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A new snake of the genus Agkistrodon (Serpentes: Viperidae) from Tsushima Island, Nagasaki Prefecture, Japan PDF

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Preview A new snake of the genus Agkistrodon (Serpentes: Viperidae) from Tsushima Island, Nagasaki Prefecture, Japan

Japanese Journal of Herpetology 15(3):1 01-111., June 1994 (C)1 994 by The HerpetologicalS ocietyo f Japan A New Snake of the Genus Agkistrodon (Serpentes: Viperidae) from Tsushima Island, Nagasaki Prefecture, Japan KIYOSHI ISOGAWA, AKIRA MORIYA AND SADAAKI MITSUI Abstract: Specimens of the mamushi (genus Agkistrodon) from Tsushima Island were examined and compared with congeners from the mainland of Japan, China, and South Korea. The Tsushima specimens collectively differed from these congeners in several characters, and thus are described as a new A. species, tsushimaensis. A brief taxonomic key to the Agkistrodon blomhoffii complex is also provided. Key words: Tsushima Island; Viperidae; Agkistrodon; A. tsushimaensis sp. nov.; Taxonomy The population of Agkistrodon snakes of Tsushima Island, Nagasaki Prefecture, Japan, MATERIALS AND METHODS has hitherto been considered to be A. blomhoffii Thirty-two specimens collected on Tsushima blomhoffii (Boulenger, 1896; Koba, 1955; Maki, Island were examined immediately after being 1931; Mori, 1929; Stejneger, 1907). Goris killed. They were morphologically compared (1965) and Hashimoto and Toriba (1983) com- with A. b. blomhoffii, A. blomhoffii pared specimens from Tsushima Island with brevicaudus, and A. ussuriensis on the basis of those from the mainland of Japan, and recogniz- specimens and literature descriptions (Table 1). ed unique features in dorsal pattern and ventral Specimens used for comparisons, obtained coloration of the former. On the basis of through commercial dealers, were: 98 A. b. allozyme data, Paik et al. argued (1991) that the blomhoffii from southern Kyushu, Japan; A. 63 Tsushima population of Agkistrodon genetical-is b. brevicaudus from the lower basin of Chang- ly closely related to A. blomhoffii and A. jiang (spelling of the pin-yin system), China; and ussuriensis, but is differentiated from both of 49 A. ussuriensis from Kangwon-do, South these species. These findings have suggested the Korea. These species and subspecies have necessity for reconsideration of the taxonomic several characteristics common to the present status of the Agkistrodon population on e., species (i. occurrence of paired pits on dorsal Tsushima Island. scales, and 21 midbody scale rows; Gloyd and In 10-12 July 1986 and 28-30 July 1987, we Conant, 1982), and hence are considered as its surveyed Tsushima Island with other members close relatives. of the Yomeishu Seizo Co., Ltd (YMS) Research External characters used for comparisons Team (Fig. 1), and collected a total of 32 were: body proportion, scutellation, body col- Agkistrodon specimens (14 males and 18 oration, and dorsal and ventral patterns. The females). Examination of these specimens con- numbers of ventral and subcaudal scales were firmed the characteristic differences in coloration counted by the wider-than-long system. Altera- of the Tsushima population of the genus. They tions of dorsal scale rows were formulated also exhibited differences in scutellation and following Dowling's (1951) method. Mor- vertebral morphology especially when compared phometric characters examined were: body mass with A. b. blomhoffii from the mainland of (BM); head length (HL); head width (HW); total Japan. Moreover, the present specimens were body length (TBL); snout-vent length (SVL); tail remarkably distinct from congeners from China length (TL); and tail length in relation to total and South Korea in body proportion and body length (RTL). karyotype. Therefore, we here describe the Also, considering variations in vertebral mor- Tsushima population of Agkistrodon as a new phology within A. the blomhoffii complex (sensu species. Gloyd and Conant, 1990) demonstrated by Toriba (1988), the following measurements were taken for every tenth vertebra to the nearest Accepted 4 Apr. 1994 0.01mm with digital calipers: overall height, ver- 102 Jpn. J. Herpetol. (3). 