Aquatic feeding in a terrestrial turtle: a functional-morphological study of the feeding apparatus in the Indochinese box turtle Cuora galbinifrons (Testudines, Geoemydidae)

The Indochinese box turtle Cuora galbinifrons is regarded as a purely terrestrial species, but our results demonstrate that it can feed both on land and in water. The inverse relationship between the relative development of the hyoid apparatus and the tongue found in the most investigated chelonians is not valid in the Indochinese box turtle. Our morphological analysis of the feeding apparatus reveals that the palate shape and the design of the tongue are consistent with terrestrial feeders, but the construction of the hyoid complex is more characteristic of aquatic feeders. Previous studies have demonstrated that tongue enlargement negatively impacts the capacity of the turtles to suction feed. The present study focuses on the aquatic intraoral prey transport kinematic patterns. Our analysis is based on high-speed films with 250 fr/s and high-speed cineradiography with 50 fr/s. The aquatic intraoral food transport mechanisms differ depending on prey size: small items are transported predominantly by “inertial suction”, whereas larger items are moved by the tongue—normally a clear terrestrial strategy. As the genus Cuora is ancestrally aquatic, the use of lingual food transport in the aquatic environment is presumably an aberrant modus typical only for the most terrestrial among the Asian box turtles.     

Non‐marine turtle plays important functional roles in Indonesian ecosystems

The Southeast Asian box turtle (Cuora amboinensis) is numerically the most important turtle exported from Indonesia. Listed as Vulnerable by the IUCN, this turtle is heavily harvested and exported for food and traditional medicine in China and for the pet trade primarily in the United States, Europe, and Japan. Despite its significance in global markets, relatively little is known about the species’ ecology or importance to ecosystems. We conducted our research in a national park in Sulawesi, Indonesia, and our objectives were to quantify trophic breadth, capacity for seed dispersal between aquatic and terrestrial ecosystems, and whether ingestion of seeds by C. amboinensis enhances germination. We obtained diet samples from 200 individual turtles and found that the species is omnivorous, exhibiting an ontogenetic shift from more carnivorous to more omnivorous. Both subadults and adults scavenged on other vertebrates. In a seed passage experiment, turtles passed seeds for 2?9 days after ingestion. Radio‐tracked turtles moved, on average, about 35 m per day, indicating that seeds from ingested fruits, given seed passage durations, could be dispersed 70?313 m from the parent tree and potentially between wetland and upland ecosystems. In a seed germination experiment, we found that ingestion of seeds by turtles enhanced germination, as compared with control seeds, for four of six plant species tested. Of these, two are common in the national park, making up a significant proportion of plant biomass in lowland swamp forest and around ephemeral pools in savanna, and are highly valued outside of the park for their lumber for construction of houses, furniture, and boats. Protection of C. amboinensis populations may be important for maintaining trophic linkages that benefit biodiversity, communities, and local economies.     

Oropharyngeal morphology in the basal tortoise Manouria emys emys with comments on form and function of the testudinid tongue

In tetrapods, the ability to ingest food on land is based on certain morphological features of the oropharynx in general and the feeding apparatus in particular. Recent paleoecological studies imply that terrestrial feeding has evolved secondarily in turtles, so they had to meet the morphological oropharyngeal requirements independently to other amniotes. This study is designed to improve our limited knowledge about the oropharyngeal morphology of tortoises by analyzing in detail the oropharynx in Manouria emys emys. Special emphasis is placed on the form and function of the tongue. Even if Manouria is considered a basal member of the only terrestrial turtle clade and was hypothesized to have retained some features reflecting an aquatic ancestry, Manouria shows oropharyngeal characteristics found in more derived testudinids. Accordingly, the oropharyngeal cavity in Manouria is richly structured and the glands are large and complexly organized. The tongue is large and fleshy and bears numerous slender papillae lacking lingual muscles. The hyolingual skeleton is mainly cartilaginous, and the enlarged anterior elements support the tongue and provide insertion sides for the well‐developed lingual muscles, which show striking differences to other reptiles. We conclude that the oropharyngeal design in Manouria differs clearly from semiaquatic and aquatic turtles, as well as from other reptilian sauropsids. J. Morphol., 2011. © 2011 Wiley‐Liss, Inc.     

