Sunday, July 10, 2016

Abstract: Diet, female reproduction and conservation of Jagor’s water snake, Enhydris jagorii in Bung Ka Loh wetland, Uttaradit province, Thailand

Diet, female reproduction and conservation of Jagor’s water snake, Enhydris jagorii in Bung Ka Loh wetland, Uttaradit province, Thailand

Jagor’s water snake (Enhydris jagorii) is a freshwater snake that is endemic to the Chao Phraya-Ta Chin basin, Thailand. However, habitat change and destruction are the main threats to this snake, where a large area of the wetland has been rapidly transformed into urban and agricultural areas. Moreover, uncontrolled fishing seriously threatens the remaining population of this snake. In order to protect this species, information on its natural history is required. This study was conducted in the Bung Ka Loh wetland during October, 2010 to August, 2014 when 108 specimens of this species were collected. Analysis of the stomach contents revealed that it is piscivorous, with cyprinids being the dominant prey. Prey items were usually less than 10% of the snake body mass and multiple prey items were occasionally found. No significant difference in diet was noted between the sexes. In addition, predation on this snake by Cylindrophis ruffus was first recorded in this study. The smallest gravid female collected had a snout-vent length of 34.0 cm. The clutch size and mass ranged from 1 to 28 embryos and 3.1 to 123.0 g, respectively, and both of these quantities increased significantly with increased female size. Reproduction was possibly seasonal and occurred in the rainy season. A preliminary study of other wetlands in the central plain of Thailand failed to detect the existence of this species. Accordingly, the conservation status of this species should be changed from Data Deficient to Critically Endangered.

Hydrops caesurus Scrocchi, Ferreira, Giraudo, Avila and Motte 2005

Hydrops caesurus Scrocchi, Ferreira, Giraudo, Avila and Motte 2005. Type locality: Departamento Itapúa, Isla Paloma, Canal de los Jesuitas, Paraguay.
Hydrops triangularis bolivianus — Williams and Couturier 1984
Hydrops triangularis — Álvarez and Aguirre 1995

Distribution. Northeast Argentina and Paraguay. The distribution is disjunct from other members of the genus. It inhabits temperate and subtropical latitudes. Type locality: Departamento Itapúa, Isla Paloma, Canal de los Jesuitas, Paraguay.

Helicops angulatus (Linnaeus, 1758)

Coluber angulatus Linnaeus 1758: 217. Type locality: “Asia” (in error).
Coluber alidras Linnaeus 1758:
Coluber Surinamensis Shaw 1802: 460
Natrix aspera Wagler 1824: 37
Helicops angulatus — Wagler 1830: 171
Helicops fumigatus Cope 1868: 308
Helicops cyclops Cope 1868: 309
Uranops angulatus — Sclater 1891: 45
Helicops angulata — Beebe 1946: 28

Distribution, Venezuela (Amazonas, Apure, Bolivar, Monagas, Delta Amacuro, Sucre, Portuguesa, Anzoátegui, Guárico, Cojedes), Colombia, Brazil (Pará, Rondonia, Goias, Mato Grosso, Sergipe, S Ceará, Acre etc.), Bolivia, Peru, Trinidad, Ecuador, French Guiana. 

Hydrops triangularis (Wagler, 1824)

Elaps triangularis Wagler 1824: 5. Type locality: Ega (= Tefé) Lago Tefé, at confluence with Rio Amazon, Brazil.

Hydrops triangularis - Wagler 1830: 170
Hydrops triangularis bassleri Roze 1957:83
Hydrops triangularis bolivianus Roze 1957:86
Hydrops triangularis fasciatus Roze 1957:76
Hydrops triangularis neglectus Roze 1957:81
Hydrops triangularis venezuelensis Roze 1957:78

Distribution. Amazonas, Orinoco and Guyana drainages includes Bolivia, Venezuela, Guyana, Surinam, French Guiana, Trinidad, E Peru, Ecuador, Brazil, Colombia, and Argentina. Type locality: Ega (= Tefé) Lago Tefé, at confluence with Rio Amazon, Brazil.

Hydrops martii (Wagler, 1824)

Elaps Martii Wagler 1824. Type locality: Provincia Maranhao, Rio Itapicuru, Brazil
Hydrops Martii — Wagler 1830: 170
Homalopsis Martii — Schlegel 1837: 356
Hydrops callostictus Günther 1868: 421
Calopisma martii — Jan and Sordelli 1868
Hydrops triangularis martii — Amaral 1930
Hydrops martii — Dowling 2002

Distribution: Distribution: Amazon basin from Colombia and eastern Peru to Maranhao, Brazil. Known from tributaries of Rio Amazonas, the Rio Ucayali and Rio Marañon, Peru. Roze (1957) reported a specimen from Rio Cairary, near Jurupary waterfall, on the boundary between Colombia and Brazil. Type locality: Provincia Maranhao, Rio Itapicuru, Brazil.

