Kenneth L. Krysko

Habitat Differences Affecting Age Class Distributions of the Hellbender Salamander, Cryptobranchus alleganiensis

Abstract Hellbender salamander (Cryptobranchus alleganiensis) populations have received considerable attention over the last few decades and recent studies show declines. We compared C. alleganiensis populations and habitat characteristics of the Little River (LR) in the Great Smoky Mountains National Park (GSMNP) of Tennessee, with those of the North Fork of the White River (NFWR), Missouri. We also compared the results of two different sampling methods for obtaining small individuals < 20 cm total length (TL) and gilled larvae. There was no significant difference in the frequency of larvae and adults in LR. There were highly significant differences in the frequency of larvae and adults in the NFWR population and in the proportion of larvae and adults between LR and NFWR. The stream bottom substrate, especially the deep gravel beds of the NFWR, provided a more secure larval habitat than in the LR. We believe this secure larval habitat was a major factor in maintaining large adult populations in NFWR. The less secure larval habitat within the LR makes larvae more susceptible to capture, and coupled with reduced crayfish populations, translates to fewer adult C. alleganiensis. Larvae were more efficiently collected by skin-diving than wading and turning rocks in these habitats. With the exception of the LR population, which is composed of 48% gilled or gilled sized larvae, all recorded populations are almost entirely composed of adult and sub-adult age groups and small larvae, especially gilled larvae are either uncommon or unknown.

Status of the Nile Monitor (Varanus niloticus) in Southwestern Florida

Abstract The Nile Monitor (Varanus niloticus), the longest lizard in Africa, was first observed in southwestern peninsular Florida in the Cape Coral area of Lee County ca. 1990. From April 2001 through 7 July 2003, we compiled 146 sightings or captures of this species by local residents or ourselves. Numerous individuals of all size classes have been observed or collected, suggesting the occurrence of a reproducing population. Although our records are mostly confined to Cape Coral, our data indicate that V. niloticus has recently expanded its range northwards and to nearby islands. Because this large lizard has the potential to disperse into nearby ecologically sensitive areas and preserves where it could pose a serious threat to waterbirds, Burrowing Owls (Athene cunicularia), sea turtles, and other native wildlife, population monitoring and eradication are warranted.

Surveying for hellbender salamanders, Cryptobranchus alleganiensis (Daudin): A review and critique

Wereview the wide array of techniques and their variants used in studying a cryptobranchid salamander and discuss their advantages and disadvantages. Electroshocking surveys are strongly discouraged because of the great potential for damaging reproductive success, immune systems, and their questionable effectiveness. Because successful Cryptobranchus alleganiensis nesting sites appear to be quite limited, the use of Peavy hooks and crowbars to breakup bedrock or dislodge large cover rocks should be restricted. Currently, skin-diving surveys coupled with turning objects is the only method shown to obtain all sizes of gilled larvae and multiple age groups of non-gilled and adult C. alleganiensis in brief periods.

Late-Holocene faunal and landscape change in the Bahamas

We report an intertidal, bone-rich peat deposit on the windward (Atlantic Ocean) coast of Abaco, The Bahamas. The age of the Gilpin Point peat (c. 950–900 cal. yr BP) is based on five overlapping radiocarbon dates (one each from single pieces of wood of buttonwood Conocarpus erectus and sabal palm Sabal palmetto, and single bones of the Cuban crocodile Crocodylus rhombifer, Albury’s tortoise Chelonoidis alburyorum, and green turtle Chelonia mydas). The short time interval represented by the charcoal-rich peat suggests rapid sedimentation following initial anthropogenic fires on Abaco. The site’s diverse snail assemblage is dominated by terrestrial and freshwater species. The peat is exposed today only during exceptionally low tides, suggesting a lower sea level at the time of deposition as well as a degrading shoreline during the past millennium. Fossils from Gilpin Point represent a late-Holocene vertebrate community at the time of first human presence; only 10 of the 17 identified species of amphibians, reptiles, birds, and mammals still live on Abaco. Numerous unhealed bite marks on the inside of the thick carapaces of the green turtle attest to consumption by Cuban crocodiles, which probably scavenged turtles butchered by humans. This concept, along with the dense concentration of bones in the peat, and charring on some bones of the green turtle and Abaco tortoise, suggests a cultural origin of the bone deposit at Gilpin Point, where the only Amerindian artifact recovered thus far is a shell bead.