Long term persistence of introduced Amblyomma geoemydae tick population under indoor conditions in Austria

An indoor terrarium population of Amblyomma geoemydae was established subsequent to the import of a single yellow‐marginated box turtle Cuora flavomarginata. This indoor tick population revealed an unexpected resistance against de‐ticking trials, with persistence between 2010 and 2015, when the ticks were successfully eliminated. Ticks were collected from the bodies and shells of turtles, as well as from terraria soil. Species diagnosis of ticks was carried out according to distinguishable morphological characters and supported by molecular analysis using DNA‐barcoding. Introduced exotic ticks are potential vectors of pathogens and can have an impact on wildlife, domestic animals and the human population. This case emphasizes the need for sharp surveillance and control measures on imported reptiles.     

Morphological characterization and phylogenetic relationships of Indochinese box turtles—The Cuora galbinifrons complex

The members of the Indochinese box turtle complex, namely Cuora galbinifrons, Cuora bourreti, and Cuora picturata, rank the most critically endangered turtle species on earth after more than three decades of over‐harvesting for food, traditional Chinese medicine, and pet markets. Despite advances in molecular biology, species boundaries and phylogenetic relationships, the status of the C. galbinifrons complex remains unresolved due to the small number of specimens observed and collected in the field. In this study, we present analyses of morphologic characters as well as mitochondrial and nuclear DNA data to reconstruct the species boundaries and systematic relationships within the C. galbinifrons complex. Based on principal component analysis (PCA) and statistical analysis, we found that phenotypic traits partially overlapped among galbinifrons, bourreti, and picturata, and that galbinifrons and bourreti might be only subspecifically distinct. Moreover, we used the mitochondrial genome, COI, and nuclear gene Rag1 under the maximum likelihood criteria and Bayesian inference criteria to elucidate whether C. galbinifrons could be divided into three separate species or subspecies. We found strong support for a sister relationship between picturata and the other two species, and consequently, we recommend maintaining picturata as a full species, and classifying bourreti and galbinifrons as subspecies of C. galbinifrons. These findings provide evidence for a better understanding of the evolutionary histories of these critically endangered turtles.     

研究和保护金头闭壳龟--再访龟故乡

于2006年初,再次走访了金头闭壳龟产地,分析了前后几次调查中发现的若干问题,并就保护问题提出进一步的建议.     

58年来首次发现生活的云南闭壳龟及其描述

最近,根据网上信息,作者专程到云南某地查看到业余龟鳖爱好者杨杰先生收集的一只生活的雌性云南闭壳龟：经作者依据云南闭壳龟的原始描述逐字逐句核对,确认为该种无疑。本文对其外部形态特征加以描述,并拍摄照片显示其各部特征以资对照。这是在依据中国云南6号标本发表(1906年)该种后,近100年以来获得第二只生活标本的正式报道。第一只是1946年张玺和成庆泰教授在云南昆明西山采集的一号未注明性别的标本,发表了极为简单的一段介绍和6项测量数据,距令也已有58年之久。目前据作者所知全世界共有12号标本,分别保存于4个国家的5个单位,但除模式标本外,尚未见有对此龟生活个体加以详细描述并正式报道者。云南闭壳龟是中国特有种,在中国也仅发现于云南省境内,研究该龟并切实做好对它们的保护工作,是摆在我们面前的迫切而又艰巨的任务!     

Species boundaries and phylogenetic relationships in the critically endangered Asian box turtle genus Cuora

Turtles are currently the most endangered major clade of vertebrates on earth, and Asian box turtles (Cuora) are in catastrophic decline. Effective management of this diverse turtle clade has been hampered by human-mediated, and perhaps natural hybridization, resulting in discordance between mitochondrial and nuclear markers and confusion regarding species boundaries and phylogenetic relationships among hypothesized species of Cuora. Here, we present analyses of mitochondrial and nuclear DNA data for all 12 currently hypothesized species to resolve both species boundaries and phylogenetic relationships. Our 15-gene, 40-individual nuclear data set was frequently in conflict with our mitochondrial data set; based on its general concordance with published morphological analyses and the strength of 15 independent estimates of evolutionary history, we interpret the nuclear data as representing the most reliable estimate of species boundaries and phylogeny of Cuora. Our results strongly reiterate the necessity of using multiple nuclear markers for phylogeny and species delimitation in these animals, including any form of DNA "barcoding", and point to Cuora as an important case study where reliance on mitochondrial DNA can lead to incorrect species identification.     

