Egtitus Thorne, 1967

Andrássy, István, 2012, On the “ Paractinolaimus ” genus group (Nematoda: Actinolaimidae), with description of five new and two rare species of Egtitus Thorne, 1967, Journal of Natural History 46 (7 - 8), pp. 453-494 : 456-462

Egtitus Thorne, 1967

With general structures of the “ Paractinolaimus ” genus group. Further characters are as follows. Body length ranging from 1.4 to 3.0 mm. Lip region set off by depression. Labial chamber wider than dental chamber, the latter smooth or slightly ribbed, without denticles. Stylet chamber narrow, exceptionally roomy. Onchia simple, unitipped. Odontostyle 0.9–1.2 (exceptionally to 1.8) times as long as labial diameter, aperture one-third to two-fifths of its length. Pharynx enlarged anterior or posterior to its middle. Pharyngeal gland nuclei often inconspicuous. Vulva a short longitudinal slit with sclerotized inner lips. Ventromedial supplements small, spaced, 7 to 13 in number. Female tail 2.5 to 14 anal body widths long, conoid, elongate-conoid to filiform, often slightly bent dorsally (see also Table 2).

Type species: Egtitus bryophilus Thorne, 1967 .

Egtitus differs from the other genera of the genus group as follows: from Paractinolaimus by the smaller and adenticulated dental chamber, from Westindicus by the dental chamber narrower than labial chamber and only slightly ribbed on its walls, and from Nothactinolaimus and Stopractinca by the small number of spaced supplements.

Heyns and Argo (1969) synonymized Egtitus with Neoactinolaimus Thorne, 1967 , this was however incorrect as Egtitus differs from Neoactinolaimus by the absence of small additional teeth on the four onchia and, especially, by the supplements arranged in a continuous series (versus in fascicles).

The genus comprises 28 species. However, it should be mentioned that some of the species where males are not known (seven species) may belong to Neoactinolaimus Thorne, 1967 . These two genera are mainly separated by the male supplements if they are arranged in series ( Egtitus ) or fascicles ( Neoactinolaimus ). Presence ( Neoactinolaimus ) or absence ( Egtitus ) of minute secondary toothlets on the four onchia, although often difficult to observe, can also help in distinguishing these genera.

Egtitus africanus sp. nov.

Neoactinolaimus elaboratus apud Heyns and Argo, 1969

Egtitus andhricus Khan and Jairajpuri, 1994

Egtitus arcuatus Choi and Khan, 2000

Egtitus L a b c ć (♀) V Lipr. w. Odontost. Phar. ex. Tail (♀) Spicula Suppl .

E. africanus 1.4–2.2 36–57 3.4–4.5 12–22 4.5–6.2 51–56 17–20 17–20 50 sp. nov. 1.6–1.8 54–61 3.2–4.1 62–76 (0.9–1.0) E. andhricus 1.4–1.6 38–44 3.5–3.8 14–17 4.4–5.2 50–54 20–22 20–22 52–53 Khan and Jairajpuri, 1994 1.5–1.9 41–42 3.4–3.5 70–108 (1.0)

E. arcuatus 1.5–1.8 43–47 3.6–4.2 14–16 4.7–5.5 52–54 16–17 20–23 50 Choi et al., 2000 – (1.2–1.4) E. biformis 1.7–2.4 36–45 3.2–4.0 10–11 6.5–6.8 48–50 16–17 24–26 48– 49 sp. nov. 1.6 34 2.9 49 1.0 (1.5–1.6) E. bryophilus 2.0–2.3 44–51 4.0–5.0 13–16 5.4–6.0 49–50 15–17 17–19 53–56 Thorne, 1967 1.8–2.1 45–56 4.2–4.8 61–72 (1.1–1.2) E. chilenus 1.8–2.2 39–45 3.8–4.4 14–16 4.3–5.3 49–52 18–19 20–23 42– 46 sp. nov. 1.9 42–46 3.8–4.2 60–65 (1.1–1.2) E. conicaudatus 1.7–2.0 40–48 4.0–4.2 24–28 2.5–3.2 50–54 22–25 20–23 50–55 Khan et al., 2008 – (0.9–1.0) E. elaboratus 1.7–1.8 30–36 3.4–4.1 11–14 4.4–5.3 50–51 22–24 22 50 ( Cobb, 1906) – (0.9–1.0) E. itanagrus 2.0–2.6 32–40 4.1–4.7 12–19 3.6–6.0 45–53 22–24 24–28 46–50 Khan et al., 1994 1.7–2.5 35–44 3.7–4.8 71–92 (1.0–1.2) E. japonicus 1.6–2.0 43–51 3.6–4.8 14–16 4.5–5.3 53 20–23 20–23 50 Khan and Araki, 2001 2.0 53 4.2 51 (1.0) E. kagoshimai 1.6–1.8 48–50 3.8–4.2 14–17 3.5–4.7 60–62 18–20 18–20 50–54 Khan et al., 2008 – (1.0) E. kazirangus 1.6–2.5 36–45 3.5–5.1 9–12 9–11 44–55 20–22 21–22 48–49 90–150

