Apalone Ferox Research Articles

Development and Application of qPCR Assay for Species-specific Identification of Two Animal-derived Tonics: Vinegar-quenched Testudinis Carapax et Plastrum and Vinegar-quenched Trionycis Carapax

Background Vinegar-quenched Testudinis Carapax et Plastrum (TCP) and vinegar-quenched Trionycis Carapax (TC) are made from the shells of Chinemys reevesii and Trionyx sinensis. However, some cheap substitutes from non-medicinal species such as Trachemys scripta, Mauremys sinensis, Chelydra serpentina, and Apalone ferox are often seen on the market, which exposes public health to high risk. Conventional methods are not applicable for the identification of these two products since their intrinsic constituents are largely destroyed after being highly processed. Objectives A new quantitative polymerase chain reaction (qPCR) method was developed to detect DNA components of Vinegar-quenched TCP and vinegar-quenched TC based on simple sequence repeat differential genes of animal-derived mitochondria. Materials and Methods Six species-specific primer reactions were designed and further validated for specificity, sensitivity, and repeatability. Finally, the developed method was used to assess the authenticity of their commercial products. Results The assay exhibited good specificity, and the limit of detection was above 1 × 102 copies/µL. There was good linearity in the concentration, ranging from 1 × 102 to 1 × 107 copies/µL. In addition, the method was validated through repeatability assessment (coefficient variation <1%). While qPCR was applied for the analysis of 36 batches of commercial products of these two tonics, it could effectively identify the authenticity of the products, and consequently, seven batches were fake or adulterated. Conclusion This newly proposed method is promising for the quality evaluation of highly processed animal-derived Chinese medicines, which will assist in ensuring safety and efficacy in clinical practice and protect fair trade in the market.

A quantum leap in the evolution of platyhelminths: Host-switching from turtles to hippopotamuses illustrated from a phylogenetic meta-analysis of polystomes (Monogenea, Polystomatidae)

While monogenean worms are mainly parasites of the gills and skin of fish, and to a lesser extent parasites of the oral cavity, urinary bladder, and/or conjunctival sacs of amphibians and freshwater turtles, Oculotrema hippopotamiStunkard, 1924 is the single monogenean polystome reported from a mammal, the common hippopotamus (Hippopotamus amphibius Linnaeus). Several hypotheses have been suggested in the last decade to explain the origin of this enigmatic parasite which infects the conjunctival sacs of H. amphibius. Based on a molecular phylogeny inferred from nuclear (28S and 18S) and mitochondrial (12S and COI) sequences of O. hippopotami and chelonian polystomes, we found a sister group relationship between O. hippopotami and Apaloneotrema moleri (Du Preez & Morrison, 2012). This result suggests lateral parasite transfer between freshwater turtles and hippopotamuses, thus likely reflecting one of the most exceptional known examples of host-switching in the course of vertebrate evolution. It also demonstrates that the proximity in the ecological habitat of parasites within host species is an important feature for their speciation and diversification. Because A. moleri and its host, the Florida softshell turtle (Apalone ferox (Schneider)), are restricted to the USA, we suggest that an ancestral stock of parasites may have been isolated on primitive African trionychids after they diverged from their American relatives, and then switched to hippopotamuses or anthracotheres in Africa.

Quantifying shell patterning helps identify species of Trionychidae.

Softshell turtles (Trionychidae) display characteristic pits and ridges, or "sculpturing," on the bony carapace. Variation in sculpturing pattern may be useful in classifying fossilized shell fragments. Although past attempts could discern qualitative differences in certain best-case scenarios, many early taxonomic uses of sculpturing traits have been reevaluated as unreliable in the face of intraspecific variation. The potential of sculpturing to contain consistently reliable, quantitative, taxonomically informative traits remains underexplored. Here, we revisit this idea by quantifying trionychid shell patterning with topographic measurement techniques more commonly applied to nonhomologous quantification of mammalian teeth and geographic surface topography. We assess potential sources of variation and accuracy of these metrics for species identification. Carapaces of extant specimens used in this study included members of the species Apalone ferox, Apalone spinifera, and Amyda cartilaginea and were obtained from the herpetology collections of the Florida Museum of Natural History. 3D scans of shells were systematically sampled to create digital "fragments." These fragments were quantified using three topographic measurements: Dirichlet Normal Energy (DNE), Relief Index (RFI), and Orientation Patch Count Rotated (OPCR). A nested MANOVA suggests there is significant variation at the species, individual, and carapace location levels of analysis. Linear discriminant analysis correctly predicts a sample's species identity from DNE, RFI, and OPCR 75.2% of the time. These promising results indicate that topographic measures may provide a method for identifying shell fragments that are currently identifiable only as Trionychidae indet. Future work should explore this approach in additional species and account for ontogenetic changes.

