Anatomy of the hyoid apparatus in odontoceli (toothed whales): Specializations of their skeleton and musculature compared with those of terrestrial mammals

Background: The hyoid apparatus of odontocetes (toothed whales) serves as a major attachment point for many of the muscles and ligaments subserving breathing, swallowing, and sound production. Methods: This study examines the hyoid apparatus in 48 specimens of ten odontocete genera (Phocoena, Lagenorhynchus, Stenella, Delphinus, Tursiops, Grampus, Globicephala, Mesoplodon, Physeter, and Kogia) collected post mortem from beach strandings. Results: The odontocete hyoid apparatus, as that of their closest terrestrial relatives, the artiodactyls, is divisible into a basal portion (bashyal, paired thyrohyals) and a suspensory portion (paired ceratohyals, epihyals, stylohyals, and tympanohyals) connecting the basal portion to the skull base. Unlike other terrestrial mammals, the basal portion lies inferior to the laryngeal aditus, is flattened dorso-ventrally, and is relatively large, thus providing a broad surface area for muscle attachments. The suspensory elements are not as flattened and are joined by synovial joints (except for epihyal-stylohyal fusion). Muscular specializations include enlargement of those which retract the hyoid apparatus (e.g., sternohyoid) or control the tongue (e.g., styloglossus, hyoglossus). These muscles may be particularly important in a specialized prey capture behavior called suction feeding. In addition, the hyoid apparatus has a tilted placement, which allows asymmetrical enlargement of the piriform sinuses. Asymmetry is also seen in the muscular attachment between the larynx and the hyoid apparatus. The most pronounced differences from the basic pattern are observed in two families: Physeteridae and Ziphiidae. Conclusions: The derived position and shape of the odontocete hyoid apparatus may have evolved to subserve several specialized upper respiratory/digestive tract functions, such as simultaneous feeding (suction and swallowing) and sound production. © 1994 Wiley-Liss, Inc.     

Mitochondrial DNA polymorphisms in Italy II. Molecular analysis of new and rare morphs from Sardinia and Rome

A molecular analysis of morphs found in a previous survey of mtDNA restriction enzyme polymorphisms in Italy revealed that different site changes can give similar patterns and that the same mutation can yield variant morphs for apparently unrelated enzymes. 1. Alternative site variations were found to yield restriction fragment patterns resembling HpaI morph 4, HaeII morph 5 and AvaII morph 2. 2. A strong association was observed between the BamHI morph 3 (gain of site a) and the AvaII morph 9 and its derivatives (loss of site d). This association appears to result from an A to G transition at base pair (bp) 13368 which simultaneously creates a new BamHI site and abolishes an AvaII site. On the other hand, the loss of the AvaII site d, which in Italy was only found in the above-mentioned association, does not always produce a new BamHI site, as observed in other Caucasian groups. Similarly, the Bam HI morph 2 (gain of site b) was always found to be associated with AvaII morphs lacking site f. An A to G transition at bp 16391 was shown to account for both changes. As in the previous case, the converse is not true. Hence, these data show that AvaII sites d and f were lost in more than one way and one of these seems to be typical of Caucasians. 3. The variation producing BamHI-3/AvaII-9 and derivatives is preferentially associated with MspI morph 4 but this is not a product of a shared mutation. Hence, this association must be the result of the linkage disequilibrium due to the maternal inheritance of mtDNA and lack of recombination. 4. The high frequency of the combination BamHI-3/AvaII-9 and derivatives with MspI-4 found in Italy (29 subjects out of 229 analysed) can best be explained by diffusion of the relevant haplotype rather than by repeated mutational events. 5. The phylogeny trees of all mtDNA morphs so far described and of mtDNA types in Caucasians have been revised taking into account both the inter- and the intra-morph heterogeneity detected by this analysis.     

Functional morphology of lingual protrusion in marine toads (Bufo marinus)

Bufo marinus catches its prey by stiffening the intrinsic muscles of the tongue, rapidly flipping the tongue out of the mouth. High-speed cinematography synchronized with computer-analyzed electromyograms (EMGs) shows that during the flip the tongue is supported by the M. genioglossus medialis and that this muscle stiffens into a rod when stimulated. Coincident stiffening of the transversely arranged M. genioglossus basalis provides a wedge under the anterior tip of this rod. Stiffening of the M. submentalis depresses the mandibular symphysis and brings the dentary tips together. The M. submentalis also acts on the wedge of the basalis to raise and rotate the rigid rod of the medialis over the symphysial attachment. The tip of this lingual rod carries along the pad and soft tissues of the tongue. The lingual pad, positioned in the posterodorsal portion of the resting tongue, rotates during eversion so that its dorsal surface impacts onto the prey object. Retraction starts by contraction of the elongate, parallel fibers of the M. hyoglossus; this retracts the medial sulcus of the pad and holds the prey by a suction cup-like effect. The extensibility of the buccal membranes allows the pad to be retracted first; it reaches the posterior portion of the buccal cavity before the still-rigid, backward rotating M. genioglossus has reached the level of the symphysis. Protraction of the hyoid facilitates the extension of the M. hyoglossus. The M. sternohyoideus only retracts the hyoid and stabilizes it when the tongue starts to pull posteriorly; it does not assist tongue protrusion. The Mm. petrohyoideus and omohyoideus show only incidental activity, and the M. depressor mandibulae participates in mouth opening but is not otherwise involved in the flip. Previous hypotheses of the flipping mechanism are reviewed and evaluated.     

Genetic mechanism and property of a whole-arm translocation (WAT) between chromosomes 8 and 9 of agile gibbons (Hylobates agilis)

C-banding analysis with 47 gibbons of the subgenus Hylobates (Hylobates) (44-chromosome gibbons) uncovered that the gibbons had a characteristic complicated C-banding pattern. The C-band pattern also revealed that a whole-arm translocation (WAT) between chromosomes 8 and 9 existed only in the species H. agilis (agile gibbon). Comprehensive consideration allows postulation that the translocation seemed to be restricted to two subspecies: H. agilis agilis (mountain agile gibbon) and H. agilis unko (lowland agile gibbon), found in Sumatra and part of the Malay Peninsula. Moreover, combined intensive analyses of C-banding and chromosome painting provided strong evidence for a plausible evolutionary pathway of chromosome differentiation of chromosomes 8 and 9. The C-banded morph 8M^t/c seemed to be the primary type of chromosome 8 in the subgenus and to have altered into the three morphs through three pericentric inversions. The newest morph (8A^M/ci) produced by the third inversion exchanged the long arm for chromosome 9, and subsequently constructed the WAT morphs of 8/9A^Mc/ct and 9/8M^i/ci.     

Movement of the hyoid in frogs during feeding

Feeding, breathing, and vocalization sequences of Bufo marinus were recorded by cineradiography. Results of film analysis indicate that the hyoid moves during all three behaviors. Movement of the hyoid is critical in tongue protrusion of frogs, and a biomechanical model of this action is presented. The hyoid appears to represent a compromise morphological system for three functions, rather than an optimal system for any one. This may explain, in part, the retention of a relatively inefficient breathing mechanism in frogs.     

Analysis of the dynamic relationships between the lingual artery and lingual markers in patients with obstructive sleep apnea

Purpose

To determine the relationships between the lingual artery and the lingual markers in tongue resting and extended positions in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) for the clinical application of functional tongue surgery.

Method

Computed tomography angiography (CTA) of the lingual artery was performed on 30 OSAHS patients using a 16-slice spiral CT scanner. The anatomical relationships between the lingual artery and the lingual markers were analyzed with the tongue in resting and extended positions using the CTA images.

Results

The course of the lingual artery resembled the configuration of the Big Dipper constellation when the tongue was in a resting position. When the tongue was in a full-extended position, the majority of the lingual artery moved forward and upward with the hyoid and formed a “√” fashion. The positions of the tip of the greater horn of the hyoid changed with the tongue positions. While the relationship between the main lingual artery and the tip of the greater horn of the hyoid, as well as the distances between bilateral lingual arteries, remained constant in both tongue positions.

Conclusions

In conditions of dynamic tongue movement, the tip of the great horn of the hyoid and the lingual midline are constant anatomical markers to indicate the course of the lingual artery.     

<Emphasis Type="Italic">Philophthalmus aweerensis</Emphasis> n. sp. (Trematoda: Philophthalmidae) found in a rhea (<Emphasis Type="Italic">Rhea americana</Emphasis>) in the United Arab Emirates

Philophthalmus aweerensis, a new eye fluke species, was discovered in the conjunctival cavities of a rhea in the UAE. This fluke was described and differentiated from other eye flukes that had been found in birds in the Middle East such as Philophthalmus palpebrarum, Philophthalmus nocturnus, Philophthalmus gralli, Philophthalmus lucipetus, Philophthalmus distomatosa, and Philophthalmus hegeneri. The new species lacks spination and is characterized by a long cirrus pouch extending behind the caudal margin of the acetabulum, long vitellaria of tubular type reaching the midbody, and a genital opening situated anteriorly to the bifurcation of the caeca.     

Body composition and the evolution of the Macropodidae (Potorous, Dendrolagus, and Macropus)

Summary The segmental distribution of body weight and the proportions of skin, muscle, and bone are compared for three genera of the Macropodidae (Potorous, Dendrolagus, and Macropus) and one genus of the Petauridae (Pseudocheirus). Potorous and Macropus possess high proportions of muscle mass to total body weight, high concentrations of musculature in the lumbar extensors, thigh, and tail, and disproportionate ratios of forelimb: hindlimb bone and forelimb: hindlimb muscle which correspond to disproportions of intermembral length. These species converge with high-speed terrestrial runners in some traits and remain distinctive in others. Macropus, larger, more muscular, and faster than Potorous, appears to store and return energy to the hopping cycle more efficiently. Dendrolagus has less than three-fourths the musculature of the other macropod genera, low proportions of the back extensor muscles compared to the other macropods, and relatively more equal ratios of forelimb: hindlimb bone and forelimb: hindlimb muscle. This species converges with slow-moving arboreal climbers such as Pseudocheirus. These data on body mass and tissue proportions translate directly into center of gravity, strength-to-weight ratio, and muscular (kinetic) chains, key elements of macropod evolution. The geometric similarity of muscle between smaller potoroids and larger macropodids, an assumption critical to allometric comparison, is not confirmed.     

Mitochondrial DNA polymorphism detected with the restriction enzymes BstNI and BclI in a French Canadian population

The enzymes Bst NI and Bell were used to detect various human mitochondrial DNA RFLPs in a sample of 104 unrelated French Canadians. These sequence variations were found in total white blood cell DNA probed with whole human mitochondrial DNA. With Bst NI, 6 mitochondrial DNA restriction patterns (morphs) were identified. Bst NI morphs 2–6 each differ from morph 1 by one single distinct restriction site gain or loss on the mitochondrial DNA molecule. Although Bst NI morph 1 was found in most of the subjects (80%), each other morph was observed at a frequency of at least 3%. With the enzyme BclI , 4 different morphs were detected. Morphs 2–4 also result from different single restriction site alteration as compared with Bcl I morph 1. The morph 1 was clearly the most frequent (95%) while morphs 3 and 4 were present in only 1% of the subjects. These data indicate that the enzyme Bst NI and, to a much lesser extent, the enzyme Bcl I detect mitochondrial Dn'A polymorphism in Caucasians. They are therefore of interest for population genetics studies.     

Innervation und Morphologie der Mm. levatores costarum

Zusammenfassung Präpariert wurden die Mm. levatores costarum bei Homo (3 adulte und 2 neugeborene Individuen) und adulten Vertretern von 12 weiteren Säugerarten. Bei allen untersuchten Individuen wurden die Mm. levatores costarum von einem Ast des R. dorsalis des jeweiligen Spinalnerves innerviert. Der Nervenast zu den Mm. levatores costarum longi, die nur bei Homo ausgebildet waren, stellt meist eine laterale Fortsetzung des R. levatorius zu dem entsprechenden cranialen kurzen Rippenheber dar, kann aber im caudalen Bereich auch aus dem caudal folgenden R. levatorius stammen oder bisegmentalen ursprung haben.Dieser Befund bestätigt die Angaben von Morrison und Fujita. Er erlaubt den Schluß, daß dieses Innervationsmuster für alle Säugetiere gilt. Entgegen der heutigen Lehrbuch-meinung, die im wesentlichen auf den Vorstellungen von Eisler beruht, müssen die Mm. levatores costarum dem lateralen Trakt der autochthonen Rückenmuskulatur zugerechnet werden.

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Innervation and Morphology of the Mm. levatores costarum

Summary Preparations from human Mm. levatores costarum breves (3 adults and 2 new-born) as well as those of 12 other mammals were investigated. In each case the muscles were innervated by the ramus dorsalis of the associated spinal nerve. The nerve branches to the Mm. levatores costarum longi, present only in man, in most instances were a lateral continuation of the ramus lateralis of the corresponding M. levator costae brevis. The nerve may, however, also arise either caudally from the caudal extensions of the ramus levatorius or bisegmentally. This finding affirms the reports of Morrison and Fujita and leads to the conclusion that such innervation is universal among mammals. Contrary to current textbook teaching and the representation chiefly attributed to Eisler, the Mm. levatores costarum must be considered to lie within the lateral tract of the autochthonic back musculature.

     

Mitochondrial DNA polymorphism in the Vietnamese population

The mitochondrial DNA variation was screened in a sample of 50 unrelated individuals of the Vietnamese population originating from Hanoi. A combination of long and standard PCR and restriction endonuclease digests with the enzymes HpaI, BamHI, HaeII, MspI, AvaII and HincII were used to reveal mtDNA variation. Twenty enzyme morphs were detected, three of which (HaeII-13^Viet, MspI-19^Viet and MspI-20^Viet) are new and are produced by a single mutational event in already known enzyme morphs. Ten already known and four new mitotypes [93^Viet (1-1-2-4-1), 94^Viet (2-1-13^Viet-1-1), 95^Viet (2-1-13^Viet-19^Viet-1) and 96^Viet (1-1-2–20^Viet-12)] were found in the Vietnamese population. The 9-bp deletion occurring in the COII/tRNA^Lys region of the mitochondrial genome was also analysed and 10 samples were found to have this deletion. The comparison of the Vietnamese with other East Asian populations showed a close genetic relationship of the population under investigation with other Orientals. However, the Vietnamese population can be differentiated by the significantly higher frequency of the enzyme morph HincII-5 and by seven new markers. These results strongly support the hypothesis of a dual ethnic origin of the Vietnamese population from the Chinese and Thai–Indonesian populations based on HLA markers and linguistic evidence.     

Disseminated Mycosis in Veiled Chameleons (Chamaeleo calyptratus) Caused by Chamaeleomyces granulomatis,a New Fungus Related to Paecilomyces viridis

An outbreak of disseminated granulomatous disease occurred in a group of veiled chameleons (Chamaeleo calyptratus) in a zoo collection. An adult female and six offspring developed large granulomas in multiple organs and were euthanized. At necropsy, roughly spherical yellow-to-white nodules 1 to 3 mm in diameter were grossly visible in the liver and other organs. Histopathology revealed fungal elements that were spherical to ovoid in shape, fragments of slender to irregularly swollen hyphae, and occasional conidia produced on phialides. Fungal isolates were initially suspected on the basis of morphology results to represent Paecilomyces viridis, a species known only from one outbreak of fatal mycosis in carpet chameleons (Furcifer lateralis). Data obtained from morphological studies and from phylogenetic analyses of nuclear ribosomal rRNA (rDNA) sequence data revealed the Danish chameleon isolates to be a related undescribed anamorphic species within the family Clavicipitaceae that includes many insect pathogens. Chamaeleomyces granulomatis gen. et sp. nov. is given as the name for the newly described fungus, and P. viridis is transferred to the new genus as Chamaeleomyces viridis comb. nov. Chamaeleomyces species are distinguished by having basally swollen phialides tapering to a narrow neck, conidia in fragile chains, and pale green to greenish-gray colonies. Both species are dimorphic, producing a transitory yeast stage characterized by ovoid-to-subglobose or subcylindrical yeast-like cells. Chamaeleomyces species appear to be rare but aggressive pathogens of chameleons.Disseminated, often fatal, mycoses caused by Paecilomyces species have previously been reported in many reptiles, including lizards and crocodiles; P. lilacinus and P. variotii are the main species involved (14). Paecilomyces viridis was first reported in 1964 as the cause of disseminated fungal infection in 4 of 50 carpet chameleons (Furcifer lateralis; formerly Chamaeleo lateralis) that were sent from Madagascar to Paris for experimental use (16, 17). The fungus was isolated from blood and multiple organs, including liver and spleen, and it produced yeast-like cells in vivo but not in vitro. There have been no subsequent reports of P. viridis causing mycosis in any reptile, and two reports of human infection have not been well substantiated and probably concerned infections by P. variotii (4). A recent outbreak of disseminated granulomatous disease in a group of veiled chameleons (Chamaeleo calyptratus) housed at the Copenhagen Zoo yielded fungal isolates with morphologies resembling those of P. viridis. However, a DNA sequence from the internal transcribed spacer (ITS) region of the nuclear ribosomal rRNA (rDNA) gene from one isolate showed only 94% similarity to that of a P. viridis sequence obtained from GenBank ({"type":"entrez-nucleotide","attrs":{"text":"AY624194","term_id":"55139830","term_text":"AY624194"}}AY624194, strain CBS 348.65, ex-type culture). This result prompted further investigation into the relationship between P. viridis and the new chameleon isolates and other Paecilomyces species.Recent taxonomic studies have shown the genus Paecilomyces to be polyphyletic. The type species, P. variotii, is placed within the ascomycete family Trichocomaceae (Eurotiales) (12). Many other Paecilomyces species, including the pathogenic species P. lilacinus and P. viridis, group within the family Clavicipitaceae sensu lato (Hypocreales), comprising many arthropod- and grass-associated fungi (7, 13, 14). Some of these Paecilomyces species have been reclassified in the genus Isaria, but P. lilacinus and P. viridis are unrelated to Isaria species and their relationships to other members of the family have not been resolved (7, 14). In a recent multigene phylogenetic study, clavicipitalean fungi were reclassified into three families, namely, Clavicipitaceae sensu stricto, Cordycipitaceae, and Ophiocordycipitaceae, but P. viridis was not examined in that study (20).Data obtained from morphological studies and phylogenetic analyses of rDNA sequences provide evidence that the Danish chameleon isolates represent a new species related to P. viridis. Both species are here described in the new genus Chamaeleomyces within the family Clavicipitaceae sensu stricto.     

