Hand‐raising a spectral tarsier (Tarsius tarsier) at the Ueno Zoological Gardens

On February 10, 2008, a newborn male spectral tarsier (Tarsius tarsier) was found on the floor of the indoor exhibit room in the Small Mammal House of the Ueno Zoological Gardens. The dam showed no signs of providing maternal care and therefore we decided to hand‐raise the infant. Its birth weight was 18.7 g. We placed the dam and infant in an incubator and gave 12.5–25% formula (for kittens), until the 145th day after birth. We limited the volume of formula intake to avoid excessive intake and to prevent diarrhea. For nutrition enrichment, we added a chicken liver homogenate to the formula 1–3 times per day. The infant was given a sunbath for 10 min on the 28th day. He showed no serious decline in health, except for diarrhea that occurred during the first few days after birth. He ate a small cricket for the first time on the 50th day and easily caught mealworms on his own on the 105th day. Gradual changes in feeding times, formula concentration, and the nutritionally enriched formula were essential for successfully hand‐raising the tarsier. Zoo Biol 30:218–224, 2011. © 2010 Wiley‐Liss, Inc.     

Growth and development of infant giant pandas (Ailuropoda melanoleuca) at the Wolong Reserve,China

From 1991 to 1993 inclusive, seven infant giant pandas (Ailuropoda melanoleuca) were born at the China Conservation and Research Center for the Giant Panda. Average daily weight gain in the first 6 months for mother-reared infants (n = 5) was 71.3 g/day; for one partially mother-reared and partially hand-reared infant, 41.5 g/day; and for one completely hand-reared infant, 50.3 g/day. There was a significant difference in growth rates across the first 6 months in all methods of rearing. In addition, a comparison of growth rates across the three rearing methods showed significant differences in the first, second, third, fifth, and sixth months. Average daily body length increase for mother-reared infants was 4.1 mm/day; for partially mother-reared/partially hand-reared infants, 4.0 mm/day; and for the completely hand-reared infant, 2.8 mm/day. In mother-reared infants, body length increase during the first month was significantly greater than during the following months, and was slowest during the sixth month. At birth, infants were all pink in color with a light white coat of lanugo. Black pigmentation was first noted at 7–10 days of age, which was also the time that initial hair coat growth was seen. Eyes opened at 35–48 days of age. Ears opened at 31–50 days of age. Deciduous dentition was first seen at 82–121 days of age, while permanent dentition began to erupt at 350 days of age. © 1996 Wiley-Liss, Inc.     

Infant formula ingestion is associated with the development of diabetes in the BB/Wor rat

The association between early exposure to cow's milk products in infancy and risk for insulin dependent diabetes mellitus (IDDM) is controversial. We examined whether the ingestion of cow's milk-based infant formula altered the expression of the diabetic syndrome in the BB/Wor rat, an animal model of IDDM. Pregnant BB/Wor dams were obtained from the NIH contract colony at the University of Massachusetts and housed under semi-barrier conditions. Rat pups were intubated with 1 to 2 ml of commercially available cow's milk-based infant formula (Enfamil or Nutramigen) or sham intubated (controls) daily from day 12 to day 25 of life. Pups were weaned at day 25 and monitored for glucosuria daily through 120 days of life. All rats including dams consumed a milk-free rat chow and acidified water ad libitum throughout the study. The mean age of disease onset was 4 to 10 days earlier in Nutramigen-fed and Enfamil-fed rats relative to controls (84+/-3, 78+/-2 and 88+/-4 days, respectively); the mean age of disease onset was significantly different between controls and Enfamil-fed animals (p<0.05). At 120 days, 60% (12/20) of control rats developed diabetes versus 100% of animals fed either type of infant formula prior to weaning (15/15:Enfamil-fed; 19/19:Nutramigen-fed) (p<0.05). These data indicate that direct, early ingestion of cow's milk-based formula was related to the expression of diabetes in the BB/Wor rat.     