15 1994 FIG. 1. Maps showing the geographic location of Tsushima Island and sampling localities of the specimens examined (closed circles). Locality names are as follows: Hidakatsu; 1, 2, Shitaru; 3, Ina; 4, Nita; 5, Mine; 6, Nii; 7, Kechi; 8, Komoda; 9, Izuhara; 10, Hotta; 11, Kunehama; 12, Sasuse; 13, Tsutsu; 14, Azamo; 15, Yora-Naiin (type locality). tical distance from top of neural spine to tip of Some of the values used for numerical com- hypapophysis; overall length, horizontal parisons were calculated from data given in the distance between tips of prezygapophysis and literature. Acronyms for catalogue numbers of postzygapophysis; neural spine height, vertical the specimens are: OMNH, Osaka Museum of distance from upper margin of spinal foramen to Natural History, Osaka; YMS, Yomeishu Seizo top of spine; and neural spine length, distance Co., Ltd Central Research Laboratories from front to rear edges of neural spine. The Kushikino Branch Lab., Kushikino. numbers of specimens used for morphometric comparisons of vertebrae were six for the pres- Agkistrodon tsushimaensis sp. nov. ent species, five for A. b. blomhoffii, eight for (Japanese name: Tsushima Mamushi) A. b. brevicaudus, and seven for A. ussuriensis. (Fig. 2) One male and one female of the present species were used for karyological study. Bone Ancistrodon blomhoffii: Boulenger, 1896, 525 (part). marrow cells from ribs were used and karyotype Agkistrodon blomhoffii: Stejneger, 1907, 457 (part); was determined on well spread metaphase cells Mori, 1929, 3 (part). following the method described by Yosida and Agkistrodon halys blomhoffii: Maki, 1931, 203 (part); Toriba (1986a). Koba, 1955, 346 (part). ISOGAWA ET AL. -NEW SNAKE FROM TSUSHIMA 103 TABLE 1. Localities of the species and subspecies of the genus Agkistrodon used for morphological comparisons. Data sources are also provided. Agkistrodon halys: Goris, 1965, 12; Yamaguchi, 620708 (skeleton), 620709; Yora-Naiin: YMS- 1966, 32 (part); Ueno and Shibata, 1970, Urata 194; 620702, 620725-26, 620727 (skeleton). and Yamaguchi, 1976, 259; Matsuo, 1989, 110 Etymology. -The name tsushimaensis refers (part). to Tsushima Island, to which the range of the Agkistron halys: Ohno, 1968, 103 (part). Agkistrodon blomhoffi blomhoffi: Hashimoto and present species is confined. Diagnosis. -This species differs from its Toriba, 1983, 50; Sengoku, 1987, 142. relatives in the following combination of Agkistrodon blomhoffii blomhoffii: Gloyd and Con- ant, 1990, 275 (part). characters: pits on dorsal scales inconspicuous; ventrals 140-151 in males, 144-153 in females; Holotype. -OMNH R3934, an adult male col- subcaudals 44-50 males, in 38-45 in females; cen- lected at Yora-Naiin, Izuhara-cho, Shimoagata- tral dark spots lacking in dorsal blotches; gun, Nagasaki Prefecture, Japan, on 28 July number of bands on trunk 21-28; postocular 1987 by the YMS Research Team. The streak poorly contrasted; venter with pepper- specimen was found on the bank of a rice paddy and-salt pattern consisting of numerous fine along a mountain stream at night (ca. 20:00). dark speckles, such pigmentation lacking in the Paratypes. -OMNH R3935, an adult male distal half of tail; tongue pink or reddish brown from Tsutsuse, Izuhara-cho, on July; 28 OMNH in life; vertebra relatively depressed in shape, its R3936, an adult female, from Kunehama, neural spine considerably low, especially com- Izuhara-cho, on 28 July; OMNH R3937, a pared to that of A. b. blomhoffii; W of sex juvenile female from Ina, Kamiagata-cho, chromosomes subtelocentric. Kamiagata-gun, on 30 July; OMNH R3938, an Description of holotype. -Measurements are: adult female from Azamo, Izuhara-cho, on 30 BM=106.3g in life; TBL=563mm; SVL=477 July; OMNH R3939-41, adult males from mm; TL=86mm; RTL=15.3%; HL=29mm; Azamo, on 30 July. All specimens were col- HW=20mm. lected in 1987 during night surveys by the YMS Dorsal surface of head covered with nine sym- Research Team. metrically arranged scales (Fig. 2A). Internasals Other specimens examined. -Azamo: YMS- curving obliquely backward, tapering posterior- 610701, 620703-4, 620705 (skeleton and skin), ly. Prefrontals as wide as long, roundish on 620706, 620713-14, 620716, 620718 (skeleton), lateral edge. Frontal bell-shaped, somewhat 620719-20, 620723, 620724 (skeleton and skin); pointed posteriorly. Supraoculars slightly con- Hotta, Izuhara-cho: YMS-610705; Ina: YMS- vex, outside margin weakly curving inward 610703, 610704 (skeleton and skin), 620712; Tsut- above orbits. Parietals longer than wide, out- su, Izuhara-cho: YMS-610702; Tsutsuse: YMS- side margin roundish, posterior edge weakly Jpn. J. Herpetol. (3). 