Herpetology Notes, volume 11: 621-623 (2018) (published online on 15 August 2018)

Crocodylus rhombifer (Cuban ) subcaudal scale irregularities

Lauren Augustine1,2,*, Adam G. Stern3, Gustavo Sosa Rodríguez4, and Etiam Pérez Fleitas4

The scalation on the ventral portion of the tail posterior the Zapata Crocodile Farm in were assessed for to the cloaca or the subcaudal region, has been used subcaudal scale irregularities. These are known to identify commercial crocodile skins in Morelet’s offspring of genetically pure C. rhombifer (Milián , moreletii, as 66% of tail whorls García et al., 2015). Of these, 403 had subcaudal were found to be irregular in this species (King and scale irregularities (62%). These animals represent 51 Brazaitis, 1971), and black , Melanosuchus niger clutches, but are not necessarily genetically distinct as a (Brazaitis, 1986). Proximal lateral caudal irregularities single male could have sired multiple clutches (Milián have been documented in C. moreletii and American García et al., 2016). crocodiles, C. acutus (Ross and Ross, 1974), and Morphological traits have historically been used to midventral inclusions in the subcaudal region are further distinguish species (Platt and Rainwater, 2005) and to typical of Siamese crocodiles, C. siamensis (Brazaitis, identify commercial crocodilian skins (Brazaitis, 1986; 1986). Phenotypic variation in scalation is unknown King and Brazaitis, 1971). There is a growing body for many species of crocodilians, however studies on of evidence that morphology alone is not sufficient in C. acutus have found that interpopulation difference detecting interspecific hybrids (Dever and Densmore, in scalation may occur (Platt et al., 2010). Herein we 2001; Hekkala, 2004; Cedeño Vazquez et al., 2008; document the occurrence of irregular subcaudal scales Weaver et al., 2008; Rodriguez et al., 2008; 2011; in Cuban crocodiles, C. rhombifer, a species previously Machkour M’Rabet et al., 2009; Milián García et al., described as having uniform and uninterrupted 2015). Morphology has been used to distinguishing C. subcaudal scales (Brazaitis, 1973). rhombifer x C. acutus hybrids (Ramos, 2013), however Captive bred C. rhombifer and museum specimens recent genetic evaluation found that morphology was not were evaluated for scale irregularities in the subcaudal sufficient as 57.7% were misidentified (Milián García region for a total of 22 specimens. Of these, 14 et al., 2015). Subcaudal tail inclusions or irregularities, (or 63.6%) exhibited irregularities. Because of the not previously documented in C. rhombifer, in rampant hybridization of C. rhombifer with C. acutus conjunction with other morphological characteristics (Milián García et al., 2015) the genetic identity of may increase the efficacy of utilizing morphology for these crocodilians as pure C. rhombifer could not be species identification in the absence of genetic testing. confirmed. To this end, 654 C. rhombifer juveniles from However, much like for C. moreletii, microsatellites are necessary to confirm the genetic identity of C. rhombifer, particularly those being used for captive propagation. The irregularities exhibited in the subcaudal region of C. rhombifer could be used for individual identification, as all seven of the C. rhombifer hatched at the 1 Saint Louis Zoo, One Government Drive, St. Louis MO 63110 Smithsonian’s National Zoological Park had unique 2 Smithsonian’s National Zoological Park, 3001 Connecticut patterns of subcaudal inclusions (Figure 1). The animals Ave. NW Washington, DC 20008 at the Zapata Crocodile Farm were only assessed for 3 Zoo Miami, Miami 12400 SW 152nd St. Miami, FL 33177 4 Enterprise for Conservation of the , Ciénaga de presence or absence of this trait, so the existence of unique Zapata, Matanzas, Cuba patterns is unknown at this time. This characteristic * Corresponding author. E-mail: [email protected] could be used as an identification method for captive or 622 Lauren Augustine et al.

Figure 1: Subcaudal scale inclusions in seven captive bred Crocodylus rhombifer at the Smithsonian’s National Zoological Park.

