BIOMEDICAL EVALUATION OF A BROWN LEMUR (EULEMUR FULVUS SPP.) POPULATION FROM MBOUZI ISLET, MAYOTTE ISLAND.

The brown lemur population (Eulemur fulvus spp.) in Mbouzi islet is not native, and was introduced in 1997. Since then, the population has grown. In 2012 the National Council for Protection of Nature of Mayotte requested to remove this population of lemurs from Mbouzi, as they were suspected to be a threat to the protected endemic flora of the islet. The Association Francophone des Vétérinaires de Parcs Zoologiques (French-speaking Zoo Veterinarians Association, AFVPZ) was asked to conduct a biomedical evaluation of the population. Fifty-two animals were captured, anesthetized, and weighed. They all underwent a general physical examination. Feces were sampled for bacterial and parasitological screening. Hair was sampled for genetic studies and blood was sampled for hematology, biochemistry, viral serology, and haemoparasitology. Results showed that three individuals had a positive feces culture for Salmonella enterica and six had Lemuricola or Callistoura parasite infestations. Blood analyses for hematology and biochemistry showed 46 animals with elevated transferrin, 42 with low ferritin levels, 19 with hyperglycemia, and 10 with neutrophilia. Finally, 10 were positive for Toxoplasma serology, one was positive for α herpesvirus, five for pox virus, five for simian virus 40, and two for flavivirus. This publication reports the first complete biomedical evaluation of lemurs on Mayotte Island.

Absence of Evidence of Rift Valley Fever Infection in Eulemur fulvus (Brown Lemur) in Mayotte During an Interepidemic Period.

The potential role of Eulemur fulvus (brown lemur) in the epidemiology of Rift Valley fever (RVF) in Mayotte, during an interepidemic period, was explored. In February and March 2016, 72 animals were blood sampled and tested for RVF. No evidence of RVF genome or antibodies was found in the samples. The role of other wild mammals on the island should, however, be further investigated.

SUMMER AND WINTER VITAMIN D3 LEVELS IN FOUR LEMUR SPECIES HOUSED AT A BRITISH ZOO, WITH REFERENCE TO UVB LEVELS.

Serum samples were collected from 18 lemurs of four diurnal/cathemeral species housed with outdoor access at Bristol Zoo Gardens (United Kingdom) to test 25-hydroxy-vitamin D3 (25OHD3) levels as part of the veterinary department's preventative health care program. Samples were collected from each lemur in August 2008 (summer) and January 2009 (winter) to examine the effect of season on 25OHD3 levels. The lemurs were fed commercial primate food and a range of fruit and vegetables, and dietary levels of vitamin D3 remained the same throughout the study period. Statistical analysis showed that the lemurs' summer 25OHD3 values (range 26.7 to >150.0 µg/L) were significantly higher than their winter 25OHD3 values (range 11.4-87.1 µg/L). UVB measurements taken during the study period confirmed that UVB levels were significantly higher in summer (mean reading for 1200-1300 GMT time period 153.8 µW/cm2) compared to winter (mean reading for 1200-1300 GMT time period 19.4 µW/cm2). The 25OHD3 levels measured were generally found to be high compared to previously published values from wild (free-ranging) lemurs in Madagascar. The most likely explanation for this was the higher vitamin D3 content of the captive lemurs' diet, as UVB levels at the zoo (latitude 51° north) are substantially lower than those that occur in Madagascar (latitude 12°-26° south). No evidence of vitamin D toxicity or deficiency was found in any of the captive lemurs. The results indicate that vitamin D3 levels in lemurs housed with outdoor access in the United Kingdom and by extension, other regions of similar latitude, vary with seasonal environmental UVB levels, in a similar way to the seasonal variations in vitamin D3 observed in humans living in these regions, but that vitamin D levels in this captive lemur population were adequate compared to wild lemur levels, even in winter.

Survey of minerals and fat-soluble vitamins in captive black and white ruffed lemurs (Varecia variegata).

