bluuebunny/crossref_metadata_2025 huggingface dataset:
Histochemical study of jaw muscle fibers in the American alligator (Alligator mississippiensis)
Authors: Sato I. , Shimada K. , Sato T. , Kitagawa T.
Published: February 2005

Seven jaw muscles of the American alligator have been analyzed for histochemical characteristics of their fiber types: Musculus depressor mandibulae (MDM), M. pseudotemporalis (MP), M. adductor mandibulae posterior (MAMP), M. adductor mandibulae externus (MAME, profound and superficial portions), M. intramandibularis (MI), M. pterygoideus anterior (MPta), and M. pterygoideus posterior (MPtp). Classification of muscle fibers in previous studies has been based on (1) the staining properties of myosin ATPase after alkaline and acid preincubations and (2) the staining reactions for SDH, α‐GPDH, PAS, and myosin ATPase after alkaline preincubations. In this study fiber types in one group of muscles (MP, MAMP, profound portion of MAME and MI) are classified (1) as type I, IIa, or IIb fibers, according to the system of Brooke and Kaiser (Arch. Neurol. 23:369–379, '70) or (2) as fast twitch glycolytic (FG), fast oxidative glycolytic (FOG), slow oxidative (SO), and tonic (few in number) fibers, according to the system of Putnam et al. (J. Exp. Zool. 214:303–309, '80). A second group of muscles (MDM, MAME superficial portion, MPta, and MPtp) reacted differently in similar histochemical tests and are classified, respectively, as (1) types 1, 2, 3 or (2) types A, B, C. We have distinguished the fiber types as red, intermediate, white, and tonic in analyses on muscle sections. The highest percentage of red and intermediate fibers is found in the MI. All three fiber types are approximately equal in superficial and medial portions of the MDM and the MPtp. Three muscles (MP, MAMP, and MAME) have the highest white fiber composition. These results indicate a correlation between the histochemical profiles of individual muscles and their functions during masticatory movements.
An ultrastructural study on the origin of glomerulocytes, a type of blood cell in a styelid ascidian, Polyandrocarpa misakiensis
Authors: Hirose Euichi , Mukai Hideo
Published: February 2005

The glomerulocyte is a type of blood cell in the compound ascidian, Polyandrocarpa misakiensis. It is a discoidal cell, measuring 12–13 μm in diameter and about 3 μm in thickness. The outer half of the cell is occupied by concentrically‐arranged fibers, usually 0.2–0.3 μm thick; the nucleus and organelles are confined to the central cytoplasm. The ordinary epidermal cells are columnar and are characterized by an apical homogeneous cytoplasmic bulge, vesicular bodies in the cytoplasm, and juctions between them. Growing or immature glomerulocytes are found only in the epidermis. They have intracellular fibers and vesicular bodies, and there are juctions between them and epidermal cells. These facts strongly suggest the origin of the glomerulocyte from an epidermal cell. However, no definite statement can be made as yet because earliest stages of differentiation have not been observed. The glomerulocyte fully differentiated in the epidermis is apparently released into the hemocoel.
The effects of silicate depletion and subsequent replenishment on the cytoplasmic fine structure of the silica‐secreting testate amoeba Netzelia tuberculata in laboratory culture
Authors: Anderson O. Roger
Published: February 2005

In the absence of silicate in the growth medium, Netzelia tuberculata cells withdraw their feeding lobopodia, become quiescent, and cease to divide. Upon replenishment of silicate, growth resumes within 18–24 hours. Cytoplasmic changes produced by a low silicate medium result in a zonal arrangement, with siliceous particles at the outer periphery of the cytoplasm in a region rich in Golgi bodies (Region A), a more centrally located layer containing endoplasmic reticulum, lipid reserves, and finely granular cytoplasm (Region B), and a region of partially digested food and waste material fringed by fine rhizopodia extending into the central space of the test (Region C). The reserve siliceous particles in the outer peripheral cytoplasm are foreign particles that contain a fragile deposit of silica and appear to be incomplet. This may be a mechanism for conserving silica in the low‐silicate medium by coating particles instead of making particles of solid silica de novo. Upon addition of silicate to the growth medium, new siliceous particles are synthesized within vacuoles in the region of the Golgi apparatus within 2–18 hours. Vacuoles containing fine silica deposits, characteristic of new particle production, are surrounded by Golgi‐derived vesicles previously shown to be a source of membrane for the silica‐secreting vacuoles. The newly synthesized particles are solid silica as is characteristic of de novo secreted test particles, in contrast to the numerous silica‐coated foreign bodies found in quiescent cells produced in low‐silicate medium.
Histological, histochemical, and biochemical changes in the annual oviduct cycle of the agamid, Calotes versicolor
Authors: Shanthakumari T. Ruth , Sarkar H. B. D. , Shivanandappa T.
Published: February 2005

