External morphology of the choanoflagellate Salpingoeca gracilis James-Clark

1977 ◽  
Vol 57 (3) ◽  
pp. 629-634 ◽  
Author(s):  
Helge Abildhauge Thomsen
Keyword(s):  
External Morphology ◽  
Anterior Flagellum

In his search for evidence illustrating the botanical/zoological affinities of the sponges (Porifera), James-Clark (1867) studied a number of colourless flagellates. The genus Salpingoeca (Craspedophyceae, Christensen, 1962; cf. Chadefaud, 1960) was thus erected to comprise certain solitary, lorica-dwelling organisms, characterized by a single anterior flagellum encircled by a ‘filmy, membranous, colourless collar’ (James-Clark, 1867).About fifty species (approximately twenty marine) are at present allocated to this genus, provided it is defined as e.g. by Norris (1965) and Bourrelly (1968) (i.e. including Lagenoeca Kent and Pachysoeca Ellis).

An annotated checklist of mesoplodont whale species (Cetacea, Ziphiidae) discovered during the nineteenth century

2015 ◽  
Vol 42 (2) ◽  
pp. 226-235 ◽  
Author(s):  
G. N. H. Waller
Keyword(s):  
Nineteenth Century ◽  
Additional Data ◽  
Original Description ◽  
Type Specimen ◽  
External Morphology ◽  
Type Locality ◽  
Type Material ◽  
Beaked Whale ◽  
Registration Number ◽  
Annotated Checklist

Eight species of mesoplodont whales (genus Mesoplodon Gervais, 1850) named during the nineteenth century are based on valid descriptions. A checklist with the original description and type material for each of these species is provided. Additional data given may include type locality and illustrative sources, type material holding institution and type registration number(s). The only type specimen for which a record of external morphology was published relates to the 1803 stranding of Sowerby's beaked whale (Mesoplodon bidens).

External morphology and internal anatomical characters of juveniles of the freshwater drum Aplodinotus grunniens

2018 ◽  
Vol 25 (6) ◽  
pp. 1161
Author(s):  
Haibo WEN ◽  
Xueyan MA ◽  
Pao XU ◽  
Bingqing ZHENG ◽  
Xinhua YUAN ◽  
...  
Keyword(s):  
External Morphology ◽  
Aplodinotus Grunniens ◽  
Anatomical Characters ◽  
Freshwater Drum

scholarly journals Effect of captivity on morphology: negligible changes in external morphology mask significant changes in internal morphology

2018 ◽  
Vol 5 (5) ◽  
pp. 172470 ◽  
Author(s):  
Stephanie K. Courtney Jones ◽  
Adam J. Munn ◽  
Phillip G. Byrne
Keyword(s):  
Sexual Dimorphism ◽  
Captive Breeding ◽  
Morphological Changes ◽  
External Morphology ◽  
Wild Animals ◽  
Internal Morphology ◽  
In Captivity ◽  
Two Generations ◽  
Breeding Programmes ◽  
Source Populations

Captive breeding programmes are increasingly relied upon for threatened species management. Changes in morphology can occur in captivity, often with unknown consequences for reintroductions. Few studies have examined the morphological changes that occur in captive animals compared with wild animals. Further, the effect of multiple generations being maintained in captivity, and the potential effects of captivity on sexual dimorphism remain poorly understood. We compared external and internal morphology of captive and wild animals using house mouse ( Mus musculus ) as a model species. In addition, we looked at morphology across two captive generations, and compared morphology between sexes. We found no statistically significant differences in external morphology, but after one generation in captivity there was evidence for a shift in the internal morphology of captive-reared mice; captive-reared mice (two generations bred) had lighter combined kidney and spleen masses compared with wild-caught mice. Sexual dimorphism was maintained in captivity. Our findings demonstrate that captive breeding can alter internal morphology. Given that these morphological changes may impact organismal functioning and viability following release, further investigation is warranted. If the morphological change is shown to be maladaptive, these changes would have significant implications for captive-source populations that are used for reintroduction, including reduced survivorship.

The External Morphology of the Eggs of Culex (Culex) saltanensis (Diptera: Culicidae) Under Scanning Electron Microscopy

2020 ◽  
Author(s):  
J R Santos-Mallet ◽  
T D Balthazar ◽  
A A Oliveira ◽  
W A Marques ◽  
A Q Bastos ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Optical Microscopy ◽  
Osmium Tetroxide ◽  
Neotropical Region ◽  
External Morphology ◽  
Metal Supports ◽  
Scanning Electron

Abstract The aim of the present study was to describe the morphology of the eggs of Culex (Culex) saltanensis Dyar that occurs in the Neotropical region. Eggs of the Cx. (Cux.) saltanensis were collected at the Mata Atlântica FIOCRUZ campus, fixed in 1% osmium tetroxide, prepared for mounting on metal supports, observed under a scanning electron microscope, and described morphologically. The eggs had a coniform shape with a length of approximately 0.5 mm (505–510 µm) and a width in the median portion of 117 µm (113–123 µm). Upper portion is lined with tubers of irregular shape and varying sizes (0.64–1.31 µm), located on a cross-linked matrix forming bands observed under optical microscopy. The micropyle is encased in a necklace of approximately 6.6-µm plates arranged in a flower-like shape. Comparing Cx. (Cux.) saltanensis eggs with several species of different genera, important divergent characteristics can be observed. However, this study points to the need for new descriptions of eggs of species belonging to the same subgenus in order to analyze if there will be differences between them. Culex (Cux.) saltanensis eggs have particular characteristics not observed in eggs of other Culicidae genera.

Three-dimensional stromatolites from Maastrichtian–Danian Yacoraite Formation, Argentina: modelling and assessing hydrodynamic controls on growth patterns

2021 ◽  
pp. 1-17
Author(s):  
Patricio Guillermo Villafañe ◽  
Carlos Cónsole-Gonella ◽  
Paolo Citton ◽  
Ignacio Díaz-Martínez ◽  
Silvina de Valais
Keyword(s):  
Environmental Factors ◽  
Methodological Approach ◽  
Three Dimensional ◽  
Growth Patterns ◽  
External Morphology ◽  
Water Dynamics ◽  
Microbial Composition ◽  
Depositional Processes ◽  
Run Off ◽  
Internal Arrangement

Abstract Stromatolites are biogenic sedimentary structures formed by the interplay of biological (microbial composition) and environmental factors (local hydrodynamic conditions, clastic input and/or water chemistry). Well-preserved, three-dimensional (3D) fossil stromatolites are key to assessing the environmental factors controlling their growth and resulting morphology in space and time. Here, we report the detailed analysis of well-exposed, highly informative stromatolite build-ups from a single stratigraphic horizon within the Maastrichtian–Danian Yacoraite Formation (Argentina). This study focuses on the analysis of depositional processes driving intertidal to shallow subtidal stromatolites. Overall depositional architecture, external morphology and internal arrangement (mega, macro, meso and microstructures) of stromatolite build-ups were analysed and combined with 3D photogrammetric models, allowing us to decipher the links between stromatolite structure and tidal dynamics. Results suggest that external morphology and architecture of elongated and parallel clusters grew under the influence of run-off channels. The internal morphology exhibits columnar structures where the space between columns is interpreted as recharge or discharge channels. This work supports the theory that stromatolites can be used as a high-resolution tool in the assessment of water dynamics, and provides a new methodological approach and data for the dynamic reconstruction of intertidal stromatolite systems through the geological record.

The tadpole of Pleurodema nebulosum Burmeister (Anura: Leiuperidae)

Zootaxa ◽  
2012 ◽  
Vol 3450 (1) ◽  
pp. 9 ◽  
Author(s):  
GUILLERMINA GALVANI ◽  
EXEQUIEL GONZÁLEZ ◽  
EDUARDO SANABRIA ◽  
LORENA QUIROGA
Keyword(s):  
Geographic Range ◽  
External Morphology ◽  
Arid Areas ◽  
Larval Morphology ◽  
Rio Negro

The genus Pleurodema Tschudi currently contains fourteen species, ten of them occurring in Argentina (Faivovich et al. 2012). However, Pleurodema nebulosum presents a wide altitudinal and latitudinal geographic range and is only distributed in arid areas of western Argentina, from Catamarca to Río Negro province (Ferraro & Casagranda 2009, Frost 2011). The external morphology was described for the tadpoles of most species of Pleurodema, but the external larval morphology of P. nebulosum was only briefly described by Fernández (1927) and Cei (1980). The aim of this work is to provide a detailed redescription of the external larval features of Pleurodema nebulosum.

Variability of external morphology ofEueremaeusMihelčič, 1963 (Acari, Oribatida, Eremaeidae) in the light of ontogeny of four species

2014 ◽  
Vol 40 (1) ◽  
pp. 81-108 ◽  
Author(s):  
Stanisław Seniczak ◽  
Anna Seniczak ◽  
Sławomir Kaczmarek ◽  
Mariola Słowikowska
Keyword(s):  
External Morphology

Variations in the External Morphology of Gall Bladder

2012 ◽  
Vol 61 (1) ◽  
pp. 9-12 ◽  
Author(s):  
Jaba Rajguru ◽  
Satyam Khare ◽  
Shilpi Jain ◽  
Rashmi Ghai ◽  
Mukesh Singla ◽  
...  
Keyword(s):  
Gall Bladder ◽  
External Morphology
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