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At least 19 recordsLinked to original sources
PubMed2003

[Low genetic differentiation and close evolutionary connection between Anas platyrhynchos and Anas poecilorhyncha: data from RAPD-PCR analysis].

Using RAPD-PCR, we examined genetic diversity and phylogenetic relationships in two groups of river ducks: Anas platyrhynchos, A. poecilorhyncha, A. strepera and A. crecca, A. formosa, A. querquedula. Molecular taxon-specific markers were found for teals (A. crecca, A. formosa, A. querquedula) and gadwall (A. strepera). Each of the species examined was shown to exhibit high genetic diversity. The mean levels of intraspecific genetic polymorphism in the groups of mallards (P = 77%) and teals (P = 74.5%) were approximately equal whereas the mean interspecific genetic distances in teals were significantly higher than in mallards (D = 0.432 and D = 0.336, respectively). The levels of interspecific genetic differentiation in the species groups were also different. The genetic distances between the teal species and between gadwall and mallards were equal to 0.668-0.971 while the genetic distance between mallard A. platyrhynchos and spot-billed duck A. poecilorhyncha was 0.401, which slightly exceeds the intraspecific values for mallards (0.356-0.377). The RAPD patterns for this species pair showed high variability and a lack of fixed differences. This was adequately reflected on both intra- and interspecific differences and on phylogenetic constructions in which the morphological species did not form their own clusters but were intermixed. In contrast to mallards, the other species, which showed high genetic variability, were reliably separated in phenogenetic and phylogenetic reconstructions. The possible explanations of the low genetic differentiation of A. platyrhynchos and A. poecilorhyncha are discussed.

Animals↗
PubMed2003

Acute toxicity of lead, steel, and an iron-tungsten-nickel shot to mallard ducks (Anas platyrhynchos).

Twenty mallards (Anas platyrhynchos) of both sexes were dosed by oral gavage with Heavi-Shot (H-S; Environ-Metal, Inc., Sweet Home, Oregon, USA) pellets, 20 with steel shot, and 10 with lead (Pb) pellets, all of equal size. All pellets were fired from a shotgun into an absorbent material, retrieved, and weighed prior to introduction into the ducks. Birds were fed whole kernel corn and grit and observed for signs of toxicity for 30 days following dosing. Hevi-Shot pellets lost an average of 6.2% of their mass and steel shot pellets lost 57% of their mass in the birds' gizzards. Almost all (90%) of the Pb shot dosed birds died before the end of the study, while no mortality was observed in the steel or H-S dosed groups. Even though total food consumption differed between the H-S and steel shot groups, mean bird weight change was not different. There were no significant morphologic or histopathologic abnormalities of the liver and kidney in the H-S and steel shot groups. Results indicated that mallards dosed orally with eight No. 4 H-S pellets were not adversely affected over a 30-day period, and that H-S provides another environmentally safe nontoxic shot for use in waterfowl hunting.

Administration, Oral↗
PubMed1987

Posthatching development of the rete ophthalmicum in relation to brain temperature of mallard ducks (anas platyrhynchos).

In posthatching mallard ducks (Anas platyrhynchos), brain cooling improves with growth. To determine whether this may be correlated with growth-related changes in morphology of the rete ophthalmicum, we studied the development of this rete in immature mallards from hatching to 29 days of age. We found that the number of arteries and veins was fixed at hatching. The rete continued to grow, however, in length and vessel diameter during body and brain growth. The vascular surface area for heat exchange in the rete therefore also increased with body and brain mass. The increase in retial heat-exchange area was faster than the simultaneous increase in brain mass. The increase in body-to-brain temperature difference (delta T) described previously occurred nearly in direct proportion to heat-exchange area, such that the ratio of delta T to exchange area was nearly constant at about 0.1 degrees C per mm2 during growth. It is concluded that the increase in heat-exchange area of the rete ophthalmicum plays a major role in the development of brain cooling capacity of posthatching ducks.

Animals↗
PubMed1991

Inflammatory cell stimulation and wound healing in Sphaeridiotrema globulus experimentally infected mallard ducks (Anas platyrhynchos).