15 1994 104 FIG. 2. Dorsal (A and D), lateral (B), and ventral views (C, E, and F) of the holotype of Agkistrodon tsushi- maensis sp. nov. (OMNH R3934). Scale bars equal 5mm in A, B, C, and E, and 10mm in D and F. zigzag. tacting prefoveal and postfoveal dorsally below Rostral broader basally, its surface slightly pit; third enlarged, highest, contacting orbit at convex forward. Nasals divided, anterior ele- dorsal tip; fourth almost equal to third one in ment larger than posterior one. Loreal single, size, but longer (Fig. 2B). Infralabials 10; first slightly longer than high, with obtuse apex in to fourth ones narrow, second smallest, sixth posterior end. Preoculars two, extending to largest, ninth and tenth much longer than high; front canthus; upper preocular twice as long as first infralabials tapering backward to pointed high, double the size of lower one; lower end, contacting each other between chin preocular much longer than high. Postoculars shields. Mental broader dorsally, tapering two; upper one small; lower one boomerang- backward to pointed end on median line. Chin shaped, extending along rear edge of orbit, con- shields in one pair; each slightly longer than tacting posterodorsal edge of third supralabial wide, distinctly enlarged as compared with sur- and anterodorsal edge of fourth supralabial just rounding scales, followed by two small median below eye. Temporals in two horizontal rows; gulars (Fig. 2C). upper row consisting of three small smooth Scales in middorsal region narrow, those in scales; lower row consisting of three enlarged, costal region broader and roundish; all dorsal hexagonal smooth scales, first one largest. scales from occipital region to tail keeled, more Supralabials seven; second one smallest, con- prominently in spinal region; paired apical pits ISOGAWA ET AL. -NEW SNAKE FROM TSUSHIMA 105 inconspicuous. Dorsal scale rows 21 at mid- ing complete crossbands near midtrunk by fus- body, altering as follows: ing to each other medially; longitudinally neighboring blotches separated from each other by lighter interspace. The interspace of one to two scales' width, brownish yellow in ground col- or, with darker stippling (Fig. 2D). Contrast of the dorsal pattern weaker dorsolaterally, with gradual increase of flesh tint or pale pink colora- tion toward ventrals. Number of discernible bands 21 on right and 22 on left on trunk, five on each side on tail. Ventral side of head pale creamy pink in ground color, with dark brown freckles on margin of each scale, especially prominent on lateral gulars (Fig. 2C). Ventrals creamy to Ventrals 152. Anal plate entire, similar to whitish pink in ground color, with typical pep- preceding ventrals in coloration. Subcaudals per-and-salt pattern consisting of numerous fine 48, each divided medially, making series of alter- brown, gray, partly reddish brown speckles (Fig. nate sutures. Terminal scute sharply pointed. 2E); such speckles almost lacking on first to sixth Coloration in life.-Dorsal ground color ventrals, sparse on breast, gradually becoming brown, darker on head than on trunk and tail; dense toward posterior abdomen with relatively parietals without lyriform figure, but with a heavy lateral stippling. Subcaudals on anterior small light spot on the median suture; waterd- half of tail reddish brown, with dark freckles; rop-like figure in the middle of occipital region those on posterior portion more reddish with no (Fig. 2A). Dorsal pattern not very distinct, but freckles (Fig. 2F). Terminal scute of tail reddish consisting of two alternating rows of relatively brown on ventral side of base, dark brown on enlarged, circular to nearly elliptical blotches the other part. outlined by dark margins of one or two scales' Temporal stripe dark brown with indistinct breadth; central dark spot lacking in each light freckles; upper side bordered by in- blotch; blotches of both sides frequently form- conspicuous light streak (postocular streak) ex- FIG. 3. Karyotype of a female Agkistrodon tsushimaensis sp. nov. Sex chromosomes (pair No. 4)are denoted by the letters Z and W. Scale bar equals 10μm. 106 Jpn. J. Herpetol. (3). 