Plasmodium alaudae

Plasmodium alaudae (Celli & Sanfelice, 1891) (Fig. 2C)

MATERIAL EXAMINED. — France. Landes, Saint-Julienen-Born, 44°03’42’’N, 1°13’33’’W, blood smears of A. arvensis number 740U, 25.X.1996 (MNHN P2 - XXV, 24-43); 741U, 25.X.1996 (MNHN P2 -XXV, 44-64).

DISTRIBUTION. — Italy (Celli & Sanfelice 1891); new record for the Landes, France.

HOSTS. — Pica pica (type host); new record for Alauda arvensis.

REDESCRIPTION

The parasites are small in size, and are found located at the apex of non-modified RBCs where nuclei are not displaced or only a little. The schizonts are compact and rounded, and the nuclei, eight in number, are dense roughly round with a clear centre. The cytoplasm is relatively abundant with a few dispersed vacuoles and two granules of black pigment. The gametocytes have not been identified but are probably elongated.

TAXONOMIC STATUS

Celli & Sanfelice (1891) described Haemoproteus alaudae (later trasferred to Plasmodium) in the blood of the skylark. At that time the authors elected to reserve Plasmodium to the parasites of humans. This species was considered to be composed of three types in the blood that were distinguished by the time required for development. When the figures published by these authors are carefully examined (Celli & Sanfelice 1891: pl. III), it became clear that they were in fact dealing with multiple species, not an unexpected occurrence in skylarks: a large species with schizonts of 22-30 nuclei where the RBC nuclei are displaced or even expelled (Celli & Sanfelice 1891: figs 19-21), a smaller apical species with 8 or 9 nuclei that does not displace the RBC nucleus or only little (same, figs 16, 17), a latero-apical species with 18 nuclei where the RBC nuclei is unaffected (same, fig. 18), and finally a very small species with 8 nuclei where the RBC is slightly rounded and its nucleus displaced (same, fig. 15). For the most part these species could not be confidently ascribed to a known species. However, the taxon H. alaudae could be retained for the form depicted in Celli & Sanfelice’s plate III, figs 16, 17, for the species described above in view of the following similarities: small size, apical position, number of nuclei = 8, and little or no displacement of the nuclei in RBCs that are neither rounded nor hypertrophied.

Gametocytes could not be linked with confidence with the gametocytes observed for this species.

DIFFERENTIAL DIAGNOSIS

Plasmodium alaudae, by virtue of the number of nuclei (8) in the schizont, could be compared to Plasmodium vaughani merulae Corradetti & Scanga, 1972, a parasite of Turdus merula Linnaeus, 1758, where 8 merozoites can be observed per schizont albeit rarely. However, the absence of a bluish refractile globule in P. alaudae clearly distinguishes it from P. vaughani.

Plasmodium alaudae is close to the rounded apical forms of P. ashfordi that also produce 7 or 8 nuclei on average. It differs with respect to the absence of the fan-shaped schizonts that characterise P.ashfordi, and by its denser and clearly delimited nature.

Plasmodium alaudae must also be distinguished from P. caloti n. sp. (see below).

Plasmodium ghadiriani Chavatte & Landau, 2007 (Fig. 2D)

MATERIAL EXAMINED. — France. Landes, Saint-Julienen-Born, 44°03’42’’N, 1°13’33’’W, blood smears of A. arvensis number 741U, 25.X.1996 (MNHN P2-XXV, 44-64).

DISTRIBUTION. — Seine-Saint-Denis, France (Chavatte et al. 2007); new record for the Landes, France.

HOSTS. — Pica pica (type host); new record for Alauda arvensis.

REMARKS

This parasite is identical to that described in the magpie. The schizonts are large and elongate and lie next to the laterally displaced nucleus of the RBC that is often enlarged. Young schizonts characteristically contain a few large chromatin masses that will fragment into smaller rounded nuclei. The older schizonts observed contained 17 nuclei, consistent with the 18 to 24 nuclei enumerated in the magpie parasite.