Ichthyophis acuminatus Taylor, 1960

Geissler, Peter, Poyarkov, Nikolay A., Grismer, Lee, Nguyen, Truong Q., An, Hang T., Neang, Thy, Kupfer, Alexander, Ziegler, Thomas, Böhme, Wolfgang & Müller, Hendrik, 2015, New Ichthyophis species from Indochina (Gymnophiona, Ichthyophiidae): 1. The unstriped forms with descriptions of three new species and the redescriptions of I. acuminatus Taylor, 1960, I. youngorum Taylor, 1960 and I. laosensis Taylor, 1969, Organisms Diversity & Evolution (New York, N. Y.) 15 (1), pp. 143-174 : 153-156

publication ID

https://doi.org/ 10.1007/s13127-014-0190-6

publication LSID

lsid:zoobank.org:pub:B81E8213-C8B3-43C8-9375-AB7A4E681B58

persistent identifier

https://treatment.plazi.org/id/03F787DE-7D11-9F4C-D0B0-F9F0FBF6C8E9

treatment provided by

Felipe

scientific name

Ichthyophis acuminatus Taylor, 1960
status

 

Ichthyophis acuminatus Taylor, 1960 View in CoL

Holotype Adult male ( AMNH A20875 About AMNH , Fig. 4 View Fig ) collected at Mae Wang Valley , Chiang Mai Province, Thailand, by Malcolm Smith ( Taylor, 1960).

Paratypes Metamorphosed female ( BMNH 1921.4.1.338) collected at the type locality, by M. Smith ( Taylor 1960). Metamorphosed female ( BMNH 1961.2055) collected at “Muang Liep, Thailand ”, by M. Smith. Metamorphosed female ( BMNH 1961.2056) and one metamorphosed specimen of unknown gender ( BMNH 1961.2057), both collected at “Pa Meang, Mae Wang, Thailand ” ( Taylor 1960). See also distributional remarks below.

Diagnosis A species of Ichthyophis without a lateral yellow stripe; total length of metamorphosed specimens at 172– 294 mm, length about 18–25 times of midbody width; snout blunt and rounded (SP/HL =0.01–0.05); tentacle 2.4–3.1 times as far from naris as from eye; premaxillary and maxillary teeth 35–43, vomeropalatine teeth 37–46, dentary teeth 31–42, inner mandibular teeth 19–32; inner mandibular tooth row about four fifths of dentary row; tail end somewhat tapered; total annuli (dorsal count) 296 to 327, encircling body in a straight line ventrally, three to seven annuli interrupted by cloacal disc, two to three tail annuli posterior to the cloacal disc; cloacal disc rounded; 108–111 vertebrae; scales in up to four rows per annulus (dosolaterally), present only in the posterior two thirds of body.

The species differs from all other known unstriped congeners in the following characters: from Ichthyophis billitonensis in having more inner mandibular teeth (19–22 vs. 2) and more annuli (301–327 vs. 251–254); from I. bombayensis by the absence of scales on the anterior third of body; from I. cardamomensis sp. nov. by a smaller eye size (HL/ ED =20.9 vs. 11.5–13.2) and fewer vertebrae (109–111 vs. 120); from I. catlocensis sp. nov. by the tentacle being situated closer to naris ( TN / ET =2.4–3.1 vs. 4.5); from I. chaloensis sp. nov. by a larger eye size (HL/ ED = 20.9 vs. 31.3); from Ichthyophis dulitensis by the absence of scales on the anterior third of body; from I. glandulosus by more annuli (301–327 vs. 273–286); from Ichthyophis javanicus in a lower number of total annuli (296–327 vs. 348–351); from I. lakimi by having fewer inner mandibular teeth (19–32 vs. 14); from I. laosensis by the absence of scales on the anterior third of body; from Ichthyophis larutensis by the presence of inner mandibular teeth; from Ichthyophis monochrous by the absence of scales on the anterior third of body and more annuli (301–327 vs. 247); from Ichthyophis orthoplicatus by a higher count of annuli (301–327 vs. 205–291); from Ichthyophis sikkimenis by having more annuli (301–327 vs. 276–292); from Ichthyophis singaporensis by the absence of scales on the anterior third of body; from Ichthyophis sumatranus by the absence of scales on the anterior third of body; from Ichthyophis weberi by the presence of inner mandibular teeth; from I. youngorum by four instead of one to two rows of scales per scale pocket and more premaxillary and maxillary teeth (35–43 vs. 22–28).

