bluuebunny/crossref_metadata_2025 huggingface dataset:
Continuous and discontinuous growth in the otolith of Macruronus novaezelandiae (Merlucciidae: Teleostei)
Authors: Gauldie R. W.
Published: February 2005

Viewed by transmitted light, the lapillus and astericus otoliths Macruronus novaezelandiae (Merlucciidae) contain radial bands of similar width to the distances between steps on the surface of the otolith. The sagitta otolith has a multi‐prismatic structure and shows differences in ultrastructure between its dorsal and ventral growth axes, as well as its sulcal (inward‐facing) and anti‐sulcal (outward‐facing) parts. The ultrastructure of the sagitta shows that not all of the optical and etched checks in the central growth axis represent true discontinuities in the crystal growth of the otolith; they are the result of refraction around narrow optically active refractive bands. Microincrement growth along the dorsal prisms of the otolith from the primordium to the growing edge shows discontinuities in crystal growth at the boundary of the primordium and at the intersection of prisms. Parts of the ventral edge of the otolith show discontinuous crystal growth apparently caused by the physical growth restriction at the point at which the otolith is supported by the skull. Both the anti‐sulcal and sulcal parts of the otolith often show discontinuities in the crystal structure alongside zones of continuous microincrement deposition, or evidence of continuous crystal growth, documenting simultaneous continuous and discontinuous growth in closely juxtaposed parts of the same otolith. © 1993 Wiley‐Liss, Inc.
Ultrastructure and cytochemistry of secretory cells in the skin of the leech, Dina lineata
Authors: Molinas M. , Huguet G.
Published: February 2005

The ultrastructure and histochemical features of the two types of secretory cells in leech skin are described. Pear‐shaped cells secrete mucus containing carboxylated mucosubstances, while tubular cells produce a mucus containing a mixture of neutral, carboxylated, and sulfated mucosubstances. Pear‐shaped secretory cells have two types of neuroglandular junctions, one containing dense‐core serotonergic vesicles and the other small clear vesicles. Tubular secretory cells have large terminals, with many clear vesicles thought to be cholinergic. © 1993 Wiley‐Liss, Inc.
Distribution and morphology of motoneurons innervating different muscle fiber types in an amphibian muscle complex
Authors: Kim Jungnim , Hetherington Thomas E.
Published: February 2005

The distribution and morphology of motoneurons innervating specific types of muscle fibers in the levator scapulae superior (LSS) muscle complex of the bullfrog (Rana catesbeiana) and tiger salamander (Ambystoma tigrinum) were studied by retrograde labelling with cholera toxin‐conjugated horseradish peroxidase (CT‐HRP). The LSS muscle complex in both of these amphibians has a segregated pattern of muscle‐fiber types (tonic; fast oxidative‐glycolytic twitch [FOG]; fast glycolytic twitch [FG]) along an anteroposterior axis. The entire motor pool was labelled by injection of CT‐HRP into the whole LSS muscle complex. The motoneurons innervating specific fiber types were labelled by injection of CT‐HRP into certain muscle regions. The organization of the motoneuron pool of the LSS complex of both species was arranged in two columns—one ventrolateral and one medial. In bullfrogs, the ventrolateral column contains motoneurons innervating FG and tonic fiber types and the medial column contains motoneurons innervating FOG fiber types. In tiger salamanders, the ventrolateral column contains motoneurons innervating FG fiber types and the medial column contains motoneurons innervating FOG and tonic fiber types. The different motoneuron types also have different soma sizes and patterns of dendritic arborization. In both species, FG motoneurons are the largest, whereas FOG motoneurons are intermediate in size and tonic motoneurons are the smallest. In bullfrogs, the main dendrites of FG motoneurons extend into the dorsolateral and the ventrolateral gray matter of the spinal cord, whereas the dendrites of FOG motoneurons extend into the ventral and medial cord. In the tiger salamander, dendrites of FG motoneurons extend into the ventrolateral spinal cord and dendrites of the FOG motoneurons extend more generally into the ventral cord. Dendrites of tonic motoneurons in both amphibians were small and short, and difficult to observe. These results establish that motoneurons innervating different types of muscle fibers in the LSS muscle complex are segregated spatially and display consistent morphological differences. © 1993 Wiley‐Liss, Inc.
Jaws and teeth of american cichlids (Pisces: Labroidei)
Authors: Casciotta Jorge R. , Arratia Gloria
Published: February 2005

The morphology of the upper, lower, and pharyngeal jaws is very similar among American cichlids. Common conditions are: (1) the presence of a premaxillary dentigerous arm shorter than the ascending arm (exceptions are Astronotus, Cichla, and Crenicichla semifasciata), (2) a narrow coulter area; in contrast, a broad coulter area is found in the Crenicichline Group, in certain chaetobranchines, and in Apistogramma, (3) the mandibular sensory canal exists to the skin through five or six simple pores; in contrast, it exits through numerous small pores that increase in number during ontogeny in the Chaetobranchine Group, certain crenicichlines, such as Cichla, Crenicichla lepidota, Crenicichla proteus, and Crenicichla vittata, and certain genera of the Cichlasomine Group A, such as Caquetaia, Petenia, Neetroplus, and “Cichlasoma,” and (4) the premaxilla and dentary of American cichlids commonly bear unicuspid, conical teeth with a few exceptions such as Neetroplus (with scraping blade teeth) and “Cichlasoma” facetum, “C.” cyanoguttatum, “C.” guttulatum, and “C.” spilurum (with bicuspid [hooked] teeth). In contrast to the near uniformity of the upper and lower jaws, the upper and lower pharyngeal jaws present a great diversity of tooth shapes. At least seven types are found in American cichlids; usually, several types exist on a single tooth plate, but the combination of tooth types differs among some genera.

