The proteins and pigment of the eggshell of the Siamese crocodile (Crocodylus siamensis) were analysed. For proteomic analysis, various decalcification methods were used when the two main surface layers were analyzed. These layers are important for antimicrobial defense of egg (particularly the cuticle). We found 58 proteins in both layers, of which 4 were specific for the cuticle and 26 for the palisade (honeycomb) layer. Substantial differences between proteins in the eggshell of crocodile and previously described birds' eggshells exist (both in terms of quality and quantity), however, the entire proteome of Crocodilians has not been described yet. The most abundant protein was thyroglobulin. The role of determined proteins in the eggshell of the Siamese crocodile is discussed. For the first time, the presence of porphyrin pigment is reported in a crocodilian eggshell, albeit in a small amount (about 2 to 3 orders of magnitude lower than white avian eggs).

• Klíčová slova
• Crocodile, Eggshell pigment, Proteins of eggshell,
• MeSH
• aligátoři a krokodýli metabolismus   MeSH
• proteiny plazů metabolismus   MeSH
• proteom metabolismus   MeSH
• vaječná skořápka metabolismus   MeSH
• vaječné proteiny metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chorion proteins MeSH Prohlížeč
• proteiny plazů MeSH
• proteom MeSH
• vaječné proteiny MeSH

An examination of three specimens of the Morelet's crocodile, Crocodylus moreletii Duméril et Bibron, from the Lagoon of Celestún, Yucatan, Mexico revealed the presence of the following eight helminth species: Acanthostomum americanum (Pérez Vigueras, 1956), Pelaezia loossi (Pérez Vigueras, 1956), Telorchis sp. juv., Pseudoneodiplostomum groschafti sp. n. (all trematodes), Dujardinascaris helicina (Molin, 1860), Contracaecum sp. Type 2 larvae, Micropleura sp. and Paratrichosoma recurvum (Solger, 1877) (all nematodes). Pseudoneodiplostomum groschafti sp. n. is established by indication based on the description of specimens from Crocodylus rhombifer from Cuba, given by Groschaft and Barus (1970). Acanthostomum acuti Caballero et Brennes, 1959 is considered a synonym of A. americanum. A. americanum and D. helicina are recorded for the first time from Mexico and Micropleura sp. is the first American representative of the genus recorded outside South America. Findings of A. americanum, Telorchis sp., P. groschafti, D. helicina and Micropleura sp. in C. moreletii represent new host records. Some observations on the early development of D. helicina are provided. All species, except for P. recurvum, are briefly described and illustrated and some problems concerning their morphology, taxonomy and geographical distribution are discussed.

• MeSH
• aligátoři a krokodýli parazitologie   MeSH
• cizopasní červi anatomie a histologie   klasifikace   ultrastruktura   MeSH
• elektronová mikroskopie MeSH
• hlístice anatomie a histologie   klasifikace   ultrastruktura   MeSH
• sladká voda MeSH
• Trematoda anatomie a histologie   klasifikace   ultrastruktura   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Geografické názvy
• Mexiko MeSH

Thirty-two specimens of the Nile crocodile, Crocodylus niloticus Laurenti (Reptilia: Crocodylidae), from the Kruger National Park, South Africa, and its vicinity were examined for pentastomid parasites during 1995 to 1999 and 2010 to 2011. Pentastomid parasites occurred throughout the year and were widespread in the study area with an overall prevalence of 97% and an overall mean abundance of 23.4 (0-81). Pentastome assemblages comprised six species in three sebekid genera: Alofia nilotici Riley et Huchzermeyer, 1995, A. simpsoni Riley, 1994, Leiperia cincinnalis Sambon, 1922, Sebekia cesarisi Giglioli in Sambon, 1922, S. minor (Wedl, 1861) and S. okavangoensis Riley et Huchzermeyer, 1995. The possible influence of host age, gender and geographic location (river system) on pentastome prevalence, abundance and species richness was investigated. Generally, neither host age, gender nor locality did affect infracommunities, likely because all hosts examined were adult or subadult and displayed comparable foraging behaviour, resulting in similar exposure pathways to fish intermediate hosts. Additionally, the longevity of pentastomids would contribute to accumulative infections as hosts mature. Structuring of pentastome assemblages was observed in as far as S. minor was the dominant species based on overall prevalence and abundance, followed by the equally common species S. cesarisi and L. cincinnalis. With an overall prevalence ranging from 34% to 41% and relatively low abundances, A. nilotici, A. simpsoni and S. okavangoensis form the rarer component of pentastome communities.

