bluuebunny/crossref_metadata_2025_split huggingface dataset:
Blood vascular system of the sea cucumber, Stichopus moebii
Authors: Herreid Clyde F. , LaRussa Vincent F. , DeFesi Charles R. 
Published: February 2005

AbstractStichopus moebii, a sea cucumber, has a closed circulatory system which is unique in its degree of development for the phylum Echinodermata. The gross anatomy, histology and fine structure of the system were studied. Blood vessels consist of a coelomic surface of ciliated epithelium, a layer of muscle and nerve cells, followed by connective tissue and luminal lining of endothelium. Basically the blood vascular system consists of two major vessels running parallel to the gut: the dorsal vessel pumps colorless blood via the vessels within the walls of the intestine into the ventral vessel. There are two specialized areas of the circulation: (1) At the upper small intestine 120 to 150 muscular single‐chambered hearts pump blood from the dorsal vessel into a series of intestinal plates. (2) At the lower region of the small intestine the vasculature is associated with the left respiratory tree. Blood passing from the dorsal pulmonary vessel can take two routes to the gut, it either passes through myriads of minute respiratory shunt vessels entangled with the respiratory tree or it passes through a unique follicle network consisting of tiny channels periodically dilated into chambers filled with iron deposits, necrotic cells and developing coelomocytes.
Fine structure of the pyloric region and Malpighian papillae of protura (Insecta Apterygota)
Authors: Dallai R. 
Published: February 2005

AbstractThe pyloric region of Eosentomon and Acerentomon (Insecta, Protura) is described. In both species the posterior cells of the midgut carry short microvilli. Beneath the epithelial cells there is a muscular pyloric sphincter for closing the intestinal lumen. Behind the sphincter is a wide pyloric chamber lined by cells with very long microvilli which point anteriorly toward the midgut. These cells regulate the passage of the intestinal contents into the hindgut. Secretions from the Malpighian papillae are emitted into the gut at this level. In Eosentomon three regions (R1, R2 and R3) are visible in the Malpighian papillae, whereas in Acerentomon region R1 is lacking. The R1 region contains secretory cells with elaborate glycoprotein‐containing granules. The R2 region is composed of cells somewhat resembling the secretory cells of Malpighian tubules of insects. Presumably R1 and R2 cells emit secretions into the central cavity of each papilla. Cells of R3 form a duct for the secretion. It is suggested that the R2 region represents a basic excretory region, common to Protura, whereas the R1 region, in Eosentomon, may be a specialized area performing supplementary excretory functions.
Function of the digastric muscle in carnivores
Authors: Scapino Robert P. 
Published: February 2005

AbstractThe general form and adaptation of the digastric muscle in carnivores are reviewed and discussed. The digastric muscle differs from the general plan in certain aquatic carnivores and felids. In the pertinent aquatic species the muscle is enlarged. The observations suggest that the enlargement is an adaptation for rapidly opening the jaws against the resistance of water. In felids, the insertion of the muscle is much farther forward than in most other carnivores. The observations suggest that the development of short jaws in felids necessitated a compensatory anterior relocation of the digastric insertion in order to preserve the ability to achieve a large gape.
Comparative analysis of the hindgut in two species of protura (Insecta, Apterygota)
Authors: Dallai R. 
Published: February 2005

AbstractThe proturan hindgut consists of two regions, with different ultrastructure. The anterior region is organized into three primary longitudinal folds alternating with three smaller, secondary ones.In Acerentomon each primary fold in a cross section contains one or two cells showing all the structures which are involved in water reabsorption. The cells of the secondary folds do not seem engaged in a similar function.In Eosentomon the primary folds present a more complicated organization. Each of them consists of one central cell concerned with reabsorption and two lateral ones. Beneath these cells, on both sides of the fold there is a longitudinal muscle fiber.The posterior region of the hindgut does not seem capable of modifying the gut contents.
The fibrocartilage skeleton and related structures of the ventral pouch of Balaenopterid whales
Authors: Pivorunas August 
Published: February 2005

AbstractThe mandibular symphysis of rorqual whales, whales of the generaMegapteraandBalaenoptera, is characterized by a Y‐shaped fibrocartilage structure that lies in the substance of the muscular ventral pouch of these animals. The stem of the structure joins with the symphysis and is usually indicated externally by an unfurrowed median strip of blubber that has been called the “cutwater” by earlier writers. The arms of the Y pass back and are superficially indicated in all rorqual whales as a ridge running parallel to the rami of the mandibles. This fibrocartilage skeleton of the pouch is most closely related to the mylohyoid muscle. The function of the fibrocartilage Y is probably linked with the jaw mechanics of these whales, but its precise function is otherwise not known.
Development of bioluminescence and photophores in the midshipman fish, Porichthys notatus
Authors: Anctil Michel 
Published: February 2005

AbstractCorrelative studies of luminescent responses, light and electron microscopy of Porichthys photophores during development were conducted. The photophores differentiate as an outgrowth of the basal cell layer of the epidermis, from which they delaminate into the dermis. Reflector cells are formed from dermal fibroblasts. Early photophore cells differentiate into three distinct cell types: photocytes, supportive and lens cells. Elaborate profiles of endoplasmic reticulum, Golgi bodies and vesicles suggest intense secretory activity in the early photocytes, while supportive and lens cells differentiate by two different transformations of the microfilament arrangement of primordial photophore cells.Luminescent capabilities of Porichthys photophores arise in two successive phases: (1) an aneural phase during which photophores become fluorescent, photocytes are in process of maturation and respond only to chemical stimulation and (2) a neural phase in which photophores luminesce upon electrical and pharmacological stimulation and are densely innervated with terminals showing relatively narrow neurophotocyte gaps. The presence of neural elements intimately associated with the early photophore anlagen suggests the involvement of the peripheral nervous system in the formation of photophores.
Fine structure and role in behavior of sensilla on the terminalia of Aedes aegypti (L.) (Diptera: Culicidae)
Authors: Rossignol P. A. , McIver S. B. 
Published: February 2005

AbstractThe terminalia of male and female Aedes aegypti (L.) bear numerous hairs of various shapes and lengths, all of which are mechanoreceptors. Each hair is innervated by one bipolar neuron which contains ciliary rootlets, two basal bodies, and a region assuming the structure of a non‐motile cilium. At the distal tip of the dendrite is a tubular body, a characteristic of cuticular mechanoreceptors. Covering the outer dendritic segment is a cuticular sheath which ends proximally in a net‐like felt‐work and distally attaches to the hair base. Each hair sensillum has two sheath cells. Presumed efferent fibers are associated with the sheath cells.On the insula of the female terminalia are a few campaniform sensilla, the domes of which are raised into small pegs.The sensilla on the terminalia function in copulation and oviposition and probably in warning. A sequence of neurological events is traced for copulation and oviposition.Other cuticular structures, viz., scales, microtrichia, acanthae, and aedeagal spines, which occur on the terminalia are not innervated.
Comparative study of the stomatogastric system of the decapod crustacea. II. Musculature
Authors: Meiss Dennis E. , Norman Richard S. 
Published: February 2005

AbstractThe stomach musculature of several species of decapod Crustacea is described in detail. All species are sufficiently similar so that muscle homologies can be established. The Natantia have a simplified muscle system while the Reptantia are characterized by a more complex muscle system. Species can be arranged in a graded series of muscle system complexity which closely follows the evolution of the decapod Crustacea. The information presented here should provide the basis for consistent identification of the stomatogastric motor neurons throughout the decapod Crustacea.
A comparative study of the organization of the sarcotubular system in ascidian muscle
Authors: Burighel P. , Nunzi Maria Grazia , Schiaffino S. 
Published: February 2005