Daily protein and energy intakes of infants fed a commercial infant formula with a reduced protein concentration of 2.2 g/100 kcal: an impact of feeding interval on energy intake

ABSTRACT

We evaluated the protein and energy intakes of infants fed commercial infant Formula A (protein, 2.2 g/100 kcal; energy, 68 kcal/100 mL) and examined whether changes in feeding intervals are involved in constant energy intake. Daily nutritional intake of 378 Formula A-fed infants was assessed using reference values and compared to that of infants fed Formulas B (protein: 2.3 g/100 kcal, energy: 68 kcal/100 mL) and C (protein: 2.4 g/100kcal, energy: 70 kcal/100 mL). From 15 to 149 days of age, the mean formula volume and protein intake were 758–887 mL/day and 11.4–13.3 g/day, respectively, higher than the protein intake of breast-fed infants. Daily energy intake (86–129 kcal/kg/day) was comparable to the estimated energy requirements. Feeding intervals were shorter in infants fed Formulas A and B than in those fed Formula C, whereas energy intake was similar. The protein intake of infants decreased as the protein concentration per energy in infant formula was reduced, and accordingly the protein intake of Formula A-fed infants was significantly lower than that of Formula C-fed infants. In conclusion, the new composition of Formula A is suitable in protein and energy intake of infants, and daily energy intake remains constant by shortening in feeding intervals when the energy concentration in infant formula is reduced.

Clinical Trial Registration: UMIN000023110     

Capacity for growth compensation in juvenile three-spined sticklebacks experiencing cycles of food deprivation

The capacity of three‐spined sticklebacks Gasterosteus aculeatus (initial mean mass 0.280 g) to compensate for recurrent periods of food deprivation of 2, 4 or 6 days followed by 2 days of ad libitum feeding on enchytraeid worms over 56 days was assessed by measuring appetite and growth. Control fish were fed daily. The total number of days on which fish were fed ranged from 14 (6‐day cycle) to 56 (controls). Deprived sticklebacks were hyperphagic on the first day of re‐feeding in a cycle and this hyperphagia increased with successive cycles. Mean daily consumption on first day of refeeding was: controls, 62.9 mg; 2 days, 108 mg; 4 days, 98.8 mg; 6 days, 101 mg. The hyperphagia did not increase as the preceding period of deprivation within a cycle increased. Hyperphagia was not maintained on the second day of re‐feeding. The 4 day and 6 day groups initially showed hypophagia on the second day of re‐feeding. Mean daily consumption on second day of re‐feeding was: controls, 62.6 mg; 2 days, 62.2 mg; 4 days, 54.2 mg; 6 days, 50.0 mg. Over the experiment, consumption on the second day of the 4 day and 6‐day groups increased towards the control level, suggesting a developing compensatory response. The highest mean daily consumption per days fed was shown by the 2 day group. The relationship between number of days fed and total food consumption and specific growth rate suggested that the 2 day group almost compensated for the periods of deprivation. Performance declined for the 4 day and 6 day groups, although even at the highest level of deprivation, a positive growth was achieved. Mean specific growth rate in mass (% per day) was: controls, 2.33; 2 days, 1.89; 4 days, 1.21; 6 days, 0.86. Initial mass and total food consumption accounted for most of the variance in specific growth rate. Other indices of performance including lipid concentration, dry matter concentration and the RNA:DNA ratio in white muscle were positively related to quantity of food consumed by each group. Growth efficiency of sticklebacks in terms of wet mass gained and wet mass consumed over the experimental period was 19.4% and did not differ among control and treatment groups. The growth rates of the sticklebacks experiencing cyclical deprivation were comparable to growth rates previously recorded for sticklebacks fed daily, but consuming similar mean daily rations.     

Selenium content of Spanish infant formulae and human milk: Influence of protein matrix, interactions with other trace elements and estimation of dietary intake by infants

The selenium content of infant formulae varies as a result of differences in the amount of intrinsic selenium compounds. Manufacturers have been gradually changing the protein profile of infant formulae to reflect human milk contents more closely. Because of these variations in infant formula composition and their potential impact on selenium content, this trace element was analysed with regard to the different protein sources.

The aims of this study were to determine the selenium content in infant formulae sold commercially in Spain, to estimate a daily dietary intake for infants fed on formulae and to compare with the selenium provided by Spanish breast milk samples used as a reference. We have also identified certain trace elements added to formulae which interact with selenium according to the type and protein matrix of the infant formulae.

Selenium concentration was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) with a hydride generator.

