bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional adaptations of the digestive system of the carnivorous mollusc Pleurobranchaea californica MacFarland, 1966
Authors: Morse M. Patricia 
Published: February 2005

AbstractThe opisthobranch mollusc Pleurobranchaea californica feeds on whole organisms and the functional morphology of the digestive system reflects this behavior. By a rhythmic behavior involving well‐developed extrinsic buccal muscles and hemocoelic fluid, the buccal mass is protracted to the tip of the everted oral tube. Here a series of repeated protractions and retractions of the intrinsic buccal muscles associated with the flat radular ribbon and jaws draws the prey into the buccal cavity and conveys it to the dorsal esophagus, where by peristaltic action it is passed to the expansible crop for storage. Prey entering the buccal cavity is mixed with acid from a large single gland and secretion from the paired salivary glands. Prey is retained in the crop over long periods of time while it is slowly broken down and passed via the stomach into the digestive glands. Special modifications that allow flexibility of the digestive organs include elongated salivary gland ducts with propulsive bulbs, long flexible nerve cords connecting the ganglia, a long, large muscular duct for storage of the acid secretion, large jaws for muscle attachment and grasping the prey, and a broad radular ribbon with many teeth that acts as a conveyor belt to move food. Additional modifications for handling whole prey include a buccal membrane that aids in maintaining hemocoelic fluid pressure, the extensive acid gland for immobilization of prey, and the expansible crop for storage of food.
Histomorophological studies of the female reproductive system of Platynotus punctatipennis (Coleoptera: Tenebrionidae)
Authors: Inamdar Ruta R. , Joshi P. V. 
Published: February 2005

AbstractThe internal reproductive apparatus of female Platynotus punctatipennis is composed of the paired ovaries, paired lateral oviducts, common oviduct, spermatheca associated with its accessory gland, and a bursa copulatrix. The accessory (colleterial) glands are absent. The ovary is made up of a large number of telotrophic ovarioles which are covered by a double‐layered peritoneal sheath. The terminal filament is separated from the germarium by the basement membrane of the latter and consists of a syncytial core surrounded by the peritoneal sheath. Nutritive cords are absent. The pedicel shows highly eosinophilic and PAS‐positive secretion of obscure origin. The spermatheca reveals a number of interesting features. It is composed of a pair of sperm‐storing tubules, enclosed in a very thin muscle layer. A winecup‐like structure, provided with a thick coat of circular muscles, connects the spermathecal gland with thespermathecal duct. Four types of intimal linings occur in the spermatheca and its associated structures. The wine‐cup‐like connection and four types of intima are entirely new features observed. Histology of the various parts of the reproductive apparatus is described.
Synganglial and neurosecretory morphology of the chicken mite Dermanyssus gallinae (DeGeer) (Mesostigmata: Dermanyssidae)
Authors: Severino G. , Oliver J. H. , Pound J. M. 
Published: February 2005

AbstractHistological techniques and paraldehyde‐fuchsin (PAF) staining were used to study the synganglion and to locate neurosecretory regions and neurosecretion within the synganglion of the chicken mite, Dermanyssus gallinae. The synganglion, which is formed internally by neuropilar ganglia, gives rise to a single esophageal and paired cheliceral, palpal, pedal (I‐IV), and opisthosomal nerves. The neuropilar ganglia are interconnected by commissures and connectives within the synganglion. Twelve PAF‐positive neurosecretory regions are present in unfed protonymphs, unfed deutonymphs, virgin males and females, and mated males. There are 11 PAF‐positive neurosecretory regions in larvae, 24–72 hours post‐fed deutonymphs and mated females. Neurosecretory regions in these developmental stadia are described in relation to their positions adjacent to individual neuropilar ganglia.
Organization of interstitial tissue in the testis of the salamander Necturus maculosus (Caudata: Proteidae)
Authors: Pudney Jeffrey , Callard Gloria V. 
Published: February 2005