The pharyngobranchial 4 tooth plate has significant evolutionary transformations in labroids. The caudal margin of the pharyngobranchial 4 tooth plate bears the frayed zone in cichlids and embiotocids. The presence of a broad frayed zone bearing one to seven concavities represents a synapomorphy for the family Cichlidae, whereas a deep, narrow frayed zone is a synapomorphy of Embiotocidae. The absence of the frayed zone is a synapomorphy of Pomacentridae, whereas the loss of the pharyngobranchial 4 is a synapomorphy of Labridae. © 1993 Wiley‐Liss, Inc.
Ultrastructural study of the mental body of Hydromantes genei (Amphibia: Plethodontidae)
Authors: Riva Francesca Testa , Serra Giuliana Paola , Loffredo Felice , Riva Alessandro
Published: February 2005

The mental glands of Hydromantes genei are considered a specialized form of the urodele serous cutaneous glands. Use of a variety of techniques of maceration and digestion as well as transmission electron microscopy (TEM) and scanning electron microscopy (SEM) has shown the three‐dimensional morphology of secretory and myoepithelial cells. Secretory cells are pyramidal and rest on an almost continuous layer of myoepithelial cells. The latter have a long ribbon‐like body from which branch off transversal and longitudinal processes with swallow‐tailed ends. Cytoplasmic processes of secretory cells, containing irregular dense vesicles, squeeze through clefts between myoepithelial cells and may reach, at some points, the basal lamina. The interstices between myoepithelium and secretory cells are extraordinarily rich in nerve endings with clear vesicles. The glandular outlets appear as elliptical stomata in the superficial layer of the epidermis and are lined by horny cells, which invaginate to circumscribe the excretory duct. The morphological results indicate that the myoepithelium of Plethodontidae mental glands differ in some respects from that of amphibian serous cutaneous glands. A double polarity for the secretory cells is also suggested. © 1993 Wiley‐Liss, Inc.
Central projections of cheliceral mechanoreceptors in the spider Cupiennius salei (Arachnida, Araneae)
Authors: Gorb Stanislav N. , Anton Sylvia , Barth Friedrich G.
Published: February 2005

Central projections of lyriform organs and tactile hairs on the chelicerae of the wandering spider Cupiennius salei were traced using anterograde cobalt fills. Different fibers arising from both mechanoreceptor types arborize in the cheliceral ganglia, which are part of the tritocerebrum, and in sensory longitudinal tracts in the center of the suboesophageal nerve mass together with afferent fibers arising from mechanoreceptors on the walking legs and the pedipalps. This convergence of sensory projections in the sensory longitudinal tracts might provide the anatomical basis for the coordination of the movements of different extremities during prey capture and feeding. The findings also support the hypothesis that the tritocerebrum originally was a preoral ganglion in spiders. © 1993 Wiley‐Liss, Inc.
Internal micromorphology of the frons plate in females of the oriental hornet
Authors: Arcan Lelia , Ishay Jacob S.
Published: February 2005

Scanning electron microscopy and energy dispersive x‐ray analysis (SEM/EDS) have been used to study the internal micromorphology of the frons plate in the Oriental hornet, Vespa orientalis. A conical shaped organ was described which is recessed into the frons plate and projects toward the interior of the acoustic box. The latter is located on the inner side of the frons plate. On the exterior of the conical region are observed aggregates containing Ca and Si, and a thin transparent membrane bearing a hole in its center. The innermost surface of the conical structure terminates bluntly as a convex lentiform tip, bearing a transparent oval‐shaped window in its center. The conical organ, excepting the window, is enclosed in several layers of epithelium.

The structure of this many‐layered conical organ is highly complex; its numerous sub‐structures and the possible role as a gravity sense organ are discussed. © 1993 Wiley‐Liss, Inc.
Structure of comblike teeth of the ayu sweetfish, Plecoglossus altivelis (Teleostei: Isospondyli): I. Denticles and tooth attachment
Authors: Uehara Kiyoko , Miyoshi Sakuichiro
Published: February 2005

The structure and tooth attachment of the comblike teeth and denticles of the ayu sweetfish, Plecoglossus altivelis, were examined by light and scanning electron microscopy. The denticle is composed of a spoonlike crown with a spine pointed anteriorly, a triangular plate in the cervical region, and a root that curves laterally and tapers off to a point. The root apex is fused with a long thin pedicle that turns abruptly anteriad toward the jaw bone. Planes of the spine, the spoonlike crown, the triangle plate and the root of the denticle are varied, and the denticle is twisted in the region of the triangle plane.

