Leucocytozoon podargii, Adlard & Peirce & Lederer, 2002

Adlard, R. D., Peirce, M. A. & Lederer, R., 2002, New species of Leucocytozoon from the avian families Otidae, Podargidae and Threskiornithidae, Journal of Natural History 36 (11), pp. 1261-1267 : 1262-1263

Leucocytozoon podargii n. sp.

(gures 1–4)

Type host. Podargus strigoides (Latham) (tawny frogmouth).

Type locality. Currumbin , Queensland, Australia .

Basis of description

Macrogametocyte. Only round morphs occur, exhibiting the usual characteristics of the genus. Maximum diameter is about 15 m m ( table 1). Cytoplasm is granular with occasional hyaline vacuoles present; nucleus generally oval in shape occupying a central to subcentral position but lacking a distinct karyosome. Maximum length of the host–parasite complex is 17 m m. The host cell nucleus forms a cap around the periphery covering about one-third (gure 1), but in most infections about half the parasites were observed without any remnant of the host cell nucleus (gure 2).

Microgametocyte. Similar in size to the macrogametocyt e with the usual diOEerentiating characteristics. The nucleus is dispersed but has a distinctive karyosome which stains a deep red (gure 3). The prevalence of microgametocytes is very low with the ratio to macrogametocyte s being 1:50.

Schizonts. In histopathology sections stained with H and E, the presence of schizonts was observed in skeletal muscle, lung and spleen. The schizonts in muscle were small compared to those in lung and spleen (gure 4). Megaloschizonts in lung and spleen tissue measured up to 163 m m in diameter and were characterized by cytomere formation with each section packed with merozoites.

Hapantotype. IRCAH:G46311 2 (gametocytes) from Podargus strigoides , coll. Reid, 14 October 1999, Currumbin , Gold Coast, Queensland, Australia ; IRCAH:G46311 3 (schizonts) from P. strigoides , coll. Lederer, 14 November 1998, Currumbin , Gold Coast, Queensland, Australia .

Parahapantotype. IRCAH: G463114 , G463115 and G463116 (gametoctyes) from P. strigoides , coll. Reid, 16 August 1999, 19 September 1999 and 10 October 1999 ; IRCAH:G46311 7 (schizonts) from P. strigoides , coll. Lederer, 14 November 1998, Currumbin , Gold Coast, Queensland, Australia .

Other hosts. Probably occurs throughout the range of the Podargidae .

Vectors. Unknown, but assumed to be simuliids.

Etymology. Named after the genus of the type host.

Comments. Leucocytozoon podargii is a parasite with only round morphs occurring in a small family of birds with a distribution restricted to the Australasian region. The inclusion of schizont stages is a bonus particularly as the presence of megaloschizonts occurs in the absence of second generation elongate morphs. In this respect L. podargii appears to have a life cycle similar to that of Leucocytozoon marchouxi Mathis and Leger (see Peirce et al., 1997). Nothing is currently known regarding the potential pathogenicity of L. podargii ; the reason for euthanasia in this particular bird was related to causes other than the Leucocytozoon infection.

The low prevalence of microgametocyte s in all the positive birds examined seems to be a characteristic of L. podargii infections. The earliest published record of leucocytozoids from the Podargidae was by Cleland (1915) who recognized Leucocytozoon sp. from P. strigoides from Eidsvold in southern Queensland. Later, Mackerras and Mackerras (1960) assigned leucocytozoids from the same host and locality to Leucocytozoon caprimulgi Kerandel originally described from the nightjar Caprimulgus fossii Hartlaub , a species with Afro-Tropical distribution. Their contention was that host relationships dictated conspeci city of the leucocytozoid. However, C. fossii is placed within the family Caprimulgidae (see Sibley and Monroe, 1990, 1993) while it has long been recognized that P. strigoides is a member of the Australasian-endemic bird family, Podargidae . Taking into account the established host-speci city at family level of Leucocytozoon spp. (see discussion in Bennett et al., 1991) and in the absence of any data to the contrary, we describe this species as L. podargii .