Gonad morphology, gametogenesis, and reproductive modes in fishes of the tribe Starksiini (Teleostei, Blenniiformes)

2013 ◽  
Vol 274 (5) ◽  
pp. 496-511 ◽  
Author(s):  
Lev Fishelson ◽  
Carole C. Baldwin ◽  
Philip A. Hastings
Keyword(s):  
Gonad Morphology ◽  
Reproductive Modes

Characterization of the Reproductive Mode in Guayule In Vitro

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 483a-483
Author(s):  
Roy N. Keys ◽  
Dennis T. Ray ◽  
David A. Dierig
Keyword(s):  
Field Experiments ◽  
Reproductive Mode ◽  
Dichlorophenoxyacetic Acid ◽  
Initial Field ◽  
Breeding Lines ◽  
Reproductive Modes ◽  
Desert Southwest ◽  
2,4 Dichlorophenoxyacetic Acid

Guayule (Parthenium argentatum Gray, Asteraceae) is a latex-producing perennial desert shrub that is potentially of economic importance as an industrial crop for the desert Southwest. It is known to possess complex reproductive modes. Diploids are predominantly sexual and self-incompatible, while polyploids show a range of apomictic potential and self-compatibility. This paper describes the development of a relatively rapid and simple technique for characterizing reproductive modes of breeding lines of P. argentatum. Initial field experiments were based on an auxin test used successfully to characterize reproductive mode in the Poaceae. The application of 2,4-dichlorophenoxyacetic acid inhibited embryo formation in P. argentatum, but this was not the case with other auxins tested. Results of field experiments were ambiguous because: 1) the floral structure of P. argentatum is such that auxins might not have penetrated to the ovules, and 2) there was potential self-fertilization by pollen released within isolation bags. Therefore, in vitro culture of flower heads was tested because it provided much better control of environmental conditions, growth regulator application, and pollen release. Auxin alone, or in combination with gibberellic acid or kinetin, inhibited parthenogenesis in vitro. Embryo production did not vary using two substantially different nutrient media. In vitro flower head culture using a (Nitsch and Nitsch) liquid nutrient medium without growth regulators, enabled characterization of the reproductive mode of seven breeding lines, ranging from predominantly sexual to predominantly apomictic. The results of this technique were substantiated using RAPD analyzes of progeny arrays from controlled crosses.

Supplemental Material: Fossilized reproductive modes reveal a protistan affinity of Chitinozoa

2020 ◽  
Author(s):  
Yan Liang ◽  
et al.
Keyword(s):  
Reproductive Modes

Extended introduction to the materials and methods, Figures S1–S4, Tables S1 and S2, and supplemental movies (Movies S1–S3).<br>

Gonad morphology and gametogenesis in the deep-sea jellyfish Atolla wyvillei and Periphylla periphylla (Scyphozoa: Coronatae) collected from Cape Hatteras and the Gulf of Mexico

2009 ◽  
Vol 90 (6) ◽  
pp. 1095-1104 ◽  
Author(s):  
Cathy H. Lucas ◽  
Adam J. Reed
Keyword(s):  
Gulf Of Mexico ◽  
Gonad Development ◽  
Bell Diameter ◽  
Western Atlantic ◽  
Gonad Morphology ◽  
Time Period ◽  
Cape Hatteras ◽  
Literature Evidence ◽  
Long Time ◽  
North Western

Observations on gonad morphology and the structure of ovaries and testes of the coronate scyphozoans Atolla wyvillei and Periphylla periphylla are described based on samples collected from the Gulf of Mexico and Cape Hatteras (north-western Atlantic). In A. wyvillei, gonads of distinguishable sex were observed in medusae as small as 17 mm bell diameter (BD). Spermatogenesis occurred within follicles (average 366 × 254 μm) that were evenly distributed throughout the gonad. Oocytes in different stages of development were observed in all the females with gonads. Oocytes arise from the gastrodermis and migrate into the mesoglea to develop from early-mid to late vitellogenic oocytes characterized by a large nucleus and granular (organic-rich) cytoplasm. The largest oocytes measured were 543 μm and 263 μm from the Gulf of Mexico and Cape Hatteras respectively. Possible reasons for this difference are discussed. In P. periphylla gonads were also initially observed in medusae 17 mm BD, although not all larger medusae had obvious gonads. Unlike A. wyvillei sperm follicles were arranged in long convoluted rows normally only one follicle thick. The organization of ooytes in female P. periphylla was very similar to A. wyvillei, although the gonads were small and the number of oocytes present in each gonad very low (<22). The largest oocyte measured was 777 μm in a 53 mm BD medusa. Although medusae were collected from one time period only (September) in this study, our findings appear to be in agreement with literature evidence indicating that coronate jellyfish produce few eggs continuously over a long time period. Aspects of gonad development and gametogenesis are discussed with respect to potential differences in site productivity and species identification.