199415 TABLE 2. Relative head lengths of A. tsushimaensis and its relatives. See the text for abbreviations. SD: standard deviation. tending backward from outer margin of eight pairs of macroelements and 10 pairs of supraocular through upper postocular to last up- microelements. In the female, chromosomes per temporal, fading posteriorly with blurred forming the fourth pair are heteromorphic, one contrast; lower side of the stripe with blackish metacentric and the other subtelocentric, margin, bordered below by sharp narrow white whereas both of those forming the fourth pair in line extending obliquely backward from the end the male are homologous metacentric elements. of lower postocular toward corner of mouth. Thus, the metacentric and subtelocentric Supralabials creamy in ground color, with fine chromosomes forming the fourth pair in the brown freckles on their surfaces, more prom- female are considered Z and W sex inently on first to third supralabials. In- chromosomes, respectively (Fig. 3). fralabials similar to supralabials in ground col- Size and form. -Morphometric data for A. or, but stippled on margin by dark speckles (Fig. tsushimaensis are summarized in Tables 2 and 2B). 3. This species is relatively slender in ap- Tongue reddish brown with numerous fine pearance. The largest male (YMS-620726, col- whitish flecks medially, its slenderly bifurcated lected on July 30 measured 1987) 587mm TBL in tips pinkish. Iris varicolored, its upper half (505mm SVL+82mm TL), whereas the largest yellowish brown zonally, lower half brown with female (YMS-620724, collected on 30 July 1987) yellowish dapples. Pupil vertically oval, measured 620mm in TBL (547mm blackish, with a fine bright edge (Fig. 2B). SVL+73mm TL). RTL greater is in males than Coloration after preservation. -Color of in females. body faded, making color pattern nearly Variation. -Variations in the numbers of ven- monochromatic and still more indistinct than in trals, subcaudals and dorsal bands are presented life. Tongue changing to dark gray. Iris dark, in Tables 4, 5 and 6, respectively. Other and pupil white. characters also vary as follows: supralabials Karyotype. -The karyotype of A. tsushimaen- usually seven, but rarely six (3.1%) or eight sis consists of 2n=36 chromosomes, including (3.1%); infralabials usually but 10, sometimes 11 3. TABLE Ratios of tail lengths to total body lengths (RTL; in percent) in A. tsushimaensis and its relatives. SD: standard deviation. ISOGAWA ET AL.-NEW SNAKE FROM TSUSHIMA 107 TABLE 4. Variation in the number of ventrals in A. tsushimaensis and its relatives. SD: standard deviation. (21.9%); dorsal pattern usually indistinct, but Nagasaki Prefecture, Japan. sometimes distinct; lyriform figure on parietals Natural history.-A. tsushimaensis seems to usually inconspicuous, but sometimes lacking; be relatively fast-moving compared to A. b. ground color varying from dark brown to light blomhoffii, and probably is nocturnal during the brown dorsally, creamy to whitish gray on ven- summer (Urata and Yamaguchi, 1976), because trals, and reddish to yellowish on subcaudals. all specimens were found during the night. The However, there are no variations in the numbers species feeds on field mice, small birds, and so of midbody rows scale (21), preoculars (two) and on (Urata and Yamaguchi, 1976). postoculars (two). One adult female (YMS- One adult female collected on 12 July 1986 610704) differed from the other specimens in ex- and three collected on 30 July gave 1987 birth to hibiting reddish brown dorsal ground color and four to six young (x=5.0) in September of the whitish pink ground color with reddish brown respective year. These newborns (N=20) freckles on venter in life. measured 4.3-7.7 (x=5.6)g in BM, 198-232 Distribution.-Only on Tsushima Island, (x=212)mm in TBL, 172-195 (x=180)mm in TABLE 5. Variation in the number of subcaudals in A. tsushimeansis and its relatives. SD: standard deviation. 108 Jpn. J. Herpetol. (3). 