Can Reptiles Use Nest Site Choice Behavior to Counter Global Warming Effects on Developing Embryos? Potential Climate Responses in a Turtle

Climate warming is forecasted to cause extinctions, but populations could theoretically avoid extinction in a rapidly changing environmentviaadaptive evolution (i.e., evolutionary rescue), precluding the need for intervention. Although strong links between a changing climate and the physiology of an organism are expected, climate effects can be buffered by behavior. Nest site choice behavior, for example, can reduce environmental variation that would be experienced by embryos placed randomly with respect to environmental temperatures. We tested four provisions of this prediction by quantifying nest sites and “potential” nest sites in the Florida softshell turtle (Apalone ferox). First, turtles chose nest sites with mean canopy openness values (32–47%) that were intermediate between the shadiest (14–17%) and the sunniest potential nest sites (36–57%) available. Second, canopy openness, incident radiation intensity, and nest temperatures were generally, positively related to one another, indicating definitive thermal consequences of nest site choice. Third, our study revealed ample, cooler nest sites available to turtle mothers within close proximity to nest sites utilized; by nesting in the most shaded sites, softshell turtle mothers could depress mean nest temperatures by ∼2°C. Fourth, the growth of vegetative cover throughout incubation had negligible effects on canopy openness, incident radiation intensity, and nest temperatures, supporting the potential for mothers to “predict” developmental temperatures using temperature cues during nest site choice. Finally, our data revealed considerable variation in canopy openness chosen by nesting mothers; such behavior could thus, be subject to natural selectionviaembryonic mortality under future warming. Collectively, our study suggests that Florida softshell turtles, and probably other turtle species nesting in relatively open areas, may be able to counter climate change effects on developing embryos by nesting in more shaded microhabitats, assuming nest site choice behavior is heritable and can evolve at a sufficient rate to keep pace with climate warming. The evolutionary and behavioral mechanisms (e.g., assessing substrate temperatures directly vs. indirect choice of canopy cover) in the repertoire of nesting mother turtles for responding to climate warming remain elusive and are required for a more complete understanding of climate responses.

A novel group of negative-sense RNA viruses associated with epizootics in managed and free-ranging freshwater turtles in Florida, USA.

Few aquatic animal negative-sense RNA viruses have been characterized, and their role in disease is poorly understood. Here, we describe a virus isolated from diseased freshwater turtles from a Florida farm in 2007 and from an ongoing epizootic among free-ranging populations of Florida softshell turtles (Apalone ferox), Florida red-bellied cooters (Pseudemys nelsoni), and peninsula cooters (Pseudemys peninsularis). Affected turtles presented with similar neurological signs, oral and genital ulceration, and secondary microbial infections. Microscopic lesions were most severe in the softshell turtles and included heterophilic/histiocytic meningoencephalitis, multi-organ vasculitis, and cytologic observation of leukocytic intracytoplasmic inclusions. The virus was isolated using Terrapene heart (TH-1) cells. Ultrastructurally, viral particles were round to pleomorphic and acquired an envelope with prominent surface projections by budding from the cell membrane. Viral genomes were sequenced from cDNA libraries of two nearly identical isolates and determined to be bi-segmented, with an ambisense coding arrangement. The larger segment encodes a predicted RNA-directed RNA polymerase (RdRP) and a putative zinc-binding matrix protein. The smaller segment encodes a putative nucleoprotein and an envelope glycoprotein precursor (GPC). Thus, the genome organization of this turtle virus resembles that of arenaviruses. Phylogenetic analysis shows that the RdRP of the turtle virus is highly diverged from the RdRPs of all known negative-sense RNA viruses and forms a deep branch within the phylum Negarnaviricota, that is not affiliated with any known group of viruses, even at the class level. In contrast, the GPC protein of the turtle virus is confidently affiliated with homologs from a distinct group of fish hantaviruses. Thus, the turtle virus is expected to become the founder of a new taxon of negative-sense RNA viruses, at least with a family rank, but likely, an order or even a class. These viruses probably evolved either by reassortment or by intrasegment recombination between a virus from a distinct branch of negarnaviruses distant from all known groups and a hanta-like aquatic virus. We suggest the provisional name Tosoviridae for the putative new family, with Turtle fraservirus 1 (TFV1) as the type species within the genus Fraservirus. A conventional RT-PCR assay, targeting the TFV1 RdRP, confirmed the presence of viral RNA in multiple tissues and exudates from diseased turtles. The systemic nature of the TFV1 infection was further supported by labeling of cells within lesions using in situ hybridization targeting the RNA of the TFV1 RdRP.