A new species of Opisthioglyphe (Trematoda: Telorchiidae) from gall bladder of turtles in Malaysia

Opisthioglyphe sharmai n. sp. is described from the gall bladder of the Malayan box turtle, Cuora amboinensis, and the black marsh turtle, Siebenrockiella crassicollis, in Malaysia. The new species is morphologically similar to Opisthioglyphe ranae and some other members of the genus parasitic in amphibians and reptiles. Opisthioglyphe sharmai n. sp. is easily differentiated from all other members of the genus by the cirrus sac extending posterior to the ventral sucker, while in all previously known species the cirrus sac is entirely or mostly preacetabular with the base of the structure not reaching beyond mid-line of the ventral sucker. Despite the overall stable morphology, O. sharmai n. sp. is characterized by highly variable arrangement of testes, from tandem to opposite. It is only the second representative of the genus described from turtles and the first species of Opisthioglyphe parasitic in gall bladder, while all previously described members of the genus are parasitic in the intestine of their hosts.     

Conservation phylogenetics of the Asian box turtles (Geoemydidae, <Emphasis Type="Italic">Cuora</Emphasis>): mitochondrial introgression,numts, and inferences from multiple nuclear loci

Asian box turtles (genus Cuora, family Geoemydidae) comprise a clade of 12 aquatic and semiaquatic nominate species distributed across southern China and Southeast Asia. Over the last two decades, turtles throughout Asia have been harvested at an unsustainable rate to satisfy demands for food, traditional Chinese medicine, and the pet trade. Consequently, all species of Cuora were recently placed on the IUCN Red List, nine are currently listed as critically endangered by the IUCN, and all species are listed in Appendix II of CITES. We compiled a 67-specimen mitochondrial (∼1,650 base pairs (bp) from two mitochondrial genes) and a 40-specimen nuclear-plus-mitochondrial (∼3,900 bp total, three nuclear introns plus an additional ∼860 bp mitochondrial gene fragment) DNA data set to reconstruct the phylogeny of Cuora species and to assess genetic diversity and species boundaries for several of the most problematic taxa. Our sampling included 23 C. trifasciata, 17 C. zhoui and 1–4 individuals of the remaining 10 species of Cuora. Maximum likelihood, maximum parsimony and Bayesian analyses all recovered similar, well resolved trees. Within the Cuora clade, mitochondrial and nuclear sequence data indicated that both C. zhoui and C. mccordi represent old lineages with little or no history of interspecific gene flow, suggesting that they are good genealogical species. Based on mtDNA, Cuora pani was paraphyletic and C. trifasciata was composed of two highly divergent lineages that were not each other’s closest relatives; both cases of non-monophyly were due to a mtDNA sequence that was widespread and identical in C. aurocapitata, C. pani and C. trifasciata. However, when combined with nuclear DNA results, our data indicate that C. trifasciata is a single, monophyletic taxon, and that mitochondrial introgression and nuclear-mitochondrial pseudogenes have led to a complex pattern of mitochondrial gene relationships that does not reflect species-level histories. Our results imply that captive “assurance colonies” of both C. trifasciata and C. pani should be genotyped to identify pure, non-hybrid members of both taxa, and we recommend that introgressed and pure taxa be managed as independent entities until the full evolutionary histories of these critically endangered turtles are resolved.     