• Klíčová slova
• Alofia, Leiperia, Pentastomida, Sebekia, abundance, crocodilians, prevalence, species richness,
• MeSH
• aligátoři a krokodýli parazitologie   MeSH
• parazitární nemoci u zvířat epidemiologie   parazitologie   MeSH
• Pentastomida anatomie a histologie   klasifikace   MeSH
• prevalence MeSH
• veřejné parky MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Jihoafrická republika epidemiologie   MeSH

During development, the ventricles of mammals and birds acquire a specialized pattern of electrical activation with the formation of the atrioventricular conduction system (AVCS), which coincides with the completion of ventricular septation. We investigated whether AVCS formation coincides with ventricular septation in developing Siamese crocodiles (Crocodylus siamensis). Comparisons were made with Amazon toadhead turtle (Mesoclemmys heliostemma) with a partial septum only and no AVCS (negative control) and with chicken (Gallus gallus) (septum and AVCS, positive control). Optical mapping of the electrical impulse in the crocodile and chicken showed a similar developmental specialization that coincided with full ventricular septation, whereas in the turtle the ventricular activation remained primitive. Co-localization of neural marker human natural killer-1 (HNK-1) and cardiomyocyte marker anti-myosin heavy chain (MF20) identified the AVCS on top of the ventricular septum in the crocodile and chicken only. AVCS formation is correlated with ventricular septation in both evolution and development.

• Klíčová slova
• Chicken, Crocodile, Embryo, Heart, Turtle,
• MeSH
• aligátoři a krokodýli * MeSH
• kardiomyocyty MeSH
• mezikomorová přepážka * MeSH
• převodní systém srdeční MeSH
• srdeční komory MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Crocodylians have highly derived elongated carpus, which is related to their use of forelimbs in many types of gaits as well as in burrowing. The objective of present study was to describe the ossification of the forelimb in five stages of Siamese crocodile (Crocodylus siamensis). The ossification begins approximately at stage 20 in arm and forearm bones moving sequentially to the metacarpal elements. The first carpal elements with ossification centers are radiale + intermedium and ulnare (stage 22-23), and their ossification mode is typical of long bones. Between stages 22 and 24 distal carpals 3, 4, and 5 fuse together to a single formation. In the stage 25, the ossification proceeds to the pisiform, which starts ossifying late during the embryogenesis. The phalangeal formula of the digits is 2,3,4,5,3. Although there are some interspecific differences, it appears that all crocodylians have similarly uniform skeletal pattern, the process of ossification, number of carpal elements and phalangeal formulas probably due to their similar lifestyles. Anat Rec, 301:1159-1168, 2018. © 2018 Wiley Periodicals, Inc.

• Klíčová slova
• embryo, hand, limb development, morphology, skeleton,
• Publikační typ
• časopisecké články MeSH

Recent molecular taxonomic advancements have expanded our understanding of crocodylian diversity, revealing the existence of previously overlooked species, including the Congo dwarf crocodile (Osteolaemus osborni) in the central Congo Basin rainforests. This study explores the genomic divergence between O. osborni and its better-known relative, the true dwarf crocodile (Osteolaemus tetraspis), shedding light on their evolutionary history. Field research conducted in the northwestern Republic of the Congo uncovered a locality where both species coexist in sympatry/syntopy. Genomic analysis of sympatric individuals reveals a level of divergence comparable to that between ecologically similar South American dwarf caimans (Paleosuchus palpebrosus and Paleosuchus trigonatus), suggesting parallel speciation in the Afrotropics and Neotropics during the Middle to Late Miocene, 10-12 Ma. Comparison of the sympatric and allopatric dwarf crocodiles indicates no gene flow between the analysed sympatric individuals of O. osborni and O. tetraspis. However, a larger sample will be required to answer the question of whether or to what extent these species hybridize. This study emphasizes the need for further research on the biology and conservation status of the Congo dwarf crocodile, highlighting its significance in the unique biodiversity of the Congolian rainforests and thus its potential as a flagship species.

• Klíčová slova
• Congo Basin, Crocodylia, overlooked biodiversity, phylogenomics, sympatry,
• MeSH
• aligátoři a krokodýli * genetika   anatomie a histologie   klasifikace   MeSH
• fylogeneze MeSH
• sympatrie MeSH
• vznik druhů (genetika) MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Jižní Amerika MeSH
• Kongo MeSH

Crocodilians have maintained very similar karyotype structures and diploid chromosome numbers for around 100 million years, with only minor variations in collinearity. Why this karyotype structure has largely stayed unaltered for so long is unclear. In this study, we analyzed the karyotypes of six species belonging to the genera Crocodylus and Osteolaemus (Crocodylidae, true crocodiles), among which the Congolian endemic O. osborni was included and investigated. We utilized various techniques (differential staining, fluorescence in situ hybridization with repetitive DNA and rDNA probes, whole chromosome painting, and comparative genomic hybridization) to better understand how crocodile chromosomes evolved. We studied representatives of three of the four main diploid chromosome numbers found in crocodiles (2n = 30/32/38). Our data provided new information about the species studied, including the identification of four major chromosomal rearrangements that occurred during the karyotype diversification process in crocodiles. These changes led to the current diploid chromosome numbers of 2n = 30 (fusion) and 2n = 38 (fissions), derived from the ancestral state of 2n = 32. The conserved cytogenetic tendency in crocodilians, where extant species keep near-ancestral state, contrasts with the more dynamic karyotype evolution seen in other major reptile groups.