AbstractIn Necturus maculosus the organization of the interstitial tissue varies according to the stage of spermatogenesis. Leydig cells at various stages of differentiation and myoid cells are always present in this tissue. The Leydig cells are undifferentiated at all phases of germ cell activity and only hypertrophy following spermiation and degeneration of Sertoli cells. These Leydig cells are structurally analogous to mammalian Leydig cells. They do not form part of the lamina propria of the seminiferous lobules and hence cannot be referred to as lobule‐boundary cells previously described in the urodele testis (Lofts, '74). When the Leydig cells hypertrophy, numerous unmyelinated axons appear in the interstitial tissue. These axons, often devoid of Schwann‐cell cytoplasm, occur in close proximity to Leydig cells. Because the levels of both Substance P and neurotensin increased in the testis of Necturus maculosus as Leydig cells differentiated, we concluded that these neural elements may regulate Leydig‐cell function locally, through the release of neuropeptides.
Cellular and ultrastructural features of the adult and the embryonic eye in the marine gastropod, Ilyanassa obsoleta
Authors: Gibsonm Barbara L. 
Published: February 2005

AbstractLight and electron microscopic techniques show that the eye of the marine prosobranch gastropod, Ilyanassa obsoleta, is composed of an optic cavity, lens, cornea, retina, and neuropile, and is surrounded by a connective tissue capsule. The adult retina is a columnar epithelium containing three morphologically distinct cell types: photoreceptor, pigmented, and ciliated cells. The retina is continuous anteriorly with a cuboidal corneal epithelium. The neuropile, located immediately behind the retina, is composed of photoreceptor cell axons, accessory neurons, and their neurites. The embryonic eye is formed from surface ectoderm, which sinks inward as a pigmented cellular mass. At this time, the eye primordium already contains presumptive photoreceptor cells, pigmented retinal cells, and corneal cells. Several days later, just before hatching, the embryonic eye remains in intimate contact with the cerebral ganglion. It has no ciliated retinal cells, neuropile, optic nerve, or connective tissue capsule and its photoreceptor cells lack the electron‐lucent vesicles and multivesicular bodies of adult photoreceptor cells. As the eye and the cerebral ganglion grow apart, the optic nerve, neuropile, and connective tissue capsule develop.
Head skeleton of the marine catfish Arius tenuispinis day (Osteichthyes: Siluriformes, Ariidae)
Authors: Rao K. Srinivasa , Lakshmi K. 
Published: February 2005

AbstractThe osteology of the head skeleton of marine catfish Arius tenuispinis is described in detail. The skeletal elements of the different regions are dealt with categorically. Bones of the ethmoidal, orbitotemporal, auditory, and occipital regions of the cranium; and the upper jaw, lower jaw, hyoid arch, hypobranchial, and opercular series of the visceral skeleton are described in detail. Identity of the ectopterygoid, mesopterygoid, and metapterygoid is established in accordance with the current nomenclature and accepted homologies. The shelving bone of the epiotic is found to be large, having articulation with the parapophyses of the complex vertebra. The head skeleton of A. tenuispinis conforms to the normal siluroid pattern.
External and internal sexual dimorphism in leiognathid fishes: Morphological evidence for sex‐specific bioluminescent signaling
Authors: McFall‐Ngai M. J. , Dunlap P. V. 
Published: February 2005

AbstractFourteen species of leiognathid fishes (Perciformes, Leiognathidae) from the Philippine Islands, Thailand, Japan, Indonesia, and Palau were examined for accessory secondary sexual dimorphism. Thirteen species exhibit either external dimorphism (a clear patch of skin on the flanks of males, a large clear patch of skin on the opercular margins of males, or a flank stripe in males) or internal dimorphism (large light organs in males) or both. Eight of the 14 species (and possibly as many as 11) exhibit both forms of sexual dimorphism. Two species show only internal light organ volume dimorphism, and one species shows neither external nor internal dimorphism. Sexual dimorphism is thus very common in leiognathids. The externally dimorphic skin patches are closely associated with the internally dimorphic light organ system in seven species (and possibly as many as ten), indicating a potential for light emission through the clear patches. A bioluminescent signaling function by males is therefore suggested for the sexual dimorphism in leiognathids, which may play an important role in the schooling behavior as well as in species and sexual recognition of these coastal fishes.
Fine structure of antennal putative thermo‐/hygrosensilla of adult Rhodnius prolixus Stål (Hemiptera: Reduviidae)
Authors: McIver Susan , Siemicki Roman 
Published: February 2005

