Early events in sea urchin metamorphosis, description and analysis.

abstract：:Most anatomical and physiological studies of the sauropsid heart have focused on species with extraordinary physiologies, and detailed anatomical descriptions of hearts from sauropsids with more common physiologies are therefore warranted. Here, we present a comprehensive study of the cardiac anatomy of the South Amer...

journal_title：Journal of morphology

authors： Jensen B,Abe AS,Andrade DV,Nyengaard JR,Wang T

更新日期：2010-09-01 00:00:00

abstract：:The ultrastructure of a well studied insect chemosensory unit is presented in this report. Two separate lumina are present in this chemosensory unit, the trichogen and sensillar lumina. The fluid within the trichogen lumen exclusively bathes the dendritic terminals, and may be involved with the reception and/or modula...

journal_title：Journal of morphology

authors： Felt BT,Vande Berg JS

更新日期：1976-11-01 00:00:00

abstract：:Reproduction was studied in a South Carolina population of the paedomorphic salamander Siren intermedia with emphasis on anatomy of the female oviduct. The oviduct forms 67-79% of the snout-vent length in this elongate species and can be divided into three portions. The atrium, 7-13% of oviducal length, is the narrow ...

journal_title：Journal of morphology

authors： Sever DM,Rania LC,Krenz JD

更新日期：1996-03-01 00:00:00

abstract：:Knowledge of oocyte development and the early differentiation of the germ layers in monotremes stems largely from two articles by J. P. Hill and T. Thomson Flynn. The completeness of their account was due to the large series of echidna ovaries and eggs collected on Tasmania by Flynn, an Australian biologist of whom a ...

journal_title：Journal of morphology

authors： Carter AM

更新日期：2021-01-03 00:00:00

abstract：:Age and sex-related variations in sternum morphology may affect the thoracic injury tolerance. Male and female sternum size and shape variation was characterized for ages 0-100 from landmarks collected from 330 computed tomography scans. Homologous landmarks were analyzed using Procrustes superimposition to produce ag...

journal_title：Journal of morphology

authors： Weaver AA,Schoell SL,Nguyen CM,Lynch SK,Stitzel JD

更新日期：2014-11-01 00:00:00

abstract：:The differences in angulation and length observed for the fibers of anatomical muscles may reflect two distinct mechanical requirements: arrangement for pinnation, reflecting an increase in physiological cross-section and arrangement for equivalent placement of sarcomeres, possibly associated with coordination. The ob...

journal_title：Journal of morphology

authors： Gans C,de Vree F

更新日期：1987-04-01 00:00:00

abstract：:The medaka, Oryzias latipes, is a model organism in experimental biology. Its ontogeny and osteology have been studied frequently, but no detailed description of its cranial anatomy exists. Based on manual dissections, histological slide sections, and 3D-reconstructions, we describe the anatomy of the jaw apparatus of...

journal_title：Journal of morphology

authors： Werneburg I,Hertwig ST

更新日期：2009-09-01 00:00:00

abstract：:The median fins in extant actinopterygians are the product of millions of years of evolution. During this time, different developmental patterns for the dorsal and anal fins emerged leading to a high variation in median fin morphology and ontogeny. In this study, the development of anal and dorsal fins in atheriniform...

journal_title：Journal of morphology

authors： Richter P,Moritz T

更新日期：2017-06-01 00:00:00

abstract：:Embryos of goodeid fishes develop to term within the ovarian lumen, where they undergo considerable increase in weight due to transfer of maternal nutrients across a trophotaenial placenta. The placenta consists of an embryonic component, the trophotaeniae, and a maternal component, the ovarian lining. The latter was ...

journal_title：Journal of morphology

authors： Lombardi J,Wourms JP

更新日期：1985-06-01 00:00:00

abstract：:Spermiogenesis in the South American leptodactylid frog Odontophrynus cultripes was analyzed ultrastructurally. The spermatids undergo morphological modification while still enclosed in microtubule-rich processes of Sertoli cells. Electron-dense plates resembling junctional structures appear in regions at which the sp...