Description of holotype Selected morphological and meristic data are given in Table 4. Condition of the preserved specimen: jaws have been cut and phallus dissected; a small, oval area of epidermal abrasion on dorsal left side of snout; a deep, ventrolateral longitudinal incision (19.5 mm) extends posterior from 65 mm posterior to snout tip; long (93 mm) midventral longitudinal incision extends anteriorly from cloaca; oval piece (ca. 4 × 11 mm) of body wall is missing ventrally, approximately 36 mm anterior of body terminus; several opened scale pockets along the body, especially close to body terminus; five small, rust-colored spots in regular intervals along the entire body (likely caused by corroded pins).

Body (see Fig. 4 View Fig ) roughly subcylindrical but slightly irregularly compressed and distorted along the entire body. In dorsal view, head slightly broadened anterior of first collar; sides of head fairly straight, converging slightly anterior of corner of mouth to a point half way between tentacular aperture and naris, where head curvature forms a blunt but comparatively pointed snout tip; curvature of lower jaw mirrors upper jaw in ventral view but ending in a more gently rounded, less-pointed tip; in lateral view, head tapers gently between collar region and point half way between tentacles and nares, more strongly tapering from this point to tip of snout; nares close to tip of snout; in lateral view, snout evenly rounded anterior to nares; lips straight edged; corner of mouth somewhat closer to bottom of head than to top of head; mouth slightly subterminal; in ventral view, gular region flattened and uniform, with transverse crease just anterior of first nuchal groove; eyes visible through unpigmented skin, circular, not elevated above adjacent skin; in lateral view eyes somewhat closer to top of head than to upper lip; tentacular aperture about twice as far from naris than from eye, smaller than naris, distance from upper lip slightly less than twice the diameter of tentacular aperture; tentacular sheaths elevated from adjacent skin, visible only in dorsal view; in preservative, tentacles slightly protruding from tentacular aperture; nares oval in shape, closer to top of head than to upper lip, visible in dorsal view, not visible in ventral view; teeth recurved and bicuspid, with accessory cusp small and very

Species Ichthyophis Ichthyophis cardamomensis Ichthyophis Ichthyophis Ichthyophis Ichthyophis acuminatus sp. nov. catlocensis chaloensis laosensis youngorum

sp. nov. sp. nov.

Specimen AMNH BMNH BMNH BMNH B LSUHC CBC LSUHC ZFMK IEBR MNHN FMNH FMNH FMNH FMNH A20875 About FMNH 1921.4.1. 1961.2055 1961.2056 MNH 9335 View Materials 01185 10106 88976 A.2011.16 1928.95 189250 189251 189252 189253 (holotype) 338 (paratype) (paratype) 1961. (holo (paratype) (paratype) (holotype) (holotype) (holotype) (holotype (paratype) (paratype) (paratype) (paratype) 2057 type)

(paratype)

Sex Male Female Female Female – Female Female Female Female Female Female Male Male? (larva) Female (larva) TL 294 199 203 215 172 183 321.7 289.1 183.5 215.7 318 208 217 82 189