Harnessing multiplex polymerase chain reaction assay for convenient and simultaneous differentiation of testudinis carapax et plastrum from trionycis carapax

Background: Testudinis Carapax et Plastrum (TCP, Guijia) and Trionycis Carapax (TC, Biejia), which made from the shell of Chinemys reevesii (CR) and Pelodiscus sinensis (PS), were two kinds of widely used animal-derived Traditional Chinese medicine (TCM). Some cheap substitutes such as the carapace and plastron of Trachemys scripta (TS), Mauremys sinensis (MS), or Apalone ferox (AF) shells obtained from restaurants are sometimes used, which expose the public health to a high risk and cause unfair competitions in the market. Objective: The objective of the study was to develop a multiplex polymerase chain reaction (PCR) approach to simultaneously differentiate five Chelonia species and identify adulteration of two natural products. Materials and Methods: Five novel species-specific primers were designed for CR, TS, MS, PS, and AF, followed by optimization of PCR conditions and validation for specificity and sensitivity. Then, a deliberate mixture was analyzed to verify the capability of adulteration detection. Finally, it was used to examine commercial products. Results: The developed method proved to be highly specific and detection limit was 1 ng for all the species tested. Particularly, it was still applicable and reliable when processed products or deliberate adulteration were examined. Two batches of commercial raw TCP products were identified to be counterfeited by TS using the newly proposed approach. Conclusion: The newly proposed multiplex PCR method showed sufficient merits to be readily employed as a regular means to authenticate edible and medicinal TCM products made of TCP and TC.

Molecular and Histopathological Data on Levisunguis subaequalis Curran, Overstreet, Collins & Benz, 2014 (Pentastomida: Eupentastomida: Porocephalida: Porocephaloidea: Sebekidae: Sebekinae) from Gambusia affinis in Alabama, USA

Levisunguis subaequalis Curran, Overstreet, Collins & Benz, 2014 , was recently described from the lungs of the definitive hosts, softshell turtles, Apalone ferox (Schneider, 1783), and Apalone spinifera aspera (Agassiz, 1857) as well as the viscera of an intermediate host, the western mosquitofish, Gambusia affinis (Baird and Girard, 1853). However, the original account lacked molecular data. Furthermore, histological examination of infected host tissues in the original account of L. subaequalis did not reveal any pathological changes in the intermediate host. The present work provides a robust morphological description of the nymph and novel molecular data from the 18S and 28S ribosomal gene regions and the cytochrome c oxidase subunit 1 (COI) mitochondrial gene. Phylogenetic analyses using Bayesian inference and maximum likelihood analysis with concatenated sequence data from these 3 regions, as well as each region individually, placed the turtle pentastomid L. subaequalis as a sister clade to the crocodilian pentastomids of the genus Sebekia Sambon, 1922. While only concatenated phylogenetic analyses agreed with the currently accepted classification of the Eupentastomida and phylogenetic signal assessment indicated that the concatenated data set yielded the most phylogenetic signal, data from more taxa are still needed for robust phylogenetic inferences to be made. The intensity of infection ranged from 2 to 171 nymphs per fish, compared with the highest previously reported intensity of 6. These high-intensity infections with L. subaequalis were characterized by the nymphs occupying 5-50% of the coelomic cavity of G. affinis. However, despite this heavy parasite infection, fish exhibited minimal pathology. Observed pathology was characterized by compression or effacement of organs adjacent to the nymphs, particularly liver, swim bladder, and intestines, as well as the formation of granulomas around shed pentastomid cuticles. Nonetheless, the morphological and molecular data provided in the present work will bolster future efforts to identify this pentastomid in other hosts where pathology may be present in addition to aiding in the advancement of the field of molecular pentastomid systematics.

