scholarly journals Reproductive Biology of Neotropical Fishes: A Guide to Identification to the Gonadal Morphology During the Reproductive Cycle of Catfish Rhamdia quelen (Siluriformes: Heptapteridae)

2020 ◽  
Vol 8 (2) ◽  
pp. 15
Author(s):  
Talita Sarah Mazzoni ◽  
Robie Allan Bombardelli ◽  
Irani Quagio-Grassiotto
Keyword(s):  
Freshwater Fish ◽  
Reproductive Biology ◽  
Morphological Characteristics ◽  
Fish Reproduction ◽  
Recent Proposal ◽  
Neotropical Fishes ◽  
Rhamdia Quelen ◽  
Reproductive Cycles ◽  
Reproductive Phases

In most Teleostei fish, the gametogenesis is a cyclical and seasonal event. The renewal of gametes, through their differentiation, development, maturation and release causes several changes in the morphological characteristics of the ovaries and testes throughout the annual reproductive cycles. These alterations are used to recognize different phases in the reproductive cycles. However, as the number of studies of fish reproduction increased, the number of types of gonadal classification and nomenclatures also diversified. This may make it difficult to communication between researchers and the aquaculture activity, since the recognition of these phases is one of the most important parameters applied in the management of fishery resources. In addition, the terminologies proposed in most of the current studies refer to reproductive stages applicable to marine fish, with marked and defined seasonality characteristics. In this way, this report presents a recent proposal for the recognition of reproductive phases originally developed for the Perciformes and here adapted for the Neotropical Siluriformes, using as a biological model a freshwater catfish Rhamdia quelen. In addition, we describe a brief characterization of the gametogenesis in this species. We hope that the material presented can be used as an easy and practical guide of identification for reproductive phases applicable to other neotropical freshwater fish, more especially Otophysi, such as Siluriformes.

Reproductive cycle of the tetra Astyanax bimaculatus (Characiformes: Characidae) collected in Amazonian streams

Zygote ◽  
2019 ◽  
Vol 28 (1) ◽  
pp. 37-44
Author(s):  
Jhennifer Gomes Cordeiro ◽  
Jeane Rodrigues ◽  
Maira da Silva Rodrigues ◽  
Rafaela Manchin Bertolini ◽  
Rafael Henrique Nóbrega ◽  
...  
Keyword(s):  
Reproductive Cycle ◽  
Winter Season ◽  
Morphological Characteristics ◽  
Gonadal Development ◽  
Asynchronous Development ◽  
Final Maturation ◽  
Phases Of Development ◽  
Water Volumes ◽  
Reproductive Phases

SummaryA histological characterization of gonadal development in the tetra Astyanax bimaculatus was performed, aimed at determining its reproductive cycle in streams localized inside the Amazonian forest. Collections were carried out monthly from August 2017 to July 2018 at the Zoobotânica Foundation of Marabá, PA. Collected specimens were weighed and measured, and their gonads and liver were removed and weighed to calculate gonadosomatic and hepatosomatic indexes. Gonads were fixed and treated for routine histology for light microscopy. Materials were stained with toluidine blue and haematoxylin and eosin. The Amazonian A. bimaculatus species presented two reproductive periods in the year, one at the end of the winter season and another during the summer. Females showed an asynchronous development of their oocytes and only two reproductive phases of development were observed during the whole period ‘developing’ and ‘spawning capable’. Males presented cystic spermatogenesis, with an anastomosing tubular testis containing spermatogonia spread along the germinal epithelium (unrestricted spermatogonial). These morphological characteristics are considered phylogenetically more primitive. Male specimens were observed to have five different phases during the period: immature, initial maturation, mid maturation, final maturation and regression. The huge fluctuations in Amazonian streams was observed, in which water volumes varied considerably across seasons, culminating even in total drought. In spite of this, A. bimaculatus could be found during all seasons, showing its impressive reproductive adaptation to its conditions.

scholarly journals Characterization of a new natural fiber extracted from Corypha taliera fruit

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Taslima Ahmed Tamanna ◽  
Shah Alimuzzaman Belal ◽  
Mohammad Abul Hasan Shibly ◽  
Ayub Nabi Khan
Keyword(s):  
Tensile Strength ◽  
Natural Fiber ◽  
Natural Fibers ◽  
Morphological Characteristics ◽  
Synthetic Fiber ◽  
X Ray Diffraction ◽  
Reinforced Composite ◽  
Potential Alternative

AbstractThis study deals with the determination of new natural fibers extracted from the Corypha taliera fruit (CTF) and its characteristics were reported for the potential alternative of harmful synthetic fiber. The physical, chemical, mechanical, thermal, and morphological characteristics were investigated for CTF fibers. X-ray diffraction and chemical composition characterization ensured a higher amount of cellulose (55.1 wt%) content and crystallinity (62.5%) in the CTF fiber. The FTIR analysis ensured the different functional groups of cellulose, hemicellulose, and lignin present in the fiber. The Scherrer’s equation was used to determine crystallite size 1.45 nm. The mean diameter, specific density, and linear density of the CTF fiber were found (average) 131 μm, 0.86 g/cc, and 43 Tex, respectively. The maximum tensile strength was obtained 53.55 MPa for GL 20 mm and Young’s modulus 572.21 MPa for GL 30 mm. The required energy at break was recorded during the tensile strength experiment from the tensile strength tester and the average values for GL 20 mm and GL 30 mm are 0.05381 J and 0.08968 J, respectively. The thermal analysis ensured the thermal sustainability of CTF fiber up to 230 °C. Entirely the aforementioned outcomes ensured that the new CTF fiber is the expected reinforcement to the fiber-reinforced composite materials.