Modulatory complexity of the feeding repertoire in scincid lizards

The kinematics of jaws and tongue, and jaw muscle activity patterns were investigated in the omnivorous lizard Tiliqua rugosa, and the herbivorous Corucia zebrata (Scincidae) during feeding. Small metal markers were inserted into different parts of the skull, the jaws, and the tongue. Video and cineradiographic images were digitized and displacements of the head, jaws, and tongue were quantified. Additionally, muscle activity patterns were recorded, digitized and several variables were determined quantitatively. The effect of food type on the jaw and hyolingual movement patterns and the jaw muscle activity patterns was investigated for both species. The kinematic data indicate that distinct aspects of gape and tongue cycles are modulated in response to the food characteristics. Similarly, in both species, muscle activity patterns are altered in response to the type of food eaten. A comparison of kinematic and electromyographic patterns during intraoral transport cycles for both species shows that these can be related to food characteristics such as toughness and mobility. Differences between both species in the response to changes in food characteristics are minor. Clearly both species are able to fine tune the activation of the jaw muscles, resulting in the appropriate movement patterns for the type of food eaten. Accepted: 30 January 1999     

Molecular phylogeny of the critically endangered Indochinese box turtle (Cuora galbinifrons)

The Indochinese box turtle Cuora galbinifrons is a polytypic, critically endangered species from Vietnam, Laos, and Hainan Island, China. We analyze up to 1790bp of mitochondrial DNA under maximum parsimony and maximum likelihood criteria to test if the five historically recognized subspecies represent evolutionary lineages, and to elucidate the relationship of C. galbinifrons to other Cuora. C. galbinifrons is composed of three major mitochondrial DNA clades corresponding to the three subspecies galbinifrons, bourreti, and picturata. These three lineages are also morphologically diagnosable, and consequently we recommend elevating each to full species. Cuora galbinifrons hainanensis nests within the galbinifrons clade, and we retain it as a synonym of galbinifrons, as supported by morphology. Cuora "serrata" is known to be a hybrid of male Cuora mouhotii and female C. galbinifrons, and our findings show that C. "serrata" originates from both female galbinifrons and bourreti. Little or no mitochondrial DNA variation was found among the morphologically distinct species Cuora aurocapitata, Cuora pani, and Cuora trifasciata, for which hypotheses are proposed. Recognizing galbinifrons, bourreti, and picturata as separate species has consequences for ongoing ex situ captive breeding programs and prioritization of in situ conservation activities, particularly in Vietnam.     

A forceful upper jaw facilitates picking-based prey capture: biomechanics of feeding in a butterflyfish,Chaetodon trichrous

Biomechanical models of feeding mechanisms elucidate how animals capture food in the wild, which, in turn, expands our understanding of their fundamental trophic niche. However, little attention has been given to modeling the protrusible upper jaw apparatus that characterizes many teleost species. We expanded existing biomechanical models to include upper jaw forces using a generalist butterflyfish, Chaetodon trichrous (Chaetodontidae) that produces substantial upper jaw protrusion when feeding on midwater and benthic prey. Laboratory feeding trials for C. trichrous were recorded using high-speed digital imaging; from these sequences we quantified feeding performance parameters to use as inputs for the biomechanical model. According to the model outputs, the upper jaw makes a substantial contribution to the overall forces produced during mouth closing in C. trichrous. Thus, biomechanical models that only consider lower jaw closing forces will underestimate total bite force for this and likely other teleost species. We also quantified and subsequently modeled feeding events for C. trichrous consuming prey from the water column versus picking attached prey from the substrate to investigate whether there is a functional trade-off between prey capture modes. We found that individuals of C. trichrous alter their feeding behavior when consuming different prey types by changing the timing and magnitude of upper and lower jaw movements and that this behavioral modification will affect the forces produced by the jaws during prey capture by dynamically altering the lever mechanics of the jaws. In fact, the slower, lower magnitude movements produced during picking-based prey capture should produce a more forceful bite, which will facilitate feeding on benthic attached prey items, such as corals. Similarities between butterflyfishes and other teleost lineages that also employ picking-based prey capture suggest that a suite of key behavioral and morphological innovations enhances feeding success for benthic attached prey items.     

