Triturus Rafinesque 1815

Duszynski, Donald W., Bolek, Matthew G. & Upton, Steve J., 2007, Coccidia (Apicomplexa: Eimeriidae) of amphibians of the world, Zootaxa 1667 (1667), pp. 1-77 : 60-62

Host genus Triturus Rafinesque 1815

(6 spp.)

Eimeria canaliculata Lavier 1936 ( Fig. 51)

Type host: Triturus cristatus (Laurenti 1768) , Crested newt.

Other hosts: Mesotriton alpestris (Laurenti 1768) , Alpine newt; Lissotriton helveticus (Razoumovsky 1789) , Palmate newt; Lissotriton vulgaris (L. 1758), Common newt.

Type locality: EUROPE: France .

Geographic distribution: EUROPE: France.

Description of sporulated oocyst: Oocyst shape: cylindroidal, symmetrical; wall thickness: ~1; wall characteristics: 2 wall layers (although line drawing shows 1), outer, smooth and contains, in the equatorial zone, 8–9 fine, radiating “canaliculi” that seem to terminate themselves in/on the internal layer of the oocyst wall ( Lavier 1936) and are arranged in an equatorial band ~12–13 wide; inner, thinner than outer one; L x W: 39.5 x 24 (36–42 x 20–27); L/W ratio: 1.6; M, PG: absent; OR: present, as a large mass of lipid-like globules that mostly obscure sporocysts (line drawing). Distinctive features of oocyst: massive OR of oil-like globules and an equatorial band, 12–13 wide, of fine radiating “canaliculi” in the oocyst outer wall that seem to encircle the oocyst wall.

Description of sporocyst and sporozoites: Sporocyst shape: lanceolate; L x W: 25–30 x 6; L/W ratio: ~4.5; SB: may be present (line drawing); SSB, PSB: absent; SR: present; SR characteristics: ovoidal mass of small granules, nearer the rounded end of the sporocyst; SZ: elongate, slightly longer than sporocyst, and pointed at one end, each with a small RB at rounded end (line drawing). Distinctive features of sporocyst: sometimes the sporocyst walls disintegrate leaving eight sporozoites free within the oocyst.

Prevalence: Unknown.

Sporulation: Unknown.

Prepatent and patent periods: Unknown.

Site of infection: Intestinal mucosa.

Endogenous stages: Unknow.

Pathology: Unknown.

Materials deposited: None.

Remarks: Laveran and Mesnil (1902a) described an intestinal coccidium ( E. prevoti ) from P. esculenta for which they created the genus Paracoccidium because the sporocyst walls disappeared after sporulation releasing eight SZ into the oocyst, a phenomenon now known to be reasonably common among eimerians of reptiles and, apparently, some amphibians. Eimeria canaliculata and E. propria are morphologically similar and are found in the same hosts (see Lavier 1936). However, sporocysts of E. canaliculata are longer, the outer wall of the oocysts has an equatorial band of tubules, and the OR is a large mass of lipid-like globules. This combination of structural features makes the sporulated oocysts of E. canaliculata unique among all caudate eimerians.

Eimeria propria ( Schneider 1881) Doflein 1909 ( Fig. 52)

Synonyms: Coccidium proprium ( Schneider 1881) Schneider 1887 ; Orthosporo propria Schneider 1881 ; Pfeifferia (Coccidium) propria Labbé (1896) ; non Eimeria propria of Matubayashi 1937.

Type host: Triturus cristatus (Laurenti 1768) , Crested newt.

Other hosts: Mesotriton alpestris (Laurenti 1768) , Alpine newt; Lissotriton vulgaris (Linnaeus 1758) , Common newt.

Type locality: EUROPE: France .

Geographic distribution: EUROPE: France.

Description of sporulated oocyst: Oocyst shape: symmetrically cylindrical; wall thickness: ~0.8; wall characteristics: 2 wall layers (although line drawing shows 1), outer, smooth; inner, thinner than outer; L x W: 38–41 x 22–24; L/W ratio: ~1.7; M: absent (but see Remarks, below); OR: present; OR characteristics: up to or>22 wide; PG: present ( Lavier 1936). Distinctive features of oocyst: large cylindrical shape with a large OR and a PG often attached to the internal surface of the oocyst wall ( Lavier 1936, but not shown in his line drawing).

Description of sporocyst and sporozoites: Sporocyst shape: cylindroid and pointed at both ends; L x W: 18–22 x 7–8; L/W ratio: unknown; SB, SSB, PSB: all absent; SR: present; SR characteristics: compact ellipsoidal mass of large granules, ~10 x 7, in center of sporocyst; SZ: 15–18 x 2.5, sausage-shaped (line drawing), each with 2 small RBs, one at each end (line drawing). Distinctive features of sporocyst: shaped like a “fat cigar.”

Prevalence: Unknown.

Sporulation: Unknown.

Prepatent and patent periods: Unknown.

Site of infection: Intestinal mucosa.

Endogenous stages: Unknown.

Pathology: Unknown.

Materials deposited: None.

Remarks: Schneider (1881) was the first to recover cylindroidal oocysts from the digestive tract of 2 salamanders, T. (= Triton ) cristatus and L. (= Triton ) vulgaris , near Poitiers ( France) and he named the oocysts O. propria in a one page note. Later Schneider (1887), abandoned the genus Orthospora that he had created from this cylindrical form, and placed it, and a new spheroidal form ( E. spherica ), into the genus Coccidium. Labbé (1894 a, 1896) considered the two species of Schneider (1881, 1887) to be a single coccidium, the oocyst of which could exhibit a variety of shapes, and called it C. proprium ( Lavier 1936) . This view prevailed for nearly half a century until Lavier (1936) dispelled it. Steinhaus (1891) described merogony of a coccidium under the name Cytophagus tritonis . In 1896, Labbé placed these intracellular stages and those known from C. proprium into his new genus, Pfeiffera , for no justifiable reasons ( Lavier 1936). Schneider (1881) made no mention of a M, but described a structure at one end of the oocyst that he called an operculum; he also described a transverse radial structure (suture?) extending like a belt along the central part of the oocyst; however, Lavier (1936), who redescribed and presented line drawings for E. propria , did not see these structures. The description above follows that of Pellérdy (1974), which differs from the measurements and line drawing given in Doflein (1909). Walton (1941, 1961 c, 1964a, b) lists S. salamandra (syn. S. maculosa ) as a host for this species and Pellérdy (1974) listed S. atra ; these are probably misidentifications. Lavier (1936, 1937) gave oocyst measurements as 36-43 x 20-27 and sporocysts 18–22 x 7–8 (line drawing of sporocyst strongly resembles an oocyst of Monocystis ). Although this may represent a different coccidium, all other structural characteristics appear to match those of Schneider (1881).