Serum and whole blood samples from 64 clinically normal captive black and white ruffed lemurs (Varecia variegata), aged 6 mo to 32 yr, were analyzed to survey mineral and fat-soluble vitamin concentrations. All animals were fed a commercial primate food and a wide range of fruits and vegetables. Specific commercial diet information was available for 52 animals that were fed one of 10 different diets. Data analysis showed no differences in the analytes attributable to sex or access to natural ultraviolet light. Serum phosphorus (range: 1.4-3.1 mmol/L) was significantly higher and retinol (range: 0.38-1.23 micromol/L) was significantly lower in young animals (< or =4 yr). Iron (range: 17.2-77.0 micromol/L) and copper (range: 10.7-53.3 micromol/L) were much higher than concentrations reported in other free-ranging lemur species, and in some animals were at levels considered potentially toxic in domestic animals. Magnesium (range: 0.66-2.04 mmol/L), sodium (range: 111-201 mmol/L), and potassium (range: 2.0-6.8 mmol/L) ranged both lower and higher than concentrations considered adequate for a mammal, but were similar to concentrations reported in wild red ruffed lemurs (Varecia rubra), a closely related species. Selenium (range: 3.5-7.7 micromol/L) was within the range expected for a mammal, but higher than concentrations reported in wild V rubra. Zinc (range: 9.2-62.7 micromol/L) was similar to concentrations reported in V. rubra. Calcidiol (range: <12.5-144.8 nmol/L) and retinol (range: 0.38-2.95 micromol/L) were both lower and higher than concentrations reported in V. rubra. Lower serum calcidiol concentration correlated with lower commercial dietary vitamin D3. Alpha-tocopherol (range: 1.2-17.6 micromol/L) and y-tocopherol (range: 0.3-3.9 micromol/L) were within a range expected in a captive frugivorous primate but higher than concentrations found in wild V. rubra.

Prosimian hemoglobins--V. The primary structures of the alpha-I, alpha-II and beta-hemoglobin chains of Hapalemur griseus, with a note on the classification of Microcebus.

1. The duplicated adult hemoglobins were isolated from a mature Hapalemur griseus and the constituent chains prepared. Sequence analysis of the isolated alpha-globins showed that the alpha-I and alpha-II chains differed by a glycine for lysine substitution at position 15. 2. The complete amino acid sequence of the single adult beta-globin of Hapalemur griseus was determined. The beta-globin sequence of Hapalemur griseus clusters with those of other authentic lemurs, and is clearly separated from the sequences characteristic of lorisiform primates. 3. Partial sequence analysis of the beta-globin of Microcebus murinus showed only a single amino acid difference when compared to the Hapalemur globin. 4. Partial sequence analysis of the alpha-globin of Microcebus murinus showed only three amino acid residues that are not found in other lemuriform alpha-globins; two of these are unique to Microcebus among all known prosimian alpha-globin sequences. 5. The Microcebus alpha- and beta-globins are more similar to the homologous lemuriform sequences than they are to lorisiform sequences.

Prosimian hemoglobins. III. The primary structures of the duplicated alpha-globin chains of Lemur variegatus.

The amino acid sequences of the alpha chains of hemoglobins purified from Lemur variegatus erythrocytes have been determined. The sequences were determined primarily from peptides generated from treatment of the isolated alpha chains with cyanogen bromide or warm formic acid. The ordering of the peptides from both alpha globins was based on the homology between lemur hemoglobins and those of other primates. The genetic difference at position 15 (Asn vs. Lys) explains the phenotypic characteristic of two hemoglobin species during alkaline electrophoresis. The function of certain residues is discussed in the context of other known sequences. The dispersion of the amino acid changes noted in lemur species falls mostly within the first 75 residues of the alpha chain (exons 1 and 2). The extent of divergence of the L. variegatus alpha-globin chains from the Lemur fulvus alpha globin is similar to that seen for the beta-globin chains of these species. This degree of separation (11-16 residues) is consistent with an extended period of independent evolution by these congeneric species after their divergence.

Diurnal variations in plasma testosterone concentrations in the male lesser mouse lemur (Microcebus murinus).