• Klíčová slova
• Chromosome, Crocodylia, Cytogenomics, FISH, Molecular cytogenetics, WCP,
• MeSH
• aligátoři a krokodýli * genetika   MeSH
• hybridizace in situ fluorescenční MeSH
• karyotyp MeSH
• malování chromozomů MeSH
• molekulární evoluce MeSH
• srovnávací genomová hybridizace MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The first description of the male and a redescription of the female of the nematode Paratrichosoma recurvum (Solger, 1877), a parasite of the abdominal skin of crocodiles, are presented on the basis of specimens collected from Crocodilus moreletii Duméril et Bibron from the Lagoon of Celestún, Yucatan, Mexico. The morphology of P. recurvum proved to be very similar to that of the only other congeneric species, P. crocodylus Ashford et Muller, 1978, but the former differed from the latter in having distinctly protruding polar plugs on eggs, reduced mesenchymal cells at the esophagointestinal junction, and a smooth spicular surface as well as in geographic distribution. The finding of P. recurvum in C. moreletii represents a new host record. Paratrichosoma spp. appear to be widely distributed in tropical countries of different continents and may be of economic importance for crocodile farms.

• MeSH
• aligátoři a krokodýli parazitologie   MeSH
• infekce hlísticemi řádu Enoplida epidemiologie   parazitologie   veterinární   MeSH
• ovum cytologie   MeSH
• trávicí systém anatomie a histologie   MeSH
• Trichinelloidea anatomie a histologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Mexiko epidemiologie   MeSH

A new nematode, Crocodylocapillaria longiovata n. gen. and n. sp., is described from the stomach of wild and farmed young crocodiles, Crocodylus johnstoni Krefft, and Crocodylus porosus Schneider, from northern Australia and Papua New Guinea; it is undoubtedly identical with the nematodes previously reported as Capillaria sp. from Crocodylus novaequineae Schmidt from Irian Jaya, Indonesia. This capillariid species represents a new genus, being characterized mainly by the presence of elongate eggs with unusually long protruding polar plugs, a well developed vulvar appendage, a weakly sclerotized spicule, proximal and distal parts of the spicular sheath with spines, and the male posterior end with 2 large lateral caudal lobes and a pair of papillae near the cloacal opening. The body length of C. longiovara males and females is 5,576-7,208 microm and 8,609-14,008 microm, respectively, the spicule is 276-369 microm long; the size of the egg proper is 48-60 x 15-21 microm, length of polar plugs 15-18 microm. Neocapillaria Yi and Guitang, 1994, a junior homonym of Neocapillaria Moravec, 1987, is re-named Sinocapillaria nom. n. and placed as a synonym of Pseudocapillaria Freitas, 1959. Indocapillaria De and Maity, 1995 is retained as a subgenus of Pseudocapillaria because of the possession of a vulvar appendage in the type species. Neocapillaria Moravec, 1987 remains a subgenus of Capillaria Zeder, 1800. A key to genera of the Capillariidae from poikilotherm vertebrates is provided; C. longiovata is the first capillariid species described from the digestive tract of crocodiles.

• MeSH
• aligátoři a krokodýli parazitologie   MeSH
• infekce hlísticemi řádu Enoplida parazitologie   veterinární   MeSH
• Trichinelloidea anatomie a histologie   klasifikace   MeSH
• žaludek parazitologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Papua Nová Guinea MeSH
• Severní teritorium MeSH

Prenatal development in crocodilians represents a very interesting model for comparative studies. As the speed of prenatal development of crocodilians varies depending on incubation conditions, the staging of embryos and fetuses is a very important prerequisite for data correlation. To establish a background for future developmental studies on Crocodylus niloticus, we characterized its prenatal development in a collection comprising 169 animals during embryonic/incubation days 9-70. The characteristics included external morphology, head morphometry, and wet body weight determined before fixation. We documented the external morphology of prenatal Nile crocodiles in a large collection of photographs and described landmarks during the morphogenesis of the head, face and limbs. In the development of the facial processes (medial nasal, lateral nasal, maxillary), three phases could be distinguished: union, separation, reunion. At the free jaw margin, a regular series of prominences was present. The outer aspect of a prominence gave rise to a labial scale, the inner aspect to a tooth. In contrast to mammals (humans and mice), the hindlimbs of C. niloticus developed faster than the forelimbs. We also determined changes in basic measures of the head and of the wet body weight. Both morphological and morphometric characteristics showed an apparent inter-individual variability among animals of the same age. This variability decreased among animals of a similar body weight (irrespective of their age). Body weight can be considered as the most representative and complex parameter for crocodile staging reflecting the overall growth of a whole embryo/fetus.

• MeSH
• aligátoři a krokodýli anatomie a histologie   embryologie   genetika   MeSH
• hlava anatomie a histologie   MeSH
• tělesná hmotnost MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH