Circadian rhythms of determined blood chemistry values in buzzards and eagle owls

• 1.1. Fifteen values were determined in blood samples from six buzzards (Buteo buteo) and six eagle owls (Bubo bubo) over the 24 hr of the day.
• 2.2. Glucose, urea, uric acid, triglyceride and calcium values showed diurnal rhythms in both species. Their respective patterns of diurnal variation were compared.
• 3.3. Phosphorus, cholesterol and cholinesterase levels underwent circadian rhythms only in the buzzards. Albumin/globulin and amylase exhibited diurnal variations exclusively in the eagle owls.
• 4.4. Glutamatic oxaloacetic transaminase, albumin, globulin, total protein and creatinine concentrations did not show diurnal rhythms in either of the species.
• 5.5. Blood values of the different parameters were studied on the basis of the ranges described in birds.

     

Erg circadian rhythm in the course of ontogeny in crayfish

• 1.1. The objective of the present work was to study the ontogeny of the ERG circadian rhythm in crayfish.
• 2.2. Long-term recordings of ERG and shielding retinal pigments position measured from the instar, the second instar, the third instar and the adult crayfish were obtained.
• 3.3. In the youngest animals (1–8 days old) an ultradian rhythm (15min-4hr periods) in the ERG amplitude was detected.
• 4.4. Older animals showed a progressive increment in the period length before they exhibited a circadian pattern. This last appeared, the first time, in 30-day-old animals and showed noticeable differences in the adult crayfish. At the same time, the crayfish began to show photomotor reflex. Later on (140-day-old crayfish) the circadian rhythm attained its final parameters.
• 5.5. The SD was used as a measure of lability in periods. The 4 hr ultradian rhythm and the 22.4 hr circadian rhythm showed the lowest SD indicating that they are the most precise period values.
• 6.6. Our results support the idea that the ERG circadian rhythm results from the coupling among high frequency (ultradian) oscillators, particularly those of 4 hr periods and that the coupling depends on the action of neurosecretions released from the sinus gland.

     

Effects of acclimation temperature,season, and time of day on the critical thermal maxima and minima of the crayfish Orconectes rusticus

• 1.1. The critical thermal minima (CTMin) and maxima (CTMax) were determined for field-acclimatized and laboratory-acclimated crayfish (Orconectes rusticus) throughout 1984.
• 2.2. The CTMin and CTMax of field-acclimatized crayfish were seasonally adjusted by 9.7 C and 14.7 C respectively.
• 3.3. Seasonal variation in both tolerance regimes persisted in crayfish acclimated in the laboratory at 5 and 25°C for one week; however, no diel variation existed in either the CTMin or CTMax of laboratory-acclimated crayfish.
• 4.4. Integration of thermal acclimation of the CTMin and CTMax with seasonal conditioning may influence the functional capacities of this species when considered in relation to the seasonal ranges in stream temperature.

     

Differences in temperature sensitivity of the orcadian systems of homoiothermic and heterothermic neotropical bats

• 1.Comparative studies of two neotropical chiropteran species—one homoiothermic (Phyllostomus discolor, Phyllostomidae) and one heterothermic (Molossus ater, Molossidae)—show that their activity rhythms are differently affected by the ambient temperature (AT).
• 2.1. Whereas the period of the free-running circadian rhythm of Molossus at 20°C.is much different from that at 30°C, and is positively correlated with AT (Fig. 2), no temperature-dependent changes in the period of Phyltostomus were observed (Fig. 4).
• 3.2. Correspondingly, trapezoidal temperature cycles 10°C in amplitude do not entrain the free-running rhythm of the homoiothermic bat, whereas they act as a Zeitgeber for Molossus ater. Even forM. ater, however, the Zeitgeber strength of such temperature cycles is relatively slight.
• 4.3. These results are inconsistent with a hypothesis of Bünning (1977) concerning the phylogenetic adaptation of temperature sensitivity of circadian rhythms of warm-blooded animals. They are consistent both with the hypothesis that heterothermic species in general have circadian systems with appreciable temperature sensitivity, and with the proposal that the more plastic circadian systems are in general more strongly influenced by AT than rigid systems.