The selenium concentrations in human milk and infant formulae determined in this study are similar to those found by other researchers in different countries. The daily selenium intake from the formulae studied was estimated according to the recommended doses from the manufacturers. The theoretical selenium intake of nursed infants has been studied in relation to the Recommended Dietary Allowance (RDA: 10 μg Se/day) and the specific recommendations for infant formula nutrient contents (10–35 μg Se/L) set by the Expert Panel of Life Sciences Research Office (LSRO) of the American Society for Nutritional Sciences.

According to our results, on an overall view, infants fed on the studied infant formulae have an intake between basal and normative requirements. This might be considered as providing an adequate selenium supply. However, the intake of selenium provided by several formulae included in this research did not reach the RDA for the first month of neonate life.     

Effect of cassava exudate and prey densities on the survival and reproduction of Typhlodromalus limonicus (Garman & McGregor) s.l. (Acari: Phytoseiidae), a predator of the cassava green mite,Mononychellus tanajoa (Bondar) (Acari: Tetranychidae)

The effects of cassava exudate and prey densities on reproduction and survival of the predatory mite, Typhlodromalus limonicus (Garman & McGregor) (Acari: Phytoseiidae), were investigated in the laboratory. Females were provided either cassava exudate ad lib. daily, low or high numbers of the cassava green mite prey, Mononychellus tanajoa (Bondar) (Acari: Tetranychidae) daily, or exudate for 5 or 10 days before switching to a low or high prey diet. Females fed only exudate laid no eggs. Females fed exudate before prey experienced a significant decrease (30%) in the number of eggs laid compared to females fed high numbers of prey daily. The reduction in fecundity was the result of prolonged preoviposition periods (2.0 days on prey daily vs 4.0 days on exudate before prey) and reduced number of eggs laid per female per day (1.7 eggs per female per day on prey daily vs 0.4 eggs per female per day on exudate before prey). Females fed only exudate had a greater survival rate and longevity than females fed prey daily or females fed exudate before a diet of prey. These results suggest that T. limonicus can survice for a limited period on cassava exudate during periods of low prey availability, but requires prey to complete oögenesis and propagate the population.     

Quantification of Clostridium botulinum type A toxin and organisms in the feces of a case of infant botulism and examination of other related specimens

Bacteriological examinations were performed on the first case of infant botulism in Japan (an infant boy aged 79 days at onset of illness). Clostridium botulinum type A toxin and organisms were detected continually in the stools of the infant for at least 31 days and 39 days, respectively. The highest levels of the toxin and of the population of the organisms, 7.8 X 10(4) LD50/g and 1.3 X 10(6) colony forming units (cfu)/g, were detected in the stool specimen taken on the 20th day of illness. Type A organisms were detected also in the honey fed to the infant before onset of illness, teats of his feeding bottle, soil specimens taken at the house entry and the vacuum-cleaner dust. Fecal excretion of the toxin and organisms was no longer detected from the 68th day of illness and he recovered.     

Pilot studies to identify the optimum duration of concomitant Helicobacter pylori eradication therapy in Thailand

Background and Aim: Eradication rate for Helicobacter pylori infection with standard triple therapy has globally declined including in Thailand, and new regimens are required that provide reliable high eradication rates. The study was designed to determine whether concomitant therapy administered for either 5 or 10 days would produce a ≥ 95% (grade A) treatment success in H. pylori infected Thai subjects with nonulcer dyspepsia. Methods: Two prospective, but separate, pilot single‐center studies were carried out during September 2009–December 2010 at Thammasat University Hospital, Thailand. H. pylori infected subjects were randomized into the two pilot studies; either 5‐day or 10‐day concomitant therapy. Thai concomitant therapy consisted of rabeprazole (20 mg) twice daily, amoxicillin 1 g twice daily, metronidazole 400 mg three times a day, and clarithromycin MR 1 g once daily. H. pylori status was assessed by ¹³C‐urea breath test 4 weeks after completion of the treatment. Successful treatment was defined as achieving a grade A result (≥95%) and failure by <90% cured. Results: A total of 110 subjects were randomized (55 to the 5‐day treatment trial and 55 to the 10‐day regimen). Baseline subject demographic and clinical characteristics were similar in both studies. All subjects completed their assigned therapies. The 10‐day concomitant treatment trial was successful in 53 of the 55 subjects (96.4%; 95% CI 87.4–99.5%). The 5‐day concomitant pilot was judged to be a failure as only 49 of 55 subjects (89.1%; 95% CI = 77.7–95.8%) were cured. The frequency of adverse events was low and similar in the two studies. Conclusion: The 10‐day concomitant regimen provided excellent treatment success (eradication rate >95%) and was well tolerated. Ten‐day concomitant therapy is likely to become useful first‐line H. pylori eradication in Thailand.     

