Seasonal changes of total lipids in the turtle Sternotherus odoratus

• 1.1. Seasonal variation in total lipids was examined in several body components of the turtle Sternotherus odoratus.
• 2.2. Carcass fat stores in both sexes were depleted during winter. Additionally, a decline in carcass lipids was associated with increases in gonadal mass.
• 3.3. Concentrations of liver lipids were maximal during August and minimal during winter.
• 4.4. Males showed little seasonal change in plasma lipid levels, whereas females had seasonal peaks temporally associated with ovarian development and carcass fat storage.
• 5.5. Ovarian concentrations of lipids were minimal after nesting and increased during fall.
• 6.6. Results suggest that S. odoratus uses stored fats both for reproduction and maintenance during winter.

     

A comparative study on the biological properties of venoms from juvenile and adult common tiger snake (Notechis scutatus) venoms

• 1.1. The biological properties of venoms from juvenile and adult common tiger snakes (Notechis scutatus) were compared.
• 2.2. The lethality, procoagulant activity and enzymatic activities of the juvenile venom were not substantially different from those of the adult venom.
• 3.3. Electrophoretic studies, however, indicated some minor differences in the protein composition of the juvenile and adult venoms.

     

Ontogenetic change in thermal tolerance of the toad Bufo woodhousii fowleri

• 1.1. Premetamorphic Bufo woodhousii fowleri tadpoles exhibit a high critical thermal maximum (CTM) of 42.5°C which decreases during metamorphosis to 37°C.
• 2.2. The CTM of progressively larger (older) postmetamorphic or juvenile toads gradually increases until the adult CTM of 41.1°C is attained.
• 3.3. This gradual increase in CTM from juvenile to adult toad suggests that the physiological systems underlying thermal tolerance change or mature following metamorphosis until the adult condition is reached.
• 4.4. Basking in juvenile toads elevates their metabolic rate and thus may facilitate the acquisition of the adult physiological state.

     

Seasonal changes in plasma prolactin concentration and carcass lipid levels in the lesser snow goose (Anser caerulescens caerulescens)

• 1.1. Plasma prolactin levels did not differ significantly between groups of birds collected at different times during the first year of life.
• 2.2. In adult males and females, highest plasma prolactin concentrations were evident in June (20.7 ± 7.8 and 20.4 ± 4.4 ng/ml respectively), probably associated with the incubation of eggs and rearing of young in the nest, whereas plasma prolactin levels in adult males and females collected at other times of the year were relatively stable and did not differ significantly between groups.
• 3.3. With the exception of the adults sampled in June, the prolactin levels in the adults were in the same range as those in the embryo gosling and yearling Snow Geese.
• 4.4. The concentrations of fat in both mature and immature birds was not related to the plasma prolactin concentration; maximal concentrations of carcass fat were observed during the northerly migration whereas maximum concentrations of prolactin were observed at the end of incubation when fat deposits were depleted.

     

Salinity tolerance of adult and juvenile red king crabs Paralithodes camtschatica

• 1.1. Juvenile king crabs were more tolerant of reduced salinities than adult crab; juvenile crab were better volume regulators at reduced salinities than adult crab.
• 2.2. Adult female king crab hemolymph was hyperosmotic to full seawater (30 ppt) and isosmotic to dilute seawater. Juvenile king crab (2 years old) were hypoosmotic at the same concentrations.
• 3.3. Lower osmotic concentration of juvenile hemolymph is at least partially due to lower sodium concentration.
• 4.4. Juvenile king crab can tolerate some dilution and survive for short periods in the reduced salinity of the lower intertidal zone.

     

Sex-specific androgen binding in spotted hyaena (Crocuta crocuta) plasma

• 1.1. A charcoal adsorption assay demonstrated a large variance in androgen binding ability in female spotted hyaenas.
• 2.2. A positive correlation between plasma androgen binding ability and ovarian steroid concentrations was demonstrated in adult females.
• 3.3. The strong plasma binding affinity for testosterone and dihydrotestosterone (DHT) (nM) together with the lack of cortisol and weaker oestradiol-17β binding suggests that a specific androgen binding substance, possibly a protein, is present in adult females of this species.
• 4.4. The lack of high affinity binding in male spotted hyaenas is unusual and deserves further investigation.
• 5.5. Some androgen binding in all, including males and immature animals suggests that albumin may bind some plasma androgens in this species.

     

Seasonal variation of LH and testosterone in the smallest deer,the pudu (Pudu puda molina) and its relationship to the antler cycle

• 1.1. In order to obtain a seasonal profile of LH, three adult male pudu (Pudu puda, Molina) were sampled monthly from the saphenous vein for a period of one year.
• 2.2. A significant circannual variation of plasma LH levels was detected with an average peak value (1.77 ng/ml) recorded in February and nadir concentrations (0.19 ng/ml) observed in November.
• 3.3. The peak level of testosterone (1.54 ng/ml) was detected in March, the time of the rut.

