The phylogenetic distribution,anatomy and histology of the post‐cloacal bones and adnexa of geckos

Post‐cloacal bones of gekkotans may be present as a single (medial) pair, two pairs (medial and lateral), or may be lacking. We, herein, demonstrate that the presence of a single medial pair is the ancestral condition for the Gekkota, that the lateral pair is of sporadic occurrence within and between families, except for the Eublepharidae where it is universal, and that absence is also of sporadic occurrence except for the Sphaerodactylidae where it is the ancestral condition. Adult male Tokay geckos (Gekko gecko) possess only the medial pair of bones, and these exhibit a regionally‐specific expression of woven, fibrolamellar, and lamellar bone, and an enclosed medullary cavity. Females and small juvenile males lack bony elements but exhibit a conspicuous band of dense connective tissue located about the anterior and lateral margins of the cloacal sacs. As males grow and attain sexual maturity, the medial post‐cloacal bones condense in this band of dense connective tissue, and are thus shown to be dermal ossifications, similar to osteoderms but with muscular associations (although this is also known for crocodylians). Based upon ontogenetic data we set forth a scenario to explain the loss of the medial post‐cloacal bones in various lineages. Differential staining of the cloacal sacs failed to reveal any specialized glandular structures. Investigation of the post‐cloacal spurs shows them to be associated with cellular connective tissue of a type similar to that found in the vicinity of the medial post‐cloacal bones. This suggests that the lateral post‐cloacal bones may also be dermal bones, but histological evidence is needed to corroborate this. J. Morphol. 277:264–277, 2016. © 2015 Wiley Periodicals, Inc.     

The female cloaca of an oviparous caecilian amphibian (Gymnophiona): functional and seasonal aspects

Kuehnel, S., Herzen, J., Kleinteich, T., Beckmann, F. and Kupfer, A. 2011. The female cloaca of an oviparous caecilian amphibian (Gymnophiona): functional and seasonal aspects. —Acta Zoologica (Stockholm) 00 :1–14. Reproductive morphology is receiving increased attention in animals that have variable reproductive modes combined with internal fertilization. Exceptionally among amphibians all caecilian species practice internal fertilization via an intromittent organ: an everted part of the male cloaca (phallodeum or phallus). Because research has mostly concentrated on males, knowledge of the female cloacal morphology is scarce. Here, we present the first single‐species study of the functional morphology of the female cloaca of an oviparous, phylogenetically basal caecilian (Ichthyophis cf. kohtaoensis). We have analyzed female cloacal shape during the reproductive cycle combining conventional histology with 3D‐reconstruction. All females are similar in their overall cloacal structure with some differences in size and histology associated with the reproductive cycle. The female cloaca is divided into two distinct chambers similar to the male condition. The cranial chamber contains urogenital pockets into which oviducts and Wolffian ducts open and which may have function during oviposition. The caudal cloacal chamber bears a novel feature – dorsolateral blind sacs, which are homologous to the male condition, but are considerably smaller. The study of female cloacal morphology is essential to understanding the evolution of the caecilian reproductive system and contributes to the understanding of tetrapod genital morphology in general.     

An Analysis of Snake-Scent Application Behaviour in Siberian Chipmunks (Eutamias sibiricus asiaticus)

Some rodents assault live snakes by mobbing. Another snake-directed behaviour is shown by Siberian chipmunks, Eutamias sibiricus asiaticus, when encountering a dead snake. They approach the carcass cautiously, gnaw the snake skin, and chew and apply the gnawed bits to their body fur. We have termed this behaviour “Snake-Scent Application” (SSA). SSA behaviour is also elicited by snake urine and feces. Chemicals in snake skin and rectal and cloacal sacs release SSA. Snake urine applied to dead mice tends to suppress ingestion by snakes.     

Comparative anatomy and phylogeny of the cloacae of salamanders (Amphibia: Caudata). II. Cryptobranchidae,Hynobiidae, and Sirenidae