AbstractAt least five nonporous sensilla with inflexible sockets (npsensilla) occur on each antenna of both sexes of adult Rhodnius prolixus. Externally the sensillum appears as a short, rounded peg set into a pit surrounded by a depression. A very electron‐dense material occurs in the peg lumen and the inner aspect of the pit. Filamentous extensions of this material radiate into the overlying outlets.Each sensillum is innervated by three neurons with unbranched dendrites. Two dendrites extend to the peg tip and distally are covered by a dendritic sheath. The portion of these dendrites within the sheath contains a large number of microtubules. The third dendrite terminates near the base of the dentritic sheath and partially wraps around the other two dendrites. Three sheath cells are associated with each sensillum.Based on similarities in structure with sensilla of known function it is probable that the np‐sensilla of R. prolixus are thermo‐/hygrosensilla responding to cold, dryness and wetness. The sensilla have a number of structural similarities with insect rectal sheath cells known to absorb atmospheric water by electroosmosis. Possibly this process leads to volumetric alterations of cuticular elements associated with the dendrites and ultimately to mechanotransduction.
Anatomy of raccoon (Procyon lotor) and coati (Nasua narica and N. nasua) forearm and leg muscles: Relations between fiber length, moment‐arm length, and joint‐angle excursion
Authors: McClearn Deedra 
Published: February 2005

AbstractMuscle architecture, moment arms, and locomotor movements in the distal limb segments of the procyonids Nasua (coati) and Procyon (raccoon) are analyzed with reference to patterns of muscle fiber length. This study addresses the hypothesis that relative fiber lengths among muscles in a muscle group can be predicted on the basis of correlates of muscle tension. The results include the following: (1) consistent patterns of fiber length of muscles in a muscle group exist within and between the two genera. (2) Differences in fiber length between muscles can be accounted for by two principal correlates of muscle excursion—length of a muscle's moment arm about a joint and jointangle excursion. (3) Muscle fiber pinnation permits increased tendon excursion, but this effect is relatively small in comparison to the effects of moment‐arm length and joint‐angle excursion. (4) Corollary action between two or more joints (or lack thereof) is an important factor in determination of fiber lengths.
Variation of lymphoid activity in the spleen of a migratory bird, the pied flycatcher (Ficedula hypoleuca; Aves, passeriformes)
Authors: Fänge Ragnar , Silverin Bengt 
Published: February 2005

AbstractThe size and microscopic structure of the spleen of the migratory pied flycatcher (Ficedula hypoleuca) show marked changes during the reproductive cycle. Upon the spring return to their northern breeding sites, the birds have a small spleen with little lymphoid activity and a poorly developed red pulp. During the breeding period the volume of red and white pulp increases, the number and distinctness of lymphoid follicles (germinal centres) in the white pulp increase, and groups of cells with intensely basophilic cytoplasm, probably B cells (plasma cells), appear. The findings suggest that the immune system of the adult pied flycatcher is activated during periods when it is bound to the nest.Young flycatchers beginning their autumn migration also show a marked increase of lymphoid activity in the spleen.
Maturation and aging of adult fat body and oenocytes in Drosophila as revealed by light microscopic morphometry
Authors: Johnson M. B. , Butterworth F. M. 
Published: February 2005

AbstractA morphological and cytometric analysis of the adult fat body cells and oenocytes was made on sections of abdomens from immature, mature and senescent Drosophila melanogaster of both sexes. There are about 18,000 fat body cells in abdomens of female and mature male flies. Immature and senescent males have about 12,000 and 15,000 cells, respectively. The size of the cells is almost the same for immature flies of both sexes and increases about six‐fold to approximately 2600μm2, so that mature flies of both sexes have equivalent amounts of fat body tissue. The proportions of lipid, glycogen, and background cytoplasm of fat body cells also remain relatively constant throughout adult life, but dense, proteinaceous granules are observed in cells of senescent flies. The amounts of cellular components change dramatically due to change of cell size with age; the amount of lipid shows the greatest sexual difference with about 2 × more in the females at all stages studied. The oenocytes number about 6,000 in the abdomens of all but immature male flies, which have approximately 4,000. Although the cells of both sexes triple in size to about 700 μm2, the oenocytes of males reach maximum size earlier than those of females. The major features of oenocytes appear to be dense background cytoplasm, putative lipid droplets found only in mature flies, and pigmented granules first seen in the cells of mature flies which accumulate with age to 33% of the cytoplasm. The number of cells and their anticipated capacity for protein synthesis is discussed in relation to the production of yolk protein precursors.
The arterial arches and their interpretation in Bipes and other amphisbaenians
Authors: Renous D'Sabine 
Published: February 2005

AbstractThe study of the arterial arches of Bipes, the only amphisbaenian with forelimbs, resolves the problem of the interpretation of the structure of the arterial arches in other forms of this group of squamate reptiles. In Bipes, as in turtles, the subclavian and common carotid arteries originate from a brachiocephalic trunk, which arises from an innominate trunk deriving from the right aortic loop.This interpretation is not only original but also emphasizes the important lengthening of the brachiocephalic part relative to the strictly carotidian one. It supposes the intercalation of a new “precardiac” region between the pectoral girdle and the heart; these two components are closely associated topographically in the quadrupedal Squamata. This lengthening, expressed by the increase in the number of precloacal vertebrae, is linked with the increase in the asymmetry of the aortic loop.
Ultrastructural analysis of spermiogenesis in Admetus pomilio (Arachnida, amblypygi)
Authors: Tripepi Sandro , Saita Abele 
Published: February 2005

AbstractThe mature spermatozoon of Admetus pomilio is a spherical cell containing nucleus and tightly coiled flagellum. In early spermatids the Golgi apparatus forms the acrosomal vesicle and at the opposite side the distal centriole gives rise to the axonemal complex of the sperm tail. As the nucleus elongates, chromatin forms twisted filaments and the spermatid nucleus takes on a helical form. Microtubules are juxtaposed with the nucleus envelope, which is separated from a central chromatin mass by an electron lucid region. A long perforatorium, located on the border of the chromatin mass, runs helically in the nucleus from the centriolar region to subacrosomal space. During tail elongation, the anterior part of the axoneme is surrounded by a long, spiral mitochondrial sheath. In the late spermatid, chromatin filaments appear twisted and become aggregated. The nucleus and flagellum undergo further contortions in which the nucleus coils and the flagellum winds up into the body of the cell and coils in a regular fashion. The mitochondrial sheath surrounds about 2/3 of the 9 + 3 axoneme. These features of spermatid ultrastructure resemble those in the primitive Liphistiomorpha.
Morphological and structural study of Landolt's club in the chick retina
Authors: Quesada A. , Génis‐Gálvez J. M. 
Published: February 2005

AbstractLight and electron microscopy were used to study Landolt's club of the bipolar cells in the newborn chick retina as well as in early embryonic stages. In the embryo, the bipolar cells were connected to the outer limiting membrane by Landolt's club. Some of the bipolar cells disconnect from this membrane, by complete retraction of Landolt's club, giving rise to bipolar cells without this process. The newly hatched chick, was used for analysis of the ultrastructure of Landolt's club. Zones of apposition between Muller cells and Landolt's club are associated with cytoplasmic vesicles in both cells. Muller cells appear to transmit vesicular material, possibly nutrients, to bipolar cells through Landolt's club. Thus, Landolt's club provides substrates to bipolar cells in the poorly vascularized region of the chick retina.
Tadpole erythrocytes: Luminescent properties with dark field microscopy
Authors: Tyler Lisa W. , Piotrowski Deborah C. , Kaltenbach Jane C. 
Published: February 2005

AbstractTo characterize and classify erythrocytes of ranid tadpoles, alcohol‐fixed blood smears were studied with dark field illumination. All preclimax stage (limb bud‐foot) Rana castesbeiana tadpoles from ponds in Massachusetts had red blood cells that were polymorphic. The majority of cells (88%) showed a bright, granular luminescence varying from white to blue‐grey, whereas, cytoplasm of the other cells was smooth, black, and nonluminescent. On the other hand, tadpoles in similar stages from other species (Rana clamitans, Mass. and Rana pipens, Vermont) and from R. catesbeiana tadpoles from other locations (Wisconsin and North Carolina) had no observable cytoplasmic luminescence in any of their red blood cells. Moreover, as Mass. R. catesbeiana underwent metamorphic climax their luminescent cells disappeared and were replaced by small, round, dark, nonluminescent cells, precursors of the oval, nonluminescent erythrocytes characteristic of adult frogs. Cells with black nonluminescent cytoplasm generally contained nuclei which were luminescent. In conclusion, two main types of red blood cells‐those with and those without cytoplasmic luminescence‐are distinguishable with dark field microscopy. Luminescence of the cells varies with species, geographic location, and developmental stage of the tadpoles.
Functional characteristics of the calf muscles of the rat
Authors: Woittiez R. D. , Baan G. C. , Huijing P. A. , Rozendal R. H. 
Published: February 2005

AbstractLength‐force relations, both active and passive, and twitch contraction characteristics were quantified for the entire complex of the superficial calf muscles, as well as individually for the Mm. soleus, plantaris, and gastrocnemius, caput mediale and laterale, of eight male Wistar rats. The M. soleus composes approximately 5% of the weight and cross‐sectional area of the entire group of superficial calf muscles and is the only muscle of the group containing mainly slow‐twitch fibers. The other superficial muscles of the calf are primarily fast‐twitch muscles.The mono‐articular M. soleus, the bi‐articular M. gastrocnemius, caput mediale and laterale, and the poly‐articular M. plantaris differ with respect to the number of joints crossed. However, contrary to the findings for cat hind limbs (Goslow et al. [1977] J. Morphol. 153:23–38), the muscles of the complex of superficial calf muscles of the rat did not differ with respect to (a) their fiber optimum length, (b) their maximum length range of active force generation, (c) the relative increase of passive force owing to lengthening of the muscle, (d) the angle of the ankle at which they produce maximal active force (the knee angle was fixed at 90°).
Distribution of myofiber types in thigh muscles of chickens
Authors: Suzuki A. , Tsuchiya T. , Ohwada S. , Tamate H. 
Published: February 2005

AbstractThe composition of myofiber types varies within thigh muscles of chickens. The present study was designed to determine whether or not myofiber types were distributed uniformly across the diameter of the thigh muscles of chickens. Cross sections from middle portions of muscles were used histochemically to examine differences in distribution and composition of myofiber types in the muscles. Myofibers that reacted moderately (M) or strongly (S) for myosin adenosine triphosphatase (ATPase) after preincubation at pH 4.3 were classified as type I. Type I myofibers reacted weakly (W), moderately (M), or strongly (S) for ATPase after preincubation at pH 10.6; these type I myofibers were subclassified into four types (ISW, ISM, ISS, and IMM). Myofibers that reacted negatively for acid‐stable ATPase and strongly for alkali‐stable ATPase were classified into two types: type IIA, with strong NADH tetrazolium reductase (NADH‐TR), and type IIB, with weak NADH‐TR activity. The M. pubo‐ischio‐femoralis pars lateralis had numerous type IIA myofibers and very few type ISM myofibers, whereas the pars medialis had many type IMM myofibers and few type ISS and IIA myofibers. The type I group of myofibers did not exceed about 50% in the other muscles, which had one to three types of type ISW, ISM, and ISS myofibers. The Mm. femorotibiales had more type ISW, and ISM myofibers in the deep regions near the femur than in the superficial regions. The M. iliotibialis cranialis, M. iliofibularis, and M. flexor cruris medialis had more type ISW, ISM, or ISS myofibers in the medial regions than in the lateral regions. A few type ISW myofibers were scattered in the cranial part of M. iliotibialis and in the M. ambiens. The M. flexor cruris lateralis pars pelvica had type IIA and IIB myofibers exclusively. All the muscles had type IIA myofibers. Type IIB myofibers existed in the muscles except the M. puboischio‐femoralis. Type IIA and IIB myofibers differed in proportion in different muscles and in their different regions. The type I group of myofibers was generally concentrated more in the deep regions near the femur and in the medial regions than in the superficial and lateral regions of the thigh muscles. The distribution of type IIA myofibers resembled that of type I group. Type IIB myofibers showed a distribution opposite to that of type I group and IIA myofibers. The spatial distribution of myofiber types within individual muscles can account for the various locomotory and postural requirements of the thigh.
Ontogeny of hemopoietic and lymphopoietic tissues in the lizard Chalcides ocellatus (Reptilia, Sauna, Scincidae)
Authors: El Deeb Somaya , Zada Suher , El Ridi Rashika 
Published: February 2005

AbstractThe first and major blood‐forming organ to develop in the viviparous lizard Chalcides ocellatus is the yolk sac, which exhibits prominent erythropoietic activity from as early as stage 21 through birth (stage 41). Myeloid cells and megakaryocytes are produced in the yolk sac from stage 23 onward. During lizard embryogenesis hemopoietic activity is also observed in spleen and bone marrow but in neither kidney nor liver. Cells capable of giving rise to lymphocytes both in vivo and in vitro are first found in the thymus at stage 35. Active lymphopolesis in thymus and spleen begins at stages 36 and 39, respectively. In contrast, the gut‐associated lymphoid aggregates are not evident before birth.