Biogenic amines and phenolics characterize the defensive secretion of saturniid caterpillars (Lepidoptera: Saturniidae): a comparative study

The morphology of the scoli of Eudia pavonia, Saturnia pyri and Eupackardia calleta last instar caterpilars has been clarified. Chemical and biochemical comparisons of scolus secretions and corresponding caterpillar haemolymphs indicate two differing defensive strategies: Eudia and Saturnia contain phenolic and related compounds, whereas Eupackardia additionally synthesizes biogenic amines (e.g. neurotransmitters) in considerable amounts. For most aromatic compounds from the caterpillars a theoretical biogenetic scheme is proposed. Deterrent effects of all secretions and most haemolymphs on particular predatory ants were ascertained.Abbrevations CI chemical ionisation - EI electronimpact ionisation - GC-MS gas chromatography-mass spectrometry - GS gland secretion - HL haemolymph - PMSF phenylmethylsulphonyl fluoride - SDS-PAGF sodium dodecyl sulphate-polyacrylamide gel electrophoresis - SEM scanning electron microscope     

Morphology and location of dense-core vesicles in the stomatogastric ganglion of the lobster,Panulirus interruptus

The appearance and distribution of dense-core vesicles in the stomatogastric ganglion of the spiny lobster, Panulirus interruptus, were examined using transmission electron microscopy. Following five fixation techniques, three types of dense-core vesicles were identified on the basis of size and morphology. Type-I vesicles are found in a distinct neuronal fiber system that appears to be involved in chemical transmission within the ganglion. Type-II vesicles occur in nerve processes in the ganglion, in major nerve trunks and in the perineural sheath of the nerves and ganglion. Type-III vesicles are present in all neuronal somata of the ganglion. The distinct morphology and location of the three types of vesicles suggest that their functional roles differ. Furthermore, the histochemical, biochemical and physiological data available for the stomatogastric ganglion indicate that Type-I vesicles may store dopamine.     

Effects of egg removal on maternal aggression, biogenic amines, and stress indicators in ovigerous lobsters (Homarus americanus)

In many disparate taxa, including crayfish, a freshwater decapod crustacean, the presence of one's offspring has been shown to be an important variable in the level of maternal aggression. Ovigerous American lobsters (Homarus americanus) show a territorial advantage against nonmaternal females, even though no posthatch care is provided. The eggs are attached to the pleopods (swimmerets) throughout embryogenesis. We evaluated the effect of stripping ovigerous H. americanus females of their eggs on maternal territoriality. In one treatment group, maternal females were stripped of all eggs. Twelve days later, including being individually isolated for an additional 48 h in a test tank, each resident was serially intruded upon by 4 non-maternal conspecific females. An identically treated control group of ovigerous female residents was left intact prior to the serial intrusions. Various biochemical parameters of the stripped and unstripped animals were measured before and after the experimental treatment (or control). The behavioral modulators measured were the biogenic amines, octopamine and serotonin, and the stress indicators were a heat-shock protein (HSP70), methyl farnesoate, and crustacean hyperglycemic hormone. The intact ovigerous residents showed a significant territorial advantage over the intruders, whereas the contest outcomes of stripped residents were reduced to chance. The presence of eggs in maternal H. americanus is therefore necessary for the maintenance of the shelter-related territorial advantage. However, no significant differences in any of the biochemical parameters were observed between or within treatment conditions. It appears that these amines are not prominently involved in the mechanism of maternal aggression, and that these changes in territorial defense are not simply due to changes in general stress as a result of stripping the females of their eggs.     

Determination of biogenic amines in fish implicated in food poisoning by micellar electrokinetic capillary chromatography

A micellar electrokinetic capillary chromatography (MECC) method for the simultaneous determination of seven biogenic amines in fish was developed. The peaks of all components were successfully separated within 11.5 min. MECC was performed with 0.06 M sodium deoxycholate in 0.02 M borate buffer (pH 9.2)–methanol (95:5, v/v) solvent. The average recoveries for all components ranged from 84.4 to 100.3%. The application of this method to detect amines in fried marlin fillet implicated in a food poisoning incident indicated that a high level (56.24 mg/100 g) of histamine was present in the sample. Another 10 fish samples collected from markets were also analyzed and did not contain detectable levels of histamine (<2.5 mg/100 g).