The superficial layer of the dentine is homogeneously calcified and is considered to be enameloid, because some of the inner dentinal epithelial cells in the tooth germ are columnar and possess cellular processes at their apical ends. The dentine is fibrous and fine dentinal tubules are visible in dentine treated with sodium hydroxide and observed by scanning electron microscopy. The upper half of the root is surrounded by a dense layer of collagen fibers running parallel to the tooth axis, and the lower half is encompassed by interlaced collagen fibers. The lower part of the root is open on its lingual side. The pedicle is a long rod which is homogeneously calcified and enmeshed by interlaced collagen fibers, and it curves mediad as it nears the jaw bone. The pedicles are interposed between a layer of gelatinous connective tissue and the jaw bone and terminate on the periosteum. Comparative aspects of ayu tooth morphology are discussed. © 1993 Wiley‐Liss, Inc.
Effects of juvenile hormone analogues upon soldier differentiation in the termite Reticulitermes santonensis (Rhinotermitidae, Heterotermitinae)
Authors: Lelis A. T. , Everaerts C.
Published: February 2005

Under the influence of juvenile hormone analogues (JHAs), termite workers are induced to differentiate into soldiers. In Reticulitermes santonensis, such induced differentiation is often incomplete, resulting in intercaste production. The morphology of the structures most affected during differentiation was analyzed descriptively and biometrically in normal workers, presoldiers, and soldiers, and in experimental intercastes. We observed that intercastes form a morphological and biometrical continuum between workers and presoldiers (presoldier intercastes), and between presoldiers and soldiers (soldier intercastes). We also compared the biochemistry of the normal individuals and of the intercastes; in contrast to workers, the intercastes possess a frontal gland secretion which differs from those of the presoldiers and soldiers. Besides intercaste characterization, we consider the mode of action of JHAs in termite differentiation. © 1993 Wiley‐Liss, Inc.
Microtopography of Nippostrongylus brasiliensis (Nematoda: Heligmosomatidae): Free‐living larval stages
Authors: Nembo B. , Goudey‐Perriere F. , Gayral P. , Perriere C. , Brousse‐Gaury P.
Published: February 2005

Microtopographic features of the various growth stages of the three free‐living larval stages of the rat hookworm Nippostrongylus brasiliensis (Nematoda) were surveyed by scanning electron microscopy. These worms have a rounded anterior end and an elongated tail. Cuticular annulations were observed along the body, which also bore two ribbon‐like lateral alae. Two rings of six lip‐like lappets were observed around the triradiate oral opening in all larval stages. The cephalic space contained two lateral amphidial pits. The excretory pore in the third anterior part was observed in a ventral view of the larvae. No deirids were observed. The anus with a crescent‐shape opening was located posteriorly. Phasmidial apertures, only observed in the third‐stage larvae, opened on the lateral alae in the tail region. © 1993 Wiley‐Liss, Inc.
Ultrastructural study of the esophagus of seawater‐and freshwater‐acclimated Mugil cephalus (Perciformes, Mugilidae), euryhaline marine fish
Authors: Cataldi Eemilia , De Merich Diego , Pesce Maurizio , Cioni Carla
Published: February 2005

The esophagus of the common grey mullet Mugil cephalus shows a single mode of organization that is common to both seawater‐ and freshwater‐acclimated specimens. A short anterior segment is lined by a stratified epithelium with mucous cells; posteriorly, this is progressively replaced by single‐layered columnar epithelium. Ultrastructural features of the columnar epithelium are quite similar in the seawater‐ and freshwater‐acclimated specimens. Apical microvillous projections, lamellar structures, and dilated intercellular spaces are observed. The present study suggests that the mullet esophagus is involved in active ion transport and water permeability, both in seawater and in freshwater environments. © 1993 Wiley‐Liss, Inc.
Polymorphic crystalline structure of fish otoliths
Authors: Gauldie R. W.
Published: February 2005

Although most otoliths of teleost fishes contain aragonite, a detailed survey of the otoliths of serveral species confirms that other crystalline forms of calcium carbonate occur. Otoliths of Hoplostethus atlanticus, Pagrus major, Macruronus novaezelandiae, Merluccius australis, Congiopodus coriaceus, Kathetostoma giganteum, Argentina elongata, Rhomobosolea tapirina, Neophrynichthys latus, Coelorinchus aspercephalus, Paranothothenia microlepidota, and Gonorhynchus gonorhynchus contained the aragonite, calcite, and vaterite morphs of calcium carbonate in varying proportions. Aragonitic otoliths of Allocyttus niger, Hoplostethus altlanticus, and Pagrus major contained sequences of calcite‐like crystals. The surface of the vateritic otolith of Acipenser brevirostrum is shown in detail. Three classes of information are stored in the crystalline structure of the otolith: shape conservation, coexisting crystal morphs, and consecutive changes in crystal morph. Analysis of this crystalline information supports the hypothesis of control of growth of the otolith by proteins from the sensory epithelium or macula. Protein variation involved may be genetic in origin, or non‐genetic arising from “stuttering” of the translation process. Proteins extracted from vateric and aragonitic morphs of the otolith of Macruronus novaezelandiae showed differences in infared absorption spectra that were consistent with two different amino acid sequences. © 1993 Wiley‐Liss, Inc.
Ultrastructure of the granulocytes of the South American lungfish, Lepidosiren paradoxa: Morphogenesis and comparison to other leucocytes
Authors: Bielek Edith , Strauss Bernhard
Published: February 2005

Ultrastructure and peroxidase cytochemistry of the granulocytes of the lungfish Lepidosiren paradoza were investigated. In peripheral blood and hemopoietic tissue (kidney and spleen) only three granulocytic types were found. After comparison with light microscopic images of Giemsa‐stained semithin sections the granulocytes were tentatively designated as eosinophilic I, eosinophilie II, and a basophilic type.