     

Relationship between brain trehalase activity and trehalosema during direct and diapausing development in Pieris brassicae

• 1.1. Brain trehalase specific activity and trehalosemia were measured during the end of the developmental life cycle in non-diapausing and diapausing insects.
• 2.2. During non-diapausing development, trehalosemia reached maximum values at the beginning of pupal life. Then a constant decrease was observed up to the end of adult life.
• 3.3. The specific activity of brain trehalase was maximum when the insects were in active feeding periods, minimum activity appearing during moulting phases.
• 4.4. During diapausing development, trehalosemia was very high at the beginning of pupal life, particularly when insects were exposed to wintering conditions.
• 5.5. When diapause was broken, trehalosemia fell, announcing adult emergence.
• 6.6. Brain trehalase activity showed the same qualitative variations as in non-diapausing larvae, but with rather lower values.
• 7.7. During pupal life, brain trehalase activity decreased markedly during the long period necessary to obtain diapause breakdown.
• 8.8. Wintering conditions allow a progressive increase of brain trehalase activity, which preceded the fall of trehalosemia.

     

A comparison of the capabilities of juvenile and adult Penaeus setiferus and Penaeus stylirostris to regulate the osmotic,sodium, and chloride concentrations in the hemolymph

• 1.1. The capabilities of juvenile and mature adult Penaeus setiferus and P. stylirostris to regulate the osmotic, sodium, and chloride concentrations in the hemolymph are compared.
• 2.2. In P. setiferus and P. stylirostris acclimated to salinities of 9.8 and 10.8%. respectively, juvenile shrimp are stronger hyperosmotic and hyperionic regulators than adults. However, the reduced regulatory capabilities of adult shrimp are not sufficient to require migration to offshore waters for survival.
• 3.3. At 40.4%. juvenile P. setiferus are more effective hypoosmotic and hypoionic regulators than adults. However, there is no difference between the regulatory capabilities of juvenile and adult P. stylirostris at 36.2%.
• 4.4. Differences in hemolymph concentration between juvenile and adult P. setiferus at 23.5%. indicate that the isosmotic and isoionic crossover concentrations are elevated with maturation.

     

Vitellogenin synthesis in female larvae of the gypsy moth,Lymantria dispar (L.): suppression by juvenile hormone

• 1.1. Fat body from feeding-phase, last instar gypsy moth females incorporates l-[³⁵S]methionine in vitro into two vitellogenins with the same molecular masses (165 and 180 kDa) as the apo-vitellogenins found in teh hemolymph and the apo-vitellins in teh eggs.
• 2.2. Both apo-vitellogenins are observed in the medium of fat body cultures, but only the 180 kDa apo-vitellogenin is observed in extracts of cultured tissue.
• 3.3. Synthesis and accumulation of the apo-vitellogenins are suppressed in a dose-dependent manner by topical treatment with the juvenile hormone analog, methoprene, prior to day 4.
• 4.4. This suppression suggests that a declining juvenile hormone titre is involved in the initiation of vitellogenin synthesis.

     

Plasma membrane: Can its structure and function be modulated by dietary fat?

• 1.1. Compositional analysis of plasma membranes from rats fed nutritionally adequate diets different in fatty acid composition establishes that fundamentally different dietary fat intake results in alteration in structural lipid composition of plasma membranes in brain, liver and the intestinal mucosa.
• 2.2. Dietary differences in fatty acid intake altered the fatty acyl tail composition of plasma membrane phospholipids in brain, liver and intestinal mucosa.
• 3.3. Diet altered the phospholipid profile observed in brain synaptosomal and liver plasma membrane.
• 4.4. Feeding high vs low polyunsaturated to saturated fat diets for 7 days altered the fatty acid composition of phosphatidylcholine, phosphatidylethanolamine, sphingomyelin and mono-glucosylceramide isolated from plasma membrane of the intestinal mucosa

     

Effects of dietary estradiol-17β on feminization,growth and body composition in the Japanese eel (Anguilla japonica)

• 1.1.Juvenile Japanese eels (Anguilla japonica) were fed on a diet supplemented with estradiol-17β (E₂) at doses of 25, 50 and 75 mg/kg. The effects on growth, sex distribution and body composition were investigated in two groups of gonadally undifferentiated stages (early and later juvenile stages).
• 2.2.Feminization (95–100%) was observed in all E₂-treated groups.
• 3.3.The growth rate of fish treated with 25 and 50 mg/kg E₂ diet at the early juvenile stage was significantly increased.
• 4.4.The amount of protein in muscle decreased and that of fat increased in the E₂-treated groups except in the early juvenile stage fed with 25 mg/kg E₂.

     

Changes in plasma glucose and lipid concentrations during treadmill exercise in domestic fowl

• 1.1. Plasma glucose, non-esterified fatty acid, triglyceride, cholesterol and lactate concentrations were measured during 90 min treadmill exercise at a work intensity of 55–60% maximum.
• 2.2. After 90 min exercise plasma glucose fell by 35% whilst the non-esterified fatty acid concentration rose to as much as 3–4 times resting.
• 3.3. Exercise had no significant effect on plasma cholesterol, triglyceride or lactate concentrations.
• 4.4. The findings indicate a progressive increase in fat utilization during prolonged exercise. Possible hormonal mechanisms underlying exercise-induced changes in lipid and carbohydrate metabolism are discussed.

