Camallanus tuckeri Kuzmin, Tkach, Snyder and Maier, 2009

Hosts and localities:

Type host: Northwestern red-faced turtle Emydura australis Gray, 1841. Prevalence 7/22 (31.8%), intensity 1-18 specimens.

Other hosts: Sandstone Snake-Necked Turtle Chelodina burrungandjii Thomson, Kennett et Georges, 2000. Prevalence 3/16, intensity 2-7 specimens.

Type locality: Ord River, Kununurra, Western Australia (15o47.533' S; 128 o42.310' E).

Other localities: Lake Argyle Spillway (16o 07.371'S, 128o 44.271'E), Donkey Hole (16o 39.275' S, 125o 29.338' E), Minah Creek (17o 06.627' S, 125o 21.012' E), Bell Creek (17o 10.159' S, 125o 21.521' E), Geike Gorge (18o 06.259' S; 125o 42.056' E) all in Western Australia.

Site of infection: intestine.

Description (after Kuzmin et al, 2009)

General. Slender worms. Body cuticle finely striated transversely, striation visible from posterior ends of tridents to tail end. Head end rounded, tail end tapering. Oral opening narrow, slit-like, with rounded corners. Eight cephalic papillae present in two circles: four minute flattened papillae closer to oral opening, and four large rounded papillae of outer circle. Buccal capsule typical for the genus. Each valve of buccal capsule usually with nine internal ridges: one median ridge, four ventral and four dorsal ridges. Ridges are angled medially from anterior to posterior. Anteriorly, distance between median ridge and nearest dorsal and ventral ridges somewhat larger than between other ridges. No incomplete or interrupted ridges were observed, however, two additional short ridges were present in one specimen. Median ridge may be shorter than two proximate ridges. Thick, sclerotized ring present at base of buccal capsule. Buccal capsule valves supported by two prominent dorso-ventral tridents having three posteriorly directed prongs. Central prongs of tridents somewhat longer than sublateral ones. Tridents' posterior ends reach beyond level of basal ring. Deirids minute, papilla-shaped, situated somewhat anterior to border between muscular and glandular esophagus.

Muscular esophagus with elongated posterior bulb. Glandular esophagus about 1.6 times longer than muscular esophagus. Three prominent large nuclei at posterior end of glandular esophagus. Intestine straight, narrow. Rectum straight, thin-walled.

Males (measurements for holotype and two paratypes). Body 11.891 (10.205, 11.642) mm long, 195 (164, 189) wide. Posterior part of body coiled ventrally. Buccal capsule 152 (135, 146) long, valves 129 (113, 123) long and 125 (115, 117) wide in lateral view. Sclerotized ring 23 (22, 23) long and 76 (67, 78) wide. Muscular esophagus 560 (520, 547) long, glandular esophagus 873 (870, 939) long. Distance from anterior end of body to posterior end of esophagus 13.8 (14.2, 15.8) % of body length. Nerve ring at 281 (248, 269) from anterior end. Deirids at 104 from border between muscular and glandular esophagus (measured in 1 male).

Anterior part of testis is slightly twisted. Caudal alae low, ventro-lateral. Anterior part of alae somewhat elevated and joined on ventral surface forming pseudosucker. Posterior ends of alae behind level of tail midlength. In precloacal portion, alae supported by 7 pairs of pedunculate papilla. Anterior pair of papillae supporting posterior part of pseudosucker. Five pairs of postcloacal papillae present. Posterior to cloacal opening, caudal alae supported by two pairs of ventrolateral papillae. Two pairs of subventral papillae situated closely to each of first ventrolateral papilla, thus forming a group of three papillae on each side. A pair of minute lateral papillae situated closer to tail tip. A pair of papilla-shaped phasmids present at level of second pair of postcloacal ventrolateral papillae. Additionally, 2 pairs of sessile papilla, surrounding cloacal opening. Spicules unequal. Right spicule 394 (381, 390) long, more sclerotized, with elongated funnel-shaped anterior part and pointed end. Its distal part needle shaped, slightly curved ventrally. Left spicule 339 (312, 326), less visible, with sharply pointed end. Anterior ends of spicules posterior to level of pseudosucker. Tail conical, with rounded end, 186 (177, 194) long (1.6 [1.5, 1.9] % of body length).

Females (measurements for 11 paratypes, mean value and limits). Body 16.368 (12.922 – 19.034) mm long, 232 (159 - 275) wide. Buccal capsule valves 143 (135 - 153) long and 149 (137 - 179) wide. Sclerotized ring at base of buccal capsule 88 (75 - 94) wide, 23 (22 – 24) wide. Total length of buccal capsule 166 (157 – 176). Muscular esophagus 621 (555 - 658), glandular 991 (712 - 1062) long. Distance from anterior end of body to posterior end of esophagus 10.8 (9.8 – 11.9) % of body length. Nerve ring at 310 (292 - 329) from anterior end.

Vulva pre-equatorial, 7.625 (6.076 – 9.273) from anterior end. In gravid females, both lips of vulva prominently elevated (Fig. 11). Tail conical, elongated, 232 (201 - 249) long (1.6 [1.4 – 1.8] % of body length), with rounded tip. Phasmids situated at about midlength of tail (Fig. 7).

Illustrations

Figures 1 – 5. Camalanus tuckeri: 1 – anterior part of body, lateral view (holotype); 2 – head end, lateral view (holotype); 3 – buccal capsule with two additional incomplete ridges (paratype); 4 – female tail end, lateral view (paratype); 5 – male, posterior part of body, lateral view (holotype). Scale bars: 1 – 500 µm; 2-5 – 100 µm. (from Kuzmin et al., 2009)

C. tuckeri, head end, lateral view. Scale bar: 100 µm	C. tuckeri, SEM of head end, sub-apical view. Inset – enlarged fragment with a pair of head papillae. Arrow indicates position of inset. Scale bars: 100 µm. (main image) and 10 µm. (inset).

C. tuckeri, female body near vulva, lateral view. Scale bar: 100 µm	C. tuckeri, tail of female, ventrolateral view (SEM); ph –phasmid. Scale bar – 50 µm.

C. tucleri, male caudal region, lateral view. Scale bar: 100 µm

C. tucleri, male caudal region, ventral view. Scale bar: 100 µm	C. tucleri, part of body at border between muscular and glandular oesophagus. Scale bar: 100 µm

References:

Kuzmin, Y., Tkach, V.V., Snyder, S.D., Maier, M.D. 2009. Camallanus tuckeri sp. n. (Nematoda, Camallanidae) from freshwater turtles (Pleurodira: Chelidae), in the Kimberley, Western Australia. Comparative Parasitology 76: 133-140.

Authors: Vasyl V. Tkach, Scott D. Snyder, Yuriy Kuzmin