The eosinophilc I cell was the most numerous granulocyte and was characterized by granules ranging in diameter from 0.2–1.8 μm. A developmental series was observed, leading from small, peroxidase (PO) positive granules to large ones with PO‐negative cores and only peripheral PO‐positive reactivity. The central electron‐dense cores of the large granules were often eroded. The eosinophlic II cell was less numerous than the eosinophilic I type and had smaller (diameter 0.4–0.9 μm) granules than the eosinophilic I type, some of them elongated and rod like. The basophilic cell was rare and contained large, homogenously dense granules measuring up to 1.2 μm in diameter. Immature stages of the granulocytic types showed vesicular rough endoplasmic reticulum. Nuclear identation and segmentation occurred early in development, in contrast to the relatively late onset of these processes in mamals. Monocytes and macrophages had an irregular or slightly indented nucleus and lacked the specific granules of the granulocytes.

Phylogenetic relationships were discussed with special reference to the question of the evolution of only one or possibly of two separate heterophilic/neutrophilic cell lines in fishes. © 1993 Wiley‐Liss, Inc.
The vomeronasal duct has a protracted postnatal development in the mouse
Authors: Coppola David M. , Budde Jason , Millar Leah
Published: February 2005

Recent evidence suggests that the accessory olfactory system (AOS) may mediate chemoreception before birth. Such a capability may allow the fetus to begin to sample chemical stimuli from the outside world, a possibility that has important developmental and evolutionary implications. Herein we describe the development in the mouse of the duct that connects the vomeronasal organ (VNO), containing the primary receptor neurons of the AOS, with the nasal cavity and thus with external stimuli. Twenty‐four mice, four at each of six different ages from the last day of gestation through 25 days of age, were fixed and embedded in glycol methacrylate. Serial sections were examined under the light microscope so that the VNO duct could be reconstructed in three dimensions. Results confirm an earlier study which demonstrated that the VNO duct is not patent before birth. The duct becomes patent sometime after the first day of life but remains in an immature condition throughout the normal prepubertal period. During this period the duct is characterized by an internal surface that is rapidly desquamating such that the lumen of the duct contains sloughed tissue. These results suggest that the VNO is unlikely to function in the prenatal period, since the route for external stimuli to reach its receptor surface is blocked. The protracted period of VNO duct development reported here is consistent with the great bulk of data on the AOS of mammals which firmly establishes its role in the detection of pheromones which coordinate reproduction. © 1993 Wiley‐Liss, Inc.
The aponeuroses of the lacertilian ankle
Authors: Russell Anthony P.
Published: February 2005

Despite pioneering and detailed work by McMurrich (Am. J. Anat. 4:33–76, '05; Am. J. Anat. 6:407–437, '07), the structure of the “plantar aponeurosis” of the lacertilian pes has remained poorly understood. In recent years a better understanding has been gained of the form and function of the mesotarsal joint of the lacertilian ankle and its role in the mechanics of sprawling locomotion. These developments have necessitated a reevaluation of the structural relationship of the “plantar aponeurosis” because McMurrich's (Am. J. Anat. 4:33–76, '05; Am. J. Anat. 6:407–437, '07) studies indicated that the aponeurosis is complex and should not be considered as a single sheet of connective tissue. The current contribution presents a detailed analysis of the anatomical relationships of the stratified aponeurotic sheets that traverse the ankle joint and attempts to relate these components to previous analyses of the functioning of the anlkle during locomotion. © 1993 Wiley‐Liss, Inc.
Cytochemical characterization of the hemocytes ofLeucophaea maderae(Dictyoptera: Blaberoidea)
Authors: Fenoglio C. , Bernardini P. , Gervaso M. V.
Published: February 2005

A correlated morphological and cytochemical approach to the hemocytes inLeucophaea maderaecharacterizes the granule contents of blood cells with May Grunwald‐Giemsa (MGG), periodic acid‐Schiff (PAS), Alcian blue (AB), and Sudan black B stainings, and after fluorochroming with acridine orange (AO). The cell nucleus and nuclear DNA is demonstrated with the Feulgen reaction. The activities of α‐naphtyl butyrate esterase (ANBE) and acid phosphatase (AcPase) have been investigated in hemocytes, by both light and electron microscopy. The study discloses five cells types: prohemocyts, plasmatocytes, granulocytes, spherulocytes, and cytocytes. Occasional Sudan black‐positive cells could represent an adipohemocyte category. The different patterns of cytochemical staining suggest a variety of functional roles for hemocytes. The most selective reaction pattern in terms of cytological differentiation among hemocytes occurred with the ANBE reaction. Ultrastructural analysis of intercellular granule contents, and the demonstration of cells with intermediate features, suggests that the hemolymph ofLeucophaea maderaecontains a developmental series from prohemocyte to plasmatocyte to granulocyte and then to spherulocyte. © 1993 Wiley‐Liss, Inc.
Increased vascularity of the lingual salt glands of the estuarine crocodile, Crocodylus porosus, kept in hyperosmotic salinity
Authors: Franklin Craig E. , Grigg Gordon C.
Published: February 2005