Thirty laboratory-reared mallard ducks (Anas platyrhynchos) were experimentally infected with Sphaeridiotrema globulus. Host cell-mediated immunity and wound healing in S. globulus infected ducks were evaluated by gross and histological examination. Establishment, location, and life span of S. globulus differed from previous reports of sphaeridiotremiasis in both naturally and experimentally infected waterfowl. No worms were recovered from the ceca, and worm migration occurred anterior to the ileo-cecal valve with greater dispersion (less worm crowding) at higher rates of infectivity. Parasite death and host lesion resolution were evident at days 8 to 10 postinfection (PI) in ducks fed a moderate dose (200 metacercariae, group A) with a 5% mean parasite recovery rate. Host death occurred at days 3 to 6 in ducks fed a high dose (550 metacercariae, group B) with a 16% mean parasite recovery rate. Mast cells increased significantly (P less than 0.005) in group A ducks from days 4 to 10 PI. Eosinophil proliferation was greater in group B than in group A on day 4 PI, but comparatively fewer eosinophils were identifiable in group B ducks on day 6 PI.

Analysis of Variance↗
PubMed2002

[Taxonomic, topical and quantitative structure of the community of intestinal flukes (Digenea) of mallards, Anas platyrhynchos Linnaeus, 1758 from the area of Szczecin].

Taxonomic, topical and quantitative structure of the community of intestinal flukes (Digenea) of mallards, Anas platyrhynchos Linnaeus, 1758 from the area of Szczecin. A total of 55 mallards (Anas platyrhynchos L.) from the area of Szczecin were examined for the presence of intestinal flukes (Digenea). This study covered the taxonomic structure (specific composition and taxonomic affiliation of the parasites), topical structure (parasites' distribution within the host's organism), and quantitative structure (infection intensity, abundance, prevalence, and infection index "Z"). Flukes were found in 69.1% of the birds studied. The highest intensity of infection and prevalence exhibited species of the family Echinostomatidae (Echinostoma revolutum, Echinostoma miyagawai, Echinostoma sp., Echinoparyphium recurvatum) and Notocotylus attenuatus of the family Notocotylidae. The mallards surveyed hosted 15 species of flukes, representing 6 families. Echinostoma miyagawai Ishii, 1932 has been found for the first time in Poland. The present findings of Psilotrema similium and Prosthogonimus ovatus in mallard constitute new host records for these parasites.

Animals↗
PubMed1983

The amino-acid sequence of Northern Mallard (Anas platyrhynchos platyrhynchos) hemoglobin.

The complete amino-acid sequence of the major hemoglobin component (HbA) of the adult Northern Mallard (Anas platyrhynchos platyrhynchos) is presented. A minor component HbD was also detected but in low concentrations. The sequences of alpha A- and beta-chains were established by automatic Edman degradation on tryptic peptides and peptides obtained by specific chemical cleavages. The alignment of the peptides was performed by comparison with the alpha A- and beta-chains of Greylag Goose hemoglobin (Anser anser). Thereby an exchange of five positions in the alpha A-chains and three in the beta-chains was observed. No exchanges were found in the surroundings of the heme, in alpha 1 beta 2-contact points, or allosteric regulatory sites. In the alpha 1 beta 1-subunit interface one amino-acid residue in alpha A-chains and one in beta-chains are exchanged. By comparison with the amino-acid sequence derived from globin genes of Domestic Duck (Anas platyrhynchos), the alpha A-chains differ by two exchanges in the N-terminal region and the beta-chains by five exchanges the in C-terminal region. The comparison of the amino-acid sequence derived from alpha A-globin gene of the Moscovy Duck (Cairina moschata) and alpha A-chains of the Northern Mallard, shows only one replacement.

Amino Acid Sequence↗
PubMed1984

Ependymal and neuronal specializations in the lateral ventricle of the Pekin duck, Anas platyrhynchos.

The lateral ventricles of the Pekin duck, Anas platyrhynchos, display characteristic ependymal and hypendymal specializations. Adjacent to the nucleus accumbens and the basal pole of the lateral septum the ventricular surface shows a highly folded pattern either with protrusions into the ventricular lumen or deep invaginations into the brain tissue. These medial and basal ependymal folds are found exclusively in a circumscribed region extending over a range of 600 micron in the rostrocaudal direction. Ependymal folds occurring in the lateral wall of the ventricles were traced up to the level of the interventricular foramen. Numerous capillaries are observed in the subependymal layer of these folds. By means of immunocytochemistry with antibodies against chicken vasoactive intestinal polypeptide (VIP) an aggregation of classical cerebrospinal fluid-contacting neurons is shown in the region of the nucleus accumbens and the lateral septum. These neurons are closely related to the ependymal folds. Additional VIP-immunoreactive neurons are scattered in deeper layers of the lateral septum and the nucleus accumbens. The latter are richly innervated by VIP-immunoreactive nerve fibers. The results of the present study are discussed with particular reference to the hypothesis of Kuenzel and van Tienhoven (1982) that ependymal specializations demonstrated in the lateral ventricles of the domestic fowl might represent a new circumventricular organ ("lateral septal organ").