     

Development of imaginal competence to adipokinetic hormone in Locusta: Lipid and carbohydrate levels,and glycogen phosphorylase activity in azadirachtin-induced over-aged nymphs

• 1.1. Adipokinetic responses to injection of synthetic adipokinetic hormone I (sAKH) and relevant physiological parameters were studied in azadirachtin-induced 31 to 34-day-old Vth-instar over-aged male nymphs of Locusta migratoria which did not undergo the metamorphic moult to adult.
• 2.2. The resting lipid and carbohydrate levels in the haemolymph and sAKH-induced activation of fat body glycogen phosporylase did not differ markedly between over-aged nymphs, normal nymphs and normal adults.
• 3.3. Total fat body glycogen phosphorylase activity and the effect of sAKH on haemolymph carbohydrate level in over-aged nymphs were similar to those in normal adults and differed from those in normal nymphs.
• 4.4. sAKH-induced elevation of haemolymph lipid level in the over-aged nymphs was higher than in normal nymphs but lower than in normal adults; thus, the over-agad nymphs attained only a partial adult competence in this respect.

     

Fermentation and the production of volatile fatty acids in the alimentary tract of the rock hyrax,Procavia capensis

• 1.1. Aspects of ruminant-like metabolism were examined in the hyrax Procavia capensis.
• 2.2. High concentrations of volatile fatty acids occurred in the cardiac stomach with a predominance of acetic and lactic acids.
• 3.3. Acetic (69%), propionic (22%) and butyric (8%) acids occurred in highest concentrations in the proximal caecum, with appreciable amounts in the proximal colon, distal caecum and appendices.
• 4.4. The depot fat contained high proportions of unsaturated C₁₈ (linoleic and linolenic) acids.
• 5.5. The glucose level in the plasma was within the range established for non-ruminant herbivores.
• 6.6. The possibility of silage-like fermentation occurring in the cardiac stomach is discussed.

     

Effects of lysine administration on plasma arginine and on some nitrogenous catabolites in rainbow trout

• 1.1. Rainbow trout were fed either graded levels of lysine (0.8, 1.8 and 3%) at a constant level of arginine (1.4%) or excess arginine (2.4%) at a fixed level of lysine (1.8%).
• 2.2. Increasing the dietary lysine level affected plasma urea, plasma arginine and ammonia excretion.
• 3.3. Trout fed graded levels of lysine received an arginine challenge (U¹⁴C-l-arginine) and it was found that excess dietary lysine led to a decrease in arginine degradation.
• 4.4. Injection of l-lysine induced a decrease in urea excretion, while injection of l-arginine increased both urea and ammonia excretion in control well-fed trout.
• 5.5. These results are discussed in the light of current knowledge on the antagonism between lysine and arginine.

     

Quantification of iron deposits in several body tissues of lampreys (Petromyzon marinus L.) throughout the life cycle

• 1.1. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) was used to measure iron concentration in several body tissues throughout the life cycle of the lamprey, Petromyzon marinus L.
• 2.2. Iron concentration in the liver rises sharply during metamorphosis, decreases in parasitic adults, and falls to the lowest value in upstream migrants.
• 3.3. In the intestine, the concentration of this metal is highest in the larval stage, but values decline steadily through transformation to their lowest levels in parasitic adults.
• 4.4. Dorsal skin has, on average, three times the iron content of ventral skin and it is only in upstream migrants that the levels of both regions increase significantly over those of other stages.
• 5.5. Differences in iron concentration in tissues of larval and adult lampreys reflect changes which take place at metamorphosis.

     

Breast,hips, and buttocks revisited: Honest fatness for honest fitness

This paper comments on: Low, B. S., Alexander, R. D., and Noonan, K.M. Human hips, breast, and buttocks: Is fat deceptive? Ethology and Sociobiology 8: 249-247, 1987. In it I argue that:

• 1.1. Sexual selection has probably not been the most important selection pressure on
• 2.female human body shape.
• 3.2. Male humans in different cultures find different aspects of the female body attractive
• 4.and therefore are unlikely to have exerted consistent directional sexual selection on
• 5.the female body.
• 6.3. Breast size is not correlated with lactation success.
• 7.4. Visible hip width is not correlated with parturition success.
• 8.5. Women would lower their fitness if they tried to deceive men about their internal
• 9.pelvic dimensions.
• 10.6. There are many alternative hypothesis to explain the existence of fat onwomen's
• 11.breast, hips, and buttocks.

     

The sterols of crustaceans: Decapods (Sub-order macrura)

• 1.1. The effects of environmental depth, geographical location, sex and seasonal changes have been studied on the sterol composition of closely related pelagic decapods.
• 2.2. In addition the sterol composition of the adult bodies have been compared with that of the eggs and the hepatopancreas.
• 3.3. The results indicated a pronounced uniformity of sterol requirements in these animals with cholesterol being easily the major structural sterol.