wild crocodilians in lieu of scale clippings, tags or other mummy DNA resurrects a cryptic species within the Nile marking methods. More research is needed to determine crocodile. Molecular Ecology 20: 4199–4215. the prevalence of this characteristic in C. rhombifer and King, F.W., Brazaitis, P. (1971): Species identification of commercial crocodilian skins. Zoologica–New York 56: 15–57. the use of this technique for individual identification. Machkour M’Rabet, S., Henaut, Y., Charruau, P., Gevrey, M., Observations such as this one can provide the basis for Winterton, P., Legal, L. (2009): Between introgression events future studies investigating crocodilian phylogeny and and fragmentation, islands are the last refuge for the American the use of morphological characteristics for individual crocodile in Mexico. Marine Biology 156: 1321– identification. 1333. Milián García, Y., Jensen, E.L, Ribalta Mena, S., Pérez Fleitas, E., Acknowledgements. We would like to thank the Zoo Miami, Sosa Rodríguez, G., Guerra Manchena, L., Espinosa López, G., The Smithsonian’s National Zoo and the Ellen Trout Zoo for Russello, M. A. (2016): Genetic evidence for multiple paternity providing photographs of their specimens, the American Museum in the Cuban crocodile (Crocodylus of National History, the Smithsonian National Museum of Natural rhombifer). Amphibia–Reptilia DOI: 10.1163/15685381– History and the Florida Museum of Natural History for access 00003056. to their collections. We thank Gordon B. Henley Jr and Robert Milián García, Y., Ramos Targarona, R., Pérez Fleitas, E., Sosa Jackson for their assistance, and Kaycee Fuance for the use of Rodríguez, G. Guerra Manchena, L., Alonso Tabet, M., her photographs. Espinosa López, G., Russello, M.A. (2015): Genetic evidence of hybridization between the critically endangered Cuban crocodile References and the : implications for population history and in situ/ex situ conservation. Heredity 114: 272–280. Brazaitis, P. (1973): The identification of living crocodilians. Platt, S.G., Rainwater, T.R. (2005): A review of morphological Zoological Society of New York 58: 59–85. characters useful for distinguishing Morelet’s crocodile Brazaitis, P. (1986): The forensic identification of crocodilian hides (Crocodylus moreletii) and American crocodile (Crocodylus and products. In Crocodiles: Proceedings of the 7th Working acutus) with an emphasis on populations in the coastal zone Meeting of the Crocodile Specialist Group of the Species Survival of Belize. Bulletin of the Chicago Herpetological Society 40: Commission of the International Union for Conservation of 25–29. Nature and Natural Resources, Caracas, Venezuela. Platt, S.G., Thorbjarnarson, J.B., Rainwater, T.R. (2010): Scalation Cedeño Vazquez, J.R., Rodriguez, D., Calme Sophie, Perran Ross J, Densmore L III, Thorbjarnarson, J. (2008): Hybridization of the American crocodile, (Crocodylus acutus), from the between Crocodylus acutus and Crocodylus moreletii in the coastal zone of Northern Belize. Caribbean Journal of Science Yucatan Peninsula: I. Evidence from mitochondrial DNA 46: 332–338. and morphology. Journal of Experimental Zoology Part A: Ramos, R., de Buffrenil V., Ross, J. (2004): Current status of Ecological Genetics and Physiology 309: 661–673. the Cuban crocodile, Crocodylus rhombifer, in the wild. In: Dever, J.A., Densmore, L.D. (2001): Microsatellites in Morelet’s Crocodiles, Proceedings of the 12th Working Meeting of the crocodile (Crocodylus moreletii) and their utility in addressing Crocodile Specialist Group. IUCN: Gland, Switzerland. crocodilian population genetics questions. Journal of Rodriguez, D., Cedeño Vazquez, J.R., Forstner, M.R.J., Densmore, Herpetology 35: 541–544. L.D. III. (2008): Hybridization between Crocodylus acutus and Hekkala, E., Shirley, M.H., Amato, G., Austin, J.D., Charter, S., Crocodylus moreletii in the Yucatan Peninsula: II. Evidence Thorbjarnarson, J., Vliet, K.A., Houck, M.L., Desalle, R.O.B., from microsatellites. Journal of Experimental Zoology Part A: Blum, M.J. (2011): An ancient icon reveals new mysteries: Ecological Genetics and Physiology 309: 674–686. Crocodylus rhombifer subcaudal scale irregularities 623

Rodriguez, D., Forstner, M.R.J., Moler, P.E., Wasilewski, J.A., Cherkiss, M.S., Densmore, L.D. III. (2011): Effect of human- mediated migration and hybridization on the recovery of the American crocodile in Florida (USA). Conservation Genetics 12: 449–459. Ross, C.A., Ross, F.D. (1974): Cuadal scalation of Central American Crocodylus. Proceedings of the Biological society of Washington 87: 231–234. Weaver, J.P., Rodriguez, D., Venegas Anaya, M., Cedeño Vazquez, J.R., Forstner, M., Densmore, L. III (2008): Genetic characterization of captive Cuban crocodiles (Crocodylus rhombifer) and evidence of hybridization with the American crocodile (Crocodylus acutus). Journal of Experimental Zoology Part A: Ecological Genetics and Physiology 309: 649–660.

Accepted by Hendrik Müller