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Journal of Morphology

Andrea K Johnson, Harry J Grier
Histological examination of ovarian morphology was conducted on the monkfish, Lophius americanus. The ovary is of the cystovarian type, that is, with a lumen. However, ovarian morphology is quite unique, compared to other fishes, in that ovarian lamellae only originate along the ventral ovarian wall rather than around the periphery. They may branch at their base, but are otherwise unbranching. Furthermore, the germinal epithelium that is, the site of germ cell production, is described for the first time in L...
November 15, 2018: Journal of Morphology
Renan A Moreira, Marcelo R de Carvalho
The subclass Batoidea comprise skates, electric rays, stingrays, guitarfishes, and sawfishes, and their interrelationships are still problematical despite recent morphological and molecular phylogenetic studies. The most recent morphological phylogeny indicates that guitarfishes are a polyphyletic group, and that the phylogenetic placement of Platyrhina and Platyrhinoidis is still unclear. Several molecular studies suggest that guitarfishes (except Zanobatus) and sawfishes comprise the monophyletic order Rhinopristiformes, and that thornback rays (Platyrhinidae, Platyrhina, and Platyrhinoidis) are more closely related to the electric rays (Torpediniformes); rhinopristiforms have recently been supported by morphological data as well...
November 15, 2018: Journal of Morphology
Kelly S Boyle, Anthony Herrel
The Weberian apparatus of otophysan fishes confers acute hearing that is hypothesized to allow these fishes to assess the environment and to find food resources. The otophysan family Serrasalmidae (piranhas and pacus) includes species known to feed on falling fruits and seeds (frugivore/granivores) that splash in rivers, herbivorous species associated with torrents and rapids (rheophiles), and carnivores that feed aggressively within shoals. Relevant sound stimuli may vary among these ecological groups and hearing may be tuned to different cues among species...
November 15, 2018: Journal of Morphology
Ewelina Prozorowska, Hanna Jackowiak, Kinga Skieresz-Szewczyk
The study describes the morphology and topography of internal reproductive organs in the domestic cat from the early prenatal period to maturity, using macroscopic and scanning electron microscope (SEM) observations with three-dimensional (3D) reconstructions. Fifty-seven female cat fetuses aged between the 27th and 63rd day postconception (p.c.), two newborn cats, three juveniles (3-month-old) cats, and three mature (12-month-old) cats were used in the study. The age of fetuses was determined on the basis of the growth curve for the domestic cat...
November 15, 2018: Journal of Morphology
Jennifer S Bigman, Sebastián A Pardo, Tanya S Prinzing, Marc Dando, Nicholas C Wegner, Nicholas K Dulvy
Fish gill surface area varies across species and with respect to ecological lifestyles. The majority of previous studies only qualitatively describe gill surface area in relation to ecology and focus primarily on teleosts. Here, we quantitatively examined the relationship of gill surface area with respect to specific ecological lifestyle traits in elasmobranchs, which offer an independent evaluation of observed patterns in teleosts. As gill surface area increases ontogenetically with body mass, examination of how gill surface area varies with ecological lifestyle traits must be assessed in the context of its allometry (scaling)...
November 14, 2018: Journal of Morphology
Letícia Aguilar, Rebeca Nuno Leite, Cleomárcia Almeida Ferreira, André Luis da Cruz
Facultative air-breathing fish can exchange respiratory gases using an air-breathing organ (ABO), such as the oral cavity of the integument, during environmental hypoxia. The goby Gobionellus oceanicus inhabits areas subject to environmental hypoxia; however, its ABO is unknown. To investigate the respiratory potential of G. oceanicus, the gill and integument surface area, diffusion capacity, and their diffusion barrier thickness were measured. Our results show that although gill surface area is smaller than observed in other facultative air-breathing fish, but it has all features necessary to perform aquatic gas exchange...
November 8, 2018: Journal of Morphology
Elysse M Craddock, Michael P Kambysellis, Lisa Franchi, Peter Francisco, Marques Grey, Angela Hutchinson, Shawn Nanhoo, Shyar Antar
Ecological diversification of the endemic Hawaiian Drosophilidae has been accompanied by striking divergence in egg morphology, and ovarian structure and function. To determine how these flies successfully oviposit in a variety of breeding substrates, we used Scanning Electron Microscopy to examine the ultrastructure of the ovipositor of a sample of 65 Drosophila species and five Scaptomyza species of this hyperdiverse monophyletic group. The Drosophila species analyzed included representatives of the fungus-breeding haleakalae group, the leaf-breeding antopocerus and modified tarsus groups, the modified mouthparts species group, the nudidrosophila, and the picture wing clade; the latter sample of 41 species from four species groups included stem- and bark-breeders, as well as tree sap flux-breeders...
November 5, 2018: Journal of Morphology
Michel Comeau, Kadra Benhalima
Light microscopy studies of the female American lobster Homarus americanus reproductive system are essentially nonexistent or outdated. Based on samples taken in the spring, summer, and autumn from the southern Gulf of St. Lawrence between 1994 and 2014, and using a combination of histological and scanning electron microscope techniques, we propose an ovarian cycle with 10 stages, identifying for the first time a recovery stage. Also, an atypical resorption stage, characterized by massive reabsorption of mature oocytes, is occasionally observed during summer months...
November 5, 2018: Journal of Morphology
David A Tarailo
Temnospondyl amphibians experienced a geologically brief interval of success in the wake of the end-Permian mass extinction. This study examines the relationship between taxonomic and ecological diversity of temnospondyls across the Permian-Triassic boundary in the Karoo Basin of South Africa. Ecomorphological diversity, as implied by differences in cranial shape, was incorporated into the study by the use of a landmark-based geometric morphometric analysis. Both taxonomic diversity and cranial disparity are low during the Permian and increase across the Permian-Triassic boundary...
November 5, 2018: Journal of Morphology
Gian N Frongia, Marco Muzzeddu, Paolo Mereu, Giovanni Leoni, Fiammetta Berlinguer, Marco Zedda, Vittorio Farina, Valentina Satta, Marco Di Stefano, Salvatore Naitana
Flight is an energetically costly form of transport imparting biomechanical stress that acts upon the wing bones. Previous studies have suggested that the cross-sectional and microstructural features of wing bones may be adapted to resist biomechanical loads. During flight, however, each wing bone potentially experiences a unique loading regime. To assess possible differences among wing bones, we analyzed the microstructural features of the humerus, radius, ulna, and carpometacarpus (CMC) in eight griffon vultures (Gyps fulvus)...
November 5, 2018: Journal of Morphology
Cassandra Pinheiro, Michaela L Venter, Lauren Sahd, Gary N Bronner, Sanet H Kotzé
Golden moles are small, fossorial, and primarily insectivorous mammals mostly endemic to South Africa. They belong to an ancient African clade of placental mammals (Afrotheria) that likely radiated from an herbivorous ancestor. Nearly half of the 21 golden mole species are listed as threatened; but remarkably little is known about their basic biology and gastrointestinal tract (GIT) morphology. This study provides a morphometric and histochemical analysis of the GIT of seven chrysochloridae species, including three threatened taxa...
October 31, 2018: Journal of Morphology
Carola Becker, Eoghan M Cunningham, Jaimie T A Dick, Lawrence E Eagling, Julia D Sigwart
Knowledge of the reproductive cycle in exploited species is important for a sustainable management of fisheries. Standardized scales to assess maturity stages are a fundamental tool to understand the demographic composition of exploited populations. Staging scales for female Norway lobster, Nephrops norvegicus, have been subject to a series of changes, and multiple inconsistent scales are in use in different fisheries regions. A unified, evidence-based scale has not previously been established. We reviewed previous staging scales for the female ovary maturation and propose a revised scale based on the correlation between macroscopic and microscopic ovary characteristics...
October 31, 2018: Journal of Morphology
Silvia I Quinzio, Marissa Fabrezi
The peripheral nervous system of anuran larvae has traditionally been assumed to be largely invariant. Here, we describe the organization of cranial, spinal, and lateral line nerves at different larval stages of Lepidobatrachus spp. based on whole mounts. This is the first detailed description of cranial, spinal, and lateral lines innervation at premetamorphic stages of anuran larvae with notes on temporal variation. We distinguish three sources of morphological variation with respect to other anuran larvae: (a) the loss or reduction of some exclusively larval elements (i...
October 31, 2018: Journal of Morphology
Michael J Ghedotti, Josephine N Gruber, Ryan W Barton, Matthew P Davis, W Leo Smith
Bioluminescent organs have evolved many times within teleost fishes and exhibit a wide range of complexity and anatomical derivation. Although some bioluminescent organs have been studied in detail, the morphology of the bacterial light organs in glowbellies (Acropoma) is largely unknown. This study describes the anatomy of the bioluminescent organs in Haneda's Glowbelly (Acropoma hanedai) and the Glowbelly (Acropoma japonicum) and places the evolution of this light-producing system in the context of a new phylogeny of glowbellies and their relatives...
October 22, 2018: Journal of Morphology
Karly Elizabeth Cohen, L Patricia Hernandez
Hypophthalmichthys molitrix, silver carp, is an invasive Asian carp that has become increasingly widespread and ecologically destructive within the upper Mississippi River Basin. Its complex trophic anatomy may help explain the apparent efficiency with which they consume phytoplankton, outcompeting native filter feeders. This cypriniform species is characterized by trophic synapomorphies that include a palatal organ, loss of upper pharyngeal jaws, and a hypertrophied lower pharyngeal jaw. However, in silver carp these structures have become greatly modified and diverge from the more basal condition that characterizes species such as goldfish...
October 22, 2018: Journal of Morphology
Ezra S Lencer, Amy R McCune
Using multiple taxa to research development is necessary for making general conclusions about developmental patterns and mechanisms. We present a staging series for Cyprinodon variegatus as a basis for further study of the developmental biology of fishes in the genus Cyprinodon and for comparative work on teleost fishes beyond the standard models. Cyprinodon are small, euryhaline fishes, widely distributed in fresh, brackish, and hypersaline waters of southern and eastern North America. Cyprinodontids are closely related to fundulids, providing a comparative reference point to the embryological model, Fundulus heteroclitus...
October 22, 2018: Journal of Morphology
Anna-Christin Joel, Hana Adamova, Peter Bräunig
Groups of mechanoreceptive sensilla form small sensory fields on the ventral rim of the most distal tarsomeres in insects. Within these fields two or three sensilla are located closely together. Anterior and posterior fields are found in all three pairs of legs with only a few exceptions. The composition, exact location, and morphology of the fields were studied in representative species of several insect orders using light and scanning electron microscopy. There was no obvious correlation between field morphology and insect phylogenetic relationships...
October 22, 2018: Journal of Morphology
Daniel G Blackburn, Luisa Lestz, Madeline S Barnes, Kathryn G Powers, Tracy Langkilde
Features of embryonic development in birds traditionally have been assumed to be shared by sauropsids in general. Herein, we document a pattern of yolk processing and cellularization in the Eastern fence lizard (Sceloporus undulatus) that is fundamentally different from that of birds. In the avian pattern, cells of the yolk sac lining phagocytose, and digest yolk material. These cells release products of digestion into underlying blood vessels for transport back to the embryo. In contrast, microscopic examination of the developing eggs of S...
October 22, 2018: Journal of Morphology
Oksana V Shatkovska, Maria Ghazali, Ivan S Mytiai, Natalia Druz
While eggs shapes and sizes have been subject of many studies, we still know little about factors affecting these characteristics of birds' eggs. We revealed that shapes of pelvis and egg correlated less than their respective sizes. Egg measurements (length or diameter) scaled with negative allometry against pelvis size, that is, eggs become relatively larger with decreasing pelvis size. Studied birds with altricial developmental mode had on average the smallest pelvic dimensions and the largest relative size of eggs...
October 22, 2018: Journal of Morphology
Elena N Temereva, Tatyana V Kuzmina
Details of spermatogenesis and sperm organization are often useful for reconstructing the phylogeny of closely related groups of invertebrates. Development in general and gametogenesis in particular usually differ in shallow water and deep-sea invertebrates. Here, the spermatogenesis and ultrastructure of sperm were studied in the deep-sea brachiopod Pelagodiscus atlanticus. The testes of P. atlanticus are voluminous sacs located along the lateral sides of the body. Germ cells develop around the blood capillaries, contact the basal lamina, and contain germ plasm, numerous mitochondria, Golgi apparatus, lipid droplets, and centrioles of the rudimentary cilium...
October 22, 2018: Journal of Morphology
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