journal_title：Journal of morphology

authors： Báo SN,Dalton GC,de Oliveira SF

更新日期：1991-03-01 00:00:00

abstract：:The Hula Painted Frog (Latonia nigriventer) is a rare frog species endemic to the Hula Valley, Israel. The species is the sole relict of a clade that was widespread mainly in Europe from the Oligocene until the beginning of the Pleistocene. The osteological characteristics of L. nigriventer are described based on X-ra...

journal_title：Journal of morphology

authors： Biton R,Boistel R,Rabinovich R,Gafny S,Brumfeld V,Bailon S

更新日期：2016-09-01 00:00:00

abstract：:The combined techniques of light microscopy, scanning (SEM) and transmission (TEM) electron microscopy were used for the first time to study the structure of unicameral lungs of a Tegu lizard (Tupinambis nigropunctatus). The lungs are prolate spheroid bags with blood supplied by superficial branches of a dorsal pulmon...

journal_title：Journal of morphology

authors： Klemm RD,Gatz RN,Westfall JA,Fedde MR

更新日期：1979-09-01 00:00:00

abstract：:To date, the phylum Cycliophora comprises only one described extant species of acoelomate marine invertebrates, Symbion pandora. Adult specimens live commensally on the mouthparts of the Norwegian lobster, Nephrops norvegicus. Its complicated life cycle includes an asexually produced Pandora larva and a sexually produ...

journal_title：Journal of morphology

authors： Wanninger A

更新日期：2005-08-01 00:00:00

abstract：:Mature spermatozoa from spermathecae of founding queens were obtained from 5 species of ants, representing the major subfamilies Myrmicinae (Acromyrmex versicolor, Crematogaster sp.) and Dolichoderinae (Tapinoma sessile, Conomyrma insana, Conomyrma wheeleri). The ultrastructure of ant spermatozoa has many features in ...

journal_title：Journal of morphology

authors： Wheeler DE,Crichton EG,Krutzsch PH

更新日期：1990-12-01 00:00:00

abstract：:The function of the septomaxilla of nonmammalian synapsids has long been problematic. Distinctive features of this bone, including a prominent intranarial process and a septomaxillary canal and foramen, are characteristic of pelycosaurs and nonmammalian therapsids, but are lost in their mammalian descendants. Numerous...

journal_title：Journal of morphology

authors： Hillenius WJ

更新日期：2000-07-01 00:00:00

abstract：:High speed cinematography was used to record the feeding activities of terrestrial Ambystoma tigrinum melanostictum. A description of these activities based on films of more than 50 feeding sequences is presented, and the mechanical units involved are defined, described, and functionally analyzed. Evolutionary implica...

journal_title：Journal of morphology

authors： Larsen JH Jr,Guthrie DJ

更新日期：1975-10-01 00:00:00

abstract：:Profiles with all orientations have been used to visualize the 3D structure of ivory from tusks of elephant, mammoth, walrus, hippopotamus, pig (bush, boar, and warthog), sperm whale, killer whale, and narwhal. Polished, forming, fractured, aged, and stained surfaces were prepared for microscopy using epi-illumination...

journal_title：Journal of morphology

authors： Locke M

更新日期：2008-04-01 00:00:00

abstract：:We investigated growth-related and sex-related morphological changes in the skulls of 144 North Pacific common minke whales Balaenoptera acutorostrata. Measurement was conducted at 39 points on the skull and mandible to extract individual allometric equations relating the length and zygomatic width of the skull. The r...

journal_title：Journal of morphology

authors： Nakamura G,Kato H

更新日期：2014-10-01 00:00:00

abstract：:Developmental studies of the Recent Australian lungfish, Neoceratodus forsteri, show that this species has two sets of functional tooth-bearing bones in the lower jaw of young hatchlings. These coincide with an early stage in the life history when the fish is strictly carnivorous. In N. forsteri, a paired tooth-bearin...

journal_title：Journal of morphology

authors： Kemp A

更新日期：1995-09-01 00:00:00

abstract：:Data describing segmental masses and moments of inertia (MOI) of limb segments are required for inverse dynamic calculations. In horses, these values are usually calculated using regression equations that have been developed from a limited number of horses representing a small number of breeds. The objective of the pr...

journal_title：Journal of morphology

authors： Nauwelaerts S,Clayton HM

更新日期：2018-07-01 00:00:00

abstract：:The ultrastructure of the adenohypophysis (AH) in the larval anadromous sea lamprey, Petromyzon marinus L., was examined. The AH is subdivided into three regions, the pro-, meso-, and meta-AH. Cells of the nasopharyngeal stalk extend directly beneath the pro- and meso-AH to form the ventral surface of the gland. Some ...

journal_title：Journal of morphology

authors： Wright GM

更新日期：1983-06-01 00:00:00

abstract：:The vertebrate head as a major novelty is directly linked to the evolutionary success of the vertebrates. Sequential information on the embryonic pattern of cartilaginous head development are scarce, but important for the understanding of its evolution. In this study, we use the oriental fire bellied toad, Bombina ori...

journal_title：Journal of morphology

authors： Lukas P,Olsson L

更新日期：2020-06-01 00:00:00

abstract：:Sipuncula is a clade of unsegmented marine worms that are currently placed among the basal radiation of conspicuously segmented Annelida. Their new location provides a unique opportunity to reinvestigate the evolution and development of segmented body plans. Neural segmentation is clearly evident during ganglionic ven...

journal_title：Journal of morphology

authors： Carrillo-Baltodano AM,Boyle MJ,Rice ME,Meyer NP

更新日期：2019-11-01 00:00:00

abstract：: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 co...

journal_title：Journal of morphology

authors： Casciotta JR,Arratia G

更新日期：1993-07-01 00:00:00

abstract：:Barnacle cypris larvae show high morphological variation in the organs used in search of and attaching to a substratum. This variation may represent adaptation to the habitat of the species. Here, we studied SEM level morphologies of cypris antennular sensory and attachment organs in a deep-sea vent endemic species (N...

journal_title：Journal of morphology

authors： Yorisue T,Chan BK,Kado R,Watanabe H,Inoue K,Kojima S,Høeg JT

更新日期：2016-05-01 00:00:00

abstract：:The morphology of 16 occipital spines of the xenacanthid Orthacanthus from Upper Carboniferous deposits of Robinson (Kansas, USA), Nýran (Czech Republic) and Puertollano (Spain) is described. The nonreplaced spines reveal the growth pattern of the shark. Moreover, the relationship between growth and paleoenvironmental...

journal_title：Journal of morphology

authors： Soler-Gijón R

更新日期：1999-10-01 00:00:00

abstract：:Recent molecular phylogenies conflict with traditional scleractinian classification at ranks ranging from suborder to genus, challenging morphologists to discover new characters that better agree with molecular data. Such characters are essential for including fossils in analyses and tracing evolutionary patterns thro...

journal_title：Journal of morphology

authors： Budd AF,Stolarski J

更新日期：2011-01-01 00:00:00

abstract：:Reconstruction of limb posture is a challenging task in assessing functional morphology and biomechanics of extinct tetrapods, mainly because of the wide range of motions possible at each limb joint and because of our poor knowledge of the relationship between posture and musculoskeletal structure, even in the extant ...

journal_title：Journal of morphology

authors： Fujiwara S

更新日期：2009-09-01 00:00:00

abstract：:The progression of ovarian follicular development in the Northern Alligator Lizard has been documented ultrastructurally and by enumeration of cells, with a focus on changes in the granulosa component of the follicle. The pattern of cellular differentiation of the granulosa entails, as in other lizards, the transforma...

journal_title：Journal of morphology

authors： Klosterman LL

更新日期：1987-05-01 00:00:00

abstract：:Early spermatids of the onychophoran Peripatopsis capensis are spherical cells with a centrally located nucleus, numerous mitochondria, Golgi complexes, microtubules and two centrioles. During spermiogenesis, Golgi vesicles migrate to one side of the cell where they form a tight aggregate, which is later shed. The mat...

journal_title：Journal of morphology

authors： Camatini M,Franchi E,Saita A

更新日期：1979-01-01 00:00:00