15 1994 FIG. 4. Overall height (OH)/overall length (OL) ratio of vertebrae and height (H)/length (L) ratio of neural spines in Agkistrodon tsushimaensis sp. nov. (open circles: N=6), Agkistrodon blomhoffii blomhoffii (closed circles: N=5), Agkistrodon blomhoffii brevicaudus (open squares: N=8), and Agkistrodon ussuriensis (closed squares: N=7). Locations of symbols and vertical bars represent means and ranges of plus and minus standard deviations from means, respectively. SVL, and 26-37 (x=32)mm in TL, and ventral 2). In each sex, RTL in A. tsushimaensis is surfaces of their tail tips were faintly pinkish smaller than in A. b. blomhoffii and markedly yellow. greater than in A. b. brevicaudus, but is nearly equal to that in A. ussuriensis (Table 3). These Comparisons with other related species and indicate that the general body shape of A. tsushi- subspecies maensis is intermediate between those of A. b. Body proportion. -Head of A. tsushimaensis blomhoffii and A. b. brevicaudus and similar to is shorter and slenderer than that of A. b. that of A. ussuriensis. blomhoffii, but is similar to those of A. b. Scutellation.-The ventral number in A. brevicaudus and A. ussuriensis in shape (Table tsushimaensis is greater than A. in b. blomhoffii ISOGAWA ET AL.-NEW SNAKE FROM TSUSHIMA 109 TABLE 6. Variation in the number of dorsal bands on trunk in A. tsushimaensis and its relatives. SD: standard deviation. and A. b. brevicaudus, whereas its subcaudal ussuriensis has generally an even more indistinct number is notably smaller than in A. b. dorsal pattern consisting of smaller circular or blomhoffii and greater than in A. b. squarish blotches. There are, however, con- brevicaudus. These values for A. tsushimaensis siderable geographic variations in the dorsal pat- are nearly equal to those for A. ussuriensis in tern of A. ussuriensis; in specimens from China each sex (Tables 4 and 5). and Russia, the dorsal pattern is usually in- The apical pits of dorsal scales in A. tsushi- distinct, but sometimes distinct; and in Cheju-do maensis and A. ussuriensis are inconspicuous, (South Korea) specimens, the pattern is con- whereas those in A. b. blomhoffii and A. b. sistently as distinct as in A. b. brevicaudus brevicaudus are conspicuous. (Toriba, priv. comm.). Most A. b. blomhoffii Coloration. -The number of dorsal bands in and some A. ussuriensis have a dark spot in each A. tsushimaensis is greater than in A. b. dorsal blotch (Toriba, 1988), whereas such a blomhoffii and smaller than A. in b. brevicaudus spot is consistently lacking in A. tsushimaensis and A. ussuriensis (Table 6). As noted is above, as well as in A. b. brevicaudus. the dorsal pattern of A. tsushimaensis is relative- Ventral pattern also differs remarkably among ly weak in contrast, consisting of relatively these species and subspecies. A. tsushimaensis enlarged elliptical blotches occasionally forming has peculiar a pepper-and-salt pattern on the ven- complete crossbands, whereas that of A. b. tral surface, whereas A. b. blomhoffii and A. b. brevicaudus is more distinct, usually consisting brevicaudus have large, well developed dark of smaller and more roundish blotches seldom speckles, making the ventral surface much forming transverse bands. In A. b. blomhoffii, darker. In A. ussuriensis, the ventral pattern is the dorsal blotches are similar to those in A. generally obscure, and the speckles are not so tsushimaensis in shape, but the pattern is com- fine as those in A. tsushimaensis. monly more contrasty. On the other hand, A. Large interspecific differences are also recognized in the coloration of the postocular streak and tongue. The postocular streak of A. tsushimaensis is inconspicuous and blurred, whereas that of the other three species and subspecies examined is sharp and bright yellowish or whitish as described by Gloyd (1972, and 1977) Toriba (1988). The tongue of A. tsushimaensis and A. ussuriensis is always pink or reddish brown, whereas that of A. b. blomhoffii and A. b. brevicaudus is invariably blackish. Karyotype. -The karyotype of A. tsushimaen- FIG. 5. Left lateral views of mid-trunk vertebrae sis seems to be identical with that of A. b. of Agkistrodon blomhoffii blomhoffii (A), Agkistrodon blomhoffii brevicaudus (B), Agkistrodon blomhoffii and A. b. brevicaudus described by ussuriensis (C), and Agkistrodon tsushimaensis sp. Yosida and Toriba (1986a, b) at least at Giem-the nov. (D). Scale bar equals 5mm. sa level. However, it seem to be distinct from 110 Jpn. J. Herpetol. 15(3). 