Effects of the timing of initial feeding on growth and survival of spotted mandarin fish Siniperca scherzeri larvae

The effects of delayed first feeding on growth and survival of spotted mandarin fish Siniperca scherzeri larvae were examined under controlled conditions. Morphometric characters [yolk‐sac volume, oil globule volume, head depth (H_D), body depth (B_D), eye diameter (E_D), musculature height (M_H), mouth diameter (M_D) and total length (L_T)], body mass (M), specific growth rate (S_GR) and survival were evaluated under different first‐feeding time (2, 3, 4 and 5 days after hatching). Larvae began to feed exogenously at 2 days after hatching (DAH) and the point of no return (P_NR) occurred between 5 and 6 DAH at 23° C, range ±1·0° C. The yolk volume of larvae first‐fed at 2 days had a significant difference compared with that of larvae first‐fed at 3, 4 and 5 days on 3 and 4 DAH. The larvae first‐fed at 2 days achieved comparatively better growth performance than that of 3, 4 and 5 days. On 5 DAH, all morphometric characters had significant differences between 2 and 5 days and 2 and 4 days initial feeding, respectively. Total mortality was recorded on 9 DAH for the larvae first‐fed at 5 days. On 12 DAH, significant differences were observed between 2 and 4 days and 3 and 4 days initial feeding for all morphometric characters. From 16 DAH to the end of experiment, all growth variables of the larvae first‐fed at 2 days were significantly higher than those in other treatments. The S_GR (2–9 DAH) first‐fed at 2 and 3 days were significantly higher than 4 and 5 day treatments, and the S_GR (9–16 DAH) first‐fed at 2 days was significantly higher than 3 and 4 day treatments. There was no significant difference, however, of S_GR (16–28 DAH) among treatments. Survival rate was significantly higher at 2 days initial feeding (27·42%) when compared with 3 (15·96%) and 4 days (7·92%) initial feeding at the end of experiment. The present study suggests that the first feeding of S. scherzeri larvae should be initiated at 2 days after hatching for achieving good growth and survival.     

The breeding biology of the Scimitarbilled Woodhoopoe

Steyn, P. 1999. The breeding biology of the Scimitarbilled Woodhoopoe. Ostrich 70 (3&4): 173–178.

The breeding biology of the Scimitarbilled Woodhoopoe Rhinopomastus cyanomelas was studied at two sites in Zimbabwe over a 13-year period from 1964–1977. The pairs were resident, remained together throughout the year, and inspected their nest sites occasionally during the non-breeding season. The breeding season extended from August to December with a marked September/October peak. Eggs were laid at daily intervals. Clutch size averaged 2.9 (range 2–4). Incubation began either with the penultimate or last laid egg. During the 13–14 day incubation period the female left the nest only occasionally each day and was reliant on the male for food. This pattern continued for four days after the chicks hatch. Thereafter she started to forage and gradually increased her contribution to chick provisioning until she overtook that of the male. With one exception, he never fed the chicks directly and delivered the food to the female. The nestlings were brooded overnight for the first two weeks. The anti-predator response of the young included a malodorous brown exudation from the preen gland and unpleasant liquid excreta. The nestling period was 21–24 days and the young left the vicinity of the nest with their parents and did not return to roost in it. Twelve breeding cycles were monitored and 76% of eggs laid (n=37) produced fledged young. Second broods were raised in the same nest on two occasions after successful rearing of the first, presumably by the same pair, but the birds were not individually marked. There was no evidence of helpers at the nest.     