Histology, histochemistry, and biochemistry of the oviduct change seasonally in relationship to the annual ovarian cycle of Calotes versicolor. Histological changes show distinct changes in various components of the infundibulum, uterus and vagina of the oviduct. The active phase in the oviduct cycle of C. versicolor is relatively long, extending from April to October. Histochemical results of the oviduct during the breeding season show PAS‐positive glycosaminoglycans in the mucosal epithelium as well as the presence of hydroxysteroid dehydrogenases, esterase, and intense acid phosphatase activity in the uterine glands. Biochemically alkaline and acid phosphatase show marked cyclic changes in the infundibulum and uterus respectively during the oviduct cycle. Greater activity was observed during the breeding season. β‐Glucuronidase, on the other hand, shows an inverse relationship with the oviduct cycle being most active during the regressive phase and least at the time of reproductive phase.
An ultrastructural study of differentiatation of pyriform cells and their contribution to oocyte growth in representative squamata
Authors: Andreuccetti Piero
Published: February 2005

An electron microscopic study of the differentiation of pyriform cells and their contribution to oocyte growth in three lizards (Tarentola mauritanica, Cordylus wittifer, Platysaurus intermedius) and one colubrid snake (Coluber viridiflavus) revealed that pyriform cells differentiate from small follicle cells via intermediate cells after establishing an intercellular bridge with the oocyte (see also Hubert: Bull Soc Zool Fr 102:151–158, 1977; Filosa et al: J Embryol Exp Morphol 54:5–15 1979; Klosterman: J Morphol 192:125–144, 1987). Once differentiated, pyriform cells display ultrastructural features indicative of synthetic activity, including abundant ribosomes, Golgi membranes, vacuoles, mitochondria, and lipid droplets. These cellular components extend to the apex of the cell at the level of the intercellular bridge, suggesting that constituents of pyriform cells may be transferred to the oocyte. Furthermore, we demonstrate for the first time that pyriform cells incorporate exogenous yolk. The yolk is segregated inside maturing yolk granules that form in the pyriform cell in the same manner as described for vitellogenic oocytes in non‐mammalian vertebrates (see Wallace: Developmental Biology, A Comprehensive Synthesis 127–177, 1985). It is the first clear evidence that pyriform cells and the oocyte may fulfill similar vitellogenic functions. The establishment of an intercellular bridge may represent a crucial event in the development of an integrated system in which pyriform cells and oocyte cooperate.
Patterns of peripheral innervation of the tongue and hyobranchial apparatus in caecilians (Amphibia: Gymnophiona)
Authors: Wake Marvalee H.
Published: February 2005

The innervation of the musculature of the tongue and the hyobranchial apparatus of caecilians has long been assumed to be simple and to exhibit little interspecific variation. A study of 14 genera representing all six families of caecilians demonstrates that general patterns of innervations by the trigeminal, facial, glossopharyngeal, and vagus nerves are similar across taxa but that the composition of the “hypoglossal” nerve is highly variable. Probably in all caecilians, spinal nerves 1 and 2 contribute to the hypoglossal. In addition, in certain taxa, an “occipital,” the vagus, and/or spinal 3 appear to contribute fibers to the composition of the hypoglossal nerve. These patterns, the lengths of fusion of the contributing elements, and the branching patterns of the hypoglossal are assessed according to the currently accepted hypothesis of phylogenetic relationships of caecilians, and of amphibians. An hypothesis is proposed that limblessness and a simple tongue, with concomitant reduced complexity of innervation of muscles associated with limbs and the tongue, has released a constraint on pattern of innervation. As a consequence, a greater diversity and, in several taxa, greater complexity of neuroanatomical associations of nerve roots to form the hypoglossal are expressed.
Histology of the reproductive tract of hybrids between gonochoristic males and parthenogenetic females of Lepidodactylus lugubris in French Polynesia (Reptilia, Gekkonidae)
Authors: Girons Hubert Saint , Ineich Ivan
Published: February 2005

Parthenogenetic populations of the gecko Lepidodactylus lugubris are widespread throughout Polynesia. They often occur parapatrically, and occasionally syntopically, with the increasingly rare bisexual populations. In these instances, a small number of hybrid individuals occur and include both “female” and “male” external phenotypes, both with greatly reduced gonads.

Histological examination demonstrates that these hybrids possess small ovotestes. The differentiation of the cortical tissue is identical in both “male” and “female” hybrids, but the medullary tissue is more developed in “males.” The remainder of the genital tract in “females” resembles that of fertile females in the parthenogenetic and bisexual populations. By contrast, the “male” hybrids are markedly intersexual. In one of the two specimens autopsied, the hemipenes are more or less the same size as those of bisexual males, and the sexual segment of the kidney is hypertrophied and serous. In the other hybrid “male,” the hemipenes have a structure similar to that seen in females, and the sexual segment of the kidney is poorly differentiated. In both hybrid “males,” the ductus deferens is extremely narrow and further reduced in its middle portion; oviducts are present and resemble those of normal or hybrid females.

Thus, embryonic‐like gonads are associated with complete and normal female reproductive ducts in hybrid “females.” Hybrid “males” also have embryonic‐like gonads and feminized genital ducts but associated with secondary sexual characters that match those of sexually active or quiescent normal males.
Development and differentiation of the eye in Platynereis dumerilii (Annelida, Polychaeta)
Authors: Rhode Birgit
Published: February 2005