Cloacae were examined from salamanders representing the three families in which fertilization of eggs is known or inferred to occur externally. The cloacae of male and female sirenids are aglandular and lack cilia. Sexual dimorphism in sirenid cloacae occurs only in the extent of epithelial stratification in the cloacal chamber in females (entire chamber) versus males (posterior angle of the vent). Both male and female Cryptobranchus alleganiensis possess ventral glands that secrete an acid mucopolysaccharide and have ciliated cloacal linings. The ventral glands are more numerous and hypertrophied in breeding male than female C. alleganiensis, but in males, ventral glands secrete only onto the surface of the cloacal lips along the anterior three-fifths of the cloacal orifice, whereas in females, the glands secrete onto the border of the entire cloacal orifice. Except for male Onychodactylus japonicus, male and female hynobiids also possess only ventral glands and have ciliated cloacal linings. Hynobiid ventral glands secrete a glycoprotein. Much variation occurs, however, among these hynobiids in cloacal conformation, extent of epidermis into the cloaca, and anatomy of the ventral gland. Male O. japonicus possess an unciliated cloaca in which three types of cloacal glands occur, each giving unique reactions to tests for carbohydrates and proteins. The glands in male O. japonicus do not seem to be homologous to those found in spermatophore producing salamanders in the Salamandroidea, but this does not negate the possibility that O. japonicus makes spermatophores. Examination of cloacal characters in additional species of hynobiids may be useful in resolving intrafamilial phylogenetic relationships.     

Sex Difference in the Cloacal Gland in the Hagfish,Eptatretus burgeri,and its Possible Significance in Reproduction

The cloacal gland of the hagfish, Eptatretus burgeri, was studied histologically in four seasons. Before the breeding season (spring and summer) the male cloacal gland was larger than the female cloacal gland. The gland was largest in the males with a more mature testis. After the breeding season (autumn and winter) there was no sex difference in the size of the cloacal gland. The cloacal gland consists of mucus and thread cells, as do the lateral slime glands. The sperm may be entangled within slime in the cloacal gland and be shed outside as a slimy sperm mass. Such a slimy sperm mass may play an important role in reproduction of the hagfish.     

Ultrastructure of the anal sacs in <Emphasis Type="Italic">Thalassema</Emphasis><Emphasis Type="Italic">thalassemum</Emphasis> (Annelida,Echiura)

The anal sacs of Thalassema thalassemum consist of an elongate tubular invagination (end sac) that is uniformly covered with numerous sessile ciliated funnels. While the funnels are composed of multi-ciliated, non-muscular cells and possess a ciliated neck-like constriction, the end sacs are lined by a simple epithelium of large, irregularly formed and sparsely ciliated cells that include masses of secretory granules. Podocytes are incorporated in the peritoneum that surrounds the anal sacs. A muscle grid consisting of inner longitudinal, outer circular and additional diagonal fibres that branch off of the circular fibres is embedded in the matrix between the end sac epithelium and peritoneum. Major structural differences between the hindgut and anal sacs support the hypothesis that the anal sacs are not gut derivatives but are instead part of a modified metanephridial system. Comparison of the anal sac morphology in Echiura reveals that T. thalassemum shares a tubular end sac with all known members of Thalassematinae and Ikedaidae, as well as with some members of Bonelliidae and Echiurinae, while the sessile funnels are apomorphic for the Thalassematinae.     

The ultrastructure of the lung of two newborn marsupial species,the northern native cat,Dasyurus hallucatus,and the brushtail possum,Trichosurus vulpecula

Summary The lungs of newborn northern native cats, Dasyurus hallucatus and newborn brushtail possums, Trichosurus vulpecula were examined by both light and electron microscopy. The native cat has a birth weight of 18 mg after a gestation of about 21 days, whereas the brushtail possum weights 200 mg at birth and has a gestation period of 17.5 days. The lungs of the native cat are two large respiratory sacs, with a respiratory lining of squamous cells and surfactant-secreting cells. The capillaries are located within the connective tissue just below this respiratory epithelium. The visceral covering of the lung is formed by squamous cells. The lungs of the possum are composed of numerous large respiratory sacs which are separated by connective tissue septa in which the capillaries are located. The sacs, as in other species, are lined with squamous cells and surfactant secreting cells. It is proposed that the structure of the lung of the newborn marsupial is related more to the size of the newborn rather than to the length of the gestation period.     

Circadian rhythm of water balance and aldosterone excretion in the whitebellied sunbird<Emphasis Type="Italic"> Nectarinia talatala</Emphasis>