In 6 isolated adult male lesser mouse lemurs, concentrations of testosterone in plasma were determinated at 6-h intervals over a 24-h period. Blood samples were collected at monthly intervals and for a period of 12 months under natural photoperiod. In this nocturnal prosimian, there were no apparent diurnal changes in testosterone concentrations during the non-breeding season (autumn). During seasonal sexual activity (January-August), diurnal changes in testosterone concentrations were characterized by a significant rise during the light phase. The daily testosterone peak occurred about 8.5 h after sunrise from February to July, but at the beginning (January) or at the end (August) of the breeding season, the daily testosterone peak was displaced to the morning. A circannual testosterone rhythm occurred with the highest testosterone values in May/June and the lowest values 6 months later. The dramatic fall in testosterone concentrations after the summer solstice may be associated with a change in the peripheral metabolism of testosterone.

Hematology and serum chemistry values of juvenile and adult ruffed lemurs (Varecia variegata).

Hematologic and serum chemistry values are presented for adult and juvenile red ruffed lemurs (Varecia variegata rubra) and black and white ruffed lemurs (Varecia variegata variegata) maintained in a zoological collection. Hematologic and serum chemical values are compared between age groups and subspecies and with other primate species. Elevated hematocrit, total protein, and serum albumin values were noted. Significant differences in cholesterol, total protein, and serum albumin values between the two age groups are discussed.

Annual variations in the plasma thyroxine level in Microcebus murinus.

There is a great annual variation of plasma thyroxine (T4) in Microcebus murinus. The averages range between 30 and 68 ng/ml from February to July, and fall to 6 ng/ml in November. Long photoperiods seem to be the environmental factor responsible for the summer increase in plasma T4 as they are for testosterone. There is no apparent phase opposition with annual testosterone variation.

Prosimian hemoglobins I. The primary structure of the beta-globin chain of Lemur catta.

The primary structure of the beta chain from the hemoglobin of a prosimian primate, Lemur catta, has been determined by automated Edman degradation of intact polypeptide chain and fragments produced by tryptic, cyanogen bromide and acid cleavage, and by homology with the sequence of Lemur fulvus. The sequence presented here differs from the human beta-globin sequence at 26 sites. This is the same degree of divergence previously reported for the beta-globin chain of Lemur fulvus. The sequences of the two congeneric lemuroid beta-globin chains are surprisingly divergent, differing at 18 sites. Of the 26 positions where L. catta differs from Homo sapiens, 7 are at positions with defined function. Of these 7 positions, 4 (2-Phe, 54-Ile, 94-Val, 112-Ile) are unique to L. catta among the primate beta-globin chains of established sequence. Residue 112-Ile is consistent with the prediction of Beard and Goodman (19) of an isoleucyl residue in this position in the ancestral primate beta-globin chain.

Hematology of the lesser mouse lemur (Microcebus murinus). A preliminary study.

Some blood values of 86 lesser mouse lemurs (Microcebus murinus) maintained in captivity are presented. These are comparable with those of other prosimians: PCV 51.7%, RBC 9.2 X 10(6)/mm3, MCV 57.5 micron3, WBC 12,900/mm3, lymphocytes 59.7%, neutrophils 30.7%, monocytes 4.8%, eosinophils 4.2%, basophils 0.6%. We noted no significant difference between the sexes except that the percentage of lymphocytes was slightly lower in the females (with a corresponding percentage of neutrophils slightly higher). The lymphocyte:neutrophil ratio decreases with age, particularly in young animals; the hematocrit does not vary in adults.

Serum concentrations of calcium and vitamin D metabolites in prosimians.

The concentrations of total calcium, 25-hydroxyvitamin D [25-(OH)D] and 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] were measured in serum obtained from prosimians, the brown lemurs. The mean serum calcium level was 10.6 mg/dl in male and female lemurs. The mean serum mean 25-(OH)D concentration in serum from male and female lemurs was 27.1 and 31.0 ng/ml, respectively. The mean serum level of 1,25-(OH)2D3 in the female and male lemurs was 65.2 and 65.9 pg/ml, respectively. A small segment of the lemurs had hypercalcemia and elevated serum concentrations of 25-(OH)D or 1,25-(OH)2D3, suggesting the idea that the episodic ingestion of a large quantity of the calcium- and vitamin D-enriched diet normally provided ad libitum might cause hypercalcemia.

Osmotic fragility of erythrocytes of lemurs.

Erythrocytes of five species of lemurs were found to be significantly more susceptible to lysis by osmotic stress than erythrocytes of man. In one lemur species, Lemur macaco, the red cell osmotic fragility profile resembles that of human subjects with hereditary spherocytosis.