Helicops apiaka Kawashita-Ribeiro, Ávila & Morrais, 2013

Holotype: UFMT-R 8512, adult male, collected on 27 October 2009 by Carolina L. Cavlac.

Diagnosis. Helicops apiaka sp. nov. is distinguished from all congeners by the following combination of characters: (1) dorsal scales in 21/21/19 rows in males and 23/21/19 rows in females; (2) subcaudals 79–103 (n = 14; 95.1 +/- 5.8) in males and 80–84 (n 1⁄4 8; 82.4 6 1.3) in females; (3) ventrals 118–127 (n = 18, 121.2 +/- 2.2) in males and 124–132 (n = 8, 126.9 +/- 2.5) in females; (4) subcaudal keels present; (5) maxillary teeth 15–16 + 2; (6) infralabials 9–12/10–11; (7) dorsal scales strongly keeled; (8) banded dorsal color pattern; (9) ventral blotches 14–19 (n = 18, 15.9 +/- 1.4) in males and 16–19 (n=8, 17 +/- 0.9) in females.

Can be distinguished easily from H. danieli, H. hagmanni, H. leopardinus, H. pastazae, H. petersi, H. polylepis, H. scalaris, and H. yacu by having a banded (instead of spotted) dorsal color pattern and by the presence of subcaudal keels (absent in these species, except in H. scalaris and H. yacu; Rossman in Peters and Orejas–Miranda, 1970). Furthermore, the new species can be distinguished from H. danieli by a higher number of dorsal and subcaudal scales (19– 21/19–20/16–19 dorsal scales in males and females, 76–86 subcaudals in males, and 61– 70 subcaudals in females of H. danieli; Yuki, 1994; Rossman, 2002b) and by its ventral color pattern (cream venter with two rows of black semicircular markings in H. danieli; Rossman, 2002b). From H. hagmanni, H. pastazae, H. polylepis and H. yacu, the new species is further distinguished by a smaller number of dorsal scale rows (23–27/27–29/19–23 in males and 27/27/21 in females of H. hagmanni [Rossman, 1975]; 23/24/19 in H. pastazae [Rossman, 1976]; 23/23/19 in both sex of H. polylepis [Dixon and Soini, 1986]; 23–29/25– 28/18–20 in females of H. yacu [Rossman and Dixon, 1975; Rossman and Abe, 1979]). From H. leopardinus, the new species is also distinguished by a generally higher number of subcaudals (75.9 +/- 4.1, range 67–86, n = 52 in males and 62.7 +/- 4.9, range 53–76, n = 40 in females of H. leopardinus), and a smaller number of maxillary teeth (18 + 2 in both sexes of H. leopardinus). The new species lacks the three nuchal bands present in H. scalaris (Rossman, 2002a).
From H. carinicaudus, H. infrataeniatus, and H. trivittatus, the new species is distinguished by having a banded dorsal color pattern (instead of a striped pattern) and by the presence of subcaudal keels (absent in these species; Rossman in Peters and Orejas- Miranda, 1970; Cunha and Nascimento, 1978).

Helicops modestus and H. tapajonicus have a uniform dorsal coloration (dark olive in H. modestus and a uniformly dark green in H. tapajonicus; Frota, 2005) and lack subcaudal keels (instead of banded dorsal color pattern and presence of subcaudal keels in the new species). The new species can further be distinguished from H. tapajonicus by a higher number of dorsal scale rows (19/19/17 in both sexes of H. tapajonicus) and subcaudals (79 in a male and 67–76 in females of H. tapajonicus; Frota, 2005).

The new species shares a banded dorsal color pattern with H. angulatus and H. gomesi. The new species can be distinguished from H. angulatus by having a generally higher number of dorsal scale rows (19–21/19–20/17 in males and 19–21/19/17–19 in females of H. angulatus), of ventrals (111.2 +/- 3.4, range 105–123, n = 49 in males and 115.2 6 2.5 range 109–123, n = 62 in females of Hangulatus), and of subcaudals (87.1 +/- 5.1, range 75–96, n = 28 in males and 75.5 +/- 4.2, range 66–83, n = 38 in females of H. angulatus), and also by generally having fewer ventral blotches (20.5 +/- 2.1, range 15–25, n = 49 in males and 21 +/- 1.8, range 17–25, n = 63 in females of H. angulatus). Finally, Helicops apiaka can be distinguished from H. gomesi by having a higher number of dorsal scale rows (19 in both sexes in H. gomesi; Amaral, 1921).

Original description.

Kawashita-Ribeiro, Ricardo Alexandre; Robson Waldemar Ávila, and Drausio Honorio Morais 2013. A New Snake of the Genus Helicops Wagler, 1830 (Dipsadidae, Xenodontinae) from Brazil. Herpetologica 69 (1): 80-90.

