Dujardinascaris

Mašová, Šárka, Baruš, Vlastimil, Seifertová, Mária, Malala, John & Jirků, Miloslav, 2014, Redescription and molecular characterisation of Dujardinascaris madagascariensis and a note on D. dujardini (Nematoda: Heterocheilidae), parasites of Crocodylus niloticus, with a key to Dujardinascaris spp. in crocodilians, Zootaxa 3893 (3), pp. 261-276 : 272-273

Key to the males of Dujardinascaris parasitizing crocodilians

1a. Dujardinascaris (male specimens) parasitizing Old World crocodilians........................................... 2

1b. Dujardinascaris (male specimens) parasitizing New World crocodilians......................................... 14

2a. Spicules equal or slightly subequal in length (difference less than 10% of body length)............................... 3

2b. Spicules markedly (evidently) different in length, the ratio of their lengths 2:1 (0.34–0.40 versus 0.84–0.92); right spicule 9.2–9.7% of body length, left spicule 3.7–4.2% of body length. Gubernaculum ( Fig. 5 A) with expanded head, brad shaft, and swollen scoop-like tip. Host: Osteolaemus tetraspis ; distribution: Africa.................................. D. petterae

3a. Spicules length less than 3, 5–34% of body length............................................................ 4

3b. Spicules length more than 3, 23–92% of body length.......................................................... 9

4a. Spicules length less than 1.5, 5–15% of body length.......................................................... 5

4b. Spicules length 1.7–3.4, 20–46% of body length............................................................. 7

5a. Spicules length 1.25, 5% of body length. Gubernaculum ( Fig. 5 B) dagger-like with narrow anterior “handle”, a straight shaft, and sharp tapering point. Host: Gavialis gangeticus , distribution: India.................................. D. woodlandi

5b. Spicules length 0.90–1.25, more than 10% and less than 16% of body length....................................... 6

6a. Spicules length 0.9–1.20; gubernaculum length 0.18–0.27, tail length 0.12, 44–66% of gubernaculum length. Gubernaculum ( Fig. 5 C) bifid proximal part with anterior and posterior expansion in lateral view, shaft straight, and tip blade-like and curved. Host: Crocodylus niloticus , distribution: Africa..................................................... D. puylaerti

6b. Spicules length 1.10–1.25; gubernaculum length 0.15–0.16, tail length 0.10, 62–67% of gubernaculum length. Gubernaculum ( Fig. 5 D) with prominent expansion of head region, shaft blade-like and gently curved, and tip sharp, without hook. Host: Crocodylus porosus , distribution: Papua New Guinea................................................... D. westonae

7a. Spicules length 1.70–2.70, 14–34% of body length; gubernaculum length 0.09–0.24, tail length 0.05–0.21, 55–110% of gubernaculum length........................................................................................ 8

7b. Spicules length 2.66–3.40, 23–46% of body length; gubernaculum length 0.19–0.23, tail length 0.20–0.33, 105–145% of gubernaculum length. Gubernaculum ( Fig. 5 E) with narrow head, tapered shaft, distal end with hook, and right angle to shaft. Host: Crocodylus porosus , distribution: Philippines.............................................. D. philippinensis

8a. Spicules length 1.7–2.7, 14% of body length; gubernaculum length 0.19–0.24, tail length 0.21, 87–100% of gubernaculum length. Gubernaculum ( Fig. 5 F) with long, rectangular proximal part, straight shaft, and rounded tip. Host: Crocodylus niloticus , distribution: Africa........................................................................ D. gedoelsti

8b. Spicules length 1.7–2.5, 24–34% of body length; gubernaculum length 0.09–0.10, tail length 0.05–0.10, 55–80% of gubernaculum length. Gubernaculum ( Fig. 5 G) consisting of head region shaped like rifle-butt, hollow straight tapering shaft, and delicate bent tip with sharp point. Host: Crocodylus johnstoni , distribution: Australia............................ D. blairii

9a. Spicules length 3.2–13.0, 36–92% of body length; gubernaculum length 0.12–0.34, tail length 0.07–0.25, 27–86% of gubernaculum length....................................................................................... 10

9b. Spicules length 5.0–6.6, 58–73% of body length; gubernaculum length 0.13–0.17, tail length 0.13–0.15, 93–100% of gubernaculum length. Gubernaculum ( Fig. 5 H) with expanded and gently curved slender shaft prolonged to a fine tip. Host: Crocodylus novaeguineae , distribution: Papua New Guinea. D. harrisae

10a. Spicules length 6.3, 66–92% of body length; gubernaculum length 0.12, tail length 0.07; 58% of gubernaculum length. Gubernaculum ( Fig. 5 I) with expansion on the proximal end, tapering shaft, distal end with hook, and right angles to shaft. Hosts: Crocodylus porosus , C. novaeguineae , C. johnstoni (probably), distribution: Papua New Guinea, Australia..... D. mawsonae

10b. Spicules length 3.2–13.0, 35–70% of body length; gubernaculum length 0.13–0.34, tail length 0.09–0.25; 27–86% of gubernaculum length....................................................................................... 11

