Plasmodium caloti Chavatte & Grès & Snounou & Chabaud & Landau 2009, n. sp.

Plasmodium caloti Chavatte & Landau, n. sp. (Fig. 2B)

TYPE MATERIAL. — France. Landes, Saint-Julien-en-Born, 44°03’42’’N, 1°13’33’’W, blood smear of A. arvensis number 741U, 25.X.1996 (MNHN 440LV PXIII, 63) (Fig. 3D).

Paratypes: same data as holotype, blood smears of A. arvensis number 741U, 25.X.1996 (MNHN P2- XXV, 44-64).

ETYMOLOGY. — This species is dedicated to the memory of Jacques Calot.

DISTRIBUTION. — Known only from the type locality, Saint-Julien-en-Born, Landes, France.

HOST. — Alauda arvensis (type host).

DESCRIPTION

The average sized parasite is found in a rounded highly hypertrophied RBC that is sometimes discoloured and whose nucleus is off-centre though not in close contact with the cell edge. Among the small or medium sized (<10 nuclei) Plasmodium species of the skylark, P. caloti n. sp. is the only one where RBCs are modified to this extent.

In general the shape of the immature and nearly mature schizonts is rounded, their contours regular and the nuclei, usually 8 in number, are dense and are predominantly found at the periphery. As they near maturity, these nuclei can bulge slightly to the outside. The abundant and homogeneous cytoplasm is pink coloured and contains a small number of vacuoles. The pigment is fine and agglomerated.

Gametocytes are rounded like the schizonts and lie in rounded RBCs.

DIFFERENTIAL DIAGNOSIS

Plasmodium caloti n. sp. should be compared to P. subpraecox, a parasite described briefly and illustrated by Grassi & Feletti in Athene noctua (Grassi & Feletti 1892: fig. 8). These authors have also recorded it in Alauda arvensis and in Passer hispaniolensis.

According to these authors the number of merozoites is 5 to 12. In a re-description of this species, Giovannola (1939), enumerated 10 to 12 merozoites in the mature schizont, and from his illustrations one can note a few similarities with P. caloti n. sp.: defined outlines, cytoplasmic abundance, and a rather peripheral location of the nuclei in mature schizonts. On the other hand, the parasite described here produces an average of 8 merozoites and leads to a much more pronounced hypertrophy of the RBC.

Plasmodium caloti n. sp. and P. alaudae differ by the following features: the larger size of P. caloti n. sp., its more or less central position in a considerably enlarged RBC with a displaced nucleus, contrasts with the small size of the apically located P. alaudae where infected RBCs are not modified nor their nuclei displaced.