TAL 3.9 2.8 2.4 3.6 2 3.1 3.8 6 2.1 3.7 3.7 2.9 3.1 1.8 3.5

BW1 10.6 7.8 6.4 8.1 6.7 7.1 9.2 8.9 5.3 6.9 11.4 8.1 8 – 7.8

BW2 13.7 10.9 8.1 10.6 8 7.9 8.6 8 7.1 7.6 16.1 11.2 10.5 4.8 10.6

BW3 5.4 4.3 3.6 5.9 3.9 4.1 5.4 4.9 3.7 3.2 6.3 5.5 5 2.5 5.3

HL 14.6 8.8 9.1 10.1 8.8 8.1 11.7 9.2 7.3 9.4 10.9 10.4 10.4 – 9.3

HW 9.8 6.7 6.2 7 6.3 5.8 7.9 7.1 4.8 6.3 9.7 7.6 7.3 3.9 7

UJL 10.6 6.4 6.2 6.2 5.9 6.9 10.2 9.5 5.4 7.2 10.8 7.6 7.3 2.8 4.5

LJL 9.3 6 5.6 5.6 5.9 6 9.7 9 5.2 6.3 10.3 6.7 6.9 2.2 4.5

SP 0.8 0.4 0.1 0.3 0.4 0.7 0.5 0.6 0.5 1.3 0.6 0.1 0.1 0.3 0.7

EL – – – – 1 1 0.6 0.8 1.7 – – – –

ES 5.8 a – – – – 4.1 6 5.5 3.6 4.8 6.3 – – – –

EN 4.8 3.1 3.2 3.2 3.1 3.5 4.7 4.2 2.9 3.6 5 3.8 3.6 1.7 2.8

ET 1.3 0.7 0.8 0.8 0.8 0.9 1.2 1.1 0.6 1.3 1.6 1.1 1 – –

TN 3.1 2 2 2.1 2.5 2.9 3.5 3.1 2.7 2.8 4.3 2.7 2.5 – –

EE 6 4.3 4 4.6 4.3 4.3 5.6 5.2 4.3 4.8 7.3 4.5 4.8 2.4 4.2

NN 2.6 1.3 1.1 1.4 1.3 2.2 2.8 2.6 2 1.8 3.2 2.4 2.2 1.4 1.7

TT 7.2 5 4.6 5.5 5 4.7 6.2 5.8 4.2 4.7 7.5 5.9 4.9 – –

ED 0.7 a – – – – 0.7 1 0.8 0.5 0.3 1 – – – –

TN/ET 2.4 2.9 2.5 2.6 3.1 3.2 2.9 2.8 4.5 2.2 2.7 2.5 2.5 – –

HL/ED 20.9 11.6 13.2 11.5 14.6 31.3 10.9

SP/HL 0.05 0.05 0.01 0.03 0.05 0.09 0.04 0.06 0.07 0.14 0.06 0.01 0.01 – 0.08 TL/TAL 43 71.1 84.6 59.7 86 59 84.7 48.1 87.4 58.3 85.9 71.7 70 45.6 54

TL/BW2 21.5 18.3 25.1 25.1 21.5 23.2 37.4 36.1 25.8 28.4 19.8 18.6 20.7 17.1 17.83

TAD 302 296 – 301 327 322 364 340 342 344 346 318 328 – 317

TAV – – – – – 320 359 338 340 342 345 – – – –

AV 6 7 5 6 3 5 4 5 5 3 3 5 6 – 6

TAT 3 2 3 2 3 6 4 6 5 5 2 4 4 – 4

VERT 109 108 – 111 111 120 120 110 110 112 108 108 104 108

PMM 40 43 37 41 35 23 38 38 44 37 33 28 22 b – 23 b

VP 46 39 38 43 37 29 28 28 51 54 36 33 b 40 – 33 b

DE 42 43 38 42 31 20 34 34 27 26 35 28 b 29 b – 28 b

IM 32 26 26 26 19 19 21 22 16 11 30 19 b 18 b – 15 b

a Based on literatureTaylor (1960, 1968)

b Damaged, no exact count possible closely positioned to main cusp; teeth in premaxillary-maxillary, vomeropalatine and dentary series of similar size and slighty larger than teeth in inner mandibular series; length of vomeropalatine row slightly exceeds length of premaxillary-maxillary row by about two tooth positions; length of inner mandibular tooth row about four fifth of dentary row ( Fig. 5e View Fig ); palate rather flat, choanae oval to slightly teardrop-shaped; tongue triangular with a broad but fairly pointed tip; both collars wider and deeper than head; second collar gradually narrowing towards trunk; collar grooves only distinct ventrally and laterally, vanishing dorsally; no transverse groove on second collar; in ventral view, anterior as well as posterior border of collars distinct; second collar slightly longer than first; annular grooves cross venter in a more or less straight line; total annuli 302; vertebrae 109; longitudinal cloacal slit situated in a round cloacal disc, interrupting six annuli; cloaca surrounded by 7/7 (right/left) denticulations ( Fig. 6e View Fig ); tail bearing three annuli (including cap), grooves not complete ventrally, terminating in a distinct cap; scales restricted to posterior two thirds of body; scales present in up to four rows per scale pocket (count- ed dorsally); scales oval in shape.

