Cantoria violacea Girard, 1858a

Figueroa, Alex, Low, Martyn E. Y. & Lim, Kelvin K. P., 2023, Singapore’s herpetofauna: updated and annotated checklist, history, conservation, and distribution, Zootaxa 5287 (1), pp. 1-378 : 205-206

Cantoria violacea Girard, 1858a — Native.

Cantoria violacea Girard, 1858a: 182 . Holotype: USNM 5523 , by original designation. Type locality: “ Singapore ”.

Cantor’s Water Snake

( Figure 23G )

Singapore records.

Cantoria violacea — Girard, 1858a: 182.— Girard, 1858b: 156.

Cantoria elongata Ģnther, 1864 : xx, 277.—Theobald, 1876: 229.

Cantoria violacea — Boulenger, 1890a: 381.—Sclater, 1891a: 55.— Boulenger, 1896: 24.— Flower, 1896: 888.— Flower, 1899: 679.— Hanitsch, 1899: 12 (“near Cross Street School”).—Ridley, 1899: 208.— Boulenger, 1912: 165.— Hanitsch, 1912b: 16.— de Rooij, 1917: 191.—Sworder, 1923: 66.— Buddle, 1929: 36 (Sembawang Naval Base [= SML]).— Smith, 1943: 399.— de Haas, 1950: 579.— Gyi, 1970: 186.—K.K.P. Lim & L.M. Chou, 1990: 54.—K.K.P. Lim & F.L.K. Lim, 1992: 147.—L.M. Chou et al., 1994: 105.— David & Vogel, 1996: 112.— Manthey & Grossmann, 1997: 330.—Chan-ard et al., 1999: 31.— Iskandar & Colijn, 2001: 87.— Jayne et al., 2002: 143.— Karns et al., 2002: 488 (Pasir Ris Park Mangroves).—K.P. Lim & F.L.K. Lim, 2002: 147.— Anonymous, 2003: 92 (Sungei Buloh Wetland Reserve).— Karns et al., 2005: 86.—J.C. Murphy, 2007: 59.—N. Baker & K.P. Lim, 2008: 109, 161.—K.K.P. Lim et al., 2008: 165, 265.—P.K.L. Ng et al., 2008: 167.—P.Z. Chen, 2010: 195.— Das, 2010: 325.—J.C. Murphy, 2011: 233.—P.K.L. Ng et al., 2011: 502.—N. Baker & K.P. Lim, 2012: 109, 161.— Das, 2012a: 105.—Voris & J.C. Murphy, 2012: 195.—J.C. Murphy & Voris, 2014: 11.—Wallach et al., 2014: 148.—Chan-ard et al., 2015: 246.— Vogrinc, 2017: 205 (Pasir Ris Park Mangroves).— Das, 2018: 123.—Jayne et al., 2018: 638.— O’Shea, 2018: 538.— Charlton, 2020: 95 (Pasir Ris Park Mangroves).—S.J.M. Yau & Kamisan, 2020: 143 (Sungei Buloh Wetland Reserve).

Remarks. Cantoria violacea was described as a new species by Girard (1858a, b) from specimen USNM 5523 collected in Singapore some time around 1842 by the U.S. Exploring Expedition ( Table 1 ). Shortly thereafter, Ģnther (1864) redescribed the specimen as a new species, ‘ C. elongata ’, because Girard (1858a) stated that C. violacea was identical to ‘ Coronella violacea ’ [= Oligodon cyclurus ], which is incorrect. Sclater (1891) reported the second specimen of C. violacea from a specimen deposited at ZSI. Later, Hanitsch sent a specimen (ZRC.2.3316) collected on 29 August 1898 by Hellier near Cross Street Primary School ( Hanitsch 1899) to Flower for identification ( Flower 1899). This area was previously surrounded by mangrove forest (Yee et al. 2011). After Buddle (1929) collected three specimens at SNB, C. violacea was not reported again from Singapore until 82 years later ( Table 2 ) during Karns et al. (2002) study of homalopsids at PRPM. The only other records of C. violacea from Singapore comes from Vogrinc (2017) who published a note on the largest C. violacea measured, and from Yau & Kamisan (2020) who found a dead one on a trail at SBWR on 8 July 2020. LKCNHM has specimens from 1929, 1967, 1977, and 2001, and BPBM 7203 was collected on 12 December 1955. The individual shown in Figure 23G was photographed at PRPM on 23 November 2014 (A. Figueroa pers. obs.). After B. hydroides , C. violacea is the rarest homalopsid in Singapore. Karns et al. (2002) only found four C. violacea during their study compared to 19 F. leucobalia, 31 G. prevostiana , and 156 C. schneiderii .

Occurrence. Restricted to mangroves of LCK, PRPM, and SBWR. Rare.

Singapore conservation status. Endangered.

Conservation priority. Highest.

IUCN conservation status. Least Concern [2010].

LKCNHM & NHMUK Museum specimens. Changi : ZRC.2.6481 (28-Apr-1967) ; Cross Street Primary School: ZRC.2.3316 (29-Aug-1898) ; Lim Chu Kang Mangroves: ZRC.2.3672 (18-Aug-1977) , ZRC.2.4991 (19- Apr-2001) ; Pasir Ris [ PPM] : ZRC.2.5000 (30-Mar-2001) ; Seletar : ZRC.2.3317 (Feb-1929) .

Additional Singapore museum specimens. Singapore (no locality): BPBM, USNM.

Singapore localities. Changi—Cross Street—Lim Chu Kang Mangroves—Pasir Ris Park Mangroves—Seletar (not specified)—Sembcorp Marine Ltd.*—Sungei Buloh Wetland Reserve.

Genus Cerberus Cuvier, 1829 (1 species)

Cerberus Cuvier, 1829: 2 (type species: Coluber cerberus Daudin, 1803 , by absolute monotypy; gender masculine).

Figures

FIGURE 23. A) Hydrophis stokesii, B) Hydrophis stokesii, C) Laticauda colubrina, D) Naja sumatrana, E) Ophiophagus hannah, F) Bitia hydroides, G) Cantoria violacea, and H) Cerberus schneiderii. Photographs by: Kelvin K.P. Lim [A], Christopher J. Jolly [B], Philip Vogrinc [C], Alex Figueroa [D, G–H], Francis L.K. Lim [E], and Evan S.H. Quah [F].