Response of bighead carp Aristichthys nobilis and Asian catfish Clarias macrocephalus larvae to free-living nematode Panagrellus redivivus as alternative feed

The use of Panagrellus redivivus as live feed for bighead carp and Asian catfish larvae was tested. In experiment 1, carp larvae were given Artemia nauplii (control) or Panagrellus twice daily for 21 days. A third treatment consisted of unfed larvae. The same three treatments were used in experiment 2 plus another with a commercial entomopathogenic nematode (EPN). Bighead carp larvae given Panagrellus in experiment 1 had much lower growth and survival than those fed Artemia nauplii. This could be due to low nematode density (5–30 mL^?1 water) during feeding. The unfed larvae had 100% mortality by days 11–13. In experiment 2, growth and survival of carp larvae given Artemia nauplii (5–10 mL^?1) and Panagrellus (50 mL^?1) did not differ significantly (P > 0.05). All unfed larvae had died by day 13, while larvae fed EPN were all dead by day 8. Two experiments on Asian catfish were likewise conducted. In experiment 1, the catfish larvae were fed Tubifex (ad libitum), Panagrellus (50–100 mL^?1 per feeding) orArtemia (5 nauplii mL^?1 per feeding) three times daily for 14 days. In experiment 2, larvae were fed Artemia alone (10 nauplii mL^?1 per feeding), Panagrellus alone (100 mL^?1 per feeding), or their combination with a 38% protein dry diet twice daily. For both experiments, catfish larvae fed Panagrellus had significantly lower growth and survival than those fed Tubifex or Artemia. The combination of Panagrellus and dry diet created little improvement in the growth and survival of catfish larvae.     

Metabolic acidosis and infant feeding.

Most cows'' milk based formulae for infant feeding present a greater acid load to the infant than breast milk. To determine the effect of this difference the acid base state of 180 healthy term infants was measured on the sixth day of life and related to the type of feed. Those infants fed on cows'' milk formula (SMA) had a mean pH of 7-34 +/- 0-05 and a base deficit of 8-8 +/- 3-1, while those fed on breast milk had a mean pH of 7-38 +/- 0-05 and a base deficit of 5-6 +/- 3-1. The difference between the two groups of infants was significant for both these measurements. Metabolic acidosis was defined as a base deficit greater than 10 mmol/l. Seventy-four per cent of the 34 infants who were acidotic at six days were bottle-fed. There was a significant correlation between the pH of the feed and the degree of acidosis in the infant as measured by the base deficit. The findings suggest that when breast milk is not available a pH-adjusted milk formula would be desirable for preventing and treating neonatal metabolic acidosis.     

Effects of feeding on survival, cannibalism, growth and feed conversion of African catfish, Clarias gariepinus (Burchell) in concrete tanks

Daily feeding rates of 0, 2, 4, 6, 8 and 10% of body weight to juvenile (average weight 0.64–65.4 g) catfish, Clarius gariepinus, for 112 days had significant effects on survival, cannibalism, growth and feed conversion ratio (FCR). Survival was significantly higher in fish fed at 6–10% of body weight than those fed at 2–4%. Mortality was mainly caused by cannibalism, being significantly higher in underfed (2–4%) fish than in fish fed at the 6–10% level. A feeding level above 6% did not further reduce cannibalism. The best growth performance was recorded for the fish fed at 8–10% body weight, followed by the fish fed at 4–6%; poorest growth was found for those fed at the 2% level. FCR significantly increased from 2–4% (FCR, 1.14–1.13) to 6, 8 and 10% (FCR, 1.37, 2.18, 2.98, respectively). The results of this study suggest that the optimum feeding rate of juvenile catfish with an average initial weight of about 0.64 g and grown to a size of about 64 g is at 6% body weight per day.     

Influence of feeding interval on reproduction and longevity ofPodisus sagitta (Het.: Pentatomidae)

The effect of various feeding intervals on reproduction and longevity of the predatory bugPodisus sagitta (Fabricius) (Heteroptera: Pentatomidae) was studied in the laboratory. Isolated pairs of adult bugs were given moisture in excess and were fed 1 seventh-instar larva of the greater wax moth,Galleria mellonella (L.), with a mean weight of 90 mg every 1, 3, 7, 14 and 21 days. Reproduction ofP. sagitta reflected well the feeding intervals. Females fed at increasing time intervals reduced reproductive outputs by decreasing oviposition frequency and size of egg batches. Predators fed every 21 days produced a mean of only 1.0 egg per day in comparison with 9.9 eggs per day for females fed daily. Longevity of females fed daily was 110.7 days; females fed less frequently tended to live longer, with a maximum mean longevity of 217.5 days for females fed every 14 days. No cannibalism among adults was observed, but females were occasionally seen to feed on their own eggs. Availability of moisture was found to be essential for the predators to survive during periods of low food supplies. These findings are discussed in relation to the predator's adaptation strategies in conditions of prey scarcity.      