Taxonomic assessment of Alligator Snapping Turtles (Chelydridae: Macrochelys), with the description of two new species from the southeastern United States.

The Alligator Snapping Turtle, Macrochelys temminckii, is a large, aquatic turtle limited to river systems that drain into the Gulf of Mexico. Previous molecular analyses using both mitochondrial and nuclear DNA suggested that Macrochelys exhibits significant genetic variation across its range that includes three distinct genetic assemblages (western, central, and eastern = Suwannee). However, no taxonomic revision or morphological analyses have been conducted previously. In this study, we test previous hypotheses of distinct geographic assemblages by examining morphology, reanalyzing phylogeographic genetic structure, and estimating divergence dating among lineages in a coalescent framework using Bayesian inference. We reviewed the fossil record and discuss phylogeographic and taxonomic implications of the existence of three distinct evolutionary lineages. We measured cranial (n=145) and post-cranial (n=104) material on field-captured individuals and museum specimens. We analyzed 420 base pairs (bp) of mitochondrial DNA sequence data for 158 Macrochelys. We examined fossil Macrochelys from ca. 15-16 million years ago (Ma) to the present to better assess historical distributions and evaluate named fossil taxa. The morphological and molecular data both indicate significant geographical variation and suggest three species-level breaks among genetic lineages that correspond to previously hypothesized genetic assemblages. The holotype of Macrochelys temminckii is from the western lineage. Therefore, we describe two new species as Macrochelys apalachicolae sp. nov. from the central lineage and Macrochelys suwanniensis sp. nov. from the eastern lineage (Suwannee River drainage). Our estimates of divergence times suggest that the most recent common ancestor (MRCA) of M. temminckii (western) and M. apalachicolae (central) existed 3.2-8.9 Ma during the late Miocene to late Pliocene, whereas M. temminckii-M. apalachicolae and M. suwanniensis last shared a MRCA 5.5-13.4 Ma during the mid-Miocene to early Pliocene. Examination of fossil material revealed that the fossil taxon M. floridana is actually a large Chelydra. Our taxonomic revision of Macrochelys has conservation and management implications in Florida, Georgia, and Alabama.

Evidence of Population Genetic Structure within the Florida Worm Lizard, Rhineura floridana (Amphisbaenia: Rhineuridae)

Abstract The Florida Worm Lizard (Rhineura floridana) is the only extant representative of the suborder Amphisbaenia occurring in the United States and the only living representative of the Rhineuridae. We updated the known distribution of this species from 510 records with known localities. We further examined geographic genetic structure within this species using 1360 bp of mitochondrial DNA sequence data from 18 samples of R. floridana. Our results suggest an ancient divergence between populations in the north-central Florida peninsula from populations in the south-central peninsula. High genetic distances are observed within south-central populations, whereas genetic structure within northern populations is less discrete and characterized by much shallower divergences. Our findings suggest that south-central populations may be candidates for taxonomic recognition (or recognition as distinct management units) if additional genetic and morphological data support our results.

A NEW SPECIES OF CYRTOPODION (GEKKONIDAE: GEKKONINAE) FROM PAKISTAN

A new species of bent-toed gecko, Cyrtopodion brachykolon is described from a series of specimens collected in 1991 from Manshera and lower Swat districts, Northwest Frontier Province, Pakistan. Specimens were examined for 45 morphological characters and measurements. Cyrtopodion brachykolon is distinguished from the morphologically similar species, Cyrtopodion walli (Ingoldby 1922), by the formers relatively shorter limbs, smaller dorsal tubercles relative to the surrounding granular scales, indistinct longitudinal rows of enlarged dorsal tubercles, and fewer number of transverse color bands. Another morphologically similar species, Alsophylax (Altiphylax) tokobajvi Eremschenko and Szczerbak 1984, can be separated from this new species by its larger supranasal scales and less angularly bent or straight digits. We also provide a brief review of the taxonomic history of the bent-toed geckos of Pakistan, herein assigned to Cyrtopodion (s. l.).