The nereid polychaete, Platynereis dumerilii, possess two pairs of post‐trochophoral eyes with one vitreous body each. The development of these eyes has first been observed in 2‐day‐old larvae. Whether the eye anlagen arise from stem cells or from undifferentiated ectodermal tissue was not determined. At first, the anlagen of the anterior and the posterior eyes adjoin each other. They separate in late 3‐day‐old larvae. The first separated eye complexes consist each of two supporting and two sensory cells. The supporting cells synthesize two different kinds of granules, the pigment granules of the pigment cup and the prospective tubules of the vitreous body. These tubules accumulate in the distal process of the supporting cell. The vitreous body is formed by compartments of the supporting cells filled with the osmiophilic vitreous body tubules. The short, bulbar photosensory processes bear microvilli that emerge into the ocular cavity. At the apex of each sensory cell process, a single cilium (or occasionally two) arises. The sensory cells contain a different kind of pigment granule within their necks at the level of the pigment cup. The rate of eye development and differentiation varies. New supporting cells are added to the rim of the eye cup. They contribute to the periphery of the vitreous body like onion skins, and sensory cells move between supporting cells. The older the individual compartments of the vitreous body are, the more densely packed is their content of vitreous body tubules. Elongation of the sensory and supporting cell processes of the older cells increases the volume of the eye. The eyespots of the trochophore are briefly described as of the two‐celled rhabdomeric type with a single basal body with ciliary rootlet.
Comments on the morphology of the pre‐oral spine in Argulus (Crustacea: Branchiura)
Authors: Swanepoel J. H. , Avenant‐Oldewage Annemarie
Published: February 2005

A histological study of the pre‐oral spine and associated structures in Argulus japonicus reveals that two exceptionally long and slender muscles casuse retraction of the spine into the spinal sheath. Originating from the body wall mid‐dorsally the two muscles proceed through the nerve ring and the blood‐filled lumen of the spinal sheath before being inserted on a bolster of tissue constituting the base of the spine. Movement of the spinal sheath is affected by two muscles originating from a common apodeme in the dorsal body wall, just posterior to the nauplius eye, and inserted on the lateral walls of the base of the spinal sheath.

Two ducts, each leading from a glandular complex in the lateral parts of the carapace, proceed rostrally through the haemocoelic spaces. After passing the tritocerebrum laterally they accompany the retractor muscles of the spine on their course to the base of the spine. Passing through the bolster of tissue at the base of the spine the two ducts run all the way up to the tip of the spine where they open separately.

The glandula praeboscoidalis is not associated with the pre‐oral spine since its duct runs posteriorly in the wall of the proboscis. The labial spines are associated with giant glandular cells located beneath the optic tracts. © 1992 Wiley‐Liss, Inc.
Morphology of the antennae of two species of biting midge: Culicoides impunctatus (goetghebuer) and Culicoides nubeculosus (Meigen) (Diptera, Ceratopogonidae)
Authors: Blackwell Alison , Mordue (Luntz) A. Jennifer , Mordue William
Published: February 2005

Scanning and transmission electron microscopy of the antennae of Culicoides impunctatus and Culicoides nubeculosus show that males and females share five sensillum types. Sensilla chaetica resemble mechanoreceptors, each innervated by a single neurone whose dendrite terminates distally in a tubular body: the arrangement of sensilla on male antennae suggests that females are located by sound. The antennae have both sharp‐ and blunt‐tipped sensilla trichodea, sharp‐tipped sensilla on only the distal third and blunttipped sensilla on all subsegments. These sensilla are typical of olfactory receptors, having multiporous walls and being innervated by a number of neurones with bifurcating dendrites ascending the hair shafts. Sensilla basiconica occur on the distal five subsegments of the female antenna and the distal three subsegments of the male antenna. Sensilla coeloconica always occur on subsegment one and sometimes on a number of other subsegments, depending on sex and species. Both basiconic and coeloconic sensilla have double walls and unbranched dendrites and may be either olfactory or thermo‐ and/or hygroreceptors. All antennae except those of male C. impunctatus antennae have sensilla ampullacea, apparently deep‐seated olfactory or thermoreceptors. Small peg sensilla fitting the description of contact chemoreceptors occur only at the tip of the male antenna. © 1992 Wiley‐Liss, Inc.
Morphological corollaries and ecological implications of flightlessness in the kakapo (Psittaciformes: Strigops habroptilus)
Authors: Livezey Bradley C.
Published: February 2005

The morphological corollaries of flightlessness of the kakapo (Strigops habroptilus) have been studied using skin specimens, skeletons, and pectoral dissection of an anatomical specimen. These have been compared with the closely related, flighted kea (Nestor notabilis), and secondarily with other Psittaciformes and the convergent hoatzin (Cuculiformes: Opisthocomus hoazin). S. habroptilus is the most massive and sexually dimorphic psittaciform in the world, and has the smallest relative wing size of any parrot. Alar pterylography of S. habroptilus is similar to that of other parrots, but remiges of the species are shorter, comparatively rounded, show less asymmetry of vanes, and have fewer interlocking barbules distally. S. habroptilus shows peculiarities of the sternum (vestigial carina, shortened spina externa), coracoid (elongate processus lateralis, enlarged angle with scapula), and humerus (prominent tuberculum ventrale, undercut crista bicipitalis). Pectoral skeletal dimensions of S. habroptilus are smaller than those of N. notabilis, whereas the reverse is true for pelvic dimensions. Most skeletal dimensions of S. habroptilus are more variable (within sexes) than those of N. notabilis. Proximal wing elements are disproportionately long and distal elements disproportionately short in S. habroptilus. The legs of S. habroptilus are characterized by disproportionately long femora and disproportionately short tarsometatarsi. Distinctive features of the pectoral musculature of S. habroptilus include a greatly reduced Mm. pectoralis thoracica and supracoracoideus, the absence of a distinct proximal muscle belly of M. propatagialis tendo longus, an extensive M. cucullaris capitis clavicularis associated with a voluminous crop, and an essentially tendinous M. sternocoracoideus. Relative to mean body mass, all dimensions of the antebrachial, carpometacarpal, digital, and patagial muscles are smaller in S. habroptilus than in N. notabilis. These aspects are compared to those of other flightless birds. Discussed are implications of flightlessness and associated large body size of S. habroptilus for issues of thermodynamics, metabolism, activity patterns, digestive anatomy, diet, reproduction, and insularit. © 1992 Wiley‐Liss, Inc.
Programmed cell death and heterolysis of larval epithelial cells by macrophage‐like cells in the anuran small intestine in vivo and in vitro
Authors: Ishizuya‐Oka Atsuko , Shimozawa Atsumi
Published: February 2005

The degenerative processes in the larval small intestine of Xenopus laevis tadpoles during spontaneous metamorphosis and during thyroid hormone‐induced metamorphosis in vitro were examined by electron microscopy. Around the beginning of spontaneous metamorphic climax (stages 59–61), both apoptotic bodies derived from larval epithelial cells and intraepithelial macrophage‐like cells suddenly increase in number. The macrophage‐like cells become rounded and enlarged because of numerous vacuoles containing the apoptotic bodies. Mitotic profiles of the macrophage‐like cells, however, are localized in the connective tissue where different developmental stages of macrophage‐like cells are present. After stage 62, the intraepithelial macrophage‐like cells decrease in number, while large macrophage‐like cells which include the apoptotic bodies and retain intact cell membranes and nuclei appear in the lumen. Degenerative changes similar to those during spontaneous metamorphosis described above could be reproduced in vitro. In tissue fragments isolated from the small intestine of stage 57 tadpoles and cultured in the presence of thyroid hormone, the number of intraepithelial macrophage‐like cells reaches its maximum around the 3rd day of cultivation when the larval epithelial cells most rapidly decrease in number. These results suggest that the rapid degeneration of larval epithelial cells occurs not only because of apoptosis of the epithelial cells themselves but also from heterolysis by macrophages. The macrophages probably originate in the connective tissue, actively proliferate, migrate into the larval epithelium around the beginning of metamorphic climax, and are finally extruded into the lumen. © 1992 Wiley‐Liss, Inc.
The development of Caretta caretta, at 25–34°C, in artificial nests
Authors: Billett F. S. , Collins P. , Goulding D. A. , Sutherland J.
Published: February 2005

Scanning electron microscopy has been used to enhance the description of a single species, Caretta caretta (the loggerhead turtle), staged according to Miller's system for the development of marine turtles. Incubation over a temperature range of 25°–34°C confirms previous observations that, under artificial conditions and at a constant incubation temperature, normal development is confined to a limited temperature range. Premature pipping is a feature of incubation at the lower end of this range; abnormal development, generated during the first third of the incubation period, occurs just above the normal range. Details of the external morphology of embryos from Miller stage 14 through to 25 are given together with an account of the developmental abnormalities produced at a high temperature of incubation. The data obtained confirm that Miller's scheme is generally applicable to C. caretta, provided that due regard is paid to the incubation temperature. © 1992 Wiley‐Liss, Inc.
Influence of web‐monitoring tactics on the density of mitochondria in leg muscles of the spider family uloboridae
Authors: Opell Brent D. , Konur David C.
Published: February 2005

From electron micrographs we determined the ratio of mitochondrial to myofibril cross sectional area in cells of the first leg anterior depressor muscles of adult females of four spider species, each from a different genus. Species with more active web‐monitoring tactics and greater tracheal supplies to their first legs have muscle cells that are better supplied with mitochondria than those with less active tactics and less well‐developed tracheal systems. These results demonstrate that, even in homologous tissues of closely related species, mitochondrial supply can change to accommodate changes in metabolic activity. © 1992 Wiley‐Liss, Inc.
Anatomy of synganglia, including their neurosecretory regions, in unfed, virgin female Ixodes scapularis say (Acari: Ixodidae)
Authors: Szlendak Ewa , Oliver James H.
Published: February 2005

The central nervous system of Ixodes scapularis is fused into a single compact synganglion. The esophagus runs through the synganglion and divides it into supraesophageal and subesophageal parts. The supraesophageal portion contains a single protocerebrum with four pairs of glomeruli, paired optic lobes and cheliceral ganglia, and a single stomodeal bridge. The subesophageal portion contains a centrally located network of commissures and connectives, a pair of palpal ganglia, paired olfactory lobes of the first pedal ganglia, four pairs of pedal ganglia, and a single opisthosomal ganglion. A retrocerebral organ complex (ROC) in close vicinity of the digestive tract, as described in some other tick species, apparently is lacking. Perhaps the function of the ROC is performed by the paired, large, ganglion‐like bodies that lie anterolaterad to the cheliceral ganglia.

The rind, which is formed from the neuronal somata and glial cells, surrounds the central fibrous core or neuropile. Neurosecretory cells (NSC) are distinct among rind cells due to their large size and concentration of cytoplasmic neurosecretions. NSC are present throughout the synganglion, although the subesophageal portion contains larger groups of these cells. Histological serial sections, stained with Meola's (Trans Am Microsc Soc 89:66–71, '70) paraldehyde fuchsin (PAF) procedure revealed 24 PAF‐stained, putative neurosecretory regions in the synganglion of virgin, unfed females. All of these regions appear to be connected and associated with the nearest ganglion and are correspondingly named. Eighteen PAF‐positive regions occur in the synganglion. In addition, PAF‐negative (green‐stained) cells occupy 6 distinct regions in the synganglion of unfed, unmated females. © 1992 Wiley‐Liss, Inc.
Three nephromixial patterns in polychaete species currently assigned to the genusPista(Annelida, Terebellidae)
Authors: Smith Ralph I.
Published: February 2005

A comparative morphological study of nephromixial systems in three Californian terebellid polchaetes currently assigned to the genusPistashows thatP. fimbriatahas all attributes of the generic type, but thatP. pacificaandP. elongatadiffer markedly. The features of typicalPistainclude (among others): two pairs of usually unequal branchiae, long‐handled anterior uncini (hooks) of crested avicular (bird‐head‐like) from, muddy, unornamented tubes, one pair of anterior excretory nephromixia (ENMX), and two pairs of separate thoracic reproductive nephromixia (RNMX) with genital papillae on segments VI and VII. A review indicates thatP. fimbriatashares these typical features with practically all adequately describedPistaspecies. However,P. pacificaandP. elongatapossess three pairs of branchiae, long‐handled uncini of distinctive crochet‐like form, and membranous tubes with apertural hoods. Both have two pairs of ENMX, the first supplied by one pair of ciliated renal funnels, the second by two pairs of such funnels. But they differ in their RNMX:P. pacificahas three pairs of complex RNMX, those on each side united by a common duct.P. elongatahas 11–13 pairs of simple RNMX united by common ducts. Although these species do not fit intoPista, no genus has been found to accommodate them. Generic placement is complicated by the fact that no instances of intra‐generic nephromixial variation have been reported in the Terebellidae, although inter‐generic variation is well known. If they are congeneric, this would be the first example of intrageneric RNMX variation in Terebellidae. But if assigned to separate genera or subgenera on the basis of their RNMX, their similarity of anterior uncini might be attributable to parallel or convergent adaptation to life in comparable tubes. More evidence, including molecular analysis, is needed for phylogenetic studies of Terebellidae. © 1992 Wiley‐Liss, Inc.
Skeletal development in Xenopus laevis (Anura: Pipidae)
Authors: Trueb Linda , Hanken James
Published: February 2005

Postembryonic skeletal development of the pipid frog Xenopus laevis is described from cleared‐and‐stained whole‐mount specimens and sectioned material representing Nieuwkoop and Faber developmental Stages 46–65, plus postmetamorphic individuals up to 6 months old. An assessment of variation of skeletogenesis within a single population of larvae and comparison with earlier studies revealed that the timing, but not the sequence, of skeletal development in X. laevis is more variable than previously reported and poorly correlated with the development of external morphology. Examination of chondrocranial development indicates that the rostral cartilages of X. laevis are homologous with the suprarostral cartilages of non‐pipoid anurans, and suggests that the peculiar chondrocranium of this taxon is derived from a more generalized pattern typical of non‐pipoid frogs. Derived features of skeletal development not previously reported for X. laevis include (1) bipartite formation of the palatoquadrate; (2) precocious formation of the adult mandible; (3) origin of the angulosplenial from two centers of ossification; (4) complete erosion of the orbital cartilage during the later stages of metamorphosis; (5) development of the sphenethmoid as a membrane, rather than an endochondral bone; and (6) a pattern of timing of ossification that more closely coincides with that of the pelobatid frog Spea than that recorded for neobatrachian species. © 1992 Wiley‐Liss, Inc.
Differences in morphological features of the sacculus of the inner ear of two hakes (Merluccius capensis and M. paradoxus, gadiformes) inhabits from different depth of sea
Authors: Lombarte Antoni , Fortuño José M.
Published: February 2005

The morphology of the sensory epithelia of the sacculus in two species of hake, Merluccius capensis and M. paradoxus, was analyzed by scanning electron microscopy (SEM). The sensory epithelia have two morphological features that are very different from other gadiform species. These include the presence of two large areas which are only linked by a narrow neck, and the larger proportion of hair cells oriented in the rostrocaudal axis than in other species. The deeper‐dwelling species, M. paradoxus, has a larger proportion of hair cell with short ciliary bundles than does the shallower‐dwelling species, M. capensis. These morphological specializations could improve the acoustic diserimination and localization capabilities of these species, possibly related to an increase in sensitivity to higher frequency sounds in the deeper‐dwelling species. © 1992 Wiley‐Liss, Inc.
Muscles of the pelvic outlet in the fowl (Gallus gallus domesticus) with special reference to their nerve supply
Authors: Akita Keiichi , Sakamoto Hirokazu , Sato Tatsuo
Published: February 2005

The manner of innervation of the pelvic outlet muscles in fowl (Gallus gallus domesticus) was examined in detail in four male pelvic halves. The segmental arrangement of the nerve supply in the sacral and pudendal plexuses was compared to that of Lacertilia and Urodela as a basis for a morphologiccal analysis of the pelvic outlet muscles. From the viewpoint of innervation, the pelvic outlet muscles of fowl are classified into two groups: a sphincter muscle group and a levator muscle group. These two groups are closely related to the ventral muscles of the pelvic limb. In contrast to the morphology of pelvic outlet muscles in lacertilians, in fowl the caudal muscle element does not contribute to the formation of these muscles. © 1992 Wiley‐Liss, Inc.
Natural and experimental reduction of the avian fibula: Developmental thresholds and evolutionary constraint
Authors: Streicher Johannes , Müller Gerd B.
Published: February 2005

Fibula reduction is a key feature of avian limb evolution. In a combined comparative and experimental approach the present study analyses the trends of fibula reduction in extant birds and their developmental basis. The study of 55 species of birds reveals four different types of tibiotarsus‐to‐fibula relationships. Extremely small fibulae are associated with two types of limb modification: (1) elongations of the limb primarily affect the tibiotarsus, increasing its length more than that of the fibula; (2) miniaturizations of the limb reduce both tibiotarsus and fibula length, but are reglarly associated with structural reductions of the distal parts of the fibula. True structrual reductions are distinguished from relative size reductions. The specific features of fibula reduction are analyzed through experimental mesenchyme excisions in chick limb buds. The methodical variation of experimental parameters resolves a long‐standing controversy about the effects of mesenchyme reductions on the patterns of skeletal formation. Mesenchyme excisions are shown to have unequal effects on the two zeugopod bones, affecting the fibula to a greater degree than the tibiotarsus. Several of the features seen in birds with advanced fibula reductions are paralleled by the effects of mesenchyme reductions. The consequences of this differential susceptibility of the skeletal blastemata are discussed both in terms of pattern formation in limb development and in terms of its bearing on the patterns of evolutionary limb reduction. It is concluded that thresholds of cell number and blastema size in development constrain the patterns of phenotypic variation in avian limbs. © 1992 Wiley‐Liss, Inc.
Fine structure of the skin of the amphibious fishes, Boleophthalmus pectinirostris and Periophthalmus cantonensis, with special reference to the location of blood vessels
Authors: Yokoya Sachihiko , Tamura Osamu S.
Published: February 2005

The skin of the amphibious fishes, Periophthalmus cantonensis and Boleophthalmus pectinirostris, was investigated by transmission electron microscopy (TEM). In both species the epidermis consists of superficial nonvacuolated epithelial cells, swollen epithelial cells with membrane limited cytoplasmic vacuoles, and basal epithelial cells in a single layer. Unicellular mucous glands, but no chloride cells are found in the epidermis of B. pectinirostris; in contrast there are chloride cells and no unicellular mucous cells in P. cantonensis. Intraepidermal blood vessels are a notable feature in the epidermis of P. cantonensis. Capillaries are distributed near the epidermal surface, offering an air‐blood barrier of sufficient thinness (2–4 μm) for cutaneous respiration. The large blood vessels (arterioles and venules) are seen in the middle stratum of the epidermis and seem to be able to regulate blood flow in the skin. In B. pectinirostris, the dermal capillaries lie immediately below the superficial epithelial cells at the apex of a dermal bulge where the air‐blood barrier is almost as thin as that of P. cantonensis despite locally different histology. In the spacious dermal bulges, the dermal tissue such as blood vessels, pigment cells, fibroblasts, and collagen fibers are scattered. Melanophores and two other types of chromatophores occur in the part adjacent to the blood vessel wall. The organization of the epidermis and blood vessels of the skin is discussed with regard to terrestrial life in these amphibious fishes. © 1992 Wiley‐Liss, Inc.
Sensilla on the mouthparts and antennae of the elephant louse, Haematomyzus elephantis piaget (Phthiraptera: Haematomyzidae)
Authors: Baker Gerald T. , Chandrapatya Angsumarn
Published: February 2005

The labial palpus of the elephant louse Haematomyzus elephantis has six sensilla that represent three different types: trichoid, basiconic, and styloconic. Two rows of basiconic sensilla are situated on the dorsal and ventral surfaces of the rostrum, and each row consists of three sensilla. Male and female antennae have 15–17 trichoid sensilla situated on the scape, pedicel, and three antennal annuli. Both sexes have two sensilla basiconica on the dorsal surface of the pedicel near the junction of the scape and pedicel. Two coeloconic (tuft) sensilla are situated on the antennae of both sexes, one sensillum on each of the last two annuli. There are three plate organs, two on the last annulus and one on the penultimate annulus of the male and female antennae. Sexual dimorphism is exhibited in the male and female antennae, in that the male has about twice as many sensilla basiconica on the apex of the last annulus as does the female. The total number of sensilla basiconica on the apex of the male antennae is at least two times the number that is known to be present in any other species of lice. © 1992 Wiley‐Liss, Inc.
Anatomy of the larva of Amathia vidovici (Bryozoa: Ctenostomata) and phylogenetic significance of the vesiculariform larva
Authors: Zimmer Russel L. , Woollacott Robert M.
Published: February 2005

Amathia vidovici (Vesiculariidae) has a lecithotrophic coronate larva. The apical disc of A. vidovici larvae is more complex than that of other vesiculariids and includes a new cell type, which may be glial‐like in function. A massive nerve nodule consists only of neural processes; as no ganglia or other evidence of interneurons were found, sensory cells apparently innervate their effectors directly. Putative synaptic junctions within the nerve nodule indicate that both receptor and effector cells send processes to this neuropile. Some 44 intercoronal cells of three types, two of which are new, are interspersed among the approximately 40 coronal cells. Juxtapapillary bodies, a unique sensory complex previously known only from Bowerbankia gracilis larvae, also occur in A. vidovici. A large refractile body, which is of uncertain function and is positioned near the center of the larva, is described for the first time.

