bstract. More than 90% of harlequin frog species (Atelopus spp.), endemic to the Americas, are currently threatened with extinction. We report the discovery of the only currently known hreeding population of the Critically Endangered/4. varius in Costa Rica. This population was located in 2008 on a private property in Las Tablas Protected Zone near San Vito, Coto Brus at 1300 m elevation. Previously, the only known remaining/remnant population of this species and genus was a single location near Manuel Antonio, Puntarenas, Costa Rica, where two individuals were documented in 2004. Subsequent searches at this location have yielded no additional sightings. Delineating the spatial limits of this population, quantifying demographics and resource use, and implementing conservation actions are necessary to ensure persistence of this population. Conducting additional surveys in this region to ascertain occurrence of additional populations is warranted.

The Neotropical crocodylian species, Caiman crocodilus, is widely distributed through Mesoamerica, northern South America, and the Amazon basin. Four subspecies are recognized within C. crocodilus, suggesting some geographic variation in morphology. In this study, we utilized mitochondrial DNA (mtDNA) sequence data from 45 individuals of C. crocodilus throughout its range to infer its evolutionary history and population structure, as well as to evaluate genealogical support for subspecies and their geographic distributions. Our molecular phylogenetic results identified five mtDNA haplotype clades with a mean sequence divergence of 3.4%, indicating considerable evolutionary independence among phylogeographic lineages. Our results were also broadly consistent with current subspecific taxonomy, with some important additional findings. First, we found substantial genetic structuring within C. c. fuscus from southern Mesoamerica. Second, though we confirmed the existence of a widespread Amazonian clade, we also discovered a cryptic and divergent mtDNA lineage that was indistinguishable from C. c. crocodilus based on external morphology. Third, we confirm the status of C. c. chiapasius as a distinct evolutionary lineage, and provide evidence that C. c. fuscus may be moving northward and hybridizing with C. c. chiapasius in northern Mesoamerica. Finally, our results parallel previous phylogeographic studies of other organisms that have demonstrated significant genetic structure over shorter geographic distances in Mesoamerica compared with Amazonia. We support conservation efforts for all five independent lineages within C. crocodilus, and highlight the subspecies C. c. chiapasius as a unit of particular conservation concern.

Few studies have conducted morphological analyses of crocodilians, and little information exists on differences between size-classes and sexes in Neotropical crocodilians. In this study, we measured nine morphological traits in 121 captive Morelet's crocodiles Crocodylus moreletii (81 females and 40 males). Our results revealed that individuals < 2 m total length do not exhibit sexual dimorphism in morphometric characteristics. However, for crocodiles over 2 m in length, males were significantly larger than females in terms of dorsal-cranial length, cranial width, snout width and snout-ventral length. In general, morphological traits demonstrated a strongly significant relationship with total length at the smaller size class of 150-200 cm length. However, in the highest size class of 250-300 cm length (large adult males), morphological traits were no longer significantly related with total length. Male crocodiles demonstrated allometric growth of cranial morphology with significantly greater increase in cranial width, snout width, and mid-snout width relative to total length at higher size classes. Morphological dimorphism and allometric growth may be associated with adaptive strategies for reproductive success.

No abstract

No abstract

No abstract

No 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.