Infant formula supplemented with polyamines alters the intestinal microbiota in neonatal BALB/cOlaHsd mice

Polyamines play a critical role in the development of intestinal and immune systems during the infant breastfeeding period, but the effect of polyamines on the microbiota has not been reported. The aim of our study was to characterize the impact on the colonization pattern in neonatal BALB/cOlaHsd mice after supplementing an infant formula (IF) with a mixture of putrescine (PUT), spermidine (SPD) and spermine (SPM). A total of 48 pups (14 days old) were randomly assigned to 4-day intervention groups as follows: breast-fed (unweaned) pups (n=12); weaned pups (n=12) fed an infant formula (IF); weaned pups (n=12) fed an IF enriched with a low concentration of PUT, SPD and SPM (2.10, 22.05 and 38.00 μg/day, respectively); and weaned pups (n=12) fed with IF enriched with a high concentration of PUT, SPD and SPM (8.40, 88.20 and 152.00 μg/day, respectively) of polyamines in accordance with normal proportions found in human milk. Microbiota composition was analyzed by fluorescent in situ hybridization (FISH) with flow cytometry detection. Microbiota changes in formula-fed mice were significantly greater following supplementation with polyamines (P<.01). Bifidobacterium group bacteria, Akkermansia-like bacteria and Lactobacillus–Enterococcus group levels were higher in the groups fed infant formula supplemented with polyamines, resulting in even higher numbers of bacteria than in the breastfed pups. Our findings indicate that infant formulas enriched with polyamines may interact with gut microbiota, suggesting that further studies in human infants are required to assess the impact of polyamines on both growth and microbiota levels.     

Life Cycle of Isospora rivolta (Grassi, 1879) in Cats and Mice*

SYNOPSIS. The endogenous development of Isospora rivolta (Grassi) was studied in cats fed oocysts, and was compared with the endogenous cycle after feeding them mice infected with I. rivolta. For the mouse-induced cycle, 14 newborn cats were killed 12 to 240 h after having been fed mesenteric lymph nodes and spleens of mice. Asexual and sexual development occurred throughout the small intestine, in epithelial cells of the villi and glands of Lieberkuhn. The number of asexual generations was not determined with certainty, but there were at least 3 structurally different meronts. Type I meronts appeared at 12–48 h postinoculation (HPI). They were 8.5(6–13) × 5.1(3–6) μm, contained 2–8 merozoites, and divide by binary division or endodyogeny. Type II meronts were multinucleate merozoite-shaped meronts within a single parasitophorous vacuole. They were found at 48–172 HPI and measured 12.6(9–18) × 9.8(9–13) μm. Individual multinucleate merozoite-shaped meronts were 7–13 × 3–5 μm in sections and contained 2–30 slender (5.5 × 1.0 μm) merozoites. Type III meronts occurred at 72–192 HPI and gamonts at 72–96 HPI. Mature microgamonts measured 11.3(9–15) × 8.0(6–9) μm in sections and up to 21.5 × 14 μm in smears, and contained up to 70 microgametes. Macrogamonts measured 13.3(11–18) × 9.0(5–13) μm in sections and 18 × 16 μm in smears. Oocysts were 10–15 × 9–15 μm in sections and 19.8(17–24) × 18.0(17–23) μm in fixed and stained smears. Unsporulated oocysts in feces were 22.3(18–25) × 19.7(16–23) μm and spomlated oocysts 25.4(23–29) × 23.4(20–26) μm. Sporulation was completed within 24 h at 22–26 C. For the study of the oocyst-induced cycle in cats, 18 newborn cats were killed between 6 and 192 HPI. The endogenous development was essentially similar to the mouse-induced cycle, but merogony and gametogony occurred 12–48 h later than in the latter cycle. Isospora rivolta was pathogenic for newborn but not for weaned cats. Newborn cats fed 10⁵ sporocysts or infected mice usually developed diarrhea 3–4 days after inoculation. Microscopically, desquamation of the tips of the villi and cryptitis were seen in the ilium and cecum in association with meronts and gamonts. For the study of the development of I. rivolta in mice, mice were killed from day 1 to 23 months after having been fed 10⁵–10⁵ sporocysts, and their tissues were examined for the parasites microscopically, and by feeding to cats. The following conclusions were drawn. (A) Isospora rivolta most frequently invaded the mesenteric lymph nodes of mice and remained there for 23 months at least. It also invaded the spleen, liver, and skeletal muscles of mice. This species could not be passed from mouse to mouse. Sporozoites increased in size from ?6.8 × 4.9 μm on day 1 to ?13.4 × 6.9 μm on day 31 postinoculation. Division was not seen. Prepatent period was 4–7 days and patent periods ranged from 2 to several weeks.     