scholarly journals Molecular and Pathogenicity Characterization of Sphaceloma manihoticola Isolates from South-Central Brazil

Plant Disease ◽  
2003 ◽  
Vol 87 (11) ◽  
pp. 1322-1328 ◽  
Author(s):  
Elizabeth Alvarez ◽  
Juan Fernando Mejia ◽  
Teresa L. Valle
Keyword(s):  
Morphological Characteristics ◽  
Restriction Pattern ◽  
Poly Merase Chain Reaction ◽  
Highly Pathogenic ◽  
Central Brazil ◽  
Host Interaction ◽  
South Central ◽  
Pcr Product ◽  
Pathogenic Variation

Isolates of Sphaceloma manihoticola, the asexual stage of Elsinoe brasiliensis, were collected from several regions of south-central Brazil. The isolates were obtained from samples of leaves, stems, and petioles of cassava (Manihot esculenta) and the weedy Euphorbia heterophylla (“amendoim bravo”) by directly plating infected tissue onto acidified potato dextrose agar. For pathogenicity studies, 19 isolates were inoculated onto each of two cassava cultivars, MBRA 703 as a susceptible cultivar and MBRA 12 as a resistant cultivar to S. manihoticola. MBRA 703, with the greatest pathogenicity to 58% (11) of the isolates, showed an intermediate pathogenic reaction to 16% (3) of the isolates, and was less pathogenic to 26% (5) of the isolates. MBRA 12, with a less pathogenic reaction to 63% (12) of the isolates, showed an intermediate pathogenic reaction to 16% (3) of the isolates, and was highly pathogenic to 21% (4) of the isolates. The isolates were verified as belonging to the genus Sphaceloma based on their morphological characteristics, including conidia and hyphae of monoconidial isolate. Conidia of isolates were small, thin-walled, ellipsoid to (rarely) globose, commonly with one or two gut-tules. Conidiophores were phialides, hyaline to slightly pigmented 0-to-1 septate; conidiophores from the weedy specie were phialides, hyaline to brown 0-to-2 septate producing hyaline conidia. The isolates also were verified as belonging to the genus Sphaceloma by using a poly-merase chain reaction (PCR) assay, which detected a 645-bp band in all isolates except two (1 and 6) for which the PCR product had 600 bp. Digestion of the amplified product with the enzymes MspI and CfoI allowed differences to be detected in restriction patterns among isolates. A homogeneous banding pattern was obtained for 17 of the isolates but a different restriction pattern was obtained for isolates 1 and 6 of E. heterophylla. This suggests the possibility of another species within this group of isolates. The results indicate the presence of pathogenic variation among isolates of the fungus and an isolate-host interaction, because statistically significant differences were observed between the two cassava cultivars in response to inoculation with the isolates of S. manihoticola.

scholarly journals Characterization of the Bull's Eye Rot of Apple in Chile

Plant Disease ◽  
2013 ◽  
Vol 97 (4) ◽  
pp. 485-490 ◽  
Author(s):  
Sylvana Soto-Alvear ◽  
Mauricio Lolas ◽  
Inés M. Rosales ◽  
Eduardo R. Chávez ◽  
Bernardo A. Latorre
Keyword(s):  
Morphological Characteristics ◽  
The United States ◽  
Apple Fruit ◽  
Maritime Transportation ◽  
Tubulin Genes ◽  
Internal Transcribed Spacer Sequences ◽  
Apple Production ◽  
Species Specific ◽  
Bull's Eye

Apple fruit in Chile are primarily produced for export to Asia, Europe, and the United States, which typically requires 15 to 40 days of maritime transportation. Therefore, Chilean apple production must fulfill the sanitization requirements imposed by the receiving countries. Under these circumstances, it was important to clarify the etiology of bull's eye rot that can severely affect ‘Cripps Pink’ apple and other late-harvest cultivars in Chile. Based on morphological characteristics and the partial sequence analysis of the internal transcribed spacer sequences and β-tubulin genes, Neofabraea alba was identified as the causal agent of the bull's eye rot of Chilean apple. These results were further corroborated using species-specific primers. The incidence of bull's eye rot varied considerably; for instance, in 2009, 0.0 to 58.7% in 38 Cripps Pink orchards surveyed in the relatively arid and humid apple-growing areas of Chile, respectively. There was no evidence for the presence of N. malicorticis or N. perennans, which are commonly identified as causal agents of bull's eye rot in other apple-producing countries. Altogether, these data suggest that N. alba might represent the predominant and possibly the only cause of bull's-eye rot of Chilean apple.

scholarly journals A taxonomic review of pterotracheoid gastropod mollusks from California Current waters off the west coast of North America

Zoosymposia ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 147-150
Author(s):  
ROGER R. SEAPY
Keyword(s):  
North America ◽  
West Coast ◽  
Morphological Characteristics ◽  
California Current ◽  
Single Species ◽  
The West ◽  
Taxonomic Review ◽  
Gastropod Mollusks ◽  
Taxonomic Characterization

Taxonomic characterization of pterotracheoid gastropods, morphological characteristics and occurrence in California Current waters are reviewed. Single species of atlantid (Atlanta californiensis) and carinariid (Carinaria japonica) from these waters are described and illustrated.

scholarly journals Characterization of indigenous barberry germplasm in Pakistan: variability in morphological characteristics and nutritional composition

Fruits ◽  
2013 ◽  
Vol 68 (5) ◽  
pp. 409-422 ◽  
Author(s):  
Maqsood Ahmed ◽  
Muhammad Akbar Anjum ◽  
Raja Mohib Muazzam Naz ◽  
Muhammad Riaz Khan ◽  
Sajjad Hussain
Keyword(s):  
Morphological Characteristics ◽  
Nutritional Composition
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