Plasmodium jeanriouxi Chavatte & Landau, 2009

Plasmodium jeanriouxi Chavatte & Landau , n. sp.

( Fig. 3A View FIG )

TYPE MATERIAL. — Holotype: 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 , 66) ( Fig. 3J View FIG ). GoogleMaps

Paratypes:same data as holotype, blood smears of A. arvensis number 740U, 25.X.1996 ( MNHN P2-XXV , 24-43); GoogleMaps 741U, 25.X.1996 ( MNHN P2-XXV , 44-64). GoogleMaps

ETYMOLOGY. — This species is dedicated to Jean Rioux.

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

HOST. — Alauda arvensis (type host).

DESCRIPTION

This is a small parasite that is found in unaltered RBCs, most often in apico-lateral position.Throughout its development, it is closely apposed to the RBC nucleus that is sometimes slightly tilted. The trophozoites and young schizonts are rounded, though flattened at the level where they are in contact with the host nucleus.The chromatin is found as two elongated and granular peripheral masses lying on either sides of a relatively abundant cytoplasm. The arrangement of the chromatin in the young forms is highly characteristic. The cytoplasm is scattered with vacuoles of variable sizes and contains 2 to 3 pigment grains. As it matures the schizont adopts a roughly trapezoid shape, 6 or 7 nuclei become distinguishable and are disposed in a crown and then protrude at the periphery of the parasite. The vacuoles are less numerous than in the less mature forms but of larger size. The pigment grains are agglomerated in a black mass.

Young gametocytes are elongated, with pointed extremities and, akin to the schizonts, are partially apposed to the host nucleus. As they mature they associate more intimately with this nucleus that is sometimes thereby altered. They contain grains of black pigment, most often rounded, and an accessory chromatin granule.

DIFFERENTIAL DIAGNOSIS

The close apposition to the RBC nucleus and the low number of nuclei (6 or 7) make this species comparable to Plasmodium snounoui Chavatte & Landau, 2007 , a parasite of Pica pica , and to P.nucleophilum Manwell, 1935 , a parasite of Dumetella carolinensis (Linnaeus, 1766) . P. jeanriouxi n. sp. can be differentiated from P. snounoui by its gathered-up dense shape, by the distribution of chromatin in two elongated lateral masses in the young forms and in a crown in the older forms. By contrast, P. snounoui is elongated in shape, its cytoplasm is clear, and the nuclei are dispersed in the young schizont and disposed in a fan-shape in the mature forms.

Plasmodium jeanriouxi n. sp. also differs from P. nucleophilum by its shape and size: the first has a compact rounded then roughly trapezoid shape and is apposed to the RBC nucleus over a limited surface, whereas for the second by contrast the schizonts are elongated and closely associated with the nucleus over their whole length, a feature specifically depicted by Manwell (1935: pl. I, figs 15, 16), and considered by this author as “especially characteristic”.