     

Relations between the growth and the molt interval in the eyestalkless crayfish,Procambarus clarki

• 1.1. An intermittent feed led to an increase in the molt interval but a decrease in the increasing rate of carapace length after each molt in eyestalkless young crayfish. Procambarus clarki.
• 2.2. In the eyestalkless, medium-sized crayfish, the molt interval slightly increased but the increasing rate of carapace length slightly decreased when either 1 or 6 walking legs were removed from their bodies.
• 3.3. The eyestalkless crayfish which were fed sufficiently can grow normally, representing that they have a normal water balance.
• 4.4. In crayfish, the rapid growth itself may be one of the factors for the precocious molt.

     

A novel inhibitor of glycogen phosphorylase from crayfish hepatopancreas

• 1.1. A novel glycogen phosphorylase inhibitor was partially purified from crayfish hepatopancreas.
• 2.2. The inhibitor was found only in two species of crayfish examined, and not in lobster, fresh and salt water clams, mussels or cockroaches.
• 3.3. The inhibitor is a small protein (M_r = 23,000) which did not show proteolytic activity.
• 4.4. Preliminary kinetic analysis of the inhibitory mechanism indicated that it bound to both glycogen and the glycogen phosphorylase protein.
• 5.5. Inhibitor binding to glycogen resulted in a competitive inhibition pattern with respect to glycogen phosphorylase (inhibition constant of ca 10 μg/ml).
• 6.6. The inhibitor also bound glycogen phosphorylase directly with a binding coefficient of 100 μg/ml resulting in a partially non-competitive inhibition pattern with respect to phosphate.

     

Phosphorylation in crayfish (Procambarus clarkii) eggs during hatching

• 1.1.|The high-energy phosphorylation metabolism in crayfish, Procambarus clarkii eggs during brooding and juvenile crayfish after hatching was studied by in vivo³¹P nuclear magnetic resonance (³¹P NMR) spectroscopy.
• 2.2.|Inorganic phosphoric acid (Pi) and adenosine-5′-triphosphate ATP(γ-,α-,β-) were detected in the dark brownish red eggs after oviposition.
• 3.3.|In orange unhatched eggs, only sugar phosphate (SP), Pi and resolved phosphometabolite from ATP were observed.
• 4.4.|Peaks of SP, Pi, arginine phosphate (Arg-P), and ATP (γ,α,β) appeared in larvae of crayfish after hatching (nauplius, zoea and juvenile crayfish).
• 5.5.|The high-energy phosphorylation metabolism changed to an anaerobic condition along with a decrease in the concentration of dissolved oxygen in fresh water.

     

Neuron-glia communicatory structures in crustaceans

• 1.1. Membrane modifications and junctional structures involved in neuron-glia exchange in crustaceans are reviewed, including some new observations on the crayfish Procambarus clarkii.
• 2.2. Neuron cell bodies and associated glia interact through trans-glial channels, modified neuronal endocytosis and gap-like junctions.
• 3.3. Tubular lattices, trans-glial channels, endocytosis and capitate projections give support to axo-glial relationships.
• 4.4. Unidentified neuron-glia membrane appositions have been also found in neuropile.

     

Circadian organization in white suckers Catostomus commersoni: The role of the pineal organ

• 1.1. Pinealectomy of the white sucker, Catostomus commersoni, had significant effects on the free-running circadian rhythm of locomotor activity. With fish kept under constant darkness pinealectomy resulted in a significant alteration in period length and decrease in the precision of circadian activity.
• 2.2. In a number of cases circadian activity was split into two components that free-ran independently.
• 3.3. The pineal organ is suggested to function in the coupling of a multi-oscillator system making up circadian organization in this fish.

     

Melatonin: A coupling device between oscillators in the circadian system of the ruin lizard Podarcis sicula

• 1.1. Chronic administration of melatonin (in silastic capsules) lengthened the free-running period of the locomotor rhythm and shortened the circadian activity time in Podarcis sicula held in constant temperature and darkness.
• 2.2. Lizards displaying a bimodal pattern of activity invariably became unimodal after melatonin administration.
• 3.3. The results support the hypothesis that melatonin acts as a coupling device between circadian oscillators driving the locomotor rhythm in Podarcis sicula.