树实验种群的繁育

探讨了树实验种群的繁育。结果是5对成年树在7个月内共产11窝31只仔树。27只出生后即人工喂养的仔树中,25只健康存活至进入动物实验。成年树平均产仔周期为（52±8.9）d;仔树的人工喂养成活率为92.6%。可以认为树实验种群的人工繁育是可行的。人工繁育的树有望取代野外捕获的树用于有关的动物实验研究。     

Effect of nematode Panagrellus redivivus density on growth, survival, feed consumption and carcass composition of bighead carp Aristichthys nobilis (Richardson) larvae

The study aimed to determine the optimum density of free‐living nematodes in feeding bighead carp, Aristichthys nobilis, larvae. In the first experiment, carp stocked at 25 larvae L^?1 were fed varying levels of nematodes (50, 75, 100, 125 and 150 per ml) twice a day for 21 days from the start of exogenous feeding. Final body weight was significantly higher (P < 0.05) in larvae fed 125 and 150 nematodes per ml than in those fed 50 and 75 per ml, but survival was low (61.8 and 63.6%, respectively). Survival rate was highest in larvae fed 100 nematodes ml^?1 (81.3%). Carcass analysis showed that larvae fed 125 and 150 nematodes ml^?1 had significantly lower body protein and higher body lipid than those fed other nematode densities. Carcass ash was similar for larvae fed 50–100 nematodes ml^?1 but it decreased significantly at the higher nematode densities. Carp larvae in a subsequent experiment were given 50, 75 and 100 nematodes ml^?1 per feeding. Newly hatched Artemia was the control feed. Nematode consumption and growth of the larvae were determined. Larvae were sampled at intervals of 2–4 days and the nematodes in the gut were counted and measured. At each nematode density, the number of nematodes present in the gut of the larvae increased significantly with time. At each sampling day, the number of nematodes in the gut did not differ significantly among treatments (P > 0.05) although it tended to increase with nematode density at day 2 and day 4 but decrease at day 7 onward. The carp larvae consumed significantly shorter nematodes on day 2 and day 4 than on the succeeding sampling days regardless of nematode density. However, the length of nematodes in the gut of the larvae did not differ significantly among the nematode densities. The final body weight of larvae increased with increasing nematode density. The body weight of larvae fed 100 nematodes ml^?1 did not differ significantly from that of larvae given Artemia nauplii. Results show that bighead carp larvae should be fed 100 free‐living nematodes per ml at each feeding time.     

Effects of information asymmetries in contests between net spinning caddis larvae (Plectrocnemia conspersa)

Summary During five days prior to the introduction of potential intruder larvae, residents were treated in four different ways. In one treatment the residents were unfed and their nets were taken away at daily intervals. Nets were not taken away in the other treatments, and residents were unfed, fed 2 or 4 items per day, respectively. Small intruders were equally successful as large ones in taking over low energy demanding nets of unfed, disturbed residents whose nets were taken away daily. Take overs of high ranked nets of larvae fed four prey items per day were mainly performed by large intruders. Low investment nets of unfed, disturbed resident larvae were often taken over during the first day upon the implantation of intruder larvae. On the contrary, unfed undisturbed larvae defending a five times as energy demanding net only suffered a slight net loss. Nets of unfed, undisturbed larvae were taken over somewhat more often than those from residents fed two prey per day. The results indicate prior treatment to inform these three resident categories of their resource values. Owners of high ranked nets fed two prey per day were most keen on defence during the first day upon introduction of potential intruders. Residents fed four prey per day suffered from a significantly higher number of take overs during the first day compared with larvae only fed two prey per day. The residents fed four prey per day stored some of the food in their nets making this resource more valuable also to intruders. After five days the number of take overs was about the same irrespective of previous treatment.