Abstract:
:The Puerto Rican tree frog, Eleutherodactylus coqui, has internal fertilization and direct development on land. In light of these reproductive adaptations, the events of fertilization and early development were studied. Cytological examination of just-fertilized eggs showed that sperm entry is restricted to about 10% of the surface of these large, yolky eggs, and all nuclear events of the first cell cycle occur near the animal pole. Although the oocytes have cortical granules, a number of polyspermic fertilizations were found. One clutch consisted of eggs with a high frequency of polyspermy and of normal development. This raises the possibility that normal development can occur despite multiple sperm entry, a situation not found in other anuran amphibians. With respect to saline requirements, the sperm and the embryo are similar to those in amphibians with external fertilization and aqueous development. Sperm motility was high in low-tonicity conditions, and the normally terrestrial embryo could develop completely from a fertilized egg to a froglet in a low-tonicity aqueous solution.
journal_name
J Morpholjournal_title
Journal of morphologyauthors
Elinson RPdoi
10.1002/jmor.1051930208subject
Has Abstractpub_date
1987-08-01 00:00:00pages
217-224issue
2eissn
0362-2525issn
1097-4687journal_volume
193pub_type
杂志文章abstract::Zambian common mole-rats are subterranean rodents that live in families with only one female breeding. Her offspring remain in the parental nest and do not reproduce. Behavioral experiments (Burda, '95) demonstrated that their apparent "sterility" is based on incest avoidance and individual recognition of family membe...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/(SICI)1097-4687(199807)237:1<33::AID-JMOR3
更新日期:1998-07-01 00:00:00
abstract::A phylogenetic survey is a powerful approach for investigating the evolutionary history of a morphological characteristic that has evolved numerous times without obvious functional implications. Restricted gill openings, an extreme modification of the branchiostegal membrane, are an example of such a characteristic. W...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.20371
更新日期:2015-06-01 00:00:00
abstract::The surface of a mature, pelagic C-O sole egg is composed of polygonal chambers having four to eight sides, most of which are hexagonally shaped. This honeycomb pattern initially appears on primary oocytes as a thin layer of compact, electron-dense material. Discrete thickenings begin to develop on the envelope of per...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051780305
更新日期:1983-12-01 00:00:00
abstract::Six locomotory muscles of wild common coots, Fulica atra, were analyzed histochemically. Capillarity and fiber-type distributions were correlated to the functional implications and physiological needs of each muscle. Leg muscles exhibit three unevenly distributed fiber types, a pattern that reflects the great variety ...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/(SICI)1097-4687(199808)237:2<147::AID-JMOR
更新日期:1998-08-01 00:00:00
abstract::A hitherto unknown sensillum type, the "intracuticular sensillum" was identified on the dactyls of the walking legs of the shore crab, Carcinus maenas. Each sensillum is innervated by two sensory cells with dendrites of "scolopidial" (type I) organization. The ciliary segment of the dendrite is 5-6 μm long and contain...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1052040311
更新日期:1990-06-01 00:00:00
abstract::Standard transmission electron microscopy (TEM) techniques have been applied to three species of phoronids to describe cytological features of their nervous systems. Four types of neurons have been distinguished by morphological and ultrastructural criteria, mainly involving their kinds of vesicles. Glial cells with c...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/(SICI)1097-4687(199612)230:3<265::AID-JMOR
更新日期:1996-12-01 00:00:00
abstract::During epidermal differentiation in mammals, keratins and keratin-associated matrix proteins rich in histidine are synthesized to produce a corneous layer. Little is known about interkeratin proteins in nonmammalian vertebrates, especially in reptiles. Using ultrastructural autoradiography after injection of tritiated...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.10181
更新日期:2004-02-01 00:00:00
abstract::Light and electron microscopy reveal that simple receptor cells in the jaw epithelium of sea urchin pedicellariae are connected by nerve tracts to the neuropile that coordinates jaw movements. The muscles responsible for jaw opening and closure and for flexion of the stem are all innervated in this neuropile. At least...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051930105
更新日期:1987-07-01 00:00:00
abstract::Burrow construction in the subterranean Ctenomys talarum (Rodentia: Ctenomyidae) primarily occurs by scratch-digging. In this study, we compared the limbs of an ontogenetic series of C. talarum to identify variation in bony elements related to fossorial habits using a morphometrical and biomechanical approach. Diamete...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.20267
更新日期:2014-08-01 00:00:00
abstract::The fiber constituents and connections of the calyces - the input-receiving regions - of the corpora pedunculata ("mushroom bodies") were studied in reduced silver preparations from the American cockroach, Periplaneta americana (L.). In the outer synaptic layer of the calyces five fiber classes were distinguished, the...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051420103
更新日期:1974-01-01 00:00:00
abstract::The ultrastructure of the coxal glands and associated tissues in the centipedes Lithobius forficatus and Lithobius crassipes has been examined in the light of two contrasting functional hypotheses postulated by different authors. Lithobiomorph chilopods possess eight sets of pores on the posterioventral border of the ...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051770204
更新日期:1983-08-01 00:00:00
abstract::Sexual dimorphism in the distribution of antennal sense organs is common among adults of the genus Periplaneta. In three out of the four strains of Periplaneta americana examined, adult males had more contact chemoreceptros than females. In the fourth strain of P. americana and in P. australasiae, P. brunnea, P. fulig...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051490202
更新日期:1976-06-01 00:00:00
abstract::At mating, female insects generally receive and store sperm in specific organs of their reproductive tract called spermathecae. Some Heteroptera, such as Cimicomorpha, lack a true spermatheca; some have receptacles of novel formation where sperm cells can transit or be stored. In Tingidae, there are two sac-like diver...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.10811
更新日期:2010-04-01 00:00:00
abstract::The masticatory pattern of Sphenodon punctatus, the sole remaining rhynchocephalian, now restricted to islands off the coast of New Zealand, has been analyzed by detailed anatomy, cinematography, cinefluoroscopy, and electromyography. Food reduction consists of a closing, crushing bite followed by a propalineal slidin...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051710307
更新日期:1982-03-01 00:00:00
abstract::Amphisabenia is a group of squamates adapted for a fossorial lifestyle. The skull is the animal's the main digging tool, and can present one of four principal shapes. The shovel-headed shape is considered to be the most specialized for digging. The South American genus Leposternon presents a shovel-headed morphotype, ...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.20899
更新日期:2018-11-01 00:00:00
abstract::An otolith increment is composed of an incremental zone and a discontinous zone. Observation of the otoliths of Oreochromis niloticus with transmission and scanning electron microscopy reveals that organic fibers are concentrated in the discontinuous zone and are relatively scarce in the incremental zone. On the other...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1052110210
更新日期:1992-02-01 00:00:00
abstract::The feeding mechanisms of two labrid fishes (Cheilinus chlorurus and C. diagrammus: Labridae: Perciformes) are modeled using four-bar linkage theory from mechanical engineering. The actions of the feeding mechanisms are simulated by a computer program that uses morphometric data to calculate the geometry of mechanism ...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1052050304
更新日期:1990-09-01 00:00:00
abstract::Hind foot drumming is a form of seismic signaling that plays a vital role in the communication of several Bathyergidae species. Hind foot drumming is initiated by the rapid movement of the whole hind limb by flexion and extension of the hip and knee. This study aimed to determine if morphological adaptations of the hi...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.21110
更新日期:2020-04-01 00:00:00
abstract::The fine structure of the shell and underlying mantle in young juveniles of the articulate brachiopod Terebratalia transversa has been examined by electron microscopy. The first shell produced by the mantle consists of a nonhinged protegulum that lacks concentric growth lines. The protegulum is secreted within a day a...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051830303