Nectarivorous whitebellied sunbirds, Nectarinia talatala, demonstrate distinct circadian patterns in osmoregulatory parameters. We recorded intake of a 1 mol/l sucrose solution which enabled calculation of total water gain, and collected cloacal fluid for measurements of volume, osmolality and aldosterone concentration. These variables were assessed hourly over 12 h of photophase, and averaged over the 12-h scotophase period. Overnight, when sunbirds were in negative water balance, aldosterone concentrations and outputs were significantly higher than diurnal levels, reflecting a shut-down of cloacal fluid production. Early morning was marked by a high rate of osmotic excretion, disproportionate to water gain or cloacal fluid output, followed by steady intake and cloacal fluid output during the morning and early afternoon. Reduced water flux (decreased feeding and cloacal fluid output) during mid-afternoon was accompanied by a paradoxical decline in osmotic excretion, whilst a significant increase in the discrepancy between water intake and output was recorded as the birds effectively stored water before the scotophase. These patterns of intake and excretion may be informative in explaining drinking and foraging behaviour in the field.Abbreviations ALDO aldosterone - CF cloacal fluid - GFR glomerular filtration rate     

Enzymatic isolation of viable nucelli at the megaspore mother cell stage and in developing embryo sacs in Nicotiana tabacum

Summary Nucelli and developing embryo sacs were enzymatically isolated from ovules of Nicotiana tabacum. Megaspore mother cells, tetrads, uninucleate, binucleate, four-nucleate, eight-nucleate and mature embryo sacs were obtained. The isolated embryo sacs were intact and living, and maintained their original shape and organization. Cytoplasmic streaming was clearly observed. Prolonged incubation of ovules or reincubation of isolated embryo sacs in the maceration mixture resulted in the liberation of the gametophytic cells as individual, living protoplasts.     

Measuring the gut microbiome in birds: Comparison of faecal and cloacal sampling

The gut microbiomes of birds and other animals are increasingly being studied in ecological and evolutionary contexts. Numerous studies on birds and reptiles have made inferences about gut microbiota using cloacal sampling; however, it is not known whether the bacterial community of the cloaca provides an accurate representation of the gut microbiome. We examined the accuracy with which cloacal swabs and faecal samples measure the microbiota in three different parts of the gastrointestinal tract (ileum, caecum, and colon) using a case study on juvenile ostriches, Struthio camelus, and high‐throughput 16S rRNA sequencing. We found that faeces were significantly better than cloacal swabs in representing the bacterial community of the colon. Cloacal samples had a higher abundance of Gammaproteobacteria and fewer Clostridia relative to the gut and faecal samples. However, both faecal and cloacal samples were poor representatives of the microbial communities in the caecum and ileum. Furthermore, the accuracy of each sampling method in measuring the abundance of different bacterial taxa was highly variable: Bacteroidetes was the most highly correlated phylum between all three gut sections and both methods, whereas Actinobacteria, for example, was only strongly correlated between faecal and colon samples. Based on our results, we recommend sampling faeces, whenever possible, as this sample type provides the most accurate assessment of the colon microbiome. The fact that neither sampling technique accurately portrayed the bacterial community of the ileum nor the caecum illustrates the difficulty in noninvasively monitoring gut bacteria located further up in the gastrointestinal tract. These results have important implications for the interpretation of avian gut microbiome studies.     

The ventral skin glands, new additional cloacal glands in Proteus anguinus (Caudata, Proteidae). I. Female

Guillaume, O. 2000. The ventral skin glands, new additional cloacal glands in Proteus anguinus (Caudata, Proteidae). I. Female. —Acta Zoologica (Stockholm) 81 : 213–221 Cloacae of female Proteus anguinus were examined by light and electron microscopy. Females possess spermathecae and anterior ventral glands such as Necturus females. However, female P. anguinus possess new additional cloacal glands of unknown homology. These tubular glands secrete on the ventral epidermis of the cloacal area. Considering these characteristics, it is proposed that they will be called the ventral skin glands.     

Structure of the inflorescence and flower ofPetalonyx linearis (Loasaceae)

Fossil chloranthoid androecia,Chloranthistemon endressii gen. et spec. nov. are described from the Upper Cretaceous (Upper Santonian or Lower Campanian) of Scania, southern Sweden. They are three-lobed and dorsiventrally flattened with all pollen sacs borne laterally and inclined toward the presumed adaxial surface. The central lobe bears two pairs of pollen sacs, the lateral lobes a single pair each. The morphology, anatomy and valvate dehiscence of the fossil androecia is very similar to that seen in extant species ofChloranthus andSarcandra, but the in situ pollen differs from that of all extantChloranthaceae in being spiraperturate. A single chloranthoid androecium from the Lower Cretaceous (Upper Albian) of Maryland, North America has a more generalized structure thanChloranthistemon endressii. It consists of three stamens that are fused at the base, and each stamen bears two pairs of oppositely positioned pollen sacs. Combined with anatomical information from recentChloranthus the Lower Cretaceous specimen suggests that the androecium in the living genus has arisen by fusion and other modifications of three separate stamens each with a normal complement of four pollen sacs. The structure of both the Upper and Lower Cretaceous androecia suggest that these fossilChloranthaceae were insectpollinated. Macrofossil evidence combined with information from dispersed pollen indicates that theChloranthaceae diversified early in angiosperm fossil history and were an important component of Mid-Cretaceous plant communities.     