AbstractThe caudal musculature of ascidian tadpole larvae consists of mononucleated muscle cells joined end to end in long rows flanking the notochord. A comparative study of the fine structure of these cells in larvae from different families has revealed wide variations in the pattern of organization of the sarcotubular system. The species examined can be distinguished in two groups according to the presence or absence of a system of plasma membrane invaginations equivalent to the T system of vertebrate and invertebrate striated muscle. Muscle cells from the first group of species, Clavelina lepadiformis, Ciona intestinalis and Molgula socialis, are characterized by absence of T system and show peripheral couplings of sarcoplasmic reticulum cisternae directly with the plasma membrane. In contrast, a T system is present in muscle cells of Diplosoma listerianum, Styela plicata and Botrylloides leachi. The presence of T system in ascidian muscle is not related to the taxonomic position of the various species, but rather to the intracellular disposition of the myofibrils, which are peripheral in the species of the first group whereas they occupy a more internal position in the species of the second group.The T system displays unique structural features in ascidian muscle. It consists of wide laminae invaginating from the plasma membrane and associated in longitudinally oriented dyads with sarcoplasmic reticulum cisternae in register with the I band of the myofibrils. It is apparent from these observations that, in contrast with the uniformity of myofibrillar structure in all chordates, there are basic differences between ascidians and vertebrates as regards the organization of the sarcotubular system. On the other hand, there are significant similarities in this respect between ascidian and invertebrate muscle.
A scanning electron microscopic study of the sacculus and lagena in the ears of fifteen species of teleost fishes
Authors: Popper Arthur N 
Published: February 2005

AbstractThe ulstrastructure of the saccular and lagenar maculae were studied in 15 species of teleost fishes, using the scanning electron microscope. Particular attention was paid to hair cell orientation patterns, composition of the ciliary bundles on the hair cells, hair cell distributions, and supporting cell types. The hair cells on both otolithic organs are divided into several groups with all of the hair cells in each group oriented in the same direction. The posterior region of the saccular macula in all species had dorsally oriented hair cells on the dorsal half of the macula and ventrally oriented hair cells on the ventral half. The cells on the anterior end of the macula were oriented anteriorly and posteriorly, with the posterior group, in most species, being on the dorsal half of the anterior region of the macula. There was considerable inter‐specific variation upon this basic pattern.Inter‐specific variation on the lagenar macula was considerably less than on the saccular macula. The basic pattern in all of the species includes one dorsal cell group and one ventral cell group.There are four more‐or‐less discrete ciliary bundles, each varying in the relative size of the kinocilia and stereocilia. Intermediary forms were also observed, making it difficult to differentiate ciliary bundles in some instances. It was apparent, however, that several of the ciliary bundles were found in particular macular regions.
Morphology of the thoracic skeleton and muscles of the mosquito, Culiseta inornata (Williston), (Diptera: Culicidae)
Authors: Owen William B. 
Published: February 2005

AbstractThe objectives of this research were to investigate the morphology of the thoracic skeleton and muscles of the mosquito, Culiseta inornata (Williston). The results are presented in 25 text figures and descriptions of each skeletal part and muscle. Undescribed exoskeletal structures are the postmediotergite, intersegmental cleft on the caudal margin of the metapleuron, and the parascutellar process. This process is considered a homologue of the fourth axillary. The acrotergite 2 and subalifer were identified. The prescutum has been called the paratergite by previous authors. The morphological basis for self amputation of legs is described. Undescribed parts of the endoskeleton are: lateral arm of sternal apophysis 1 and its socket on the mesal surface of coxa 1, furcopleural apodeme on sternal apophysis 1, precoxal and postcoxal apodemes arising from the ventral pleural arm, upper and lower laterotergite apodemes on the postnotum, and the pleural and intersegmental apodemes for attachment of halter muscles. Seventy‐two muscles are illustrated with their attachments and the origin, insertion, and action of each is described. Ten of the muscles are newly described for the mosquito. There are no muscles inserted on the subalare, second axillary, or third axillary.
Banding pattern and fibrillogenesis of ceratotrichia in shark fins
Authors: Kemp Norman E. 
Published: February 2005