Methyl methacrylate corrosion casts were made of the blood‐vascular system of the lingual salt glands of the estuarine crocodile, Crocodylus porosus, and examined with light and scanning electron microscopy. The 28–40 individual salt glands, each opening separately via a single pore onto the dorsal surface of the tongue, are supplied by a pair of lingual arteries. Each gland is richly vascularized and is composed of 14–20 lobular sub‐units, each having a dense network of capillaries. The blood flow in each gland is from the centre to its periphery, opposite to the direction of the flow of secretions in the ducts of the gland. The main collecting duct leading from the gland to the external pore was well vascularized. The blood supply to the glands of juvenile crocodiles raised in 20‰ salt water was more dense than in freshwater and, from cast masses, had a three‐fold greater vascular volume. This study provides the first evidence which shows that the salt glands of crocodiles are morphologically labile and can adapt to the environmental salinity. © 1993 Wiley‐Liss, Inc.
Morphology of the basilar papilla of the budgerigar, Melopsittacus undulatus
Authors: Manley Geoffrey A. , Schwabedissen Gabriele , Gleich Otto
Published: February 2005

The budgerigar is a representative of the parrot‐like birds that, like song birds, have developed complex communication signals. This species is interesting in a psychoacoustic sense, in that it shows unusually good frequency discriminative abilities above about 1 kHz. To begin to understand whether the peripheral hearing organ plays a role in such specializations, we have carried out a quantitative study of the fine anatomy of the basilar papilla and compared it to data from other avian species.

The budgerigar basilar papilla is about 2.5 mm long in the living animal and contains about 5,400 hair cells. The hair cells of the papilla show regional specializations similar to those found in other birds and are described from scanning electron microscopic and light microscopic studies. Regiona changes in the basilar papilla, and in the basilar and tectorial membranes are described from light microscopic data. As noted for other avian species, the constellation of morphologic features found in the budgerigar is unique. In general, the hair cell patterns of the budgerigar papilla showed fewer specializations than found in, e.g., a songbird, the starling, but more than seen in a primitive land bird, e.g., the pigeon. There were no features that were obviously related to the unusal psychoacoustic performance of this species. © 1993 Wiley‐Liss, Inc.
Stages of oocyte development in the zebrafish, Brachydanio rerio
Authors: Selman Kelly , Wallace Robin A. , Sarka Andrew , Qi Xiaoping
Published: February 2005

Oocyte development has been divided into five stages in the zebrafish Brachydanio rerio, based on morphological criteria and on physiological and biochemical events. In stage I (primary growth stage), oocytes reside in nests with other oocytes (Stage IA) and then within a definitive follicle (Stage IB), where they greatly increase in size. In stage II (cortical alveolus stage), oocytes are distinguished by the appearance of variably sized cortical alveoli and the vitelline envelope becomes prominent. In stage III (vitellogenesis), yolk proteins appear in oocytes and yolk bodies with crystalline yolk accrue during this major growth stage. Ooctes develop the capacity to respond in vitro to the steroid 17α, 20β‐dihydroxy‐4‐pregnen‐3‐one (DHP) by undergoing oocyte maturation. In stage IV (oocyte maturation), oocytes increase slightly in size, become translucent, and their yolk becomes non‐crystalline as they undergo final meiotic maturation in vivo (and in response to DHP in vitro). In stage V (mature egg), eggs (approx. 0.75 mm) are ovulated into the ovarian lumen and are capable of fertilization. This staging series lays the foundation for future studies on the cellular processes occurring during oocyte development in zebrafish and should be useful for experimentation that requires an understanding of stage‐specific events. © 1993 Wiley‐Liss, Inc.
Ultrastructural study of the ovary of the sessile scyphozoan, Haliclystus octoradiatus (Cnidaria: Stauromedusae)
Authors: Eckelbarger Kevin J. , Larson Ronald J.
Published: February 2005

An ultrastructural study of the ovary of the sessible jellyfish, Haliclystus octoradiatus, indicates that it is fundamentally different from that of other scyphozoans and is the most structurally complex within the class. Oocytes develop within a series of spherical, sac‐like ovarian follicles consisting of an enlarged intercellular space between two layers of subumbrellar gastrodermis. Developing oocytes are largely restricted to a thin germinal epithelium at the periphery of each follicle and gradually migrate toward the lumen as they mature. Individual oocytes are surrounded by early germ cells and follicle‐like accessory cells of presumed somatic origin. Similar folliclelike cells have not been described in the Cnidaria previously. Vitellogenesis appears to involve the combined activity of the Golgi complex and associated rough endoplasmic reticulum. Ovarian morphology may be helpful in deciphering phylogeneitc relationships within the Cnidaria. © 1993 Wiley‐Liss, Inc.
Reproduction, placentation, and embryonic development of the Atlantic sharpnose shark, Rhizoprionodon terraenovae
Authors: Castro José I. , Wourms John P.
Published: February 2005