黄喉拟水龟（♀）与三线闭壳龟（♂）杂交后代的形态特征及其与父母本的比较研究

本研究通过黄喉拟水龟Mauremys mutica（♀）与三线闭壳龟Cuora trifasciata（♂）进行杂交,成功获得了杂种龟。这说明黄喉拟水龟和三线闭壳龟是可以进行属间远缘杂交的,但杂交组合的受精率及孵化成功率均低于黄喉拟水龟的同种组合。杂种稚龟与黄喉拟水龟稚龟在背甲纹路、腹甲黑斑、四肢和尾腹面的皮肤颜色、喉盾前端形状及起点位置、喉盾宽/喉盾缝长、喉盾缝长/肱盾缝长、股盾缝长/肛盾缝长存在差异。1龄前,杂种龟生长快于黄喉拟水龟。形态特征上,杂种龟头顶部淡棕黄色,头侧眼后有两条黑色纵纹,颈腹部淡黄色;背甲棕色,腹甲浅黄色,每一盾片中间都有边缘呈放射状的黑斑;四肢、尾腹面及裸露皮肤部分为黄褐色。形态可量数据分析显示杂种龟在形态上接近黄喉拟水龟。建立了三种龟的形态判别公式,判别的准确率为100%（p<0.01）,判别分析中贡献最大的4个变量分别是腹甲后半部长/背甲长、喉盾宽/背甲长、肱盾缝长/背甲长、股盾缝长/背甲长,可见三线闭壳龟、黄喉拟水龟与杂交种腹部的腹甲后半部长、喉盾宽、肱盾缝长、股盾缝长等参数可作为鉴别三者的直接依据。本实验的结果对杂种龟的鉴定、龟类的杂交育种及养殖生产实践都有一定的借鉴作用。     

Kinematics of the jaw and hyolingual apparatus during feeding in Caiman crocodilus

Movements of the neck, jaws, and hyolingual apparatus during inertial feeding in Caiman crocodilus were studied by cineradiography. Analysis reveals two kinds of cycles: inertial bites (reposition, kill/crush, and transport) and swallowing cycles. They differ in their gape profile and in displacement of the neck, cranium, and hyolingual apparatus. Inertial bites are initiated by an elevation of the neck and cranium; the head is then retracted backward, the prey simultaneously being lifted by the hyolingual apparatus. Next the lower jaw is depressed, and the prey is rapidly pushed further upward by the hyolingual apparatus. Thereafter fast mouth-closure occurs with the neck and cranium being abruptly depressed, the lower jaw elevated, and the hyolingual apparatus rapidly retracted ventrally. Depression of the neck and cranium thrusts the head forward and impacts the backward moving prey more posteriorly in the oral cavity. Swallowing cycles initially involve movement of the hyoid in front of the prey followed by rapid posteroventrad retraction of the hyoid, forcing the prey into the esophagus during opening and closing of the mouth. After mouth-closure, the hyoid apparatus is again protracted. Jaws, neck, tongue, and hyoid apparatus play an active role during intertial feeding sequences. At the beginning of a feeding sequence, the hyolingual apparatus mainly moves dorsoventrally, whereas toward the end of a sequence anteroposterior displacements of the hyoid are prominent. © 1992 Wiley-Liss, Inc.     

Feeding biomechanics in Acanthostega and across the fish–tetrapod transition

Acanthostega is one of the earliest and most primitive limbed vertebrates. Its numerous fish-like features indicate a primarily aquatic lifestyle, yet cranial suture morphology suggests that its skull is more similar to those of terrestrial taxa. Here, we apply geometric morphometrics and two-dimensional finite-element analysis to the lower jaws of Acanthostega and 22 other tetrapodomorph taxa in order to quantify morphological and functional changes across the fish–tetrapod transition. The jaw of Acanthostega is similar to that of certain tetrapodomorph fish and transitional Devonian taxa both morphologically (as indicated by its proximity to those taxa in morphospace) and functionally (as indicated by the distribution of stress values and relative magnitude of bite force). Our results suggest a slow tempo of morphological and biomechanical changes in the transition from Devonian tetrapod jaws to aquatic/semi-aquatic Carboniferous tetrapod jaws. We conclude that Acanthostega retained a primitively aquatic lifestyle and did not possess cranial adaptations for terrestrial feeding.     