A comparison of vesiculariid larvae that have been studied at the ultrastructural level reveals that larvae of Amathia vidovici and Bowerbankia gracilis are more similar to each other than either is to B. imbricata. Differences between the two Bowerbankia species, however, may reflect relative detail of their study and differences in interpretation rather than intergenic plasticity. Nevertheless. a distinctive suite of larval characteristics are shared by other members of the family Vesiculariidae, justifying a specific name—vesiculariform—for their larvae. A number of the defining characteristics of vesiculariform larvae also appear in the carnosan superfamily Victorelloidae. This finding is consistent with arguments based on adult characteristics that the Victorelloidea are ancestral to the Vesicularioidea. If this geneology is correct, one can predict that those vesiculariform traits which originated in the victorellids are plesiomorphic not only to the Family Vesiculariidae but to all sister taxa placed in the Vesicularioidea. © 1993 Wiley‐Liss, Inc.
Morphological and functional bases of durophagy in the queen triggerfish, Balistes vetula (Pisces, tetraodontiformes)
Authors: Turingan Ralph G. , Wainwright Peter C.
Published: February 2005

Tetraodontiform fishes are characterized by jaws specialized for powerful biting and a diet dominated by hard‐shelled prey. Strong biting by the oral jaws is an unusual feature among teleosts. We present a functional morphological analysis of the feeding mechanism of a representative tetraodontiform, Balistes vetula. As is typical for the order, long, sharp, strong teeth are mounted on the short, robust jaw bones of B. vetula. The neurocranium and suspensorium are enlarged and strengthened to serve as sites of attachment for the greatly hypertrophied adductor mandibulae muscles. Electromyographic recordings made from 11 cranial muscles during feeding revealed four distinct behaviors in the feeding repertoire of B. vetula. Suction is used effectively to capture soft prey and is associated with a motor pattern similar to that reported for many other teleosts. However, when feeding on hard prey, B. vetula directly bit the prey, exhibiting a motor pattern very different from that of suction feeding. During buccal manipulation, repeated cycles of jaw opening and closing (biting) were coupled with rapid movement of the prey in and out of the mouth. Muscle activity during buccal manipulation was similar to that seen during bite‐captures. A blowing behavior was periodically employed during prey handling, as prey were forcefully “spit out” from the mouth, either to reposition them or to separate unwanted material from flesh. The motor pattern used during blowing was distinct from similar behaviors described for other fishes, indicating that this behaviors may be unique to tetraodontiforms. Thus B. vetula combines primitive behaviors and motor patterns (suction feeding and buccal manipulation) with specialized morphology (strong teeth, robust jaws, and hypertrophied adductor muscles) and a novel behavior (blowing) to exploit armored prey such as sea urchins molluscs, and crabs. © 1993 Wiley‐Liss, Inc.
Testicular and androgen dependence of skin gland morphology in the anurans, Xenopus laevis and Rana pipiens
Authors: Thomas Eric O. , Licht Paul
Published: February 2005

In anuran amphibians, there is increasing evidence that exocrine glands dispersed throughout the general integument are secondary sex characters (SSC). Following the recent discovery of sexually dimorphic “breeding glands” in the dorsum of male Rana pipiens, we studied the effects of castration and testosterone treatment on the dorsal skin glands of male Xenopus laevis and R. pipiens to determine whether the dorsal breeding glands, or any other dorsal skin glands, are androgen dependent. The dorsal skin glands of X. laevis were unaffected by androgen status. By contrast, in R. pipiens, breeding, mucous, and seromucous glands responded to testosterone stimulation. Mucous glands were significantly (P < 0.05) larger in testosterone‐treated frogs than in castrates. There was a large, but statistically insignificant, increase in the size of the dorsal breeding glands. Testosterone treatment also increased the epithelial cell height of breeding and seromucous glands (P < 0.05). In the skins of castrated and testosterone‐treated frogs, there was a reciprocal relationship between the abundance of seromucous and breeding glands: in castrates, seromucous glands were abundant and breeding glands virtually absent, whereas in testosterone‐treated frogs, breeding glands were abundant and seromucous glands less common. The total number of the two gland types was similar in both treatment groups. Glands that appeared to be intermediate in form between seromucous and breeding glands were observed in some frogs. These data suggest that seromucous glands may be the regressed form of breeding glands in the dorsal skin of R. pipiens and that the dorsal skin of R. pipiens is a SSC. © 1993 Wiley‐Liss, Inc.
Ultrastructure of the spermatozoon of the teleost fish Acanthopagrus schlegeli (Perciformes: Sparidae)
Authors: Gwo Jin‐Chywan , Gwo Han‐Hwang , Chang Su‐Lean
Published: February 2005