     

Mitochondrial malic enzyme from the crayfish abdomen muscle,purification, regulatory properties and possible physiological role

• 1.1. Mitochondrial malic enzyme (l-Malate: NADP oxidoreductase (oxaloacetate decarboxylating) EC 1.1.1.40) has been isolated from abdomen muscle of crayfish Orconectes limosus by chromatography on Sepharose 6B and DEAE cellulose. Specific activity of the purified enzyme was about 5 μmols per min per mg protein, which corresponds to about 30-fold purification.
• 2.2. This enzyme showed extremely small reversiblity, since the reaction in the direction of decarboxylation is at least 37, 190 and 760 times that for the carboxylation at pH 7.0, 7.5 and 8.0 respectively.
• 3.3. Purified enzyme showed allosteric properties, which was more accentuated at more alkaline pH (Hill coefficients were 1.1, 1.7 and 1.8 at pH 7.0, 7.5 and 8.0 respectively). The activity of malic enzyme was increased considerably in the presence of succinate and fumarate.
• 4.4. Mitochondira isolated from abdomen muscle of Orconectes limosus incubated in the presence of malate, fumate and succinate catalysed pyruvate production which was stimulated by ADP and inhibited by respiratory chain inhibitors.
• 5.5. NADH but not NADPH oxidation was catalysed by broken mitochondria or sonic particles. When NADPH and NAD were added simultaneously the rate of oxidation. This suggests the presence of active NADPH:NAD transhydrogenase in mitochondria isolated from the crayfish abdomen muscle.
• 6.6. A possible metabolic role for NADP-linked malic enzyme/transhydrogenase couple in abdomen muscle of crayfish Orconectes limosus is proposed.

     

Differential weighting of electrophoretic data in crayfish and fiddler crabs (decapoda: astacidae and ocypopidae)

• 1.1. Muscle proteins from the chelae of six crayfish species and ten species of Uca were compared through disc electrophoresis (split gel technique).
• 2.2. No intraspecies variation of the electrophoretic pattern was found.
• 3.3. In interspecies comparisons all components (bands) were weighted individually and specified as ancestral or derived characters.
• 4.4. In the crayfishes the phylogenetic trees constructed from electrophoretic and classical data were found to be congruent. In Uca some branches of either tree remained undefined. Each tree, however, helped complete the other one.

     

Topography and distribution of motor neurons supplying uropod muscles of a crayfish

• 1.1. The pathway and distribution of motor neurons in the uropod muscles of the crayfish, Procambarus clarkii, was investigated electrophysiologically and histologically.
• 2.2. There were three crossing points of motor neurons between the peripheral motor bundle originating from the second and third roots of the sixth abdominal ganglion.
• 3.3. It seems that there are no anatomical and functional regularity in the innervation pattern of the uropod muscles.

     

Effect of polarized light on the ERG circadian rhythm in crayfish

• 1.1. Crayfish subjected to constant darkness and temperature displayed an electroretinographic circadian rhythm with both non-polarized and polarized light stimuli.
• 2.2. In the ERG circadian rhythm associated with polarized light there was an observed reduction in period and increment in both amplitude and activity: rest ratio.
• 3.3. The change from non-polarized to polarized light also produced phase advances or delays in the ERG circadian rhythm depending on the circadian time when the change was introduced.
• 4.4. Separate recording of HI and HII ERG components showed that HII is always less conspicuous and more easily saturable than HI circadian rhythm.
• 5.5. These results support that: (a) the detection of polarized light contributes to extend the differences between night and day; (b) the two structures involved in the generation of HI and HII ERG components, i.e. the rhabdom and the retinular cell, operate as two independent elements of the circadian system responsible of ERG circadian rhythm.

