Duttaphrynus Frost et al. 2006

Duszynski, Donald W., Bolek, Matthew G. & Upton, Steve J., 2007, Coccidia (Apicomplexa: Eimeriidae) of amphibians of the world, Zootaxa 1667 (1667), pp. 1-77 : 23-25

Host genus Duttaphrynus Frost et al. 2006

(6 spp.)

Eimeria himalayana Ray and Misra 1943 ( Fig. 4)

Synonym: Eimeria himalyanum Ray and Misra 1941 , lapsus calami and species inquirenda.

Type host: Duttaphrynus himalayanus (Günther 1864) , Himalayan toad.

Other hosts: None reported to date.

Type locality: ASIA: India, U.P. Mukteswar-Kumaun (2500 m) .

Geographic distribution: ASIA: India, Mukteswar.

Description of sporulated oocyst: Oocyst shape: spheroidal; number of walls: 2; wall thickness: very thin; L x W: 9.2 (7.5–10.5) along broadest diameter; L/W ratio: 1.0; M, OR, PG: all absent (line drawing). Distinctive features of oocyst: sporulation occurs intracellularly and the wall is very thin.

Description of sporocyst and sporozoites: Sporocyst shape: naviculoidal (spindle-shaped); L x W: 5.2 x 2.8 (4.5–6.5 x 2.5–3.5); L/W ratio: 1.9; SB, SSB, PSB: all absent; SR: present; SR characteristics: globular mass of small granules between SZ; SZ: club-shaped, 4.0 x 1.4, with 1 RB and a centrally-located N with a karyosome. Distinctive features of sporocyst: sporulation occurs intracellularly and sometimes SZs excyst and lie free within the oocyst in the host cell cytoplasm.

Prevalence: 1 of 1 (100%).

Sporulation: Endogenous, strictly intracellular.

Prepatent and patent periods: Unknown.

Site of infection: Epithelial cells of the intestine.

Endogenous stages: The entire life-cycle, including formation of sporulated oocysts, takes place in epithelial cells of the small intestine. Two kinds of meronts were found. Micromeronts measured 1.8 x 2.2 and had a ragged appearance with a faintly developed N membrane, while macromeronts were 5.2 wide with a homogeneous cytoplasm and a prominent N membrane. The smaller meronts were found either distal to the N of the epithelial cell or they passed beyond it toward the basement membrane of the cell to complete merogony. These formed 16–32 merozoites which were 4–6 x 0.4. Mature micromerozoites had a ragged cytoplasm and a deeply staining area at 1 pole. Ray and Misra (1943) believed that these micromerozoites (from their micromeronts) produced the microgamont, which is about 6–8 wide when mature with about 8 microgametes that aggregate around the periphery of the cytoplasm. Microgametes were 2.6 x 0.9, but flagella were not seen.

In contrast, the larger meronts have a cytoplasm that stains homogeneously and a central N with a prominent karyosome. Fully developed macromeronts, found below or above the N, were 10–12 wide and contained up to 32 elongate merozoites; these measured 4.3 x 0.7, with a homogeneously staining cytoplasm and a central N with a central karyosome. Ray and Misra (1943) stated that these merozoites produced macrogamonts that were 7–12 x 6–10, and had a spheroidal N, about 3–5, with a karyosome. At this later stage, the nuclear membrane becomes irregular in outline and formed a fertilisation spindle parallel to the long axis of the gamont.

Pathology: Unknown.

Material deposited: None.

Remarks: Ray and Misra (1941) first named this species in an abstract for a paper read at the 28 th session of the Indian Science Congress, held in Benares in 1941. Technically, of course, this violated the International Code of Zoological Nomenclature and made the name a nomen nudum since no species description existed in the published literature and no specimen was deposited in an accredited museum. Two years later they named it as new, again, when they published the name as E. himalayanum . In their published species description, Ray and Misra (1943) describe merogony and sporogony occuring at the same time in this 1 individual. Mandal (1976) gives a sporulation time of 48–72 h, conflicting with the original description of endogenous sporulation ( Ray & Misra 1943).

Eimeria laminata Ray 1935a ( Fig. 5)

Type host: Duttaphrynus melanostictus (Schneider 1799) , Black-spined toad.

Other hosts: None reported to date.

Type locality: ASIA: India, Calcutta .

Geographic distribution: ASIA: India, Calcutta.

Description of sporulated oocyst: Oocyst shape: spheroidal; number of walls: 1 (line drawing of Ray 1935a) or double layered with outer one thicker ( Mandal 1976); wall thickness: unknown; wall characteristics: colorless and very delicate; L x W: 9.8 (8–11 x 8–11); L/W ratio: 1.0; M, OR, PG: all absent. Distinctive features of oocyst: colorless, thin, fragile wall.

Description of sporocyst and sporozoites: Sporocyst shape: fusiform or spindle-shaped (pointed at both ends); L x W: 4.5–6.5 x 3; L/W ratio: ~2.0 ( Mandal 1976); SB, SSB, PSB: all absent; SR: present; SR characteristics: irregular mass of small granules in center of sporocyst (line drawing); SZ: sausage-like (line drawing of Ray 1935a) with 1 end more pointed than the other and a centrally-located N. Distinctive features of sporocyst: small, spindle-shaped body pointed at both ends and 4 of them do not fill the interior of the oocyst (line drawing).

Prevalence: 2 of 200 (1%).

Sporulation: Endogenous, strictly within host intestinal epithelial cell.