1994 the karyotype of A. ussuriensis in the sex large, usually elliptical, occasionally form- chromosome morphology, because the W- ing complete crossbands, numbering 16- chromosome of the latter is reported to be 23 on trunk; small dark spots commonly telocentric (Yosida and Toriba, 1986b; Toriba, present in blotches; ventral side of tail tip 1988). in adults usually dark-colored; sub- Vertebral morphology.-The overall caudals 47-56 in males, 41-50 in females. height/overall length ratio of the vertebra and … A. blomhoffii blomhoffii the height/length ratio of the neural spine 3b. Tail short, 12-14% of TBL in males, 10- markedly differ in A. tsushimaensis and its 12% in females; dorsal blotches relatively relatives. These ratios in A. tsushimaensis are small, generally roundish, seldom form- close to those A. in b. brevicaudus, but are much ing transverse bands, numbering 25-38 on smaller than A. in b. blomhoffii and greater than trunk; dark spots lacking in blotches; ven- in A. ussuriensis (Fig. 4). The general shape of tral side of tail tip in adults usually the middle vertebrae of these four taxa is com- yellowish; subcaudals 36-42 in males, 30- pared in Fig. 5. The degree of development of 37 in females.… A. blomhoffii bervicaudus the neural spine and hypapophysis in A. tsushi- maensis and A. b. brevicaudus is intermediate thank the other members ACKNOWLEDGMENTS.-We between that A. in b. blomhoffii and A. ussurien- of the YMS Research Team for collecting the sis. specimens on Tsushima Island. also We to wish thank M. Toriba (Japan Snake Institute), R. C. Goris Remarks.-Comparison suggests that A. (Yokohama City University), and H. Ota (University tsushimaensis is morphologically intermediate of the Ryukyus) for critical reading and correction of between A. blomhoffii and A. ussuriensis. our manuscript and for valuable comments. M. However, further character analyses are needed Toriba provided useful literature and helpful sugges- to define the phylogenetic relationships between tions for karyotyping and measuring the vertebrae of these species and A. tsushimaensis appropriate- the present material. ly. LITERATURE CITED Key to the Agkistrodon G. A. 1896. BOULENGER, Catalogue of the snakes in blomhoffii complex the British Museum (Natural History), Vol. III, con- There are considerable differences among the taining the Colubridae (Opisthoglyphae and Pro- four members of the Agkistrodon blomhoffii teroglyphae), Amblycephalidae, and Viperidae. Taylor and Francis for the Trustees, London. 727 complex in external characters, on which this p. +37 figs. +25 pls. key depends. H. G. 1951. DOWLING, A proposed method of express- 1a. Tongue pink or reddish brown; paired ing scale reductions in snakes. Copeia (2): 1951 apical pits of dorsal scales inconspicuous. 131-134. … 2 A. A. 1929. EMELLANOV, Snakes of the Far Eastern 1b. Tongue dark brown or nearly black; district. Mem. Vladivostok Sec., Russ. State Geogr. Soc. 3(20), 1: 1-208. (in Russian, with English paired apical pits of dorsal scales con- resume) spicuous. … 3 GLOYD, H. K. 1972. The Korean snakes of the genus 2a. Dorsal blotches relatively large, usually Agkistrodon (Crotalidae). Proc. Biol. Soc. elliptical, numbering 21-28 on trunk; Washington 85 (49):5 57-578. small dark spots lacking in blotches; GLYOD, H. K. 1977. Descriptions of new taxa of postocular streak poorly contrasted; ven- Crotalid snakes from China and Ceylon (Sri tral scales with pepper-and-salt pattern Lanka). Proc. Biol. Soc. Washington (4): 1002-90 1015. consisting of numerous fine speckles. … A. tsushimaensis sp. nov. GLYOD, H. K. AND R. CONANT. 1982. The classifica- 2b. Dorsal blotches relatively small, usually tion of the Agkistrodon halys complex. Jpn. J. Herpetol. (3): 9 75-78. circular, sometimes squarish, numbering GLYOD, H. K. AND R. CONANT. 1990. Snakes of the 22-34 on trunk; small dark spots in blot- Agkistrodon Complex: A Monographic Review. ches usually lacking, but sometimes pre- SSAR, Oxford, Ohio, USA. 614 p. +52 pls. with sent; postocular streak sharp, bright respective explanation pages. yellowish or whitish; ventral scales dappl- GORIS, R. C. 1965. A herpetological survey of ed with ill defined dark speckles. Tsushima Island. Acta Herpetol. Japon. (2): 9-2 … A. ussuriensis 15. 3a. Tail long, 15-18% of TBL in males, 13- K. HASHIMOTO, AND M. TORIBA. 1983. Notes on the 16% in females; dorsal blotches relatively coloration of Japanese Mamushi, Agkistrodon

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