Coloration Presumably somewhat faded (see Fig. 4 View Fig ) in preservative and now dark brown on dorsum and somewhat lighter on sides and ventrally; cloacal disc and tail cap light colored; tentacular apperture with narrow light colored margin. Overall color presumably darker in life.

Variation Selected morphological and meristic data are given in Table 4. The paratypes BMNH 1921.4 .1.338, BMNH 1961.2055 , BMNH 1961.2056 , and BMNH 1961.2057 (all metamorphosed specimens with lower TL) show a wider range in numbers of annuli (296–327) and lower numbers of inner mandibular teeth ( IM =19–26). However, all paratypes resemble the holotype in several characteristic features, e.g., the characters of the holotype are within the variation range shown by the paratypes: TN/ ET =2.5–3.1; their coloration as well as in the shape of the annuli (grooves completed on venter in a strate line); the absence of scales on anterior third of body .

Differences from the description of Taylor (1960) The following characters measured or counted by us deviate from the data provided by Taylor (1960) (marked with an asterisk): holotype: EE=6 vs. 7.8*; SP=1.8 vs. 1*; TAD=302 vs. 315*; PMM=40 vs. 49*; VP=46 vs. 53*; DE 42 vs. 49*; IM 32 vs. 44*. While Taylor (1960) stated that the metamorphosed paratypes all have a TL of 205 mm and TAD=315–331, our measurements revealed a variation in sizes (see Table 4) and a different TAD range: TAD=296–327.

Distribution According to Chan-ard (2003) and Chan-ard et al. (2011), the species is known only from northern Thailand: (1) Mae Wang District, Chiang Mai Province and (2) Pa Sang District, Lamphun Province, northwestern Thailand. However, Taylor (1960) mentioned one paratype (BMNH 1961.2055; M. Smith no. 5656) as collected by M. Smith in “Muang Liep, Thailand.” This locality is not associated with the Kingdom of Thailand in its current borders, but this locality was also reported by Smith (1923) in the description of Tropidophorus laotus : “type loc. Muang Liep, N. of Pak Lai, Upper Mekong, French Laos ” (now in Sayaboury Province, Central Laos). Taking into account that this part of Laos belonged to the Kingdom of Siam until 1904 ( Jerndal & Rigg 1998), we propose that this locality was wrongly interpreted by Taylor (1960) as being situated in “modern” Thailand. This interpretation receives further support from four additional specimens from the collections of the Natural History Museum, London. These larval specimens are catalogued as I. acuminatus (BMNH 1974.2351 to 54; note: because of the larval stage of these specimens a confirmation of their taxonomic allocation is currently not possible) and were collected by M. Smith at “Muang Liep, Laos ” and “Pak Mat, Laos ” as part of the Day Expedition 1919–1920. The field numbers of these larvae, No. 5654 and 5655 from Pak Mat and No. 5657 and 5658 from Muang Liep, bracket the field number (5656) of paratype BMNH 1961.2055, indicating that this specimen was indeed collected in Laos. Hence, we consid- er that I. acuminatus is present in Laos too (see Fig. 1).

Conservation status Since the collection of the type series and associated material from Thailand and Laos by M.A. Smith in the early 1920s, no additional specimens of I. acuminatus have been recorded. It is currently listed as data deficient by IUCN ( van Dijk et al. 2004a) and further research is urgently needed to gather data on the actual distribution and population size of I. acuminatus .

AMNH

American Museum of Natural History

ET

East Texas State University

LSUHC

La Sierra University, Herpetological Collection

ZFMK

Zoologisches Forschungsmuseum Alexander Koenig

MNHN

Museum National d'Histoire Naturelle

FMNH FMNH FMNH FMNH

Field Museum of Natural History

IM

Indian Museum

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