Comparative mitogenomic and phylogenetic analysis of Apalone spinifera and Apalone ferox (Testudines: Trionychidae).

The soft-shell turtles Apalone spinifera (AS) and Apalone ferox (AF) are two important economic species. AF is found in the Yellow River of China, and is a confirmed member of the Trionychidae family. However, the classification of AS was in dispute. Mitochondrial genomes (mitogenomes) have been widely used for species identification, as well as population and phylogenetic analysis. In order to understand the phylogenetic and mitogenomic features of AS and AF, the complete mitogenomes were sequenced, annotated and analyzed in this study. The complete mitogenomes of AS and AF are 16,817bp and 16,756bp in length, respectively. Both mitogenomes contain 37 genes, seven short intergenic spacers and two long intergenic spacers. Comparative analysis showed that there are 1,137 variation sites (6.79%) between the two mitogenomes. AS and AF mitogenomes both show a usage preference in terms of nucleotides, codons and amino acids. In addition, the non-synonymous substitution rate/synonymous substitution rate indicates that all protein-coding genes (PCGs) have undergone a strong purifying selection. Phylogenetic trees constructed by 13 PCGs show a clear phylogenetic relationship of the soft-shell turtles and suggest that AS is a sister species to AF of the genus Apalone. The data could be useful for further research of species identification, population analysis and the mitogenomic features of soft-shell turtles.

The complete mitogenome of Pelochelys cantorii (Guangning) and the comparative analysis of different habitats

Pelochelys cantorii has become one of the most critically endangered species in the world. The complete mitochondrial DNA (mtDNA) genome of P. cantorii (Guangning) was generated by polymerase chain reaction (PCR) amplification, primer-walking sequencing and fragment cloning. The mitochondrial genome is 17,424 base pairs (bp) and contains 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes and one control region. Comparative analyses of complete mitochondrial genome sequences from different habitats, we found that the P. cantorii (unknown) may be wrong identified. And the phylogenetic position of P. cantorii also support this result, maximum likelihood (ML) and Bayesian (BI) analyses were conducted based on 12 heavy-strand PCGs and 2 rRNAs from 18 taxa. P. cantorii (unknown) is not closely related to other P. cantorii, but formed a clade with Apalone spinifera and Apalone ferox.

Population Structure of the Florida Softshell Turtle,Apalone ferox,in a Protected Ecosystem, Wekiwa Springs State Park, Florida

The Florida softshell turtle, Apalone ferox (Schneider 1783) is considered common and easily visible in many freshwater habitats throughout its range. However, very little population research has been completed on the species due to difficulties associated with capture and long-term marking. We have conducted a mark–recapture study of this species since 2007 as part of a long-term freshwater turtle population monitoring program at Wekiwa Springs State Park, Apopka, Florida. From 2007 to 2012 we captured 56 individual Florida softshell turtles with 101 total captures. The male∶female ratio was 1∶2.6 and females were larger than males. Population estimates were 92 adults and 49 juveniles with a total estimate of 141 Florida softshell turtles in the 2.67-ha study site. Our data from a protected population centrally located within the species range provide a baseline for comparison to other populations.

Large-scale predation by river otters (Lontra canadensis) on Florida cooter (Pseudemys floridana) and Florida softshell turtles (Apalone ferox).

Abstract We observed predation by river otters (Lontra canadensis) on large numbers of Florida cooter (Pseudemys floridana) and Florida softshell turtles (Apalone ferox) in two small lakes in North Central Florida, USA during a period of unusually low water levels. Carcasses were strewn on the shoreline and accumulated around floating boat docks, where some residents observed turtles being killed. We found 76 carcasses, including predominantly skeletons, and two live, severely injured turtles from one lake; however, numerous remains undoubtedly were unrecovered. The otters frequently eviscerated the turtles and removed the head and one or more appendages, including the phallus of mature males. In skeletal remains, injuries inflicted by otters were nonspecific, indistinguishable from damage caused by scavengers, or easily missed in incomplete carcasses. This report of large-scale mortality of freshwater turtles in Florida suggests that otters could have a significant impact on local turtle populations.

Susceptibility of fish and turtles to three ranaviruses isolated from different ectothermic vertebrate classes.