The mitochondrial DNA control region comparison studies of four hinged turtles and its phylogentic significance of the genusCuora sensu lato (Testudinata: Geoemydidae)

The complete sequences of the mitochondrial DNA (mtDNA) control region (CR) ofCistoclemmys flavomarginata, Cistoclemmys galbinifrons, Cuora aurocapitata andCyclemys atripons were amplified by long-polymerase chain reaction (Long-PCR). The lengths were 1207 bp, 1722 bp, 1379 bp and 980 bp, respectively. Combining with the CR sequence ofPyxidea mouhotii (DQ659152), we compared the CR structure, and identified three functional domains (TAS, CD and CSB) in which the conservation sequences (TAS, CSB-F, CSB-1, CSB-2 and CSB-3) were also successfully identified according to their homology to those of other turtles. These 5 turtles have the identical CSB-2 and CSB-3 sequences, and 4 of them have the same CSB-1 sequence while there is one base transversion (T → A) inCy. atripons. We analyzed the variable number of tandem repeat (VNTR) sequences or microsatellites at the 3′ end of CR. The motifs of tandem repeats (7 types) are made up of 2–8 nucleotides, and the copy numbers are from 4 to 48. All of the 5 turtles exceptCy. atripons have the “TATTATAT” repeats and are ended by TA. The results of CR structure analysis displayed that theCuora, Cistoclemmys, andPyxidea have many similarities, but differ fromCyclemys. WithIndotestudo elongate (DQ080043) andIndotestudo forstenii (DQ080044) as outgroups, using the CR sequences (1123bp) excluded the microsatellites at the 3′ end of CR, we constructed the molecular phylogenetic trees using the MP, ML and BI methods. The results showed that there was a strong support to the monophyly of theCuora group consisting ofCuora,Cistoclemmys andPyxidea, which has a close relationship withMauremys andChinemys but far fromCyclemys, which are consistent with the analysis of the CR structure of the 5 turtles.     

The Evolution of Feeding Motor Patterns in Lizards: Modulatory Complexity and Possible Constraints

Previous research indicated that the evolution of feeding motorpatterns across major taxonomic groups might have occurred withoutlarge modifications of the control of the jaw and hyolingualmuscles. However, the proposal of this evolutionary scheme washampered by the lack of data for some key taxa such as lizards.Recent data on jaw and hyolingual feeding motor patterns ofa number of lizard families suggest extensive variability withinand among species. Although most lizards respond to changesin the structural properties of food items by modulating theactivation of the jaw and hyolingual muscles, some food specialistsmight have lost this ability. Whereas the overall similarityin motor patterns across different lineages of lizards is largefor the hyolingual muscles, jaw muscle activation patterns seemto be more flexible. Nevertheless, all data suggest that boththe jaw and hyolingual system are complexly integrated. Theelimination of feedback pathways from the hyolingual systemthrough nerve transection experiments clearly shows that feedingcycles are largely shaped by feedback interactions. Yet, novelmotor patterns including unilateral control seem to have emergedin the evolution from lizards to snakes.     

Structure and function of the hyolingual system in Hynobius and its bearing on the evolution of prey capture in terrestrial salamanders

The Hynobiidae is generally regarded as the most phylogenetically basal and least derived extant family of terrestrial salamanders. As in the other families of terrestrial salamanders, prey capture in the Hynobiidae is accomplished by lingual prehension. In Hynobius, the prey capture system appears to be a mosaic of derived and primitive features. This, in conjunction with previous studies, suggests that the hyolingual systems of all families of terrestrial salamanders have evolved various degrees of specialization since the appearance of the common ancestral condition. We propose that the generalized feeding system for the extant terrestrial salamanders includes a hyolingual skeleton comprised of one basibranchial, one pair of radial or radial-like structures, two pairs of ceratobranchials, two pairs of epibranchials, one pair of ceratohyals, and one urohyal arranged in a configuration similar to that of Hynobius; a simple, sac-like secondary tongue pad; a lift and thrust system of tongue projection; a four-part gape cycle; and a forward head and body surge. Modifications to this general plan, previously described for the disparate families, include various changes in the size, shape, and definition of the tongue pad, changes in the specific types of structures and configurations in the anterior hyolingual skeleton, secondary ossification in the posterior hyolingual skeleton, the appearance of various protrusion, projection, and flipping systems for tongue protraction, simplification of the kinematic gape profile, and loss of the forward head and body surge. The evolutionary trends in these modifications have provided a rich data set from which much phylogenetic information has been inferred. © 1996 Wiley-Liss, Inc.