The Atlantic sharpnose shark Rhizoprionodon terraenovae (Richardson) is a small carcharhinid that is a common year‐round resident along the southeast coast of the United States. It is viviparous and its embryos develop an epithelio‐vitelline placenta. Females enter shallow water to give birth in late May and early June. Mating occurs shortly after parturition, and four to seven eggs are ovulated. Fertilized eggs attain the blastoderm stage in early June to early July. Separate compartments for each egg are formed in the uterus when the embryos reach 3–30 mm. Embryos depend on yolk for the first 8 weeks of development. When embryos reach 72 mm their yolk supply is nearly depleted and they shift to matrotrophic nutrition. When the embryos reach 40–55 mm, placental development begins with the vascularization of the yolk sac where it contacts the uterine wall. Implantation occurs at an age of 8–10 weeks by which time the embryos reach 70–85 mm. The expanding yolk sac engulfs the maternal placental villi, and its surface interdigitates with the villi to form the placenta. The rest of the lumenal surface of the uterus is covered by non‐placental villi that appear shortly after implantation. Histotrophe production by the non‐placental villi begins just after their formation. The placenta grows continuously during gestation. The egg envelope is present throughout gestation, separating maternal and fetal tissues. Embryos develop numerous appendiculae on the umbilical cord. Young sharks are born at 290–320 mm after a gestation period of 11 to 12 months. © 1993 Wiley‐Liss, Inc.
Structure and swimming behavior of the larva of Haliclona tubifera (Porifera: Demospongiae)
Authors: Woollacott Robert M.
Published: February 2005

Early developmental stages of Haliclona tubifera are retained by the parent and larvae are released on illumination of dark‐adapted colonies. Larvae are parenchymellae without provision for feeding on particulate matter and without identifiable sensory and neuronal elements. Larvae, however, are strongly photonegative on release and remain so throughout the duration of larval existence. The anterior and lateral epidermal fields are composed predominantly of elongate flagellate cells which form a pseudostratified columnar epithelium. Interspersed among elongate cells are globular flagellate cells which, based on ultrastructural criteria, are thought to be secretory in function. The posterior surface is not flagellated and is composed of a cuboidal epithelium. A 5–7 cells wide ring of epidermal cells with flagella 50 μm in length forms a prominent flagellar band separating the posterior from lateral fields. Measurements of swimming speeds in the horizontal plane indicate that H. tubifera larvae swim at speeds intermediate between Halichondria melanadocia, which have a posterior tuft of 25 μm flagella and Haliclona sp, with a posterior ring 75 μm flagella. Morphometric analysis of larval length, larval diameter, and flagellar band diameter shows significant correlations in all pair‐wise tests. Band diameter varies less than larval length or width suggesting that it is a conserved trait. A negative allometry exists between band diameter and larval length. As larval length increases elongate flagellar cells of the lateral and anterior surfaces become relatively more important for locomotion. A prominent cup‐like sheath of subepidermal cells separates the epidermis from the central region of the larval interior. These cells are not associated with collagen as are cells similar in appearance and location in several other haplosclerid larvae. Their function remains unknown. Spicules occur in the posterior region. As in the adult, these spicules are hastate oxeas, but they are significantly different in length, width, and length/width from those of the adult. Their function is unknown, but several obvious potential functions in both larval and postlarval life exist and await further study. Archeocytes are the dominant cell type of the central region. Bacteria are found inter‐ and intracellularly. Based on morphological data, they appear to be of a single type, pleomorphic rods without thick walls, but further study utilizing isolates in culture is needed to establish their diversity and identity. Intracellular bacteria are associated with a cell type provisionally designated a bacteriocyte. Three stages of bacteriocytes are described based on anatomical criteria, presence/absence of bacteria, and what appear to be stages in degradation of bacteria. The significance of this association and of the bacteriocyte cell type remain to be explored. © 1993 Wiley‐Liss, Inc.
Ultrastructure of the paraphysis in Bufo bufo larvae
Authors: Farnesi Rosalba M. , Tei Simonetta , Vagnetti Daniela , Santarella Bruna , Pollacci Paola
Published: February 2005

A study of the ultrastructure and function of the paraphysis in Bufo bufo larvae was carried out. The structure is a tubular‐ramified gland made up of numerous tubules with monolayered epithelial walls surrounded by connective tissue and sinusoids. The epithelial cells secrete glycoprotein to contribute to production of the cephalorachidian fluid. The role of the paraphysis in the transport of fluids and electrolytes from the blood to the cephalorachidian fluid in regulation of ionic and osmotic homeostasis is discussed. © 1994 Wiley‐Liss, Inc.
Eversible abdominal vesicles and some observations of the male reproductive system of the spoon wing lacewing Palmipenna (Neuroptera: Nemopteridae)
Authors: Walker M. H. , Picker M. D. , Leon B.
Published: February 2005

The anatomy and histology of the abdominal eversible vesicles and the male reproductive tract of the spoonwing lacewing Palmipenna (Neuroptera: Nemopteridae) have been examined. The eversible vesicles open as a pair of large bulbous sacs between tergites five and six, each folding into halves during retraction. They consist of highly pleated cuticle, beneath which are typical gland cells, each having a circular or oval end apparatus surrounded by closely packed microvilli. These communicate to the surface via cuticularized channels. In spite of considerable behavioral observations, male Palmipenna were never noted with everted vesicles. Even during mating trials, where females were presented to males in the field, the vesicles were never everted during the attempted copulation that ensued. Our observations indicate that mate attraction is mediated by the release of a female pheromone. The function of the eversible vesicles and their associated gland cells remains unknown, and their structure appears to be unique to the Nemopteridae. The reproductive tract is similar to that of other Neuroptera, consisting of a pair of five‐lobed testes, a medium‐to‐large pair of seminal vesicles, and three pairs of accessory glands. The major accessory glands are surrounded by circular and longitudinal muscle, and are lined by an epithelium, the cells of which presumably secrete the amorphous rods of material always present in this pair of glands. The sperm in the seminal vesicles are elongate, with a pointed head and a 9 + 9 + 2 configuration in the flagellum. A single spermatophore, similar in shape to that described for other Neuroptera, was found occluding the bursa copulatrix of a teneral female. © 1994 Wiley‐Liss, Inc.
Furrowing surface contraction wave coincident with primary neural induction in amphibian embryos
Authors: Brodland G. Wayne , Gordon Richard , Scott Michael J. , Björklund Natalie K. , Luchka Kurt B. , Martin C. Cristofre , Matuga Cindy , Globus Morton , Vethamany‐Globus Swani , Shu Dongwei
Published: February 2005