95–114

104–123

178–225

130–158

114–160

70–83

126–153

118–194

110–128

108–115

171–230 43–50

43–45

–

58

50–58

50–54

–

–

47–60

47

–

48–49

7–9

7–8

–

10

7–9

10–11

–

–

8–10

8

–

8

Khan and Jairajpuri, 1994 1.9–2.6 41–45 4.0–4.3 76–78 (1.0–1.1) E. koriensis 1.8–2.0 44–53 3.4–4.1 14–18 5.2–5.3 52–54 20–21 20–21 52–56 Khan et al., 1999 – (1.0) E. longicaudatus 2.7–2.8 52–55 4.2–4.3 7.0–7.1 13–14 44–45 17–18 22–23 50 sp. nov. 2.5 48 4.1 76 1.0 (1.2–1.3)

E. naunii 1.6–2.1 34–41 3.4–4.1 13–17 4–5 50–55 22–24 22–24 47–50 Khan and Jairajpuri, 1994 – (1.0) E. neocyatholaimus 2.2–2.6 32–51 4.7–4.8 9.4–11.0 8 42–46 15–16 22–24 52–54 ( Kreis, 1936) 2.4–2.5 46–50 4.0–4.3 86–92 (1.3–1.5) E. neoelaboratus 1.9–2.0 43–46 4.0–4.3 8.0–8.2 9–10 50–54 20–22 23–24 46–47 ( Rahman et al., 1986) 1.3–1.7 40–43 3.6–3.7 70–73 (1.1–1.2) E. nipponicus 1.8–2.0 41–45 3.9–4.3 15–19 4–5 52 20–23 21–23 50 Khan and Araki, 2002 – (1.0)

E. nudus 2.0–3.0 41–49 3.8–5.1 10–12 10 50??? ( Wu and Hoeppli, 1929) 2.6 37 4.9 129 (1.0)

E. peteri – – – 14–16 24–26 50 Khan et al., 2008 2.0–2.3 39–41 3.6–3.7 70–74 (1.6–1.8) E. prodenticulatus 2.2 44 3.9 14.7 5 55 25–28 27 43 ( Heyns and Argo, 1969) 1.9–2.1 39–42 3.5–3.9 48–52 0.8 (1.0)

E. proximus 1.6–2.0 42–44 3.6–3.8 8.8–9.2 8 50–51? 23–24? ( Yeates, 1973) 1.7–1.9 40–45 3.4–3.8 66–70 (1.0–1.1) E. remotus 2.4 40 3.6 28 2.6 51 15–17 20–22 51– 54 sp. nov. 2.2–2.6 41–50 3.6–4.0 55–76 (1.2–1.4) E. shillongensis 2.4–2.7 37–38 4.4–4.7 20 3–4 48–50 23–25 24–26 48–51 Khan and Jairajpuri, 1994 2.5 38 4.4 109 (1.0–1.1) E. siddharthi 2.3–2.4 34–38 4.3–4.6 15–17 4.0 50–51 26–28 25–28 47–53 121–132

380–385

108–135

232–238

234–260

106–126

200–250

–

150

175–230

86

125–132

131–150

–

70

–

54–58

40–43

–

?

60–68

50–60

48–52

68–70

56

63–65

–

9

–

12–13

7–8

–

?

12–13

7–8

9–10

10–11

11

8–9

(Continued)

Egtitus biformis sp. nov.

Egtitus bryophilus Thorne, 1967

Neoactinolaimus bryophilus ( Thorne, 1967) Heyns and Argo, 1969

Egtitus chilenus sp. nov.

Egtitus conicaudatus Khan, Tanaka and Yoshiga, 2008

Egtitus elaboratus ( Cobb, 1906) Thorne, 1967

Dorylaimus elaboratus Cobb, 1906

Actinolaimus elaboratus ( Cobb, 1906) Cassidy, 1930

Neoactinolaimus elaboratus ( Cobb, 1906) Heyns and Argo, 1969

Egtitus itanagrus Khan, Ahmad and Jairajpuri, 1994

Egtitus japonicus Khan and Araki, 2001

Egtitus kagoshimai Khan, Tanaka and Yoshiga, 2008

Egtitus kazirangus Khan and Jairajpuri, 1994

Egtitus koriensis Khan, Park and Choi, 1999

Egtitus longicaudatus sp. nov.

