scholarly journals Fine structure of the spermatozoon in three species of Cambaridae (Arthropoda: Crustacea: Decapoda)Cambarus robustus,Orconectes propinquusandOrconectes rusticus: a comparative biometrical study

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2363 ◽  
Author(s):  
Buket Yazicioglu ◽  
Přemek Hamr ◽  
Pavel Kozák ◽  
Antonín Kouba ◽  
Hamid Niksirat
Keyword(s):  
Fine Structure ◽  
Morphological Feature ◽  
Anterior Part ◽  
Morphological Features ◽  
Intermediate Position ◽  
Freshwater Crayfish ◽  
Orconectes Rusticus ◽  
Whole Cell ◽  
Orconectes Propinquus ◽  
Biometrical Study

The ultrastructure of spermatozoa in three species of cambarid crayfish,Cambarus robustus,Orconectes propinquus, andOrconectes rusticus, were studied and compared with eight previously studied species from different crayfish families using morphological features and biometrical data. The ultrastructure of spermatozoa show a generally conserved pattern including an acrosome and nucleus in the anterior and posterior parts of the cell, respectively, radial arms that wrap around the nucleus, and the whole cell is enclosed by an extracellular capsule. The most outstanding morphological feature in spermatozoa of three studied cambarid crayfish is the crest-like protrusions in the anterior part of the acrosome that can be used as one of the features for distinguishing the members of this family. Results of biometrical data reveal that acrosome size in the representatives of Parastacidae are the smallest, while representatives of Astacidae show the biggest acrosome. The acrosome size in species belonging to Cambaridae occupy an intermediate position between the two other families of freshwater crayfish. In conclusion, a combination of morphological features and biometrical data of spermatozoa can help distinguishing different species of the freshwater crayfish.

Fine structure of the rectal papillae of the oriental fruuit fly, Dacus dorsalis Hendel (Tephritidae, Diptera Insecta)

1990 ◽  
Vol 48 (3) ◽  
pp. 498-499
Author(s):  
Len Wen-Yung ◽  
Mei-Jung Lin
Keyword(s):  
Fine Structure ◽  
Cell Membrane ◽  
Intercellular Space ◽  
Anterior Part ◽  
Apical Cell ◽  
Posterior Part ◽  
Apical Cell Membrane ◽  
Dacus Dorsalis ◽  
Radial Cell ◽  
Circular Base

Four cone-shaped rectal papillae locate at the anterior part of the rectum in Dacus dorsalis fly. The circular base of the papilla protrudes into the haemolymph (Fig. 1,2) and the rest cone-shaped tip (Fig. 2) inserts in the rectal lumen. The base is surrounded with the cuticle (Fig. 5). The internal structure of the rectal papilla (Fig. 3) comprises of the cortex with the columnar epithelial cells and a rod-shaped medulla. Between them, there is the infundibular space and many trabeculae connect each other. Several tracheae insert into the papilla through the top of the medulla, then run into the cortical epithelium and locate in the intercellular space. The intercellular sinuses distribute in the posterior part of the rectal papilla.The cortex of the base divides into about thirty segments. Between segments there is a radial cell (Fig. 4). Under the cuticle, the apical cell membrane of the cortical epithelium is folded into a regular border of leaflets (Fig. 5).

Remarkable biodiversity of flabelligerids in Japan: seven new species of Diplocirrus (Annelida: Flabelligeridae) from Japanese waters

Zootaxa ◽  
2017 ◽  
Vol 4337 (3) ◽  
pp. 344
Author(s):  
NAOTO JIMI ◽  
YOSHIHIRO FUJIWARA ◽  
HIROSHI KAJIHARA
Keyword(s):  
New Species ◽  
Morphological Feature ◽  
Morphological Features ◽  
The Body ◽  
Sediment Particles ◽  
Japanese Waters

Seven new species of Diplocirrus are described from Japan: D. asamushiensis sp. nov., D. imajimai sp. nov., D. mamoi sp. nov., D. ohtsukai sp. nov., D. seisuiae sp. nov., D. tohokuensis sp. nov., and D. toyoshioae sp. nov. These species are distinguished from all the known species of Diplocirrus by the following features: length of the cephalic cage, length of lateral papillae, presence of gonopodial lobe, adhering pattern of sediment particles, length of caruncle, length and morphological feature of branchiae, articles and morphological features of neurochaetae, and swollen area along the body. 

Classification of Wear Particles Based on Qualitative Morphological Features

2005 ◽  
Author(s):  
R. H. Chang ◽  
Hosung Kong ◽  
Eui-Sung Yoon ◽  
Dong-Hoon Choi
Keyword(s):  
Image Recognition ◽  
Morphological Feature ◽  
Wear Debris ◽  
Morphological Features ◽  
Multidimensional Space ◽  
Semantic Features ◽  
Wear Particles ◽  
Wear Mode ◽  
Wear Monitoring

Wear debris morphology is closely related to the wear mode and mechanism occurred. Image recognition of wear particles is, therefore, a powerful tool in wear monitoring. An algorithm of classification of wear particles is proposed based on qualitative morphological features. The standard classes are presented as a set of vectors of coded ratings. Descriptions of the standards are based on the knowledge-base of experts. A distance between the particle and the standard classes in the multidimensional space of features showed rating of the similarity. The classification of particles is determined by identifying the closet standard. The coding of the semantic features of the morphological feature of wear particles was demonstrated to be useful for classification with statistical methods. The results showed that the presented method was satisfactory in solving practical problems.