Helicops carinicaudus (Wied-Neuwied 1825)

Helicops carinicaudus (Wied-Neuwied 1825)

Coluber carinicaudus Wied-Neuwied 1825: 300. Holotype: AMNH 3365, a 909 mm specimen
Homalopsis carinicaudus — Schlegel 1837: 350
Helicops carinicaudus — Wagler 1830: 170.

Distribution. Brazil (Espirito Santo, Rio Grande do Sul), Colombia.

Helicops hagmanni Roux 1910

Helicops hagmanni Roux 1910:439. Holotype: NMBA 6281, a 630 mm male (G. Hagmann). Type locality: Santarem, Brazil.

Distribution: N Brazil (Pará etc.), Colombia ?, Venezuela (TF Amazonas), Peru.

Original description.

Roux, J. 1910. Eine neue Helicops-Art aus Brasilien. Zool. Anz. 36: 439-440 

Helicops gomesi Amaral 1921

Helicops Gomesi Amaral 1921: 7

Holotype: Institute Butantan 1,843. Type locality: Costa Pinto Station, Railway Sorocaba, São Paulo, Brazil.

Distribution: Brazil (Sao Paulo).

Original description.

Amaral, A. 1921. Contribution to the knowledge of the Brazil snakes. Part I Four nine species of snakes brasileires. Anex. Mem. Inst. Butantan 1 (1): 1-37,

Helicops infrataeniatus Jan 1865

Helicops infrataeniatus Jan 1865: 253.

Lectotype: ZMH - R04331 (formerly no. B88 da) The other syntype from Brazil is deposited in Essex Inst. Salem according to Jan (1865). Types: ZMH R04340-4 (5 specimens) type locality "Mexico" in error. The type specimens of Calopisma septemvittata are a species inquirenda (Smith & Taylor , 1945), and cannot allied to any known species in the Mexican herpetofauna (Flores-Villela 1993 [Calopisma septemvittata] Syntypes: (2) ANSP 11206-07; Brazil, Rio Grande do Sul. [baliogaster] 

Distribution: Southern Brazil, Uruguay, Argentina, ?Paraguay.

Original description
Jan, G. 1865. Enumerazione sistematica degli ofidi appartenenti ai gruppo Potamophilidae. Archive per la Zoologia, l’Anatomia et la Fisiologia 3 (2): 201-265 

Helicops danieli Amaral 1938

Helicops danieli Amaral 1938: 232

Holotype: Instituto Butantan 9872, juvenile female. Type locality: Colombia, Santander, Carare.

Original description.

Amaral, A. D. 1938. Estudo sobre ophidios neotropicos 34. Novas notas sobre a fauna da Colombia e descripcao de uma especie nova de Colubrideo aglypho. Mem. Inst. Butantan 11 [1937]: 232-240

Helicops modestus Günther 1861

Helicops modestus Günther 1861: 425. Holotype BMNH 1946.1.14.42. Type locality. Tropical America?
Tachyplotus hedemanni Reinhardt 1866
Helicops assimilis Reinhardt 1866: 156. Type locality. Minas Gerais, Brazil.

Distribution. Brazil: Minas Gerais, Distrito Federal, Goias, Bahia.

Original description.
Günther, A. 1861. On the ophidian genus Helicops. Ann. Mag. Nat. Hist. (3) 7: 425-428. 

Helicops leopardina Schlegel 1837

Homalopsis leopardina Schlegel 1837: 358. Holotype. ? Type locality: unknown
Helicops leprieurii Dumeril Bibron & Duméril 1854 750
Helicops leprieurii - Günther 1861: 427
Helicops leopardinus - January 1865

Distribution. Guiana, Suriname, French Guiana, Brazil, Bolivia, Paraguay, northern Argentina,? Colombia? Ecuador, Peru.

Original description
Schlegel, H. 1837. Essay on the faces of serpents. General section: xxviii + 251 S. Descriptive part: S. 606 + xvi. The Hague (J. Kips, J. HZ. And van Stockum WP).

Sea snakes anticipate tropical cyclone.


Here, we report anticipatory behaviors of sea snakes and provide the first evidence for a sensory mechanism by which they survive a catastrophic cyclone. Sea kraits (Laticauda spp.) are normally abundant in littoral habitats at Lanyu (Orchid Island), Taiwan but disappeared coincident with falling barometric pressure prior to typhoon Morakot, which impacted the island severely during 7–9 August 2009. The abundance of sea kraits that are visible within the littoral zone correlates with barometric pressure, but not with precipitation or wind speed, which drives the surf. We found very little evidence of direct mortality caused by the storm, and the visible abundance of sea kraits following the storm returned to pre-storm levels. Data suggest that survival of sea kraits depends on the sensory perception of low pressures preceding a tropical cyclone, followed by behaviors which avoid the lethal storm energies potentially affecting this coastal population. Sea kraits likely find refuge in cavernous spaces beneath volcanic rocks of the seacoast.

Liu, Y. L., Lillywhite, H. B., & Tu, M. C. (2010). Sea snakes anticipate tropical cyclone. Marine biology, 157(11), 2369-2373.