AbstractStudy by light microscopy, scanning electron microscopy and transmission electron microscopy of the distribution, structure and growth of ceratotrichia in the anterodorsal fin of a lemon shark, Negaprion brevirostris, and in the tailfin of a nurse shark, Ginglymostoma cirratum, shows that the ceratotrichia are large collagen fibers which develop in bilateral rows within the dermis. Surrounding each ceratotrichium is a layer of peritrichial fibroblasts containing secretory vesicles, which appear to be the source of matrix constituents. The peritrichial matrix contains bundles of fine, unbanded collagen fibrils as well as larger, banded fibrils like those in the matrix of ordinary connective tissue. The structure of the peritrichial fibroblasts and of the subjacent peritrichial matrix is the same as that of the fibroblasts and matrix of the conventional connective tissue throughout the fin dermis. Ceratotrichia grow by apposition of collagen fibrils from the peritrichial matrix. In cross section the ceratotrichia appear layered, evidently because of close packing of constituent fibrils in lamellae. In longitudinal section the ceratotrichia exhibit the conventional a, b, c, d and e bands of collagen. The e bands of show two distinct subbands, and the b bands three subbands. Periodicity of the banding pattern is approximately 640 Å like that of conventional collagen fibrils.
A microscopical study of the innervation of flight muscles in the tsetse fly
Authors: Anderson M. 
Published: February 2005

AbstractThe gross morphology of the nervous system supplying the dorsal longitudinal flight muscles of tsetse flies is described. Electron microscopical investigation of the nerves reveals that the dorsal longitudinal muscles are innervated by branches from four main axons. A detailed description of the neuromuscular junctions in the flight muscle is presented.
Melanin deposits associated with the venom glands of snakes
Authors: Pough F. Harvy , Kwiecinski Gary , Bemis Willy 
Published: February 2005

AbstractMelanin deposits in the heads of both true vipers (Viperinae) and pit vipers (Crotalinae) are concentrated over the dorsal and dorsolateral aspects of the venom glands. This pigment may occur in any or all of six sites which include the epidermis, dermis, tissues covering the venom glands, and the interior of the glands themselves. The extreme localization of these melanin deposits suggests that they shield the venom glands from light. Calculations indicate that without such shielding the light energy penetrating the venom glands in the visible and ultraviolet portions of the solar spectrum would damage the venom‐synthesizing apparatus and detoxify stored venom.Elapid and hydrophiid snakes have less dense pigment over the venom gland than vipers. Literature reports indicate that elapid venom is less sensitive to photodetoxification than is venom from vipers. Most colubrid snakes, including several with protein‐secreting Duvernoy's glands, have little or no melanin associated with the glands. Venomous colubrids in the genera Ahaetulla, Dryophis, Leptophis, and Oxybelis have pigment over the glands as dense as that seen in vipers.Iridophores probably also shield venom glands from radiation. In puff adders and Gaboon vipers (Bitis) there appears to be an ontogenetic change in the shielding of the venom glands from melanocytes in young individuals to iridophores in adults.
Further scanning electron microscope studies of lizard auditory papillae
Authors: Miller Malcolm R. 
Published: February 2005

