Misconceptions about the taxonomy and distribution of Caiman crocodilus chiapasius and C. crocodilus fuscus (Reptilia: Crocodylia: Alligatoridae)

Abstract

Four subspecies are currently recognized for the Spectacled Caiman, Caiman crocodilus (Linnaeus 1758): Caiman crocodilus fuscus (Cope 1868: Perosuchus fuscus), described from a single specimen from the Magdalena River, Colombia; C. c. chiapasius (Bocourt 1876: Alligator chiapasius), described from the Tonalá Valley, Chiapas, México; C. c. apaporiensis (Medem 1955) from the upper Apaporis River, Colombia; and, C. c. crocodilus (Linnaeus 1758: Lacerta crocodilus), named for the species originally described (Smith & Smith 1977; Busack & Pandya 2001). Caiman yacare was previously considered to be a fifth subspecies (i.e., C. c. yacare), but it is now generally accepted that it is a full species (King & Burke 1989), and is no longer treated as a subspecies (Velasco & Ayarzagüena 2010). There is some confusion about the current distributions of C. c. chiapasius and C. c. fuscus, and although some works have attempted to clarify this situation (Busack & Pandya 2001), the confusion still remains (i.e., Rueda-Almonacid et al. 2007; Velasco & Ayarzagüena 2010). Here, we present a brief review of the taxonomic status of caiman subspecies, and its implications for their distributions.

Biogeographic and Systematic Implications of a Caimanine from the Late Miocene of Southern Mexico

“…This is consistent with other fossil evidence showing that closely-related extant lineages within Caiman have been distinct longer than molecular data suggest; Oaks (2011), for example, put the divergence between C. crocodilus and C. yacare (which is sometimes treated as a subspecies of C. crocodilus) in the Quaternary, but fossils referable to C. yacare or a close extinct relative are known from the Miocene (Fortier et al, 2009;Bona et al, 2013b). Earlier divergences reinforce the notion that Mesoamerican C. crocodilus-all of which are under considerable pressure from habitat loss and hunting-are units of diversity worthy of conservation (Amato and Gatesy, 1994;Venegas-Anaya et al, 2008;Escobedo et al, 2011).…”

“…All of the six recognized species of caimanine alligatorid are found in South America, but one-the Spectacled or Common Caiman, Caiman crocodilus Linnaeus 1758-has a range extending into North America (Velasco and Ayarzagü ena, 2010;Escobedo-Galvá n et al, 2011). At first, this seems be a simple case of northward range expansion during the Great American Biotic Interchange (GABI) following closure of the Isthmus of Panama within the past 5 million years (Estes and Bá ez, 1985;Vanzolini and Heyer, 1985).…”

The Crocodile Museum at Zoológico Regional Miguel Álvarez del Toro (ZooMAT), Mexico: ‘How to exhibit a bullfrog’ put into reality

“…The IUCN listing for the Spectacled caiman does not distinguish the Chiapas' caiman, although studies by Medem [, cited in Escobedo‐Galván et al . ()] suggest that the subspecies occurs ‘from México, through Central America, … to the Pacific lowlands of Colombia and Ecuador’.…”

Variation in diet of hatchlings, juveniles and sub-adults of Caiman crocodilus chiapasius in La Encrucijada, Chiapas, Mexico

“…The Chiapas spectacled caiman, Caiman crocodilus chiapasius (Bocourt, 1876), is distributed along the coasts of the state of Chiapas (Mexico) and of El Salvador (Escobedo-Galván et al, 2011, 2015Venegas-Anaya et al, 2008). This species inhabits mostly coastal marshes, estuaries and river mouths on the Pacific slope (Álvarezdel Toro, 1974).…”