/ka-/ negative prefix of Choswateng Tibetan of Khams (Shangri-La, Yunnan)

2021 ◽  
Vol 22 (4) ◽  
pp. 593-629
Author(s):  
Hiroyuki Suzuki ◽  
Lozong Lhamo
Keyword(s):  
Morphological Feature ◽  
Morphological Features ◽  
The Self ◽  
The Other ◽  
The South ◽  
Rhetorical Question ◽  
The Third ◽  
South Eastern

Abstract Choswateng Tibetan, spoken in the south-eastern corner of the Khams region, has three negative prefixes: /ȵi-/, /ma-/, and /ka-/. The first two are derived from two morphemes which are ubiquitous across Tibetic languages, whereas the third is a newly generated negative prefix found in Choswateng Tibetan as well as its surrounding dialects belonging to the rGyalthang subgroup of Khams and its neighbours. This article describes the morphological feature and use of the prefix /ka-/ in Choswateng Tibetan. Morphologically, the prefix /ka-/ can co-occur with most verbs except for the copulative verb /ˊreʔ/. Pragmatically, the prefix /ka-/ occurs and is restricted in the following ways: (1) expresses ‘definitely not’ for statements regarding the self, and ‘possibly not, judging from the speaker’s knowledge’ for statements regarding others; (2) co-occurs with egophoric and sensory evidentials; (3) is not used for a negation of accomplished aspect; and (4) does not deprive the function of the other two negative prefixes. These two analyzes are mutually related; it is suggested that the reason why /ka-/ cannot co-occur with the copulative verb /ˊreʔ/ is triggered by a contradiction of implied evidentials: /ka-/ is related to egophoric and sensory, whereas /ˊreʔ/ is statemental. Following the description of its use, we discuss the origin of /ka-/, claiming a possible grammaticalization from an interrogative word gar (‘where’ in Literary Tibetan and common throughout the rGyalthang area) in a rhetorical question to a prefix. Referring to several morphological features of /ka-/, we consider its grammaticalization as ongoing, but most advanced in Choswateng Tibetan.

THE FINE STRUCTURE OF GROWING HUMAN GLIA AND GLIOMA CELLS Whole Cell Preparations

2009 ◽  
Vol 87A (1-6) ◽  
pp. 29-36
Author(s):  
V. P. COLLINS ◽  
U. T. BRUNK ◽  
B.-A. FREDRIKSSON ◽  
B. WESTERMARK
Keyword(s):  
Fine Structure ◽  
Glioma Cells ◽  
Whole Cell

scholarly journals New And Neglected Morphological Features in the Taxonomy of Asian Lejeunea (Marchantiophyta)

2014 ◽  
Vol 59 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Gaik Ee Lee ◽  
Ahmad Damanhuri ◽  
Abdul Latiff ◽  
S. Robbert Gradstein
Keyword(s):  
Morphological Feature ◽  
Morphological Characters ◽  
Species Level ◽  
Morphological Features ◽  
Phenetic Analysis ◽  
Infrageneric Classification ◽  
Surface Wax ◽  
Taxonomic Feature ◽  
Large Genus

Abstract The infrageneric classification of the large genus Lejeunea Lib. is poorly understood due to the lack of stable morphological characters characterizing supraspecific groups. Phenetic analysis of 26 morphological features of 31 Asian Lejeunea species separated two main species clusters based on the number of superior central cells at underleaf bases. The number of superior central cells had not previously been utilized in the classification of Lejeunea and appears to be new and stable morphological feature within this genus. The presence of surface wax was confirmed in L. flava (Sw.) Nees and was newly recorded in L. mimula Hürl. and L. tuberculosa Steph. We suggest that wax ornamentation may be a useful taxonomic feature at species level in Lejeunea.

The Australian freshwater crayfish (Crustacea : Decapoda : Parastacidae), with descriptions of a new species

1969 ◽  
Vol 17 (5) ◽  
pp. 855 ◽  
Author(s):  
EF Riek
Keyword(s):  
New Species ◽  
Morphological Features ◽  
Freshwater Crayfish ◽  
Distribution Maps ◽  
Australian Freshwater ◽  
A New Species

The nine Australian genera of freshwater crayfish are diagnosed, their main morphological features illustrated, and a key for the separation of these genera is presented. Modified keys are given for those genera in which new species have been accommodated. Distribution maps of all generaand of thespecies of Engaeus (23 species), Cherax (27 species), and Euastacus (28 species) are presented. Twenty new species are described, making a total of 97 species.

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