Ranaviruses have been associated with mortality of lower vertebrates around the world. Frog virus 3 (FV3)-like ranaviruses have been isolated from different ectothermic vertebrate classes; however, few studies have demonstrated whether this pathogen can be transmitted among classes. Using FV3-like ranaviruses isolated from the American bullfrog Lithobates catesbeianus, eastern box turtle Terrapene carolina carolina, and Pallid Sturgeon Scaphirhynchus albus, we tested for the occurrence of interclass transmission (i.e., infection) and host susceptibility (i.e., percent mortality) for five juvenile fish and three juvenile turtle species exposed to each of these isolates. Exposure was administered via water bath (10(3) PFU/mL) for 3 d and survival was monitored for 28 d. Florida softshell turtles Apalone ferox experienced no mortality, but 10% and 20% of individuals became infected by the turtle and fish isolate, respectively. Similarly, 5% of Mississippi map turtles Graptemys pseudogeographica kohni were subclinically infected with the turtle isolate at the end of the experiment. Channel Catfish Ictalurus punctatus experienced 5% mortality when exposed to the turtle isolate, while Western Mosquitofish Gambusia affinis experienced 10% mortality when exposed to the turtle and amphibian isolates and 5% mortality when exposed to the fish isolate. Our results demonstrated that interclass transmission of FV3-like ranaviruses is possible. Although substantial mortality did not occur in our experiments, the occurrence of low mortality and subclinical infections suggest that fish and aquatic turtles may function as reservoirs for FV3-like ranaviruses. Additionally, our study is the first to report transmission of FV3-like ranaviruses between fish and chelonians.

Levisunguis subaequalis n. g., n. sp., a tongue worm (Pentastomida: Porocephalida: Sebekidae) infecting softshell turtles, Apalone spp. (Testudines: Trionychidae) in the southeastern United States

A new tongue worm (Pentastomida) belonging to the Sebekidae Sambon, 1922 (Porocephaloidea Sambon, 1922) is described based on exemplars collected from softshell terrapins Apalone spinifera aspera (Agassiz) and Apalone ferox (Schneider) in the southeastern United States; a new genus is erected to accommodate the new species. The new species belongs in the Sebekidae because adults possess four simple hooks arranged in a trapezoid pattern on the ventral surface of the cephalothorax, a mouth opening between the anterior and posterior pairs of hooks, a terminal anus, an elongated uterus with preanal uterine pore, and a Y-shaped seminal vesicle. Nymphs possess geminate hooks, and the new species has an aquatic life-cycle in which nymphs become encapsulated in the body cavity of a freshwater fish and mature in the lungs of a terrapin. The new genus is distinct from other genera in the Sebekidae primarily by differences in hook morphology and the fact that representatives use a terrapin as a definitive host. Nymphs infecting fish and presumed to be the new species matured as postlarval juveniles conspecific with the new species when they were fed to the eastern mud turtle, Kinosternon subrubrum (Lacépède). Nymphs of the new species are anatomically similar to but larger than nymphs of Sebekia mississippiensis Overstreet, Self & Vliet, 1985 found in the mesentery of fishes captured in Florida, U.S.A. Adults of the new species differ from those of S. mississippiensis based on hook features, chloride cell pore pattern on annuli, body size, and use of a turtle rather than crocodilian definitive host. The new species is the third North American member of the Sebekidae.

Forelimb kinematics during swimming in the pig-nosed turtle,Carettochelys insculpta, compared with other turtle taxa: rowing versus flapping, convergence versus intermediacy

Animals that swim using appendages do so by way of rowing and/or flapping motions. Often considered discrete categories, rowing and flapping are more appropriately regarded as points along a continuum. The pig-nosed turtle, Carettochelys insculpta, is unusual in that it is the only freshwater turtle to have limbs modified into flippers and swim via synchronous forelimb motions that resemble dorsoventral flapping, traits that evolved independently from their presence in sea turtles. We used high-speed videography to quantify forelimb kinematics in C. insculpta and a closely related, highly aquatic rower (Apalone ferox). Comparisons of our new data with those previously collected for a generalized freshwater rower (Trachemys scripta) and a flapping sea turtle (Caretta caretta) allow us to: (1) more precisely quantify and characterize the range of limb motions used by flappers versus rowers, and (2) assess whether the synchronous forelimb motions of C. insculpta can be classified as flapping (i.e. whether they exhibit forelimb kinematics and angles of attack more similar to closely related rowing species or more distantly related flapping sea turtles). We found that the forelimb kinematics of previously recognized rowers (T. scripta and A. ferox) were most similar to each other, but that those of C. insculpta were more similar to rowers than to flapping C. caretta. Nevertheless, of the three freshwater species, C. insculpta was most similar to flapping C. caretta. 'Flapping' in C. insculpta is achieved through humeral kinematics very different from those in C. caretta, with C. insculpta exhibiting significantly more anteroposterior humeral motion and protraction, and significantly less dorsoventral humeral motion and depression. Based on several intermediate kinematic parameters and angle of attack data, C. insculpta may in fact represent a synchronous rower or hybrid rower-flapper, suggesting that traditional views of C. insculpta as a flapper should be revised.