11a. Spicules length 3.5–7.3, 35–67% of body length; gubernaculum length 0.18–0.21, tail length 0.07–0.15; 40–83% of gubernaculum length. Gubernaculum ( Fig. 5 J) head with dorsal projection in lateral view, longitudinally riffled straight tapering shaft, and single sharp tip curved to a small hook. Hosts: Crocodylus niloticus , C. cataphractus , distribution: Madagascar, Africa...................................................................................... D. madagascariensis

11b. Spicules length more than 7............................................................................ 12

12a. Spicules length 7.0–12.9, 34–55% of body length; gubernaculum length 0.33–0.34, tail length 0.09–0.12; 27–35% of gubernaculum length. Gubernaculum ( Fig. 5 L) relatively long, with dorsal end that has a distinct posterior process, and tip trifurcate. Host: Crocodylus niloticus , distribution: Africa..................................................... D. dujardini

12b. Spicules length less than 7............................................................................. 13

13a. Spicules length 3.2–6.2, 37–51% of body length; gubernaculum length 0.28–0.31, tail length 0.10–0.25; 36–80% of gubernaculum length. Gubernaculum ( Fig. 5 K) relatively long, slender, with deeply cleft head, blade-like shaft, and sharp tip. Host: Crocodylus porosus , distribution: Papua New Guinea................................................. D. angusae

13b. Spicules length 5.1, 46–65% of body length; gubernaculum length 0.15, tail length 0.13; 86% of gubernaculum length. Gubernaculum ( Fig. 5 M) is quite short, tip resembling a hypodermic needle, head of gubernaculum elongate and narrow, tip comprising two sharp points, posterior one shorter than anterior and without hook at tip. Host: Crocodylus porosus , C. novaeguineae ; distribution: Australia, Papua New Guinea.............................................. D. taylorae

14a. Spicules length less than 1.5, 7–18% of body length......................................................... 15

14b. Spicules length more than 2, 41–66% of body length......................................................... 16

15a. Spicules length 1.1, 17.7% of body length; gubernaculum length 0.10, tail length 0.10; 100% of gubernaculum length. Gubernaculum ( Fig. 5 N) hook-like with complex tip, with small expansion at proximal end, thick cylindrical shaft and complex distal end, and composed of cup-like expansion on left side of tip and anchor-like process on right. Host: Caiman crocodylus , distribution: Venezuela........................................................................ D. chabaudi

15b. Spicules length 0.64–0.80, 7.1–7.2% of body length; gubernaculum length 0.12, tail length 0.11–0.17; 92–141% of gubernaculum length. Gubernaculum ( Fig. 5 O) with a hook-like structure at its rounded tip. Host: Caiman crocodylus , distribution: Brazil.......................................................................................... D. paulista

16a. Spicules length 2.2–3.9, 43–46% of body length; gubernaculum length 0.06–0.10, tail length 0.11; 54–100% of gubernaculum length. Gubernaculum ( Fig. 5 P) slender with small a non-expanded proximal end, slightly inflated rounded tip, and tapered shaft. Host: Caiman crocodylus , distribution: Brazil, Venezuela....................................... D. longispicula

16b. Spicules length more than 4.5, 41–66% of body length; gubernaculum length 0.10 and more, tail length 0.13 and more; 115–207% of gubernaculum length....................................................................... 17

17a. Spicules length 4.8–5.9, 41–66% of body length; gubernaculum length 0.10–0.14, tail length 0.13–0.17, 115–127% of gubernaculum length. Gubernaculum ( Fig. 5 Q) with expanded proximal part that curved back into posterior process and straight broad shaft tip with curved blade-like point. Hosts: Crocodylus acutus , C. rhombifer , C. moreletii ; distribution: Molin (1860) - unknown locality, Cuba, Mexico, Zoos (San Diego, Amsterdam)........................................ D. helicina

17b. Spicules length 5.4–6.7, 48–54% of body length; gubernaculum length 0.14–0.19, tail length 0.20–0.29; 153–207% of gubernaculum length. Gubernaculum ( Fig. 5 R) with proximal part expanded and usually cleft by fissure into two rounded processes, shaft of gubernaculum relatively wide and straight, and a tip forked with terminal cuticular bulb. Host: Alligator mississippiensis ; distribution: USA.......................................................................... D. waltoni

Figures

FIGURE 5. Reproduced line drawings of Dujardinascaris gubernacula. A, E – H, and K based on Sprent et al. (1998); B, C, I, J, L – N, and P – R based on Sprent (1977); O based on Travassos (1933); J and L marked with asterisk based on our material. A, D. petterae. B, D. woodlandi. C, D. puylaerti. D, D. westonae. E, D. philippinensis. F, D. gedoelsti. G, D. blairii. H, D. harrisae. I, D. mawsonae. J, D. madagascariensis. K, D. angusae. L, D. dujardini. M, D. taylorae. N, D. chabaudi. O, D. paulista. P, D. longispicula. Q, D. helicina. R, D. waltoni.