Egtitus naunii Khan and Jairajpuri, 1994

Egtitus neocyatholaimus ( Kreis, 1936) Thorne, 1967

Actinolaimus neocyatholaimus Kreis, 1936

Neoactinolaimus neocyatholaimus ( Kreis, 1936) Heyns and Argo, 1969

Egtitus neoelaboratus ( Rahman, Jairajpuri, Ahmad and Ahmad, 1986) Jairajpuri and Ahmad, 1992

Neoactinolaimus neoelaboratus Rahman, Jairajpuri, Ahmad and Ahmad, 1986 Egtitus nipponicus Khan and Araki, 2002

Egtitus nudus ( Wu and Hoeppli, 1929) Thorne, 1967

Actinolaimus nudus Wu and Hoeppli, 1929

Neoactinolaimus nudus ( Wu and Hoeppli, 1929) Heyns and Argo, 1969

Egtitus peteri ( Khan, Tanaka and Yoshiga, 2008) comb. nov. ∗

Stopractinca peteri Khan, Tanaka and Yoshiga, 2008

Egtitus prodenticulatus ( Heyns and Argo, 1969) comb. nov. ∗∗

Paractinolaimus prodenticulatus Heyns and Argo, 1969

Egtitus proximus ( Yeates, 1973) Vinciguerra, 1988

Neoactinolaimus proximus Yeates, 1973

Egtitus remotus sp. nov.

Egtitus shillongensis Khan and Jairajpuri, 1994

Egtitus siddharthi Khan and Jairajpuri, 1996

Egtitus sinensis Wu and Liang, 1999

Egtitus surinamensis ( Micoletzky, 1925) Thorne, 1967

Actinolaimus surinamensis Micoletzky, 1925

Neoactinolaimus surinamensis ( Micoletzky, 1925) Heyns and Argo, 1969

Egtitus zealandicus ( Clark, 1963) Vinciguerra and Heyns, 1984

Actinolaimus zealandicus Clark, 1963

Mactinolaimus zealandicus ( Clark, 1963) Andrássy, 1970

∗ In Egtitus peteri , the small number of supplements and the narrow stylet chamber differ from the representatives of Stopractinca . This species appears to be closer to the members of Egtitus .

∗∗ Egtitus prodenticulatus has a non-denticulate dental chamber and a low number of supplements so this species probably belongs to the genus Egtitus .

Other nominal species in Egtitus

Egtitus cheongsongensis ( Choi, Duan and Baek, 1998) Andrássy, 2011 . It was described as Westindicus cheongsongensis Choi, Duan and Baek, 1998 from Korea. At present, I would rather place it in its original genus (see there).

Egtitus cyatholaimus ( Daday, 1905) Thorne, 1967 . Daday (1905) rather inadequately described it on the basis of male specimens from Paraguay. In having numerous (18) contiguous supplements, this species is transferred to Stopractinca (see there).

Egtitus keralaensis (Khan, Ahmad and Jairajpuri, 1994) Andrássy, 2011 . This Indian species has a strongly sclerotized buccal structure, therefore it should be retained in the genus Westindicus (see there).

Egtitus lacustris ( Loof, 1973) Andrássy, 1976 . Presently, I prefer to retain this species, which was found in Surinam, in its original genus, Nothactinolaimus (see there).

Egtitus occalescens ( Schneider, 1937) Thorne, 1967 . Schneider (1937) described this species as Actinolaimus occalescens Schneider, 1937 from the Sunda Islands. When synonymized Egtitus with Neoactinolaimus, Heyns and Argo (1969) named it as Neoactinolaimus occalescens ( Schneider, 1937) Heyns and Argo, 1969 . Vinciguerra (1988) transferred it to Paractinolaimus as Paractinolaimus occalescens ( Schneider, 1937) Vinciguerra, 1988 which can be accepted as its updated name.

Egtitus propinquus (Cobb in Cobb, 1915) Thorne, 1967. It was described in a single female with broken tail, without illustration, from the USA. As this species cannot be identified with certainty, it is considered species inquirenda.

Egtitus sanaensis ( Khan, Park and Choi, 1999) Andrássy, 2011 . Described from Korea. It can provisionally be left in the genus Westindicus (see there).

The genus Egtitus is distributed in tropical and subtropical regions. Of the 28 species, 23 are widespread in Asia–Australasia ( India, Seychelle Islands, Korea, China, Japan, Papua New Guinea, New Hebrides and New Zealand), three in Central and South America ( Puerto Rico, Hawaii, Surinam, Guayana, Peru and Chile), and two species are known to occur in Africa ( Congo, South Africa and Mauritius).