Phylogenetic relationships and evolution of reproductive modes within flattened syllids (Annelida : Syllidae) with the description of a new genus and six new species

2018 ◽  
Vol 32 (1) ◽  
pp. 224 ◽  
Author(s):  
Patricia Álvarez-Campos ◽  
Sergio Taboada ◽  
Guillermo San Martín ◽  
Carlos Leiva ◽  
Ana Riesgo
Keyword(s):  
New Species ◽  
Phylogenetic Relationships ◽  
Reproductive Strategy ◽  
New Genus ◽  
Entire Group ◽  
Reproductive Modes ◽  
Taxonomic Descriptions ◽  
The Status ◽  
New Material ◽  
Phylogenetic Hypotheses

Syllid annelids from the so-called ‘ribbon clade’ are flattened, ribbon-shaped worms of the genera Parahaplosyllis Hartmann-Schröder, 1990, Eurysyllis Ehlers, 1864, Xenosyllis Marion &amp; Bobretzky, 1875, Trypanosyllis Claparède, 1864, Ramisyllis Glasby, Schroeder &amp; Aguado, 2012, Trypanobia Imajima &amp; Hartman, 1964, Plakosyllis Hartmann-Schröder, 1956, Pseudosyllis Grube, 1863 and Trypanedenta Imajima &amp; Hartman, 1964. Some species possess a remarkable reproductive strategy using multiple stolons that has been recently suggested to be ancestral to the group. Here, to evaluate the evolution of reproductive modes in the group, we assess, for the first time, the phylogenetic relationships within the ribbon clade and related genera. We collected new material of Trypanobia and Trypanosyllis from Japan, Spain, Philippines and Indonesia and sequenced it for the nuclear markers 18S rRNA and the mitochondrial markers 16S rRNA and cytochrome c oxidase I for phylogenetic inference and also performed ancestral character reconstruction for the reproductive strategy in the entire group. Formal taxonomic descriptions of a new genus and six new species are provided. The new genus, Trypanospina, gen. nov., is characterised by the spines that cover its surface. Most genera within the ‘ribbon clade’ are monophyletic and the relationships appeared well supported in most cases. However, our phylogenetic hypotheses are not conclusive in regard to the relationships of the genera Trypanedenta and Trypanobia, nor to the status of those to genera as distinctive, since they seem to be paraphyletic and they appear in low-supported clades. In contrast, our results shed light on the evolution of the reproductive modes within the group, showing that scissiparity (development of a single stolon each time) is the ancestral character for the entire group and gemmiparity (development of more than one stolon at the same time) then appeared twice in two independent clades.

Do Reproductive Modes and Swimming Ability Influence Occurrence of Non-Marine Ostracod (Crustacea) Species among Aquatic Habitats?

2019 ◽  
Vol 36 (6) ◽  
pp. 511 ◽  
Author(s):  
Okan Külköylüoğlu ◽  
Derya Akdemir ◽  
Mehmet Yavuzatmaca ◽  
Ebru Çelen ◽  
Şükran Dere ◽  
...  
Keyword(s):  
Swimming Ability ◽  
Aquatic Habitats ◽  
Reproductive Modes

Does the Growth Rate of Different Reproductive Modes of an Introduced Plant Cause Invasiveness?

2004 ◽  
Vol 1 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Stephane Baret ◽  
Soudjata Radjassegar . ◽  
Thomas Le Bourgeois . ◽  
Dominique Strasberg .
Keyword(s):  
Growth Rate ◽  
Reproductive Modes

scholarly journals High diversity in species, reproductive modes and distribution within the Paramacrobiotus richtersi complex (Eutardigrada, Macrobiotidae)

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Roberto Guidetti ◽  
Michele Cesari ◽  
Roberto Bertolani ◽  
Tiziana Altiero ◽  
Lorena Rebecchi
Keyword(s):  
Reproductive Modes ◽  
High Diversity
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