Animals↗
PubMed2006

A genetic and cytogenetic map for the duck (Anas platyrhynchos).

A genetic linkage map for the duck (Anas platyrhynchos) was developed within a cross between two extreme Peking duck lines by linkage analysis of 155 polymorphic microsatellite markers, including 84 novel markers reported in this study. A total of 115 microsatellite markers were placed into 19 linkage groups. The sex-averaged map spans 1353.3 cM, with an average interval distance of 15.04 cM. The male map covers 1415 cM, whereas the female map covers only 1387.6 cM. All of the flanking sequences of the 155 polymorphic loci--44 monomorphic loci and a further 41 reported microsatellite loci for duck--were blasted against the chicken genomic sequence, and corresponding orthologs were found for 49. To integrate the genetic and cytogenetic map of the duck genome, 28 BAC clones were screened from a chicken BAC library using the specific PCR primers and localized to duck chromosomes by FISH, respectively. Of 28 BAC clones, 24 were detected definitely on duck chromosomes. Thus, 11 of 19 linkage groups were localized to 10 duck chromosomes. This genetic and cytogenetic map will be helpful for the mapping QTL in duck for breeding applications and for conducting genomic comparisons between chicken and duck.

Animals↗
PubMed1991

Cutaneous herpesvirus infection in a mallard duck (Anas platyrhynchos).

Investigations of mortalities involving wild mallard ducks (Anas platyrhynchos) revealed the presence of a herpesvirus associated with skin lesions on the plantar surface of the foot web of one duck. Ultrastructurally, the paracrystalline arrays of viral core particles and unencapsidated nucleoids in the nucleus, and the enveloped viruses in cytoplasmic vacuoles are compatible with a herpesvirus. This appears to be the first report of cutaneous lesions in a mallard duck attributable to a herpesvirus. Whether this lesion is due to duck virus enteritis (DVE), suggesting that cutaneous shedding is possible, or due to another uncharacterized herpesvirus of ducks is unclear.

Animals↗
PubMed1990

Retinal photoreceptor fine structure in the mallard duck (Anas platyrhynchos).

The retinal photoreceptors of the mallard duck (Anas platyrhynchos) consist of rods, single cones and double (unequal) cones present in a ratio of about 1:2:1. The rods have relatively large cylindrical outer segments which in the light-adapted state reach to the retinal epithelial (RPE) cell bodies and are surrounded by the pigment-laden apical processes of these RPE cells. The inner segment displays an apically located ellipsoid of mitochondria and plentiful polysomes, some rough ER and Golgi zones. The rod nucleus is located within the outer nuclear layer and the synaptic pedicle displays both invaginated (ribbon) and superficial (conventional) synaptic sites. Single cones display a thin tapering outer segment, a large often heterogeneous oil droplet in the apical region of the inner segment, an ellipsoid of mitochondria and a prominent paraboloid of glycogen. Double cones consist of a larger chief member which shows a thin tapering outer segment, a large heterogeneous oil droplet and a prominent paraboloid. The small accessory cone shows a thin outer segment, a small granular oil droplet and a paraboloid. As in the single cone, polysomes, RER and Golgi zones are also present within the inner segment. Near the outer limiting membrane the two members of the double cone show a membrane specialization on their contiguous surfaces. Both single and double cones display several invaginated (ribbon) synapses as well as numerous superficial synaptic sites.

Animals↗
PubMed1975

Sorbitol dehydrogenase in Anas platyrhynchos and Zenaida auriculata auriculata during development.

Sorbitol dehydrogenase (E.C.N. 1.1.1.14) was studied in liver, kidney and gonads of Zenaida auriculata auriculata (golden pigeon) and of Anas platyrhynchos (creole domestic duck) from South American faunes. The specific activity of SDH increased from embryonic to adult stage and is higher in the Anas platyrhynchos tissues. The electrophoretic studies performed in liver and kidney of both species during development showed variations in the number and intensity of the bands in accordance with the age and the species.

