals. While this phenomenon is well understood among vertebrates, the role that respiration plays in the acid-base balance of insects is in need of much further study. To measure changes in insect haemolymph pH, we implanted micro pH optodes into the haemocoel of cockroa...