We predicted, and have now observed, a surface contraction wave in axolotl (Ambystoma mexicanum) embryos that appears to coincide temporally and spatially with primary neural induction and homoiogenetic induction, and with involution of the chordomesoderm. The wave starts from a focus anterior to the dorsal lip of the blastopore and spreads as an ellipse, until part of it encounters the rim of the blastopore and vanishes there. The remaining are then continues over the dorsal hemisphere until it reforms an ellipse that decreases in size. About 9 to 12 hours after it begins, the wave vanishes at a focus diametrically opposite its point of origin. The wave involves both local contraction and furrowing in the monolayer ectoderm. To a good approximation, the hemispherical portion of the ectoderm traversed by the wave becomes neuroepithelium, while the ectoderm not transversed by the wave becomes epidermis. The wave might provide a mechanism to determine the time and location at which neuroepithelial differentiation occurs. © 1994 Wiley‐Liss, Inc.
Fine structures on the surface of nuptial pads of male hylid and rhacophorid frogs
Authors: Kurabuchi Shingo
Published: February 2005

Nuptial pads, secondary sexual characteristics of male frogs, develop on the first digit of the hand of Hyla japonica in the family Hylidae and of Rhacophorus schlegelii in the family Rhacophoridae, and on both the first and second digits of the rhacophorids Buergeria buergeri and B. japonica. By scanning electron microscopy (SEM), it was seen that numerous mounds covered the surface of the pads. Mounds were similarly hemispherical in R. schlegelii and B. buergeri and flat in B. japonica. The mounds of H. japonica were irregular in shape and size and some of them stood in rows. Fine columnar protuberances were present all over the surfaces of the mounds in this species. Numerous peg‐like protuberances projected radially upward from the top of the mounds in B. buergeri and B. japonica. Irregular‐shaped, leaf‐like protuberances bearing knobby or rod‐shaped apical protrusions were present on the top of the mounds in R. schlegelii. In pads observed by transmission electron microscopy, the outermost epithelial monolayer of the mounds was generally thick, especially at the top, compared to that of the rest of the skin. Epidermal cells in this layer were well keratinized, devoid of organelles, and contained closely packed, fine filaments within a dense matrix. Apical accessory protuberances projecting from the outermost cells were also packed with dense filamentous materials, showing rigid comb‐like structures. © 1994 Wiley‐Liss, Inc.
Composite, haustellate mouthparts in netwinged beetle and firefly larvae (Coleoptera, Cantharoidea: Lycidae, Lampyridae)
Authors: Cicero Joseph M.
Published: February 2005

During lycid embryogenesis, labral and mandibular anlagen develop separately. Each anterolateral corner of the labrum elongates into a stylet, while the whole of each mandible involutes into a flute that is open to the lateral aspects. The stylets and flutes interlock in such a way as to leave canals, fashioning left and right haustellate apparatuses. During lampyrid embryogenesis, only one pair of anlagen forms instead of two. The pair matures into sharp, arcuate appendages that appear to be typical mandibles, but nevertheless a canal forms internally. The canal is not formed by coadaptation of two appendages; instead, cells within the pair create the canal autonomously. Indications are that the canal is homologous between these two families. It is suggested that in lampyrids, labral and mandibular cell fields develop together in the same anlage but behave according to their own respective programs, forming the canal with morphogenetic movements that are comparable to those of lycids. © 1994 Wiley‐Liss, Inc.
Antennal sensilla of Rhodnius
Authors: Catalá Silvia , Schofield Christopher
Published: February 2005

By scanning electron microscopy, sensilla type and distribution were studied on the antennae of ten species of Rhodnius. No sexual dimorphism was apparent. Intraspecific differences in sensillar pattern were shown to be potentially useful in species determination and to agree with results from biochemical studies and previous morphometric studies in terms of species affinities. © 1994 Wiley‐Liss, Inc.
Mechanism of internal fertilization in Pegea socia (Tunicata, Thaliacea), a salp with a solid oviduct
Authors: Holland L. Z. , Miller R. L.
Published: February 2005

The ovary of the salp Pegea socia (Bosc, 1802) is located at the end of an atrial diverticulum. The ovary consists of a single oocyte encased in a layer of follicle cells and is connected to the atrial epithelium by an oviduct. Transmission electron microscopy shows that the oocyte lacks a vitelline layer, cortical granules, and yolk granules and that the oviduct lacks a continuous lumen. What previous authors thought was a lumen is a line of dense intercellular junctions running down the center of the oviduct. The sperm nucleus in this species, as in other salps, is elongate. The tubular mitochondrion spirals about the sperm nucleus giving it a corkscrew‐shape appearance. Sperm reach the ovary when the oocyte is still at the germinal vesicle stage. Many sperm swim up the atrial diverticulum and burrow through the cells of the atrial epithelium, oviduct, and follicular epithelium. Thus oviduct shortening, which occurs when the oocyte is in the meiotic divisions, is evidently unrelated to sperm moving up the oviduct. All previous authors, who argued either that a continuous lumen is necessary for sperm to move up the oviduct or that sperm bypass the oviduct, were incorrect. © 1994 Wiley‐Liss, Inc.
Effects of the anabolic steroid nandrolone phenylpropionate on craniofacial growth in rats
Authors: Noda Kazunobu , Chang Hong‐Po , Takahashi Ichiro , Kinoshita Zennosuke , Kawamoto Tatsuo
Published: February 2005