The vocal sac of Hylodidae (Amphibia,Anura): Phylogenetic and functional implications of a unique morphology

Anuran vocal sacs are elastic chambers that recycle exhaled air during vocalizations and are present in males of most species of frogs. Most knowledge of the diversity of vocal sacs relates to external morphology; detailed information on internal anatomy is available for few groups of frogs. Frogs of the family Hylodidae, which is endemic to the Atlantic Forest of Brazil and adjacent Argentina and Paraguay, have three patterns of vocal sac morphology—that is, single, subgular; paired, lateral; and absent. The submandibular musculature and structure of the vocal sac mucosa (the internal wall of the vocal sac) of exemplar species of this family and relatives were studied. In contrast to previous accounts, we found that all species of Crossodactylus and Hylodes possess paired, lateral vocal sacs, with the internal mucosa of each sac being separate from the contralateral one. Unlike all other frogs for which data are available, the mucosa of the vocal sacs in these genera is not supported externally by the mm. intermandibularis and interhyoideus . Rather, the vocal sac mucosa projects through the musculature and is free in the submandibular lymphatic sac. The presence of paired, lateral vocal sacs, the internal separation of the sac mucosae, and their projection through the m. interhyoideus are synapomorphies of the family. Furthermore, the specific configuration of the m. interhyoideus allows asymmetric inflation of paired vocal sacs, a feature only reported in species of these diurnal, stream‐dwelling frogs.     

Upatoia barnardii gen. et sp. nov., an araucarian pollen cone with in situ pollen from the Late Cretaceous (Santonian) of Georgia,USA

Upatoia barnardii gen. et sp. nov., a conifer pollen cone from the Late Cretaceous (Santonian) Eutaw Formation of Upatoi Creek, Georgia, USA, is known from lignified and fusainised mesofossils that preserve its three-dimensional structure. The cone consists of numerous helically arranged microsporophylls, each composed of a thin stalk and distal lamina. Three elongate pollen sacs are attached to the base of the lamina. Pollen grains isolated from the pollen sacs are relatively large (52 – 75 μm), spheroidal to ellipsoidal in outline, lack sacci, and have a thickened equatorial exine that is often strongly folded. Pollen of Upatoia barnardii indicates a close relationship to extant Araucariaceae. Microsporophylls of U. barnardii confirm suggestions from previous studies of fossil material that some Mesozoic Araucariaceae had only three pollen sacs per microsporophyll, in contrast to extant species that often have more than ten pollen sacs per microsporophyll.     

Enzyme Cytochemistry of the Alveolar Sacs and Golgian-Like Cisternae in the Ciliate Ichthyophthirius multifiliis

In the cell cortex of the parasitic ciliate Ichthyophthirius multifiliis different kinds of cisternae were observed: the alveolar sacs, thick membrane cisternae and the endoplasmic reticulum. The thick membrane cisternae possess coated dilated rims and sometimes could be observed close to the endoplasmic reticulum. Using cytochemical techniques acid phosphatase, thiamine pyrophosphatase and nucleoside diphosphatase activities were detected in the thick membrane cisternae and in the alveolar sacs of trosphozoites. In the endoplasmic reticulum acid phosphatase activity was not detected and only very small amounts of thiamine pyrophosphatase and nucleoside diphosphatase reaction product were observed. After exit from the host, a reduction in acid phosphatase activity was evident in the alveolar sacs. At theront stage acid phosphatase activity is absent from these structures. However, high thiamine pyrophosphatase and nucleoside diphosphatase activities remain in the alveolar sacs during the whole life cycle. On the other hand, acid phosphatase, thiamine pyrophosphatase and nucleoside diphosphatase activities were detected in thick membrane cisternae of theronts. Based on the morphological aspects and enzymatic content the thick membrane cisternae of the cell cortex are designated as golgian-like cisternae. The cytochemical results point out a relationship between the alveolar sacs and the Golgi complex.     