Ultrastructural identification of Merkel cells around the mouth of the newborn marsupial

Summary The ultrastructure of the epidermal cells surrounding the mouth of three newborn marsupial species, the Northern native cat Dasyurus hallucatus, the brush tail possum Trichosurus vulpecula and the Northern brown bandicoot Isoodon macrourus were examined. The presence of Merkel cells, highly sensitive touch receptors, would suggest that the sense of touch aids the relatively underdeveloped newborn marsupial to move from the urinogenital sinus to the pouch and to locate the teat.     

Distribution of sand flies in El-Nekheil province,in Al-Madinah Al-Munawwarah region,western of Saudi Arabia

An entomological survey for sand flies was conducted at an area of cutaneous leishmaniasis—El-Nekheil in Northeast Al-Madinah Al-Munawwarah, Saudi Arabia. Standardized sampling with Centers for Disease Control (CDC) light traps and sticky traps was employed to determine monthly trends in species composition, density, sex ratio, and reproductive status and Leishmania infection rate of vector sand flies. A total of 621 sand flies were collected from March 2006 to November 2007. Six species representing two genera were identified, three Phlebotomus species: P. papatasi, P. sergenti, and P. bergeroti; and three Sergentomyia species: S. antennata, S. sergenti, and S. shewtzi. Phlebotomus papatasi was the predominant anthropophagic species found and comprised more than 70% of the sand fly population. A population peak (June) was observed for this species. The density of P. papatasi intra-domiciliary was higher than extra-domiciliary stations and inflated by a greater proportion of female flies. Of 189 dissected Phlebotomus females, 43% were blood-fed. No Leishmania parasites were found. The proportion of gravid P. papatasi increased progressively during the 5-month period from May to September and averaged 38%. Proportions of gravid flies may be a valid indicator of the physiological age and epidemiologic importance of the vector sand fly population at this focus.     

Vocal anatomy, tongue protrusion behaviour and the acoustics of rutting roars in free-ranging Iberian red deer stags (Cervus elaphus hispanicus)

Roaring in rutting Iberian red deer stags Cervus elaphus hispanicus is unusual compared to other subspecies of red deer, which radiated from the Iberian refugium after the last glacial maximum. In all red deer stags, the larynx occupies a permanent low mid‐neck resting position and is momentarily retracted almost down to the rostral end of the sternum during the production of rutting calls. Simultaneous with the retraction of the larynx, male Iberian red deer pronouncedly protrude the tongue during most of their rutting roars. This poses a mechanical challenge for the vocal tract (vt) and for the hyoid apparatus, as tongue and larynx are strongly pulled in opposite directions. This study (i) examines the vocal anatomy and the acoustics of the rutting roars in free‐ranging male C. e. hispanicus; (ii) establishes a potential mechanism of simultaneous tongue protrusion and larynx retraction by applying a two‐dimensional model based on graphic reconstructions in single video frames of unrestrained animals; and (iii) advances a hypothesis of evaporative cooling by tongue protrusion in the males of a subspecies of red deer constrained to perform all of the exhausting rutting activities, including acoustic display, in a hot and arid season.