Reproduction of the Burmese python (Python molurus bivittatus) in southern Florida

Kenneth L. Krysko1,5, James C. Nifong1, Ray W. Snow2, Kevin M. Enge3, Frank J. Mazzotti4 1 Florida Museum of Natural History, Division of Herpetology, University of Florida, Gainesville, Florida 32611, USA 2 Everglades National Park, 40001 State Road 9336, Homestead, Florida 33034, USA 3 Florida Fish and Wildlife Conservation Commission, 4005 South Main Street, Gainesville, Florida 32601, USA 4 Department of Wildlife Ecology and Conservation, University of Florida, Fort Lauderdale Research and Education Center, 3205 College Avenue, Davie, Florida 33314, USA 5 Corresponding author; e-mail: kenneyk@flmnh.ufl.edu

Predation of a Tree Snail Drymaeus multilineatus (Gastropoda: Bulimulidae) by Iguana iguana (Reptilia: Iguanidae) on Key Biscayne, Florida

Abstract Iguana iguana is a well-established introduced species in southern Florida, including a large population on Key Biscayne. In its native range, I. iguana is known to be almost strictly herbivorous. Juveniles are often reported to be somewhat omnivorous, but prey items are rarely identified. The tree snail Drymaeus multilineatus is common in southern Florida, where it is found on stems and leaves and in edificarian habitats. The examination of I. iguana stomachs from Bill Baggs Cape Florida State Park, Key Biscayne, resulted in the discovery of D. multilineatus in two lizards, including 12 snails in one juvenile I. iguana. The large and rapidly growing I. iguana populations in southern Florida may have the potential to devastate some highly localized native species of tree snails.

Pliocene–Pleistocene lineage diversifications in the Eastern Indigo Snake (Drymarchon couperi) in the Southeastern United States

Indigo Snakes (Drymarchon; with five currently recognized species) occur from northern Argentina, northward to the United States in southern Texas and eastward in disjunct populations in Florida and Georgia. Based on this known allopatry and a difference in supralabial morphology the two United States taxa previously considered as subspecies within D. corais (Boie 1827), the Western Indigo Snake, D. melanurus erebennus (Cope 1860), and Eastern Indigo Snake, D. couperi (Holbrook 1842), are currently recognized as separate species. Drymarchon couperi is a Federally-designated Threatened species by the United States Fish and Wildlife Service under the Endangered Species Act, and currently being incorporated into a translocation program. This, combined with its disjunct distribution makes it a prime candidate for studying speciation and genetic divergence. In this study, we (1) test the hypothesis that D. m. erebennus and D. couperi are distinct lineages by analyzing 2411 base pairs (bp) of two mitochondrial (mtDNA) loci and one single copy nuclear (scnDNA) locus; (2) estimate the timing of speciation using a relaxed phylogenetics method to determine if Milankovitch cycles during the Pleistocene might have had an influence on lineage diversifications; (3) examine historical population demography to determine if identified lineages have undergone population declines, expansions, or remained stable during the most recent Milankovitch cycles; and (4) use this information to assist in an effective and scientifically sound translocation program. Our molecular data support the initial hypothesis that D. melanurus and D. couperi should be recognized as distinct species, but further illustrate that D. couperi is split into two distinct genetic lineages that correspond to historical biogeography and sea level changes in peninsular Florida. These two well-supported genetic lineages (herein termed Atlantic and Gulf lineages) illustrate a common biogeographic distributional break previously identified for other plants and animals, suggesting that these organisms might have shared a common evolutionary history related to historic sea level changes caused by Milankovitch cycles. Our estimated divergence times suggest that the most recent common ancestor (MRCA) between D. melanurus and southeastern United States Drymarchon occurred ca. 5.9Ma (95% HPD=2.5-9.8Ma; during the late Blancan of the Pleistocene through the Hemphillian of the Miocene), whereas the MRCA between the Atlantic and Gulf lineages in the southeastern United States occurred ca. 2.0Ma (95% HPD=0.7-3.7Ma; during the Irvingtonian of the Pleistocene through the Blancan of the Pliocene). During one or more glacial intervals within these times, these two lineages must have become separated and evolved independently. Despite numerous Milankovitch cycles along with associated forming of physical barriers (i.e., sea level fluctuations, high elevation sand ridges, clayey soils, and/or insufficient habitats) since their initial lineage diversification, these two lineages have likely come in and out of contact with each other many times, yet today they still illustrate near discrete geographic distributions. Although the Atlantic and Gulf lineages appear to be cryptic, a thorough study examining morphological characters should be conducted. We believe that our molecular data is crucial and should be incorporated in making conscious decisions in the management of a translocation program. We suggest that source populations for translocations include maintaining the integrity of the known genetic lineages found herein, as well as those coming from the closest areas that currently support sizable Drymarchon populations.