Characteristics of the membranes of the pellicle of the ciliatePseudomicrothorax dubius

Summary The membranes of the pellicle of the ciliatePseudomicrothorax dubius are investigated using thin section electron microscopy and freeze-fracture replicas. The plasma membrane is covered by a surface coat and is connected to the outer alveolar membrane by short, sometimes branched, bridges. The inner alveolar membrane is coated on both sides. The epiplasm lies in intimate contact with the cytoplasmic surface of this membrane, and there is a corresponding deposit on the other surface. This deposit is regularly striated.The epiplasmic layer and the alveoli are interrupted at sites of cytotic activity,e.g., the attachment sites of trichocysts, the cytoproct, and the parasomal sacs. The striated deposit ends where the epiplasm ends, indicating a direct relationship between these two epimembranous layers.There is a deposit along the sides of the first part of the tip of the trichocysts, and in this region the trichocyst membrane is free of intramembranous particles.The membrane of the parasomal sacs has a coat on both surfaces. That on the extraplasmic surface is similar to the surface coat of the plasma membrane. The origin of the cytoplasmic coat is unknown. The cytotic activity of these sacs is indicated by their highly irregular profiles.     

Sex-specific asymmetry within the cloacal microbiota of the striped plateau lizard, <Emphasis Type="Italic">Sceloporus virgatus</Emphasis>

The structure and diversity of microbial communities in wild vertebrate populations remain poorly understood, but are expected to have important consequences for individual survival and reproductive success. For instance, recent work has demonstrated that cloacal microbe assemblages of wild birds are related to the phenotypic quality of the host. To contribute to this field of study, we examined the composition and diversity of the cloacal microbiota of free-ranging striped plateau lizards, Sceloporus virgatus, using 16s rRNA-based culture independent techniques. Our dataset, generated from cloacal swabs of six males and six females, and based on twenty five 16s rRNA clones from each sample, revealed (i) low overall microbial diversity, (ii) a striking sex asymmetry in microbial community composition with males displaying cloacal microbiota more typical of gastrointestinal residents found in other organisms, while females display only gammaproteobacterial phylotypes, (iii) a significant sex difference in microbial community structure, with females having significantly lower microbial diversity and richness than do males, and (iv) that the diversity of the female microbial community is negatively correlated to her ectoparasitic mite load. It is not yet clear if the female-specific paucity of cloacal microbial diversity is due to host function or microbe-microbe interactions, or whether the relationship to female mite load is causal, however these findings are expected to have relevance to the species’ life history and ecology. Although the diversity of microbiota from humans, mice, birds, zebrafish, and invertebrates is widely investigated, this is one of only a few reports in the literature describing the cloacal microbiota of a wild vertebrate, and is perhaps the first report for wild reptiles that utilizes culture-independent techniques.     

The utilization of the calcareous deposits of the endolymphatic sacs of Bufo Bufo Bufo in the mineralization of the skeleton. Investigations by means of Ca45

Summary In Bufo bufo bufo larvae treated with Ca⁴⁵ prior to the onset of the mineralization of the skeletal pieces, fixed after 7 days treatment (early hind-limb bud stage), the greatest amount of Ca⁴⁵ is detectable in the lumens of the endolymphatic sacs. A small amount of Ca⁴⁵ is concentrated in the membranous labyrinth. By the end of metamorphosis the lumina of the endolymphatic sacs are only partially occupied by Ca⁴⁵CO₃ crystals. On the other hand Ca⁴⁵ localization is evidenced in the epithelium lining the sacs and in the developing bones. The present observations seem to afford a demonstration that the Ca salts of the endolymphatic sacs take part in the ossification process.The present investigations have been supported by grants of the Consiglio Nazionale delle Ricerche and the University of Torino to the Institute of Comparative Anatomy and Histology.     

Plasma homeostasis and cloacal urine composition inCrocodylus porosus caught along a salinity gradient

Summary Juveniles of the Estuarine or Saltwater Crocodile,Crocodylus porosus, maintain both osmotic pressure and plasma electrolyte homeostasis along a salinity gradient from fresh water to the sea. In fresh water (FW) the cloacal urine is a clear solution rich in ammonium and bicarbonate and containing small amounts of white precipitated solids with high concentrations of calcium and magnesium. In salt water (SW) the cloacal urine has a much higher proportion of solids, cream rather than white in colour, which are the major route for excretion of potassium in addition to calcium and magnesium. Neither liquid nor solid fractions of the cloacal urine represent a major route for excretion of sodium chloride. The solids are urates and uric acid, and their production probably constitutes an important strategy for water conservation byC. porosus in SW. These data, coupled with natural history observations and the recent identification of lingual salt glands, contribute to the conclusion thatC. porosus is able to live and breed in either fresh or salt water and may be as euryhaline as any reptile.