     

Yolk synthesis in the marine shrimp,Penaeus vannamei

• 1.1. In vitro yolk synthesis was measured in fragments of the ovary of developing shrimp, Penaeus vannamei.
• 2.2. Progesterone and estradiol stimulated yolk synthesis in vitro, while ecdysterone, testosterone and estrogen had no effect.
• 3.3. A peptide factor from the eyestalks of crayfish stimulated yolk synthesis in vitro. A peptide factor from shrimp eyestalks inhibited yolk synthesis in vitro.

     

A study of visual pigments in the two antarctic crustaceans Orchomene plebs (Amphipoda) and Glyptonotus antarcticus (Isopoda)

• 1.1. Total chromophore contents as well as the contributions made by 11-cis retinal were determined by high pressure liquid chromatography in light- and dark-adapted eyes of Orchomene plebs and Glyptonotus antarcticus (Amphipoda and Isopoda, respectively).
• 2.2. In O. plebs the highest amount of total chromophore in pmol/eye was found to be 18.5 in 36 hr dark-adapted animals. The lowest amount (11.6 pmol/eye) was recorded in 24 hr light-adapted individuals.
• 3.3. In dark-adapted O. plebs, irrespective of whether dark-adapted for 36 or 60 hr, the percentage of 11-cis retinal was maximally 96.6%. In the light-adapted material it reached 71.2%
• 4.4. In eyes of 20 hr dark-adapted Glyptonotous antarcticus, possibly because of insufficient dark adaptation, a total chromophore content of only 3.2 pmol/eye was found. The percentage of 11-cis retinal was 55.8.
• 5.5. Porphyropsin with its testable 3-dehydroretinal (vitamin A₂-aldehyde) was not encountered in any of our samples.
• 6.6. Calculations of photopigment per gram body weight and a comparison with data from freshwater crayfish show that dark-adapted O. plebs possess approximately 20 times the relative photopigment amount of the crayfish. Absolute sensitivity of the eye of O. plebs is, therefore, expected to be very high.

     

The slow muscles in the uropod of crayfish,Procambarus clarkII

• 1.1. The fiber types of uropod muscles of the crayfish, Procambarus clarkii, were determined by the myofibrillar ATP-ase histochemistry and electrophysiology.
• 2.2. The ATP-ase histochemistry was carried out on the sections of the whole tailfan and the slow muscles were identified as being of the slow type on the basis of their low staining intensities.
• 3.3. The location of slow bundles in the mixed type muscles i.e. the dorsal rotator (DRT), the ventral rotator (VRT), and the telson-uropodalis posterior (TUP) was confirmed.
• 4.4. TUP was newly revealed in this study to be a mixed muscle.

     

Temperature regulation and metabolic rhythms in populations of the house sparrow,Passer domesticus

• 1.1. The house sparrow, Passer domesticus, has a circadian rhthym of metabolism and body temperature.
• 2.2. Evolutionary adaptation to a hot and humid climate is reflected in the lower metabolism and greater insulation of the Houston population than observed in populations from Ann Arbor, Michigan; Boulder, Colorado and Syracuse, New York.
• 3.3. There are no significant differences in either body temperature or evaporative water loss of all four populations.
• 4.4. The Houston population is able to survive higher ambient temperatures than is found in the Ann Arbor, Michigan or Boulder, Colorado population.

     

Analysis of postembryonic development of locomotor activity rhythm by corpora allata implantation in the cricket gryllus bimaculatus

• 1.1. Male crickets Gryllus bimaculatus show a drastic change in circadian rhythm from nymphal diurnality to adult nocturnality, in association with an increase in activity level several days after the imaginai moult.
• 2.2. The corpora allata implantation into male 7th or 8th instar nymphs produced supernumerary instar nymphs in about 30% of the implanted animals, but did not affected the normal development in the remaining animals.
• 3.3. The majority of the supernumerary instar nymphs were diurnal and sexually inactive, although their internal reproductive organs appeared to be fully mature.
• 4.4. The supernumerary instar nymphs became nocturnal with an increase in activity level several days after the imaginai (9th) moult.
• 5.5. The roles of the nervous system in the regulation of the rhythm reversal are discussed.