Age Factors↗
PubMed1995

Experimental vitamin A deficiency in mallards (Anas platyrhynchos): lesions and tissue vitamin A levels.

Captive mallards (Anas platyrhynchos), fed an all-grain diet for up to 5 months during the winters of 1991 to 1992 and 1992 to 1993, developed lesions of squamous metaplasia; some had no detectable hepatic vitamin A. Vitamin A deficiency in mallards was defined as hepatic levels of retinyl palmitate < 2 micrograms/g liver. Lesions were found only in ducks with low levels of hepatic vitamin A, but not all ducks with these low levels of hepatic vitamin A had histological lesions. The prevalence of lesions in the esophagus was greatest cranially and caudally and less common in the central region. Palatine salivary glands rarely were affected. Mallards with liver stores > 600 micrograms of hepatic retinyl palmitate per g liver, fed a diet deficient in vitamin A were unlikely to become deficient over a 5 month period. Birds fed an all-grain diet had significantly lower vitamin A concentrations in their liver compared to those fed an all-grain diet with vitamin A added. Liver weight, when corrected for body size, did not affect vitamin A concentration. Serum retinol levels were conserved over a large range of hepatic vitamin A levels but levels below 300 micrograms retinol/l were useful in detecting vitamin A deficiency in captive mallards. Based on the findings, the presence of lesions provides a conservative measure of vitamin A status in ducks and tissue levels should be measured in instances when mallards have questionable vitamin A status.

Animals↗
PubMed1991

A percutaneous liver biopsy technique in ducks (Anas platyrhynchos) experimentally infected with duck hepatitis B virus.

Aylesbury ducks (Anas platyrhynchos) chronically infected with the duck hepatitis B virus provide a useful model for studying hepadna-virus infection, replication and the effects of antiviral therapy. In these studies, it is necessary to have an effective method for obtaining repeat liver specimens for histological and molecular analyses. We have therefore developed a percutaneous liver biopsy technique which has a low rate of complications, can be performed at repeated intervals, and provides sufficient quantities of liver tissue for histological and nucleic acid hybridization analysis.

Animals↗
PubMed1989

Comparative toxicity of lead shot in black ducks (Anas rubripes) and mallards (Anas platyrhynchos).

In winter, pen-reared and wild black ducks (Anas rubripes), and game farm and wild mallards (Anas platyrhynchos), maintained on pelleted feed, were sham-dosed or given one number 4 lead shot. After 14 days, dosed birds were redosed with two or four additional lead shot. This dosing regimen also was repeated in summer using pen-reared black ducks and game farm mallards. Based upon mortality, overt intoxication, weight change, delta-aminolevulinic acid dehydratase activity and protoporphyrin concentration, black ducks and mallards were found to be equally tolerant to lead shot. However, captive wild ducks were more sensitive than their domesticated counterparts, as evidenced by greater mortality and weight loss following lead shot administration. This difference may be related to stress associated with captivity and unnatural diet.

Analysis of Variance↗
PubMed1997

Effects of induced hypo- and hyperthyroidism on immune function and plasma biochemistry in mallards (Anas platyrhynchos).

Hypo- or hyperthyroid states were induced in adult male mallards (Anas platyrhynchos) by subchronic exposure to daily injections of methimazole or a 9:1 ratio of thyroxine (T4): triiodothyronine (T3). The levels of T4 given were 0, 125, 250, or 500 micrograms/kg/day and for methimazole; 10 mg/kg/day for 22 or 21 days. Plasma T3 showed a lasting decrease with T4:T3 treatment, despite the attempt to maintain the normal T4:T3 ratio. Antibody formation to sheep red blood cells was decreased only at the 125 micrograms/kg/day dose of T4, and was unaffected by methimazole treatment. Natural killer cell activity to RP-9 tumor cells and macrophage phagocytosis of killed, opsonized Saccaromyces cereviseae were unaffected by treatment throughout the study. However, lectin-dependent cellular cytotoxic activity to RP-9 tumor cells was significantly decreased after 21 days of methimazole treatment, indicating that hypothyroidism may have an influence on cell-mediated immunity. Hypo- and hyperthyroid conditions had opposing effects on plasma cholesterol levels.

Animals↗