更新日期:1985-03-01 00:00:00
abstract::Swimming crabs of the taxon Portunoidea show specialized, paddle-shaped fifth pereiopods (P5), which play a role in these crabs' ability to swim. In this study, the morphology of the fifth pereiopod in swimming and non-swimming crabs was studied in detail and the mobility in the articulations between podomeres was cal...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.21268
更新日期:2020-12-01 00:00:00
abstract::Liolaemus elongatus (Liolaemidae) is a viviparous, mainly lecithotrophic species with placental structures specialized for uptake of oxygen and inorganic nutrient transport. An allantoplacenta and an omphaloplacenta are present during early embryonic stages (25-28) and there is a moderate distension of the uterine wal...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.10632
更新日期:2008-07-01 00:00:00
abstract::Three lineages of cartilaginous fishes have independently evolved filter feeding (Lamniformes: Megachasma and Cetorhinus, Orectolobiformes: Rhincodon, and Mobulidae: Manta and Mobula); and the structure of the branchial filters is different in each group. The filter in Rhincodon typus has been described; species withi...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.20160
更新日期:2013-09-01 00:00:00
abstract::The amphibian tongue contains two types of papilla which are believed to function in gustation and in the secretion of salivary fluid. Scanning electron microscopy reveals that columnar, filiform papillae are compactly distributed over nearly the entire dorsal surface of the tongue of the frog, Rana cancrivora, and fu...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1052150106
更新日期:1993-01-01 00:00:00
abstract::The hypotheses of relationships within Lari (gulls) are highly unstable, and depend on whether morphological or molecular data are examined. Developmental sequence data are thought to contain phylogenetic information, but have never been applied to the problem of avian systematics. In this article, we describe the oss...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.10633
更新日期:2008-09-01 00:00:00
abstract::The nurse shark, Ginglymostoma cirratum, is an obligate suction feeder that preys on benthic invertebrates and fish. Its cranial morphology exhibits a suite of structural and functional modifications that facilitate this mode of prey capture. During suction-feeding, subambient pressure is generated by the ventral expa...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.10626
更新日期:2008-09-01 00:00:00
abstract::Mengenillidae is a small, basal family of Strepsiptera, mainly characterized by free-living females in contrast to the endoparasitic females of Stylopidia. Here, we describe external and internal structures of the female abdomen of Eoxenos laboulbenei (Mengenillidae). The external morphology was examined and documente...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.20981
更新日期:2019-05-01 00:00:00
abstract::Annual fish development differs from that of other teleosts because a phase of blastomere dispersion-reaggregation spatially and temporally separates epiboly from embryogenesis. The fate of dispersed blastomeres was assessed in diblastodermic eggs of the annual fishes Cynolebias whitei and C. nigripinnis. In typical t...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1052150309
更新日期:1993-03-01 00:00:00
abstract::It has been hypothesized that fluctuating asymmetry (FA) may provide an indication of the functional importance of structures within an organism, with structures that more strongly impact fitness being more symmetric. Based on this idea, we predicted that for tetrapods in which the forelimbs and hindlimbs play an uneq...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.20967
更新日期:2019-04-01 00:00:00
abstract::The vascular system of the digits of the tokay is more complex than has hitherto been suspected and has a configuration which suggests it is intimately involved in the process of adhesion. Distinction can be made between lamellae (expanded scales beneath the proximal portion of the digit) and scansors (elaborations of...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051690305
更新日期:1981-09-01 00:00:00
abstract::Ultrastructural observations and glyoxilic acid-induced fluorescence of catecholamines indicate that tracts of axons lie at the base of the ciliary bands and run throughout their length in bipinnaria and brachiolaria larvae of Pisaster ochraceus. Two types of nerve cells occur at regular intervals within the ciliary b...
journal_title:Journal of morphology
pub_type: 杂志文章
doi:10.1002/jmor.1051780103
更新日期:1983-10-01 00:00:00