Primary testosterone and its derivatives are anabolic steroids used in the treatment of osteoporosis and Turner syndrome. They also enhance fast‐twitch muscle weight in female rats. The present study examines the effect of an anabolic steroid on craniofacial growth and development in rats. Five‐week‐old female Sprague‐Dawley rats (125) were divided into experimental and control groups. The experimental group was injected subcutaneously with 1 mg nandrolone phenylpropionate in the interscapular region on alternate days, whereas those in the control group were injected with a vehicle, arachis oil. Rats were sacrificed at 60 and 120 days of age. Cephalometric analysis of soft X‐ray cephalograms showed that chronic administration of the anabolic steroid, nandrolone phenylpropionate, resulted in: (1) about a 20% increase in body weight, (2) an increase in total skull length, (3) elongation of the maxillary and mandibular incisors, (4) an increase in the depth of the antegonial notch, and (5) downward‐forward growth of the viscerocranium against the neurocranium. These results suggest that nandrolone phenylpropionate may accelerate craniofacial growth and/or induce high functional activity of the masticatory muscles in female rats. © 1994 Wiley‐Liss, Inc.
Cochlear and lagenar ganglia of the chicken
Authors: Fischer Franz Peter , Eisensamer Brigitte , Manley Geoffrey A.
Published: February 2005

Cochlear and lagenar components of the statoacoustical ganglion in the inner ear of one chicken were studied quantitatively in the TEM. Both myelinated and unmyelinated nerve fibers were present in these two parts of the ganglion and in a putative efferent bundle within the ganglion. The cochlear portion had the lowest, the efferent bundle the highest percentage of unmyelinated fibers. Compared to the other parts of the ganglia, the cochlear fibers had a high degree of homogeneity, especially in fiber size. Some gradients in the baso‐apical direction were found, such as an increase in the size of myelinated cochlear fibers from the base to the apex. Based on the ultrastructure of cellular components, no distinct populations of cell bodies within the statoacoustical ganglion were definable.

The ganglion contained some 8,000 cochlear and about 1,200–2,000 lagenar neurons. The putative efferent bundle had only 150–200 fibers. This cannot be the total number of efferents to the hair cells in both the basilar papilla and the lagena. A large number of efferent fibers to the auditory papillae presumably run mingled among the afferent fibers. © 1994 Wiley‐Liss, Inc.
Pigment pattern formation in larval ambystomatid salamanders: Ambystoma talpoideum, Ambystoma barbouri, and Ambystoma annulatum
Authors: Olsson Lennart
Published: February 2005

The pigment pattern formation in embryos and larvae of three ambystomatid salamanders was investigated in an evolutionary context. Early neural crest development was studied with scanning electron microscopy. Pigment cell migration and pattern formation were investigated at the light microscopy level with markers that labelled the two pigment cell types specifically before they were fully differentiated. In all three species, the pigment pattern formation started when xanthophores that had first formed aggregates in the crest migrated ventrally. As previously observed in other species, vertical bars always form by a mechanism involving earlier onset of migration in melanophores than in xanthophores and aggregate formation in the crest. In Ambystoma talpoideum and A. annulatum, a pattern of vertical chromatophore bars formed, which was superimposed on a pattern of horizontal stripes. In Ambystoma barbouri, the tendency to form this pattern was obscured by the high density of melanophores. It is suggested that variation among species may be due to differences in the chromatophore density and in the melanophore/xanthophore ratio. Mapping of the evolution of vertical bars onto existing phylogenies for the group was confounded by controversies about how to interpret the phylogenetic data. On the phylogeny that takes all the available evidence into account, there are two equally parsimonious mappings. Vertical bars have either evolved only once and been lost twice, or evolved twice and been lost once. This rather conservative pattern can be explained both as an effect of stabilizing selection and as a result of developmental constraints. © 1994 Wiley‐Liss, Inc.
Harderian gland ultrastructure of the black sea bottlenose dolphin (Tursiops truncatus ponticus)
Authors: Bodyak Natalie D. , Stepanova Lily V.
Published: February 2005

Examination of the Harderian gland structure of the Black Sea bottlenose dolphin, Tursiops truncatus ponticus, at macroscopic, microscopic, and electron microscopic levels shows significant sexual dimorphism. The epithelial cells of male and female glands are different cell types, capable of producing chemically different products. Secretory cells in both sexes contain secretion granules that produce a secretion consisting mainly of proteins and carbohydrates, but thought to be sex‐specific in composition. The female glands also contain lipid secretion granules. It is suggested that in the bottlenose dolphin the Harderian gland functions to produce sexually distinct pheromones and may have other physiological activities, e.g., participating in local immunological or endocrine‐related reactions. © 1994 Wiley‐Liss, Inc.