Ultrastructurally the spermatozoon of Acanthopagrus schlegeli (Sparidae) has a spherical, homogeneously electron‐dense nucleus with a deep axial nuclear fossa, and an unusual notch, shaped like a bowtie, in the nuclear region. The short midpiece contains four spherical mitochondria and encircles the basal body of the flagellum. It is concluded that the spermatozoon is of a primitive type, although it is characterized by several unique features which may provide useful systematic characters. © 1993 Wiley‐Liss, Inc.
Structural characteristics of marsupial brood pouches of the antarctic sea urchins Abatus nimrodi and Abatus shackletoni (Echinoidea: Spatangoida)
Authors: Schinner Gottfried O. , McClintock James B.
Published: February 2005

Marsupial spines, tubercles, and pedicellariae of the antarctic brooding spatangoids Abatus nimrodi and Abatus shackletoni have been examined by scanning electron microscopy. Individual brood pouches of A. nimrodi may hold up to 28 embryos and juveniles and those of A. shackletoni may hold up to 38 lecithotrophic embryos and juveniles. Juveniles can be divided into (a) those with early development of external elements and a mean size of 2.0 and 1.6 mm, respectively, and (b) those equipped with fully developed external elements and a mean length of 4.3 and 2.8 mm, respectively. Mean diameters of aboral brood pouch openings of A. nimrodi and A. shackletoni were 6.5 and 4.1 mm, respectively. Brood pouches contain tall, distally enlarged spines, and smaller, layered cover‐spines, which form a protective arch over the marsupia. There are also slender brood‐pouch‐bottom spines, which have an extremely thickened spinal epidermis. A. nimrodi has mainly bidentate, but also triand quadrodentate pedicellariae. A. shackletoni has two forms of tridentate, rostrate, and globiferous pedicellariae. In A. shackletoni, marsupial spine density is significantly lower than in A. nimrodi. These differences may be related to distinct sediment characteristics in their respective habitats. © 1993 Wiley‐Liss, Inc.
Cleavage pattern in embryos of Haliotis tuberculata (Archaeogastropoda) and gastropod phylogeny
Authors: van den Biggelaar Jo A. M.
Published: February 2005

The early cleavage pattern in embryos of the archaeogastropod Haliotis tuberculata strongly resembles the cleavage pattern of the archaeogastropods Trochus and Patella. It typically deviates from the cleavage patterns found in embryos of more advanced Archaeogastropoda, Caenogastropoda (the majority of the meso‐ and neogastropods), and Euthyneura (opisthobranch and pulmonate gastropods). It is assumed that the cleavage pattern found in Haliotis, Trochus, and Patella represents the ancestral pattern. A regular pattern of heterochronic changes in the succession of the formation of the larval trochoblasts and the stem cell of the adult mesoderm can be observed from the more primitive Archaeogastropoda to the more advanced Euthyneura. This observation strengthens the idea that the early cleavage pattern contains significant phyletic information. © 1993 Wiley‐Liss, Inc.
On the structure of the aortic valves in snakes (Reptilia: Serpentes)
Authors: Young Bruce A. , Lillywhite Harvey B. , Wassersug Richard J.
Published: February 2005

Aortic valve morphology was examined in 32 species of snakes representing 28 genera and 11 families and a diversity of habitat preferences. The results largely agree with previous studies but include some previously undescribed features, such as the cranial displacement of the cusps in the left aorta in some species and the structure of the opposing cusps of the interaortic foramen. Few features of the aortic valves are uniform among species. The pattern of morphological variation does not correlate with simple habitat preference (e.g., terrestrial, arboreal); however, some of the variation, particularly in the valves themselves, correlates with taxonomic relationships. We suggest that the presence of an interaortic foramen, with its associated valve, could result in an interaortic shunt of blood that potentially alters hemodynamics and flow patterns in the systemic circulation of snakes. © 1993 Wiley‐Liss, Inc.
Development of the inner ear of the brown trout (Salmo trutta fario): I. Gross morphology and sensory cell proliferation
Authors: Becerra Manuela , Anadón Ramon
Published: February 2005

The gross development of the trout inner ear between embryonic and juvenile stages was studied by light microscopy. The otocyst has already formed in 3–4 mm embryos. The semicircular canals begin to separate from the utriculo‐saccular cavity in 6 mm embryos, the anterior canal first, then the posterior and the horizontal canal later. The formation of the saccular cavity begins in 7 mm embryos, whereas that of the lagena occurs in 18 mm fry. The first macular primordia appear before the separation of cavities. The anterior and horizontal crests arise from the primordium of the utricular macula, and the posterior crest, macula lagena, and macula neglecta arise from that of the saccular macula. The macula lagena and macula neglecta appear later. The sensory areas of the labyrinth and the number of receptor cells grow continuously between the embryonic and juvenile stages. © 1993 Wiley‐Liss, Inc.
Development of the inner ear of the brown trout (Salmo trutta fario): II. Cytodifferentiation and innervation of sensory cells
Authors: Becerra Manuela , Anadón Ramon
Published: February 2005

The study of the sensory organs of the trout labyrinth by means of electron microscopy show that hair cells differentiate gradually in these organs; all of them produce new cells over a long period. The course of cytodifferentiation follows a similar pattern in all organs. Afferent nerve fibers and terminals are found at approximately the same time that sensory cells are being differentiated; the efferent synapses appear latter in development. The maturation of the both types of synapses is described. © 1993 Wiley‐Liss, Inc.