Eimeria Schneider, 1875

Munhoz, Ana Maria Duque de Araujo, Fernandes, Ema Albuquerque, Marques, Jo ˜ ao David Molarinho & Berto, Bruno Pereira, 2024, Remarks on Eimeria spp. (Apicomplexa: Eimeriidae) from Kobus spp. (Bovidae: Reduncini), with supplementary morphological data of Eimeria congolensis Ricci-Bitti et al., 1973 from a new host subspecies, the common waterbuck Kobus ellipsiprymnus ellipsiprymnus (Ogilbyi, 1833), International Journal for Parasitology: Parasites and Wildlife 24, pp. 100952-100952 : 100952-

Genus: Eimeria Schneider, 1875

Oocysts (n = 30) ovoidal to pear-shaped, 33–40 × 25–31 (36.0 × 27.8); length/width (L/W) ratio 1.2–1.5 (1.30). Wall bi-layered, 2.9–3.1 (3.0) thick, outer layer slightly to medium rough, c.2/3 of total thickness. Micropyle present, polymorphic in width and prominence, 4.0–8.8 (6.8) wide; occasionally with an invagination of the inner layer. Oocyst residuum absent, but one or two small polar granules are present. Sporocysts (n = 30) ovoidal to ellipsoidal, 14–18 × 8–10 (16.0 × 9.0); L/W ratio 1.5–2.0 (1.78). Stieda body present, flattened to nipplelike, 0.6–1.0 × 1.5–2.0 (0.7 × 1.8); sub-Stieda body present, rounded to trapezoidal, 0.7–1.6 × 1.8–3.0 (1.1 × 2.4); para-Stieda body absent; sporocyst residuum present, composed of granules, in variable quantities, that appear to be membrane-bound, 2.2–5.6 × 1.5–4.9 (3.7 × 3.0). Sporozoites vermiform, with a robust posterior refractile body, 5.7–7.2 × 4.2–5.4 (6.3 × 4.9), and a noticeable nucleus.

3.2. Diagnosis

Eimeria congolensis was the second species described by Ricci-Bitti et al. (1973) from defassa waterbucks Kobus ellipsiprymnus defassa (Rüppell, 1835) captured in different areas of the Albert National Park in the Democratic Republic of the Congo. Although the oocysts of this species are similar in measurements to Eimeria macieli Yakimoff and Matschoulsky (1938) , Eimeria kobi Ricci-Bitti et al., 1973 and Eimeria katangensis Ricci-Bitti et al., 1973 , it can be differentiated by shape and measurements of the sporocysts, which are typically more ovoidal, as they have a shorter length in relation to width (Table 1) ( Yakimoff and Matschoulsky, 1938; Ricci-Bitti et al., 1973). Added to this, the current study added some taxonomic characters not included in the original description of Ricci-Bitti et al. (1973), although these were observed in the original photomicrographs shown, such as: Stieda body flattened to nipplelike, sub-Stieda body rounded to trapezoidal, sporocyst residuum granular and membrane-bound, in addition to greater details of the micropyle and other taxonomic characters. Thus, these new characteristics presented in the current study easily differentiate and typify E. congolensis in comparison with other Eimeria spp. of reduncin bovids Kobus spp. (Table 1).

3.3. Taxonomic summary

Type host: Kobus ellipsiprymnus defassa (Rüppell, 1835) ( Mammalia: Cetartiodactyla: Bovidae : Hippotraginae : Reduncini ), defassa waterbuck ( Ricci-Bitti et al., 1973).

Other host: Kobus ellipsiprymnus ellipsiprymnus (Ogilbyi, 1833) ( Mammalia: Cetartiodactyla: Bovidae : Hippotraginae : Reduncini ), common waterbuck (current study).

Type locality: National Park Albert , Kivu and North Katanga, Democratic Republic of the Congo ( Ricci-Bitti et al., 1973) .

Other locality: Badoca Safari Park (38 ◦ 02′29.3″S, 8 ◦ 44′40.0″W), Portugal (current study) .

Type-material: Not stated in the original description of Ricci-Bitti et al. (1973).

Representative specimens (current study): Photomicrographs, line drawing and oocysts in 2.5% K 2 Cr 2 O 7 solution ( Williams et al., 2010) are deposited and available (http://r1.ufrrj.br/labicoc/colecao.html) in the Parasitology Collection of the Laboratorio´de Biologia de Coccídios, at UFRRJ, under the repository number 135/2023. Photographs of the host specimens are deposited in the same collection.

ZooBank registration: The data relating to this species, which was supplemented in its description and deposited in taxonomic collection in the current work, were submitted to ZooBank ( ICZN, 2012). The Life Science Identifier ( LSID) of the article is urn:lsid:zoobank.org:pub:9525E798-C449-4CFE-8C0A-252E4D19F3BB .

Site of infection: Unknown, oocysts were recovered from feces.

2

3

Prevalence: 50% (2/4) in the original description from K. e. defassa ( Ricci-Bitti et al., 1973); 100% (2/2) in the current study from K. e. ellipsiprymnus .