AbstractThe papillae basilares of 12 species of lizards from seven different families were studied by SEM. The iguanids, Sceloporus magister and S. occidentalis, have typical “iguanid type” papillae with central short‐ciliated unidirectional hair cell segments and apical and basal long‐ciliated bidirectional hair cell segments. These species of Sceloporus are unique among iguanids in that the bidirectional segments consist of but two rows of hair cells. The agamids, Agama agama and Calotes nigrolabius, have an “agamid‐anguid type” papilla consisting of an apical short‐ciliated unidirectional hair cell segment and a longer basal bidirectional segment. Agama agama is unusual in having a few long‐ciliated hair cells at the apical end of the apical short‐ciliated segment. The agamid, Uromastix sp., has an “iguanid type” papilla with a central short‐ciliated unidirectional segment and apical and basal bidirectional segments. The anguid, Ophisaurus ventralis, has an “iguanid” papillar pattern with the short‐ciliated segment centrally located. All the short‐ciliated hair cells of the above species are covered by a limbus‐attached tectorial network or cap and the long‐ciliated hair cells, only by loose tectorial strands.The lacertids, Lacerta viridis and L. galloti, have papillae divided into two separate segments. The shorter apical segment consists of opposingly oriented, widely separated short‐ciliated cells covered by a heavy tectorial membrane. The apical portion of the longer basal segment consists of unidirectionally oriented hair cells, while the greater part of the segment has opposingly oriented hair cells.The xantusiids, Xantusia vigilis and X. henshawi, have papillae made up of separate small apical segments and elongated basal segments. The apical hair cells are largely, but not exclusively, unidirectional and are covered by a heavy tectorial cap. The basal strip is bidirectional and the hair cells are covered by sallets. The kinocilial heads are arrowhead‐shaped.The papilla of the cordylid, Cordylus jonesii, is very similar to that of Xantusia except that the apical segment is not completely separated from the basal strip.The papilla of the Varanus bengalensis is divided into a shorter apical and a longer basal segment. The hair cells of the entire apical and the basal three quarters of the basal segment are opposingly oriented, not with reference to the midpapillary axis but randomly to either the neural or abneural direction. The apical quarter of the basal segment contains unidirectional, abneurally oriented hair cells. The entire papilla is covered by a dense tectorial membrane.The functional correlations of the above structural variables are discussed.
Structure and ultrastructure of the testis and sperm formation in goodeid teleosts
Authors: Grier H. J. , Fitzsimons J. M. , Linton J. R. 
Published: February 2005

AbstractTestis structure in four species of goodeid teleosts is described. Testicular tubules terminate blindly at the testis periphery where spermatogonia are located. In goodeid teleosts, development of sperm takes place synchronously within cysts whose periphery is made up of a single layer of Sertoli cells. Upon completion of spermiogenesis, spermiation ensues wherein sperm are shed, as spermatozeugmata, into the testis efferent duct system. Subsequently, Sertoli cells, which comprised the cyst periphery, transform into efferent duct cells.Sertoli cells phagocytize residual bodies and are involved in the formation of spermatozeugmata. The structure of the goodeid spermatozeugmatum is quite different from that observed in the related poeciliids. It is concluded, in view of this and other considerations, that the goodeids and poeciliids have independently evolved solutions to the problems of internal fertilization and gestation.
Sense organs on the antennae of two species of collembola (insecta)
Authors: Slifer Eleanor H. , Sekhon Sant S. 
Published: February 2005

AbstractThe antennae of Folsomia candida and Hypogastrura copiosa are provided with tactile hairs on all four segments and, in addition, with chemoreceptors on segments three and four. The cuticle of the thin‐walled chemo‐receptors of Folsomia, as in most other insects, is penetrated by many small pores uniformly distributed over the surface. In contrast, the cuticle of the thin‐walled chemoreceptors of Hypogastrura is unusual in that a band of cuticle without perforations spirals around, or partly around, the hair. The cuticle between the spirals is very thin, and has extremely small openings in it. The tip of the antenna of Folsomia is thin, permeable to dyes in aqueous solution and apparently glandular. The antennal tip of Hypogastrura is definitely glandular.
Papillary projections at the lingual margin in the striped dolphin, Stenella coeruleoalba, with Special Reference to Their Development and Regression
Authors: Yamasaki Fusao , Komatsu Shunro , Kamiya Toshiro 
Published: February 2005

AbstractPapillary projections along the anterolateral margin of the tongue were observed in fetal and young stages of the striped dolphin, Stenella coeruleoalba. Papillary projections appear in the prenatal period and attain maximum development in the early postnatal period. They almost disappear by weaning. Vestigial eminences remain at the corresponding region, but they completely disappear in the adult. The papillary projections observed differ markedly from the lingual papillae of the general mammalian tongue as they are temporary, localized at the anterolateral margin and large in size. The projections were also present in young individuals of some other dolphins. No taste buds could be seen on the projections in any of the stages of all specimens observed. Such projections may have important mechanical functions during suckling in these mammals.