Apterichtus

Hibino, Yusuke, 2015, A review of the finless snake eels of the genus Apterichtus (Anguilliformes: Ophichthidae), with the description of five new species, Zootaxa 3941 (1), pp. 49-78: 52-53

publication ID

http://dx.doi.org/10.11646/zootaxa.3941.1.2

publication LSID

lsid:zoobank.org:pub:ECDCBC06-96AC-4D91-9C24-7A0A30A3E375

persistent identifier

http://treatment.plazi.org/id/03D24013-FD50-FFC5-FF36-F946C6FDFAA3

treatment provided by

Plazi

scientific name

Apterichtus
status

 

Key to the species of Apterichtus 

(In that specimens of Apterichtus  possess small cepehalic pores, lack scales, and are usually faded in preservative, their identification can often be difficult.)

1 a. Anterior nostril without a prominent tube, its opening flush or nearly flush with underside of snout ( Fig. 4 AView FIGURE 4. A)............. 2

1 b. Anterior nostril within a prominent tube ( Fig. 4View FIGURE 4. A B).......................................................... 3

2 a. Preopercular pores 4; snout length equal to or more than twice eye diameter; trunk length 35 – 35 % of TL; numerous small spots on head, less than eye diameter in size; MVF (Mean Vertebral Formula) 58–140, total vertebrae 138–142 .................................................................................................... A. jeffwilliamsi 

2 b. Preopercular pores 3; snout length less than twice eye diameter; trunk length 40 % of TL; small spots and a few large spots on head; VF 60–137, total vertebrae 137 ............................................................ A. nariculus 

3 a. Supratemporal pores 3; preopercular pores 3 ( Fig. 3View FIGURE 3 A)........................................................ 4

3 b. Supratemporal pores 5–9; preopercular pores 3 or 4 ( Fig. 3View FIGURE 3 B)................................................. 10

4 a. Head length 11–16 times in TL.......................................................................... 5

4 b. Head length 17–21 times in TL.......................................................................... 7

5 a. 3–4 vomerine teeth; total vertebrae 150–157 ............................................. Apterichtus anguiformis 

5 b. 5–7 vomerine teeth; total vertebrae 132–146 ................................................................ 6

6 a. 5–7 vomerine teeth; preanal vertebrae 61–63; MVF 62–142, total vertebrae 137–145 ................ Apterichtus kendalli 

6 b. 4–6 vomerine teeth; preanal vertebrae 53–60; MVF 59–138, total vertebrae 132–146 ............. Apterichtus equatorialis 

7 a. None, or 1–2 vomerine teeth............................................................................ 8

7 b. More than 5 vomerine teeth............................................................................. 9

8 a. Tail 1.6–1.7 in TL; MVF 54–139, total vertebrae 137–141 ..................................... Apterichtus hatookai 

8 b. Tail 1.8–2.4 in TL; MVF 77–158, total vertebrae 154–166 .................................. Apterichtus flavicaudus 

9 a. Snout sharply pointed in lateral view, dorsal profile ca. 30 O above lower jaw; snout 4.4–5.4 in HL; tip of lower jaw beneath anterior margin of orbit; anterior nostril tube 3 times in eye; MVF 82–164, total vertebrae 162–167 .... Apterichtus australis 

9 b. Snout less pointed in lateral view, dorsal profile ca. 45–50 O above lower jaw; snout 5.1–5.8 in HL; tip of lower jaw in advance of a line beneath anterior margin of orbit; anterior nostril tube 4 times in eye; MVF 75–148, total vertebrae 146–153 ............................................................................................... Apterichtus mysi 

10 a. Supratemporal pores 7–9 .............................................................................. 11

10 b. Supratemporal pores 5 (rarely 6)....................................................................... 12

11 a. Head length 16–20 in TL; body depth 63–71 in TL; MVF 66–143, total vertebrae 147–151 .................... A. monodi 

11 b. Head length 12 in TL; body depth 45 in TL; MVF 54–132, total vertebrae 131–133 ....................... A. orientalis 

12 a. Preopercular pores 4 ................................................................................. 13

12 b. Preopercular pores 3 ................................................................................. 15

13 a. Vomerine teeth numerous, 8–14 in a single or irregularly biserial row; MVF 52–134, total vertebrae 132–139 ..... A. caecus 

13 b. 2–4 vomerine teeth; total vertebrae 123–132 .............................................................. 14

14 a. Body moderately elongate, body depth 43–53 in TL; tail length 1.7–1.8, head length 12–15 in TL; MVF 54–128, total verte- brae 123–132 .................................................................................... A. ansp 

14 b. Body extremely elongate, body depth 67–100 in TL; tail length 1.7, head length 14 in TL; MVF ~ 52–130, total vertebrae 129–132 .................................................................................... A. gracilis 

15 a. Total vertebrae 131–145 ............................................................................... 16

15 b. Total vertebrae 155–162 .............................................................................. 17

16 a. Center of orbit above tip of lower jaw; tail 1.8–1.9 in TL; head 12–14 in TL; MVF 58–138, total vertebrae 131–145 ................................................................................................... A. klazingai 

16 b. Anterior margin of orbit behind tip of lower jaw; tail 1.9–2.1 in TL; head 16–18 in TL; MVF 66–143, total vertebrae 141–145 ............................................................................................. A. moseri 

17 a. Head length 16–17 in TL; preanal vertebrae 68–74, MVF 70–160, total vertebrae 160 ..................... A. dunalailai 

17 b. Head length 18–19 in TL; preanal vertebrae 73–80, MVF 78–158, total vertebrae 155–162 ................... A. malabar