Comparison research and phylogenetic implications of mitochondrial control regions in four soft-shelled turtles of Trionychia (Reptilia, Testudinata)

The mitochondrial control regions (CRs) and flanking sequences of Pelodiscus sinensis, Apalone ferox, Palea steindachneri and Carettochelys insculpta were obtained using Long-PCR with gene-specific primers. The CR lengths of the four species were 1843 bp, 1356 bp, 1725 bp, and 969 bp. The base composition percentages of A+T were 60.5%, 60.7%, 65.7%, 64.7%, respectively. Combined with CR sequences of other three soft-shelled turtles published in GenBank (Pelodiscus sinensis, Korea, AY962573; Dogania subplana, AF366350; Lissemys punctata, EF050073), we compared the CR structures and identified three functional domains (TAS, CD and CSB) in which conserved sequence blocks (TAS, CSB -F, CSB-1, CSB-2 and CSB-3) were also successfully identified according to their sequence similarities to those of other turtles. The variable numbers of tandem repeats (VNTRs 1) with 50–52 bp motif were identified at 5′-end of CR among the five soft-shelled turtles P. sinensis (China), P. sinensis (Korea), A. ferox, P. steindachneri, D. subplana. The copy number of the VNTRs varied from 5 to 15. VNTRs 2 with 2–11 bp motif were identified in the 3′- end of CR among all of the six soft-shelled turtles with variable number of motifs from 4 to 29. Moreover, VNTRs 3 with 6 bp motif were identified between CSB-1 and CSB-2 of CR both in P. sinensis (China) and P. sinensis (Korea), in which the number of motifs varied from 19 to 29. The types and distribution of VNTRs of the six soft-shelled turtles were also discussed. With Alligator mississippiensis as an outgroup, combined with the CR sequences (excluding VNTRs) of other five turtles which were published in GenBank, the molecular phylogenetic trees were constructed using PAUP 4.0b10 and MrBayes ver. 3.0. The results strongly supported the monophyly of Carretochelyidae and Carettochelyidae as sister group to an assemblage of Cryptodira. Our research suggested that the earliest phylogenetic tree splits into three separated basal branches; the Pelomedusidira (Pelomedusa subrufa), the Carettochelyidae (C. insculpta), and an assemblage of Cryptodira and the C. insculpta that might be a representation of distinctive suborder.

Environmental Correlates of the Abundances of Three Species of Freshwater Turtles in Lakes of Northern Florida

The high densities of freshwater turtles, along with their longevities and tendencies toward omnivory, can make them critical influences on the energy flow in lakes and the resilience of lake food webs. Despite this potential importance, there is little understanding of whether turtle abundances are driven by bottom-up (productivity) or top-down (predation) vectors. In this study I examined the environmental correlates of abundance of three dominant turtle species in 17 northern Florida lakes that span a gradient in primary productivity. I examined the associations between the abundances of the Yellow-Bellied Slider (Trachemys scripta), Florida Cooter (Pseudemys floridana), and Florida Softshell Turtle (Apalone ferox) and 18 environmental factors that varied either discretely or continuously across the lakes. Mantel analyses revealed significant associations between abundance of T. scripta, P. floridana, and A. ferox and periphyton and presence of mud and muck substrates, revealing a significant bottom-up influence. However, abundances were also associated with the presence or absence of alligators, important predators of turtles, indicating a significant top-down influence. The abundances of P. floridana and A. ferox were correlated with additional factors that suggest a role for specific dietary items and trophic position. The results indicate that both bottom-up and top-down controls are important limiting factors to turtle populations and implicate turtles as critical elements in the structure and, perhaps, the stability, of food webs in southeastern lakes.