Prepatent and patent periods: Unknown.

Site of infection: Epithelial cells of the small intestine.

Endogenous stages: There are two kinds of meronts: macromeronts, 12 x 6, which release 20–30 merozoites, which develop into macrogamonts, and micromeronts, producing 6–8 merozoites, 3 x 1.3, which give rise to microgamonts with numerous uniflagellate microgametes. Early micromeronts were readily distinguished from macromeronts by the absence of darkly staining granules in their cytoplasm; early forms were 6 x 2 and mature forms were 12 x 5.5 with 6–8 merozoites, arranged parallel to the long axis of the meront. Ray (1935a) said that it was these merozoites that produced the male forms of the parasite. The mature microgamonts measured ~13 x 9 and showed numerous N at the periphery. Fully formed microgametes were 2.8–3 x ~1, with a single flagellum at 1 end about the same length as its body. Early macromeronts have “from a very early stage dark-staining granules scattered through the cytoplasm” ( Ray 1935a). Fully mature macromeronts within the host cell were spheroidal, 9–10 wide when filled with up to 30 merozoites, each with darkly-stain- ing granules in their cytoplasm. Fully developed macrogamonts were 11 x 5.6 with a spherical N, ~3. Both micro- and macromeronts were seen to have a structure at one end that Ray (1935a) called a hyaline laminae. Fertilization, oocyst formation, and sporulation all occurred intracellularly.

Pathology: Unknown.

Materials deposited: None.

Remarks: Ray (1935a) looked at fresh smears of frog rectal and intestinal contents in saline and saw what he said were, “active gregarinulae...in large numbers,” which he later said were liberated merozoites of two sizes. Very little information about the sporulated oocyst is included in the original description, although description of other life stages is given. Mandal (1976) gives a sporulation time of 60–72 h, conflicting with the original description of endogenous sporulation ( Ray 1935a, b).

Isospora wenyoni Ray and Das Gupta, 1935 ( Fig. 6)

Type host: Duttaphrynus melanostictus (Schneider 1799) , Black-spined toad.

Other hosts: Fejervarya limnocharis (Gravenhorst 1829) , Indian cricket frog and Hoplobatrachus tigerinus (Daudin 1802) , Turkey frog.

Type locality: ASIA: India, Bengal , Calcutta .

Geographic distribution: ASIA: India, Bengal, Calcutta.

Description of sporulated oocyst: Oocyst shape: subcylindroidal; number of walls: double contoured with the inner more prominent than the outer; wall thickness: unknown; L x W: 16–20 x 11–14; L/W ratio: unknown; M, OR, PG: all absent (line drawing). Distinctive features of oocyst: unsporulated oocysts are ovoidal or spheroidal, but become broadly ellipsoidal or ovoidal after sporulation; also, the very thin, fragile, 2- layered wall.

Description of sporocyst and sporozoites: Sporocyst shape: ellipsoidal; L x W: 8 x 4; L/W ratio: ~2; SB, SSB, PSB: all absent (photomicrograph); SR: present; SR characteristics: scattered granules (photomicrograph); SZ: unknown. Distinctive features of sporocyst: their long axis is at a right angle to the long axis of the oocyst.

Prevalence: Two of several hundred (~1%) Duttaphrynus melanostictus .

Sporulation: Exogenous, oocysts sporulated in ~3 days when kept in 1% chromic acid.

Prepatent and patent periods: Unknown.

Site of infection: Epithelial cells of the small intestine.

Endogenous stages: Young undivided meronts (trophozoites) were 10 x 3; when mature they measured 20–25 wide and had 8–12 spindle-shaped merozoites which were 12 x 5. Each merozoite was reported to possess a pair of hyaline blades or lamina at their anterior end, similar to those reported in the merozoites of E. laminata by Ray (1935a). Young microgamonts were difficult to distinguish from developing meronts, but as they aged, a large number of N were seen around the periphery of the gamont. Individual microgametes were reported to measure 2.4 x 1.5. Early macrogamonts were easily distinguished by darkly staining cytoplasmic granules and a spheroidal N with a karyosome. Mature macrogamonts were 16–20 x 11–14, have the posterior end usually turned upon itself giving the impression of a short tail, and have an elongate N in which the karyosome fragments into many small granules scattered irregularly.

Pathology: Unknown.

Materials deposited: None.

Remarks: In an abstract, Chakravarty and Kar (1944) (erroneously?) mentioned finding oocysts of this species in two dicroglassid species, F. limnocharis and H. tigerinus . Later, in 1952, they redescribed the oocysts and sporocysts from these same hosts saying the oocysts were 19.8–15.4 x 15.4–13.3 and sporocysts 13.2–9.9 x 9.8–7.7, much larger than in the original description by Ray and Das Gupta (1935). Mandal (1976) said the oocysts were 17.5 x 14.5 (15–20.5 x 13.5–15.5) with a shape index of 1.2 and that an OR was present, but he did not show it in his line drawing; he also said the sporocysts were 11.8 x 8.5 (10–13.5 x 7.5–9.5), with L/W ratio 1.3, measurements that are significantly larger than in the original description. Finally, Mandal (1976) noted that the sporulation time he observed was 60–70 h, similar to the 2–3 days cited by Ray and Das Gupta (1935) in their original description. It is our opinion that both Chakravarty and Kar (1944) and Mandal (1976) were dealing with oocysts of a species that was not I. wenyoni .