Comparative growth in the postnatal skull of the extant North American turtle Pseudemys texana (Testudinoidea: Emydidae)

AbstractBever, G.S. 2007. Comparative growth in the postnatal skull of the extant North American turtle Pseudemys texana (Testudinoidea: Emydidae). —Acta Zoologica (Stockholm) 88: 000–000Postnatal growth is one of the many aspects of developmental morphology that remains distinctly understudied in reptiles. Variation and ontogenetic scaling within the skull of the extant emydid turtle, Pseudemys texana is described based on 25 continuous characters. Results indicate that skull shape in this species changes little during postnatal growth relative to the only cryptodire taxa for which comparable datasets are available (Apalone ferox and Sternotherus odoratus). This relative lack of change results in the paedomorphic retention of a largely juvenile appearance in the adult form of P. texana. The skulls of males and females, despite the presence of distinct sexual dimorphism in size, grow with similar scaling patterns, and the few observed differences appear to reflect alteration of the male growth trajectory. Comparisons with A. ferox and S. odoratus reveal a number of similarities and differences that are here interpreted within a phylogenetic context. These preliminary hypotheses constitute predictive statements that phylogenetically bracket the majority of extant cryptodire species and provide baseline comparative data that are necessary for the future recognition of apomorphic transformations. Plasticity of ontogenetic scaling as a response to the homeostatic needs and behaviour of individuals commonly is evoked as a limitation of ontogenetic scaling as a means to inform phylogenetic studies. These evocations are largely unfounded considering that variability itself can evolve and thus be phylogenetically informative.

Spermatogenic Cycle of the Florida Softshell Turtle, Apalone ferox

Spermatogenesis in Apalone ferox from Palm Beach County, Florida, is found to follow a postnuptial or dissociated pattern. Reduction of epididymis mass and clearing of sperm from the epididymides suggest spring mating. Histology of the testes, somatic index, and tubule diameter all suggest fall spermatogenesis. Males as small as 15.2 cm PL were found to be mature, and all males were reproductive in a given year. The distribution of postnuptial spermatogenesis is mapped on a phylogeny of turtles and suggests that this pattern has evolved at least six times among living turtles.

The mock turtle syndrome: genetic identification of turtle meat purchased in the south‐eastern United States of America

AbstractMuch of the demand for turtle meat in North America and Europe during the past four centuries has been met using green turtle (Chelonia mydas) and other marine turtles. As stocks of marine turtles dwindled, harvest of the alligator snapping turtle (Macroclemys temminckii), the largest freshwater turtle in North America, increased in the south‐eastern USA. As a result, this species has declined and is now protected in every state of the USA except Louisiana. There is concern that the remaining legal trade in turtle products may serve as a cover for illegally harvested species. To assess the composition of species in commerce, we purchased 36 putative turtle meat products in Louisiana and Florida. Using cytochrome b and control region sequences of the mitochondrial genome, we identified 19 samples as common snapping turtle (Chelydra serpentina), three as Florida softshell (Apalone ferox), one provisionally as softshell turtle (Apalone sp.), one as alligator snapping turtle, and eight as American alligator (Alligator mississippiensis). It appears that M. temminckii is no longer the predominant species in markets of Louisiana. The presence of alligator meat in a quarter of the samples indicates that the trade in turtle products is not entirely legitimate. As is often the case for unsustainable wildlife harvests, large, esteemed species, such as green turtle and alligator snapper, have been replaced by smaller, more‐abundant or mislabelled species, a phenomenon we refer to as the mock turtle syndrome.

Comparative Molecular Phylogeography of North American Softshell Turtles (Apalone): Implications for Regional and Wide-Scale Historical Evolutionary Forces

We use a comparative analysis of partial cytochrome b sequences to evaluate the evolutionary forces shaping wide-scale phylogeographic patterns of all three North American softshell turtles (Apalone ferox, A. mutica, and A. spinifera). The overall phylogeographic patterns are concordant with results from both extensive regional studies of southeastern species, implicating historical vicariant processes during the Pliocene and Pleistocene, and investigations of more northerly distributed species, indicating a bottleneck effect of recent dispersal into postglacial habitat. We also resolved a novel, shared genetic break between northern–western and southeastern populations within both A. mutica and A. spinifera, demonstrating the value of using widespread taxa to evaluate both regional and wider scale phylogeographic patterns. The extensive phylogenetic structure and sequence divergences within both A. mutica and A. spinifera contrast sharply with most previous studies of turtles and with the hypothesis that turtles in general have slow rates of mtDNA evolution.